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Propagation and management of ornamental and commercial cacti– a review
The Journal of Horticultural Science and Biotechnology
Abstract
Cacti are one of the most diverse and widespread plants globally. They are useful in numerous ways, including food, medicine, and ornamental plants. This review aimed to synthesise current and potential uses of cacti, methods of propagation, threats by invasive cacti, control andnmanagement of invasiveness, and socio-economic synthesis of the cacti industry. Because ofbthe attractive unique morphology of the plant, it’s used as ornamental plant globally. Forbcommercial scale cacti production, both molecular and classical breeding methods are employed. Advantages of micropropagation of cacti for mass-scale production, compared to sexual propagation were identified. The potential for the application of molecular techniques in the cacti industry is high. Regardless of slow growth, cacti trade is a highly profitable market. However, due to slow growth, the cost of cultivation and maintenance should be considered. Sometimes, wild cacti are used for commercialisation in the international and illegal market. The species selection for commercialisation is vital for farmers. However, introduction of high quantities of ornamental cacti to other countries increases the risk of cacti being invasive in the
future. In this review, while managing invasive cacti, the international trade in rare expensive cacti is addressed.
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Environmental, Physiological and Chemical Controls of Adventitious Rooting in Cuttings provides a review of the environmental, physiological and chemical controls of adventitious rooting in cuttings obtained from plants. In plants, adventitious roots, which are highly useful for vegetative propagation (or clonal propagation) are produced mainly from leaves, hypocotyls, stems or shoots. Vegetative propagation may occur naturally by using propagules such as roots, underground and aerial stems, leaves, buds and bulbils. It may also be done artificially through regenerative organs (rhizomes, bulbs, and corms) and by utilizing specialized methods, like cutting, grafting and layering. This book covers the latest tactics surrounding these processes.
As a plethora of factors affect the adventitious rooting of cuttings, adding to the complexity of the phenomenon. The main factors which control adventitious root formation are types of cuttings, presence of leaf area on cuttings, types of hormones and their concentration, duration of hormonal treatment (quick dip, long soak, dry dip, spray dip, or total immerse method), maturation (juvenile or mature), genotype, explant position, and more, all of which are discussed here.
Although illegal wildlife trade (IWT) represents a serious threat to biodiversity, research into the prevalence of illegal plant collection and trade remains scarce. Because cacti and succulents are heavily threatened by overcollection for often illegal, international ornamental trade, we surveyed 441 members of the cacti and succulent hobbyist collector community with a mixed quantitative and qualitative approach. We sought to understand collector perspectives on the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES) and on the threats IWT poses to cactus and succulent conservation. Most respondents (74% of 401 respondents) stated that illegal collection in cacti and succulents represents a “very serious problem” and that the problem of wild plant collection is increasing (72% of 319 respondents). Most forms of illegal collection and trade were seen as very unacceptable by respondents. Self‐reported noncompliance with CITES rules was uncommon (11.2% of 418 respondents); it remains a persistent problem in parts of the cacti and succulent hobbyist community. People engaging in rule breaking, such as transporting plants without required CITES documents, generally did so knowingly. Although 60.6% of 381 respondents regarded CITES as a very important tool for conservation, sentiment toward CITES and its efficacy in helping species conservation was mixed. Collectors in our survey saw themselves as potentially playing important roles in cactus and succulent conservation, but this potential resource remains largely untapped. Our results suggest the need for enhanced consultation with stakeholders in CITES decision‐making. For challenging subjects like IWT, developing evidence‐based responses demands deep interdisciplinary engagement, including assessing the conservation impact of species listings on CITES appendices.
Forage cactus (Opuntia spp. and Nopalea spp.) is a crop tolerant to drought, high temperatures, and less fertile soils, which favors its cultivation in arid and semi‐arid regions and production of cladodes to animal feed. Intercropping may improve water use efficiency and increase agricultural production sustainability. The aim of this research was to evaluate the growth and yield of forage cactus genotypes intercropped with timber species under semi‐arid conditions. Three forage cactus genotypes, erect prickly pear ‘Orelha de Elefante Mexicana’ [O. stricta (Haw.) Haw.], ‘Miúda’ [N. cochenillifera (L.) Salm‐Dyck: syn. O. cochenillifera (L.) Mill.], and ‘Baiana’ [N. cochenillifera (L.) Salm‐Dyck] in three cropping systems (monocropping; intercropped with Prosopis juliflora (Sw.) DC.; and intercropped with Mimosa caesalpiniifolia Benth.) were studied. All species were irrigated with treated domestic effluent water. Plants were evaluated after 2 yr of cultivation. The forage cactus intercropped with timber species had lower cladode weight, dry matter yield, and lower carrying capacity than forage cactus in monocropped system regardless of genotype. These results suggest that timber species may inhibit the yield of forage cactus, and intercropping is not recommended. In addition, there was no significant difference in the performance of forage cactus when intercropping with M. caesalpiniifolia and P. juliflora. The P. juliflora had greater growth performance when compared with M. caesalpiniifolia intercropped with Miúda and Orelha de Elefante Mexicana. However, when intercropped with the Baiana, the growth of P. juliflora and M. caesalpiniifolia are similar to each other.
Opuntia dillenii (Ker Gawler) is an invasive plant species in Bundala National Park. The outstanding success of the cochineal insect, Dactylopius spp. in bio-control of the prickly pear, Opuntia spp. has been investigated worldwide. The present study reports the emergence of D. opuntiae as a pest of O. dillenii after several decades of its introduction to Sri Lanka. The intensity of infestation was 100% along three of the five transects surveyed and the overall damage was more than 50%. This recent outbreak of D. opuntiae may have resulted from an unnoticed existing population of D. opuntiae in the vicinity.
This study describes the technological processes and characteristics of biomass direct combustion power generation, biomass gasification power generation, biomass mixed combustion power generation, and biomass biogas power generation in terms of their importance and application in China. Under the perspective of environmental and economic sustainability, the life cycle assessment (LCA) method and dynamic analysis method based on time value are used to simulate and evaluate the environmental loads and economic benefits of different power generation processes. By comparing with coal-fired power generation systems, the environmental and economic benefits of different biomass power generation technologies are illustrated. The results shows that biomass gasification power generation has the best environmental benefits, with a total load of 1.05 × 10−5, followed by biomass biogas power generation (9.21 × 10−5), biomass direct combustion power generation (1.23 × 10−4), and biomass mixed combustion power generation (3.88 × 10−4). Compared with the environmental load of coal-fired power generation, the reduction rate was 97.69%, 79.69%, 72.87%, and 14.56% respectively. According to the analysis of the technical economy evaluation results, when the dynamic pay-back period and IRR (internal rate of return) were used as evaluation indicators, the biomass direct combustion power generation has the best pay-back period (7.71 years) and IRR (19.16%), followed by the biogas power generation, with higher dynamic payback period (12.03 years), and lower IRR (13.49%). For gasification power generation and mixed-combustion power generation, their dynamic payback period is long, and the IRR is low. If net present value (NPV) is selected as the evaluation index, the biogas power generation appears to be the best because its net present value per megawatt is 11.94 million yuan, followed by direct combustion power generation (6.09 million yuan), and the net present value of mixed-combustion power generation and gasification power generation is relatively low. Compared with coal-fired power generation, direct combustion power generation and biogas power generation present significant economic benefits.
The family Cactaceae Juss. contains some of the most widespread and damaging invasive alien plant species in the world, with Australia (39 species), South Africa (35) and Spain (24) being the main hotspots of invasion. The Global Cactus Working Group (IOBC GCWG) was launched in 2015 to improve international collaboration and identify key actions that can be taken to limit the impacts caused by cactus invasions worldwide. Based on the results of an on-line survey, information collated from a review of the scientific and grey literature, expertise of the authors, and because invasiveness appears to vary predictably across the family, we (the IOBC GCWG): (1) recommend that invasive and potentially invasive cacti are regulated, and to assist with this propose five risk categories; (2) recommend that cactus invasions are treated physically or chemically before they become widespread; (3) advocate the use of biological control to manage widespread invasive species; and (4) encourage the development of public awareness and engagement initiatives to integrate all available knowledge and perspectives in the development and implementation of management actions, and address conflicts of interest, especially with the agricultural and ornamental sectors. Implementing these recommendations will require global co-operation. The IOBC GCWG aims to assist with this process though the dissemination of information and experience.
The use of cactus for forage may cause soil contamination by allelochemicals in order to compromise the future planting or even reforestation of that site. The objective of this work was to evaluate the allelopathic action of cladodes and roots of Cereus jamacaru, Pilosocereus gounellei and Tacinga inamoena on the germination and development of Cenchrus echinatus and Calotropis procera in order to suggest actions that increase efficiency in restoration strategies. Of the species of Cactaceae mentioned above, cladodes and roots were collected for the preparation of the extracts in which two types of extracts were prepared for each organ, one treatment by hot infusion and one cold treatment. Germination Percentages (GP) and Germination Speed Index (GSI) were analyzed. In order to analyze if the extracts presented some allelopathic activity regarding the development of the seedlings, the lengths of the stem and the radicle of the recipient species were measured. The results of this research show that cacti don’t significantly affect GP from seeds of other plants. However, for GSI, roots and cladodes of T. inamoena presented negative allelopathic activity for C. echinatus and C. procera, respectively. In addition to GSI, T. inamoena negatively affected the development of C. echinatus rootlets. In this way T. inamoena is a forage cactus that affects the development of the initial structures of surrounding plants. Thus, the exacerbation of this forage species in natural areas should be avoided, since the released allelochemicals can interfere with the ecological succession of the plant species of that environment.
Objective:
This study ascertained effects of cactus pear in association with different roughage in the diet of F1 Holstein/Zebu cows on intake, nutrient digestibility, nitrogen balance, ingestive behavior and performance.
Methods:
Eight cows with 72 ± 11 days of lactation were used. The experimental design was simultaneous in two 4 x 4 Latin squares. Four experimental diets were used: Diet 1 - sorghum silage as exclusive roughage; Diet 2 - sorghum silage associated with cactus pear in a proportion of 50% of the roughage (dry basis); Diet 3 - elephant grass (Pennisetum purpureum cv. Roxo) as exclusive roughage; Diet 4 - elephant grass associated with cactus pear in a proportion of 50% of the roughage. The roughage:concentrate ratio was 75:25. Dry matter intake (P = 0.01) was higher with sorghum silage.
Results:
There were differences in dry matter intake (P = 0.01), crude protein (P <0.01), ether extract (P = 0.01), non-fibrous carbohydrates (P <0.01) and total digestible nutrients (P = 0.01) among the diets. Cactus pear in the diet reduced water intake by 44.52% (P < 0.01). The nitrogen balance was 59.71% and 27.49% lower in animals treated with exclusive sorghum silage and sorghum silage associated with cactus pear in relation to diets with elephant grass and elephant grass associated with cactus pear, respectively (P < 0.01). The diets did not influence the milk production (P = 0.70), 3.5% fat corrected milk production (P = 0.72) or feed efficiency (P = 0.61).
Conclusion:
The association of cactus pear with sorghum or elephant grass silage does not alter milk production, reduces the intake of dry matter and water and improves the digestibility of nutrients.
Livestock production in arid and semi-arid regions is facing the challenges of low and erratic rainfall, poor nutrient soils, and high temperatures, which all contribute to inadequate forage production to support livestock. Under these challenging conditions, promoting forage species, such as cacti, that are tolerant and well adapted is important to sustain and improve livestock production. This study analyzes the potential of adopting a spineless cactus through analysis of smallholder farmers’ perceptions with respect to its potential use as a livestock feed in South Asia. A total of 456 households were stratified into three groups in 2017: Farmers not familiar with cactus (non-adopters), farmers familiar with cactus but not growing it (potential adopters), and those already growing it (actual adopters). Main findings confirm that farmers already growing cactus are satisfied with its potential. A considerable proportion of non-adopter farmers cited the unavailability of plant material and technical information as the main reason for their lack of interest in cultivating spineless cactus. Therefore, the potential gains of livestock farming from spineless cactus production in the world’s dry areas could be immense, although more efforts, through farmer education and information sharing, are needed to ensure that the plant’s potential is effectively realized.
The FAO-ICARDA International Technical Cooperation Network on Cactus (CactusNet) was established in 1993 to support the promotion of this underutilized crop. The first edition of this book, Agro-ecology, cultivation and uses of cactus pear, was published in 1995. During the last 20 years much knowledge on cactus pear has been generated, and this is reflected in this extensively revised edition in 2017.
Many cactus species have been introduced around the world and have subsequently become major invaders, inducing social and ecological costs. We recorded the distribution of Opuntia stricta in eastern Africa, and conducted 200 household interviews using semi-structured questionnaires to assess local perceptions of O. stricta in Laikipia County, Kenya. Opuntia stricta was widespread and abundant in parts of Kenya, Tanzania and Ethiopia and present at low densities in Uganda. In Laikipia County, pastoralists identified that O. stricta had been present for more than 10 years, and were of the opinion that it was still spreading and increasing in density. Two-thirds of respondents estimated that 50–75% of valuable grazing land had been invaded, and all felt that it contributed to the ill-health and death of livestock. Other negative impacts included reductions in native plant populations, rangeland condition, human health, and mobility of humans and animals. These negative impacts resulted in economic losses of US$ 500–1000 per household per year for 48% of households. Only 20% of respondents reported actively managing O. stricta, yet all respondents believed a reduction in the abundance of this weed would improve well-being. Management interventions are needed to reduce negative impacts.
Background: South Africa has a long history of managing biological invasions. The rapid increase in the scale and complexity of problems associated with invasions calls for new, more strategic management approaches. This paper explores strategic management approaches for cactus invasions in South Africa. Cacti (Cactaceae) have had a long history of socio-economic benefits, considerable negative environmental and socio-economic impacts, and a wide range of management interventions in South Africa.
Objectives: To guide the future management of cactus invasions, a national strategic framework was developed by the South African Cactus Working Group. The overarching aim of this framework is to reduce the negative impacts of cacti to a point where their benefits significantly outweigh the losses.
Method: Four strategic objectives were proposed: (1) all invasive and potentially invasive cactus species should be prevented from entering the country, (2) new incursions of cactus species must be rapidly detected and eradicated, (3) the impacts of invasive cacti must be reduced and contained and (4) socio-economically useful cacti (both invasive and non-invasive species) must be utilised sustainably to minimise the risk of further negative impacts.
Results: There are currently 35 listed invasive cactus species in the country; 10 species are targeted for eradication and 12 are under partial or complete biological control. We discuss approaches for the management of cactus species, their introduction and spread pathways and spatial prioritisation of control efforts.
Conclusion: A thorough understanding of context-specific invasion processes and stakeholder support is needed when implementing strategies for a group of invasive species.
Online trade of CITES listed species has become a persistent threat which is difficult to measure and control. The use of online markets is growing day by the day as technology becomes more available and familiar to people of all ages and interests. Species trade can now be propagated remotely hardly without any real human interaction. We develop a quick-easy method to assess the online availability of the genus Strombocactus, a highly collectible cactus, to understand the real magnitude of this new form of threat and the possible menace it could be for these Mexican cacti. We used the Google.com site to do an online search in four languages (Spanish, English, French and German) for the offer of adult plants or seeds. We found specimens and seeds available in major online markets like ebay, amazon, cactusplaza.com and mercado libre. Plant price range from €10.00 to €30.00 plus shipping and handling. The plants were also offered in local online stores in countries like the USA, France, Germany, Australia, Czech Republic, the United Kingdom, and others; some sellers claim they have no obstacles for “shipping across countries” and others openly declare the natural localities where seeds were extracted. Only a minority of these online stores openly stated that the cacti were obtained from CITES registered nurseries or that the cacti were grown through propagules or seeds. Our method is easily transferable to estimate the illegal market for any species. There is an active online trade of Strombocactus species and other species listed in CITES without the necessary documentation. Compliance or other regulation mechanisms are needed in order to promote species conservation.
Cacti and succulents represent some of the most diverse and interesting plants in the plant kingdom. Cacti can have ornamental forms, spines, and large ornamental flowers that are occasionally fragrant. Succulents can have ornamental forms and can have ornamental fragrant flowers on inflorescences that often have a long postharvest life. Aside from their ornamental potential, cacti and succulents are often drought, heat and/or cold tolerant, and can have minimal nutritional requirements. Taken together, cacti and succulents represent a group of plants with potential as ornamental potted, bedding and/or landscape plants. We initiated a project 3 years ago to evaluate the potential of unstudied species in these two plant groups as new ornamental crops. Early studies focused on determining what factors induce flowering and assessing the potential of each species as a new ornamental potted, bedding and/or landscape plant. Thus far, we have determined the flowering requirements for over 75 cactus species across six genera. Among succulents, we have focused on identifying how to induce flowering on already identified ornamental crops (often due to plant/leaf form). Other than flower induction work, we developed criteria for assessing the ornamental potential within each plant group. Follow-up experimentation to develop production protocols were also conducted and will be outlined. This study is an example of a case study of what experiments may be considered when initiating work on a new group of species with potential for ornamental commercialization. Which species show the greatest potential, future experiments planned, breeding needs, and future collections planned will be discussed.
Cactaceae is an American plant family found from Canada down to Argentina. Cacti have evolved anatomical and physiological adaptations, which allow them to grow and thrive under desert conditions. Therefore, cacti are a main part of the arid and semiarid landscape. The greatest cacti diversity, for genus and species (63 and 669, respectively), is located in Mexico, where approximately 78% of cacti is endemic. Cacti have been used since pre-hispanic times for food, medicines, fodder, and raw material. Furthermore, cacti are considered as one of the most important ornamental plants nowadays, given that they have beautiful flowers and low water requirements. Unfortunately, the meaningless exploitation, poachers and habitat destruction (for agriculture, grazing, housing development, etc.) have posed cacti on an unstable situation, near extinction. Pressure increases as time goes by, since more human developments are found everyday. Currently, more than 250 Mexican cacti are considered as threatened species. Cacti, usually, have a long life cycle and low growth rates, which are prone conditions for vulnerability. One of the main hindrances for cacti conservation is that they have a low multiplication rate, mostly in those species that are not asexually propagated. Cacti sexual multiplication has a low efficiency, and sometimes cacti seeds are very scarce. The precedent cacti multiplication dilemma has caused that enough cacti plants for reforestation are not easily available. In this context, in vitro plant tissue culture techniques are a feasible alternative to effortlessly propagate numerous cacti. These techniques use plant fragments, under lab and axenic conditions, to massively propagate cacti plants. The in vitro-obtained cacti can be hardened under greenhouse conditions, where they grow as wild type cacti. Plant tissue culture methods allow the fast asexual multiplication of cacti in a short time and in a reduced space, even starting from a scarce supply of plant material. Several successful evidences on cacti propagation using plant tissue culture protocols can be found in the literature; consequently these techniques may be valuable tools to overcome the cacti extinction.
Introduction: Approximately 1600 species are recognized in the family Cactaceae and, with one possible exception, all are native to the New World (Gibson and Nobel, 1986; Wallace and Gibson, 2002). The exception is an epiphyte, Rhipsalis baccifera (previously cassutha) (J. S. Miller) Stern, which appears to be indigenous in Africa and Madagascar (Wallace and Gibson, 2002). Most species of the Cactaceae have leafless photosynthetic stems that bear spines on modified axillary buds called areoles. The cacti are predominantly succulent and adapted to survive in extreme xeric habitats. Because of their often bizarre structures and appearances, many species are now cultivated widely around the world mostly as curiosities and ornamentals. Some species of cacti are used as a source of fruit and fodder, and as hedge plants (Casas and Barbera, 2002). The most common and commercially important species in the Cactaceae is Opuntia ficus-indica (Linnaeus) Miller, usually known as either “prickly pear” or “cactus pear”. This species is cultivated in many countries for its fruit and as fodder (Barbera et al., 1995) but also as the main host for production of the carmine cochineal insect, Dactylopius coccus Costa (Homoptera: Dactylopiidae) (Casas and Barbera, 2002), and supports a flourishing dye industry in Peru, Chile, Bolivia, and the Canary Islands (Flores-Flores and Tekelenburg, 1995). Several species of Cactaceae, introduced either deliberately or accidentally into countries outside the Americas, have become invasive.
Flowers and floral parts have seldom been used successfully as explants to initiate tissue culture. Flower buds of Mammillaria albicoma, M. carmenae, and M. schiedeana (Cactaceae) were cultured on solid Murashige and Skoog medium containing 0.1 mg I-1 α-naphthaleneacetic acid (NAA) and 5.0 mg l-1 6-benzylaminopurine. The formation of vegetative buds (areoles) and the development of shoots were observed in all three species. Both direct and indirect mechanisms of shoot morphogenesis were observed. Direct shoot morphogenesis from the perianth (especially from the axils of the perianth segments) in M. albicoma and M. carmenae was confirmed by microscopic examination. Shoots that formed on explants were isolated and used to establish proliferating cultures. Finally, proliferated shoots were rooted in vitro on MS medium containing 0.01 mg l-1 NAA and acclimated to ex vitro conditions. M. carmenae shoots were also rooted non-aseptically in horticultural substrate. This is the first report of the complete micropropagation of cacti initiated from floral explants. In this family of leafless stem succulents, harvesting of flowers may be a convenient way to micropropagate valuable genotypes, as it avoids injury to stock specimens.
Cacti species are plants that are well adapted to growing in arid and semiarid regions where the main problem is water availability. Cacti have developed a series of adaptations to cope with water scarcity, such as reduced leaf surface via morphological modifications including spines, cereous cuticles, extended root systems and stem tissue modifications to increase water storage, and crassulacean acid metabolism to reduce transpiration and water loss. Furthermore, seeds of these plants very often exhibit dormancy, a phenomenon that helps to prevent germination when the availability of water is reduced. In general, cactus species exhibit a low growth rate that makes their rapid propagation difficult. Cacti are much appreciated as ornamental plants due to their great variety and diversity of forms and their beautiful short-life flowers; however, due to difficulties in propagating them rapidly to meet market demand, they are very often over-collected in their natural habitats, which leads to numerous species being threatened, endangered or becoming extinct. Therefore, plant tissue culture techniques may facilitate their propagation over a shorter time period than conventional techniques used for commercial purposes; or may help to recover populations of endangered or threatened species for their re-introduction in the wild; or may also be of value to the preservation and conservation of the genetic resources of this important family. Herein we present the state-of-the-art of tissue culture techniques used for ornamental cacti and selected suggestions for solving a number of the problems faced by members of the Cactaceae family.
A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31% of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands. The distribution of threatened species and the predominant threatening processes and drivers are different to those described for other taxa. The most significant threat processes comprise land conversion to agriculture and aquaculture, collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder livestock ranching and smallholder annual agriculture. Our findings demonstrate that global species assessments are readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation priorities and actions to those derived from species assessments of key animal groups.
This Workshop was jointly organized by the Tigray Agricultural Research Institute
(Mekele, Ethiopia), The Tigray Bureau of Agriculture and Rural Development,
Ethiopian Institute of Agricultural Research, Food and Agriculture Organization
(FAO), FAO- ICARDA CACTUSNET, International Center for Agricultural research
in the Dry Areas (ICARDA), Swiss Association for International Development
(Helvetas-Ethiopia), and International Society for Horticultural Science (ISHS).
The choice of East Africa and Ethiopia to host this workshop was not incidental.
Indeed, (i) East Africa is facing food security and poverty issues challenges; (ii)
FAO has been and still implementing fruitful projects in Tigray to promote cactus
crop as food, feed and income diversification option; (iii) Tigray region and its
research institutes and centers are obviously the most advanced in East Africa in
the field of cactus pear crop development and uses (iv) the interest and support
of the FAO Sub-Regional Office for Eastern Africa was a guarantee for the success
of the workshop. The workshop coincides with the first shipment of cochineal
to abroad to be processed to produce red carmin; this new initiative is most
welcomed to diversify and increase poor farmers’ income.
The impact of FAO projects was highly visible. Indeed, the rich contribution of
Ethiopian scientists in the workshop and the field visit witness how both research
and development are increasingly mastering techniques of cactus pear cropping
and uses. During the entire workshop, lunches offered to participants were
basically prepared using cactus cladode, and all of us appreciated the hospitality
of farmers offering simple cactus-based dishes. All these good examples that need
to by outscaled to other regions in Ethiopia and Africa.
Moreover, the reader can easily acknowledge the quality of the research presented
in this volume, mostly produced in Africa. Many problems are addressed and
many questions are still open, but the road is paved and the experience and the
vision of the local scientists and farmers will be able to launch the cactus pear as
one of the primary crops in East Africa Countries, particularly if the political and
technical support of local Institutions will continue.
Greater percentages of rare and highly restricted cacti are found in the Chihuahuan Desert than in any other desert in the Americas, with as many as 35 species confined to areas no larger than 2,500 square kilometers in the CDE in Mexico (Hernández and Bárcenas 1995, 1996). Mexico, home to more cacti species than any other country in the Americas, covers about 80 percent of the Chihuahuan Desert, with Arizona, New Mexico, and Texas making up the remaining 20 percent of the desert’s total area (Bravo Hollis 1978; Bravo Hollis and Sánchez Mejorada 1992a, 1992b; Hunt 1999; Hernández and Godínez 1994; Hernández and Bárcenas 1995, 1996).
Mexico’s cactus diversity attracts the interest of international markets and collectors who employ illegal tactics to obtain wild-collected specimens of desirable species, some of which may be newly named to science, rare, or threatened with extinction. Even though collecting wild plants in Mexico for the sole purpose of resale or export is strictly prohibited, cactus specimens, such as seeds and live plants, are the target of unscrupulous collectors, uninformed tourists, and impoverished villagers. Additional threats such as habitat loss and grazing exist for many species, especially those whose wild populations are limited to only a few locations.
A survey of nurseries in more than 100 Mexican establishments in 13 states reveals 94 cactus species native or endemic to the Chihuahuan Desert in domestic trade, with three genera (Mammillaria, Turbinicarpus, and Ferocactus) accounting for 53 percent of the total species traded. Approximately 300 cactus species native to the Chihuahuan Desert of Mexico were also documented in the international marketplace, with the maximum number of species offered in the United States, the United Kingdom, Germany, and Sweden. More than half of the species documented in international trade are listed in CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) Appendix I and, therefore, cannot be commercially traded unless artificially propagated; are included in the list of threatened species recognized by the World Conservation Union (IUCN); or receive special status under Mexican law.
Regrettably, many of the species now commercially available as artificially propagated plants in foreign markets are descendants of seeds or live plants that were illegally exported from Mexico by private collectors. Illegal trade continues to threaten many cactus species of limited distribution and of conservation concern in the Chihuahuan Desert in Mexico, as is evident from the number of seizures involving several endemic taxa: Astrophytum myrisotigma, Ariocarpus retusus, Aztekium hintonii, Cephalocereus senilis, Geohintonia mexicana, and Lophophora williamsii.
The illegal trade in cactus species of the Chihuahuan Desert is a symptom of a combination of problems, including a lack of nurseries propagating rare species to meet international demand, confusing and often contradictory Mexican laws posing a barrier to establishing commercial plant breeding operations, and insufficient outreach efforts to rural villages to communicate the economic benefits of sustainable cactus harvest. Stronger enforcement of existing Mexican laws is also needed to deter individuals, particularly foreign private collectors, from collecting and bringing into their countries protected cactus plants. These issues require a multifaceted approach, ranging from investing in commercial propagation to improving monitoring and law enforcement. Unless these issues are addressed, they will continue to undermine the conservation of Mexico’s outstanding, yet dwindling cactus populations.
Micropropagation of 11 rare or endangered cacti species belonging to the subtribe Cactinae was achieved by rooting of proliferated axillary shoots. Shoot tip explants were obtained from seedlings of Escobaria missouriensis D.R. Hunt, E. robbinsorum (Earle) D.R. Hunt, Sclerocactus spinosior (Engelm.) Woodruff & L. Benson, and Toumeya papyracantha (Engelm.) Br. & Rose, and from mature plants of Mammillaria wrightii Engelm., Pediocactus bradyi L. Benson, P. despainii Welsh & Goodrich, P. knowltonii L. Benson, P. paradinei B.W. Benson, P. winkleri Heil, and S. mesae-verdae (Boissevain) L. Benson. Three or four species were used in each of a series of experiments investigating the effects of basal media and auxin and cytokinin types and concentrations on axillary shoot proliferation. Low or no auxin but moderate to high cytokinin concentrations were required for axillary shoot production. All species rooted spontaneously on hormone-free media; however, several species rooted better on media containing auxin. All species were re-established in the greenhouse.
Invasive plants seriously impact our environmental, agricultural and forestry assets, and the ornamental plant trade is a major introduction pathway. The variety and extent of ornamental plant trade is growing in reach and is increasingly facilitated by the internet (i.e., through e-commerce). A lack of surveillance and regulation of e-commerce has resulted in invasive species being widely traded on these platforms. Here, we investigated the illegal trade in invasive plant species occurring in Australia by collecting advertisements found on a popular e-commerce website. Across a 12-month period we found 155 plant taxa advertised online that were prohibited to trade in Australian. From 10,000 advertisements (4.25% of total advertisements found), we found 1,415 instances of these invasive plants advertised, of which 411 breached local jurisdictional (i.e., State or Territory) laws. Opuntia cacti and invasive aquatic plants were traded in the greatest quantities. A variety of uses for plants prohibited to trade were purported by sellers, where aquatic uses were the most popular (i.e., water filtering and habitat for aquatic animals). Despite Australia’s strict internal biosecurity regulations, we found that trade prohibitions had no influence on the quantity and price of illegal invasive plants traded. Given this, and the extent of illegal invasive plants traded, we believe increased monitoring and regulation of online plant trade is warranted. However, to obtain the most optimal outcomes, regulations should be coupled with increased cooperation from e-commerce platforms and public awareness campaigns. Future weed risk assessments should consider online trade as a key factor in the long-distance dispersal and propagule pressure of a plant. Jurisdictions would also benefit from greater alignment on plant trade prohibitions and revision of associated compliance policies.
Cryopreservation allows the long-term storage of plant germplasm, but can cause damage to plant tissues, which must be repaired for survival to occur. This repair process is fuelled by the metabolic function of mitochondria; however, little is known about how metabolic function is affected by the cryopreservation process in plants. We compared metabolic rates of shoot tips of two Australian native species, Androcalva perlaria and Anigozanthos viridis. Overall, cryopreservation resulted in a significant reduction in the metabolic rates of shoot tips from both species, even in tissues that regenerated after cryopreservation. Metabolic rate did not increase within 48 h after of thawing, even in shoot tips which later regenerated. When examined in isolation, both pre-treatment on desiccation medium and exposure to cryoprotective agents significantly decreased metabolic rates in regenerating shoot tips of A. viridis, however both caused a significant increase in shoot tips of A. perlaria, suggesting diversity of response to cryopreservation stresses across species. Measurements of shoot tip metabolic rate during cryopreservation will inform investigations into cellular energy production and provide critical information on the state of shoot health after exposure to different cryoprotective treatments, which could play a useful role in guiding protocol optimisation for threatened species to maximise post-cryopreservation regeneration.
Success in propagation of woody or tree species through conventional methods like cuttings is hindered due to the fact that cuttings in such species often fail to respond to rooting treatments. This failure to root is often linked to increased maturity (or decreased juvenility) in stem cuttings. To overcome from this situation, an alternative method of propagation has been used in tissue culture techniques (in vitro methods). In this technique, aseptic conditions are needed for culture of plant tissues (explants) and rapid mass propagation can be done in a limited space. Of the different in vitro methods, micrografting is an important and potential method to induce juvenility in tissues taken from mature plant, hence improving rooting efficiency in hardy or recalcitrant varieties. This chapter attempts to highlight the concept of juvenility and its significance in plant tissues culture, methods to induce juvenility, with special reference to micrografting and its significance in rooting in clonal propagation of elite tress species.
An axillary bud (areole) of Opuntia polyacantha is composed of an extremely short axis which bears highly modified leaves (spines). After producing the spines, the bud apical meristem becomes quiescent. When the axillary bud is excised and cultured with benzylaminopurine (BAP), the apical meristem increases in complexity and produces leaves on an elongated axis. Gibberellic acid (GA) induces spine production with no elongation of the axis. Naphthaleneacetic acid (NAA) causes no structural change in the meristem but induces root formation in adjacent tissue. The initiation of roots, spines, or leaves is visible within three days. Explants on medium lacking hormones show no structural change, but by the tenth day are insensitive to BAP or NAA. These aged explants can be made to respond to BAP or NAA by merely rewounding them at the time of hormone application. With concentrations previously found to be optimal for single hormone responses, NAA in combination with BAP prevents shoot formation, or in combination with GA prevents spine production. When all three hormones are combined, spines are produced, indicating that GA is active morphologically while BAP and NAA counteract each other. If the level of NAA is decreased, BAP counteracts the NAA and also overrides the GA and leafy shoots are produced. By varying the proportions of BAP and GA, in the absence of NAA, four types of lateral appendage can be produced: leaves, mildly altered leaves, leaf-spine transition forms, and spines.
Small island developing states (SIDS) have some of the highest electricity tariffs globally. Renewable energy (RE) technologies could thus have reached grid parity in various SIDS. Furthermore, the abundance of resources such as solar and wind provides ample potential for SIDS to switch from high cost diesel generators to renewables. Despite favourable conditions, RE remains a largely underinvested sector in these regions. This paper aims to undercover the reasons why grid parity does not necessary translate into private sector investments in RE. With a focus on SIDS, this paper presents an evidence that achieving grid parity based on LCOE estimates is an incomplete benchmark for decision making in the power generation industry. In particular, LCOE and grid parity do not take into account financing constraints of RE projects which are often more pronounced compared to conventional forms of power generation. This paper thus presents the business perspective of RE projects, by employing a discounted cashflow model that includes various profitability metrics and effects of taxation and depreciation. The study shows that financing conditions exert strong influence on the economic feasibility of solar projects, both in LCOE terms and profitability terms. Thus, key policies should be targeted at improving financing conditions to ensure mobilization of private sector finances in solar PV.
This chapter focuses on cactus-feeding insects and cactus pathogens. In the known cactus-feeding insect community, the Pyralidae (pyralids) are most numerous, with approximately 58 species feeding on cacti, followed by Cerambycidae (long-horned beetles), with about 20 species. The insect pests on Opuntia species vary considerably, depending on the country and the continent in which they are cultivated. The largest number of pests are recorded from Mexico, where Opuntia species are extensively cultivated. In the Mediterranean countries, pathogens cause considerable damage to cultivated plantings comprised mainly of Opuntia ficus-indica and its many cultivars. The most important cactus pear diseases are grouped according to their pathogenic agents. The biotic diseases are caused by bacteria, yeasts, fungi, phytoplasmas, viruses, and phytoplasma/virus-like organisms.
The multiplication of cacti is difficult, especially in chlorophyllien-deficient species. To facilitate the multiplication of cacti species: Echinocactus mihanovichii (red cactus) Echinopsis chamaecereus f. lutea (yellow cactus) and Aylostera heliosa (green cactus) by vitrotechniques, we used spheroid buds as explants, taken from adult stems. This explants were inoculated on a basic medium culture with Murashige-Skoog (1962) macroelements, end Fe EDTA, Heller (1953), end microelements. Added in the medium were the vitamins: HCl thiamine, HCl pyridoxine and nicotinic acid, each 1 mg / l, 100mg / l meso-inositol, to which - depending on the organized experimental variant - growth regulators were added, such as: 1 mg / l benzyladenine (BA), or 1 mg / l β-indolil-butyric acid (AIB), or a mixture - in equal parts - among them. The vitrocultures evolution was observed for a period of 90 days. The reaction of explants cultivated "in vitro" was different depending on the species with which was worked and on the nature of growth regulator present in the culture medium. Finally, inoculums of Echinocactus mihanovichii and those of Echinopsis chamaecereus f. lutea showed a caulogenesis phenomena; in time, the initial explant presented necrosis. Aylostera heliosa explants were better adapted to "in vitro" micropropagation, but they generated callus, largely hyperhydric. The largest morphogenesis, in general, has been manifested in the growing medium with a mixture of BA and AIB, 1mg / l of each. In general, risogenesis was absent.
The genus Mammillaria, the largest in the Cactaceae family, constitutes one of the most popular groups of cacti. This popularity lies basically in the huge variability of the genus, in its forms, color of flowers, its small size, and relative ease of culture and maintenance, all of which make it a horticultural favorite. Unfortunately, these factors mean that many species of the group are threatened with extinction. The following sections present a brief description of this genus.
Prickly pear or cactus pear (Opuntia ficus-indica) is a commonly used cactus plant in Northeastern Brazil, mainly as cattle feed. It is of utmost importance to analyze the genetic variability for germplasm conservation and characterization and to group the genotypes for a more adequate management and optimized use of collections. This study aimed to evaluate the level of genetic diversity in cactus clones by molecular markers to gather information for future breeding programs of the crop. Eleven clones of the Breeding program of Empresa Pernambucana de Pesquisa Agropecuária - IPA, state of Pernambuco, Brazil, were evaluated by ISSR (Inter Simple Sequence Repeat) markers. Of these, 52 primers were used and 12 selected for their high repeatability and polymorphism level. A total of 175 polymorphic bands was produced, i.e., on average 14 bands per primer. Average linkage (UPGMA) clustering revealed low genetic diversity in the cactus pear clones, suggesting that the genetic differences between them are minimal. The ISSR markers however obtained useful results for the identification of polymorphisms and of cultivar-specific markers in cactus pear.
The application of biotechnological techniques and procedures for the conservation of plant germplasm is of increasing importance to plant genetic resource management. This review examines the various biotechnological strategies which may be currently employed in plant germplasm conservation. Particular emphasis is given to the development of in vitro conservation techniques in genebanks which are dedicated to the storage of vegetatively propagated crop plant species. The role of biotechnology in the conservation of potato genetic resources is highlighted. This crop is vegetatively propagated and cannot be easily conserved using seed banking procedures. A range of biotechnological approaches are appraised: tissue culture, slow growth, molecular biology, cryopreservation and germplasm collection. New advances in in vitro plant genetic resource management are presented and the value of fundamental research in underpining conservation biotechnology development is discussed. The importance of conservation biotechnology in supporting plant breeding programmes is addressed. The full. potential of plant conservation biotechnology will only be realised through the interdisciplinary co-operation of genetic resource managers, biotechnologists and plant breeders.
Marginal lands often represent fragile ecosystems. Ploughing and indiscriminate vegetation removal can result in large-scale degradation and destruction of vegetation cover. To reverse the desertification trend and to restore vegetation cover in such areas, appropriate integrated programs are needed for rangeland monitoring, livestock control, and conservation of natural resources. The identification of plant species able to grow and produce in arid areas has been a permanent concern in most WANA countries. The characteristics of cacti fit most of the requirements of a drought-resistant fodder crop. Indeed, they possess a specialized photosynthetic mechanism, which leads to a more efficient production of dry matter per unit water consumed than that of grasses or legumes. Spineless cactus (O. ficus-indica), which is drought and erosion tolerant, is being advantageously and widely established in Tunisia and Algeria to slow and direct sand movement, to enhance the restoration of the vegetation cover, and to avoid the destruction by water of the land terraces built to reduce runoff. Large scale plantation of spineless cactus in Central and Southern Tunisia proved that this plant species play a key role in natural resources conservation and prevent long term degradation of ecologically weak environments. These plantations provide a valuable fodder used extensively to cover feed gaps especially during severe droughts. Cacti cladodes are unbalanced feed nutrientwise but a cost-effective source of energy and water. In arid and semi-arid regions, cereal crop residues and natural pastures generally do not meet the nutrient requirement of livestock. Cladodes can provide cost-effective supplement, such as for raising sheep and goat on rangelands. National strategies in several countries of WANA region started since several decades to overcome feed gaps and to restore degraded rangelands. These strategies focused mainly on large-scale plantations of fast growing species, such acacias and saltbushes. Pertinent experiments showed that sustainable feeding systems based on these feed sources associated with cactus are beneficial to these areas. Supplying livestock with water during the summer and drought periods is crucial in arid zones. Water scarcity depresses feed intake, digestion, and therefore animal performance. Therefore, the high water content of cladodes is beneficial in dry areas.
The Republic of Argentina has 1650 ha of cactus pear for production of fruit, of which 604 are located in the province of Santiago del Estero. The cultivar 'Yellow Spineless' is the most widely grown, both in traditional orchards of small size with little or no management (TO) and in high technologies orchards (HTO). One of the problems raised in both is the concentration of the harvest. The implementation of the scozzolatura would yield fruit out of season and with a higher price. The objective was to study the economic feasibility of making scozzolatura in TO and HTO. Orchards in full production were used. Costs were stabilized and yields of 10,000 and 22,000 kg ha-1 were estimated respectively. The basic analyses of the operations were performed according to the available literature and research of FAyA-UNSE. The autumn fruit production was 5% according to that of the season. In the TO costs were higher than income, so the benefits were negative, even though the application scozzolatura increased incomes. In HTO, scozzolatura did not maximize the revenue despite tripling the price of fruit. In HTO small areas (1 ha) this technique allows an extra income to the production of the season, which would justify its application. With respect to this technique TO sacrifices total production season, but would facilitate the commercialization of total fruit with a high gross income. Further study is needed in this cultivar and others in the province in order to recommend this technique.