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Images depicting stages of seed germination and early seedling growth of hollong. (a) An excised seed showing emergence of radicle. (b) Geotropic movement of radicle. (c) Emergence of plumule. (d) First pair of cotyledonary leaves flushing. (e) A complete seedling still receiving nourishment from reserves in the seed. (f) An aberration with emergence of two seedlings from a single seed.
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In species with seeds losing viability shortly after dispersal and exhibiting inherently low germination, quick decisions
are required with respect to seeds that should be selected to maximize germination success and vigorous growth of seedlings.
In ‘hollong’ (Dipterocarpus macrocarpus Vesque), I address the following questions: (a) are seeds that...
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Citations
... In the earlier report, it was found that the germination rate of heavy seeds is faster in comparison to light seeds. In many tropical species, superior and quicker germination of heavier seeds has been reported (Devi et al., 2018;Howe et al., 1982;Dunlop et al., 1983;Tripathi et al. 1990, Barik et al. 1996, Bhuyan et al., 2000Khan and Shankar, 2001;Shankar, 2006). Although it has been reported that some other species the seed weight may not be dependent on germination (Gross, 1986). ...
A few plant species of the Thymelaeceae family are highly valuable and demanding because they contain resinous oil in their stems, branches, and roots. From this plant, resinous oil is extracted through the distillation process. Traditionally and from the religious point of view, the oil has a higher potential in the manufacturing of perfume, incense sticks, smoke, and many other medicinal and religious purposes. It is a highly economic plant, so its conservation is very important. Aquilaria plants are propagated through seeds and the seeds are recalcitrant, i.e., they are chilling sensitive and also cannot be stored at room temperature because of their high moisture content. They are also called desiccation sensitive. Below a certain level of moisture content, their embryos become death or inviable. Conservation of germplasm in the case of recalcitrant seeds is a major issue to be solved in the current situation. Our main focus was to enhance the germination of the Aquilaria malaccensis seeds for the early development of the seedlings within a short time. Here we are applying different pretreatments of Aquilaria seeds, such as Acetone for 1 min, 2 min, and 3 min, likewise Methanol, Ethanol, hot water, acetic acid, etc for enhancing seeds germination and it was found that highest germination percentage in the treatment where seeds are soaked in 1 min acetone (70%) in comparison to the control, which shows only a 56.7% germination rate. Their germination rate was determined by regular observation for up to 2 months, and the growth curve was also prepared by calculating the weight of the seeds. The findings of the current study will help to develop a protocol for early germination as well as mass propagation within a short period of time. The results of the Aquilaria species are significantly different from each other.
... Fruit widths locationd from Gbongan and Ayetoro, Otun and Ayetoro including Otun and Gbongan were not significantly different from each other due to overlapping. This implies that locations with overlapping were hereditarily similar (Shankar, 2006) [7] . Seed coat is one of unique genetic factor that varies with crop in most cases and sometimes with varieties. ...
... Fruit widths locationd from Gbongan and Ayetoro, Otun and Ayetoro including Otun and Gbongan were not significantly different from each other due to overlapping. This implies that locations with overlapping were hereditarily similar (Shankar, 2006) [7] . Seed coat is one of unique genetic factor that varies with crop in most cases and sometimes with varieties. ...
Fruits and seeds source variability studies of Pycnanthus angolensis (Welw).were carried out to investigate the variation in fruit and seed weight, length and width among six provenances; Otun, Ayetoro, Gbongan, Ajaba, Adewumi and Idito. Highest fruit weight (19.9±0.2), width (5.3±0.0) and length (4.2±0.0) were obtained from Ajaba, Otun and Gbongan, respectively. Ayetoro had the least weight (12.5±0.2), while Idito had the least width (3.9±0.0) and length (2.7±0.
... In Aijung cultivar at 50µM As, CAT activity of plumule and radicle was enhanced by 124.82% and 141.74% but at 100µM As stress, CAT activity of plumule and Radicle was reduced by 15.04% and 14.57% as compared to control.Overall SOD and CAT activity was higher in Aijung cultivar than Ranjit cultivar signifying its more strong antioxidative response than Ranjit cultivar under As stress. Under As stress, germination of seeds is reported to be very sensitive and is considered as the first physiological process affected by As stress (Liu et al., 2005;Shankar et al., 2006). The decrease in germination percentage and growth parameters may be attributed to lowered uptake of water, nutrients, and reduction of cell elongation under As stress as reported by Yadu et al., (2019). ...
Arsenic (As) toxicity profoundly affects the yield and quality of rice worldwide and it is one of the crucial threats in the world as rice being one of the major staple cereal crops. The present study was designed to investigate the growth (germination, growth of the seedlings), stress (H2O2 and lipid peroxidation), and biochemical parameters (amylase activity, enzymatic and nonenzymatic antioxidant activity) of Ranjit and Aijung, the two most edible cultivars of Assam under arsenic stress. Both the rice cultivars responded differentially to As treatments and showed differences in all noted parameters. With increasing arsenic concentration, reduction in germination, plumule–radicle length, reduced fresh and dry mass, and declination in amylase activity was prompted. The reductions of most of the observed parameters were higher in Ranjit than Aijung cultivar as compared to their respective control. Alteration of stress-related parameters and antioxidant enzymes were also inferred under As stress. Analysis of growth and the biochemical study revealed that Aijung cultivar is more tolerant to As stress than Ranjit cultivar and that might be associated with a potent antioxidative defense system.
Key words: Arsenic stress, Assam, most edible, rice cultivar, tolerant
... For this reason, seeds should be divided into fractions based on a trait that promotes even seedling development and prevents seedling dominance [14]. According to many authors, the average seed mass in a given fraction significantly affects germination in a seed batch [15][16][17][18][19][20][21]. The simplest solution would be to divide seeds into fractions based on their mass. ...
Research Highlights: Seed separation criteria and the optimal parameters of sorting devices were described. Background and Objectives: Seeds are often sorted into fractions which are sown separately to promote uniform seed germination and seedling emergence. Therefore, the aim of this study was to determine the correlations between the basic physical properties of European black pine (Pinus nigra J.F. Arnold subsp. nigra) seeds for the needs of planning seed sorting operations. Materials and Methods: Black pine seeds were divided into 5 batches representing individual parent trees, and the physical properties (terminal velocity, thickness, width, length, angle of external friction, mass) of each seed were determined. The measured geometric parameters and seed mass were used to calculate the respective indicators for each seed. The values of the analyzed parameters were used to plan the seed separation process. Results: The average values of the basic physical properties of seeds were determined in the following range: Terminal velocity—8.32 to 8.73 m s−1, thickness—2.24 to 2.27 mm, width—3.34 to 3.44 mm, length—5.87 to 6.08 mm, angle of external friction—28 to 32°, mass—18.8 to 20.0 mg. Seed mass was most highly correlated with terminal velocity, and it was least correlated with the angle of external friction. Conclusions: The results of this study indicate that black pine seeds should be sorted with the use of pneumatic separators or, alternatively, mesh sieves with longitudinal openings. These sorting devices separate seeds into fractions characterized by similar seed mass, which delivers both economic and environmental benefits in nursery practice.
... Generally controlled experienced the higher speed of germination than the As treatments ones. According to Shankar (2006) [32] seed germination is very sensitive physiological process affected by heavy metals. There were 35 %, 6.4 %, 2.6% and 42.5 % decrease in speed of germination when the As concentration increased from 0 to 50 μM/L in V1, V2, V4 and V5, respectively. ...
... Generally controlled experienced the higher speed of germination than the As treatments ones. According to Shankar (2006) [32] seed germination is very sensitive physiological process affected by heavy metals. There were 35 %, 6.4 %, 2.6% and 42.5 % decrease in speed of germination when the As concentration increased from 0 to 50 μM/L in V1, V2, V4 and V5, respectively. ...
Arsenic (As), at present, a major problem in agricultural production. The concomitant increase in As concentration in rice belt areas affects early establishment and production of rice. So, it is necessary to choose a proper variety. The objective of the study was to evaluate the germination performance and initial growth habits of indigenous rice varieties in response to the different As concentration in the growing solution. Therefore, the effects of As (0, 50, 100, 150, 200 μ M/L) on germination percentage, speed of germination, hypocotyls and radicle length, fresh and dry weight of root and shoot and their percentage reduction were determined. Increasing As concentration caused a decrease in both germination percentage and speed of germination except Variety-4 (V4) and rest of the variety were unable to germinate above 100 μ M/L concentration. Root growth was halted in V3, whereas V4 showed resistance. Most sensitivities regarding relative water content were expressed by V1 and V5 retained more turgidity in 50 μ M/L concentration. In case of the speed of germination, V4 affected much less as compared to others. Root and shoot fresh and dry weight percent reduction showed maximum reduction for V4T4. All the growth parameters were negatively correlated with As concentration. The speed of germination was significantly positively correlated with germination percentage. From the results obtained in the present study, it can be concluded that indigenous rice varieties are sensitive to As concentration and among the varieties, V4 is come out to be the most resistant to As stress. 1. Introduction Arsenic (As) is a toxic metalloid that is ubiquitous in the environment. It has raised serious concern for both environmental and human health perspectives. Contribution of As in soil gathered from both geogenic and anthropogenic sources, which include, metal mining and smelting, arsenic-containing pesticides, herbicides uses and irrigation with arsenic-contaminated water (Mitra et al. 2017 [24]). The groundwater is getting contaminated with As and drinking of the water cause great exposure of As to human kind. (Smith et al. 2000 [35]). Moreover, the agricultural soils are being contaminated by As at a rate of 1000 t As per year as for the irrigation with As laddened ground water. (Duxbury and Panaullah 2007 [8]). So, crops grown on the arsenic-contaminated soils serve as a secondary source of arsenic for human beings. Studies showed that As concentrations in rice plant depends firstly on the presence of As in soil and secondly on the As contaminated groundwater sources and other factors depend on plant-rhizopheric characters which do play role in As mobilization and stabilization. (Mandal et al. 1996 [20] ; Ullah 1998 [37] ; Rahman et al. 2007 [27]). In recent times, the south east Asian countries are facing serious threat to arsenic (As) toxicity due to the extensive cultivation of boro (winter) rice with As contaminated groundwater and that results in people of Bangladesh, India, China, Korea, Taiwan, and Thailand to arsenic intake from rice i.e. the staple food of these region. (Bakhat et al. 2017 [4] ; Zhao et al. 2010 [38]). Occurrence of it in ground water beyond permissible limit has become a serious threat for these countries. The transfer of arsenic from soil to plant systems is a serious issue that leads to considerable human exposure. Concentration of As in plants depends on plants root ability to uptake and transport it from soil to roots/shoots. Rice is the most severely affected staple food crop to arsenic contamination as compared with other crops like wheat, maize, and barley due to its (rice) cultivation in flooded conditions. The most widely adopted conditions to cultivate the rice in field are water submerged conditions. Anaerobic conditions of the paddy fields
... Germination rate index increased with a rise in achene mass, which means that larger achenes germinated faster. Similar observations were made in studies of Dipterocarpus macrocarpus (Shankar 2006), European larch (Kaliniewicz et al. 2012a) and Norway spruce (Kaliniewicz et al. 2012b), whereas a reverse relationship was reported for seeds of tropical trees (Norden et al. 2009). According to many authors (Mikola 1980, Sabor 1984, Castro 1999, Khan 2004, Parker et al. 2006, Upadhaya et al. 2007, Wu and Du 2007, Castro et al. 2008, Buraczyk 2010, seed mass significantly influences sprout development and seedling growth. ...
The simplest method of improving seed quality involves the elimination of non-germinated or damaged seeds from the propagating material. The aim of this study was to determine correlations between the basic physical properties of black alder achenes and their germination capacity to generate valuable data for improving the seed material. The experiment was performed on 5 batches of achenes harvested from tree stands in 4 seed zones in 3 forest regions of north-eastern Poland. The thickness, width, length, angle of sliding friction and mass of every achene were measured. The results were used to calculate the geometric mean diameter, aspect ratio and sphericity index of black alder achenes. Achenes were germinated for 28 days, and the results were recorded daily to determine the germination rate index of every achene. The relationships between the examined parameters were determined in a t-test for independent samples and by correlation analysis. The analyzed physical parameters of achenes had a minor impact on their germination rate. The results indicate that the classification of black alder achenes based on all measured parameters would not significantly contribute to germination uniformity. The fraction of longest or widest achenes had higher potential germination capacity than unsorted achenes. Germinated achenes were generally characterized by greater thickness, width, length, mass, geometric mean diameter, aspect ratio and sphericity index, but lower angle of sliding friction in comparison with non-germinated achenes.
... Na kiełkowanie nasion wpływa przede wszystkim ich masa [Mikola 1980;Khan 2004;Parker i in. 2006;Shankar 2006;Upadhaya i in. 2007;Norden i in. ...
Information about the variations and correlations between the physical properties of seeds is essential for designing and modeling seed processing operations. The aim of this study was to determine the variations in the basic physical properties of seeds of selected spruce species and to identify the correlations between these attributes for the needs of the seed sorting processes. Terminal velocity, thickness, width, length, mass and the angle of external friction were determined in the seeds of 11 spruce species. The measured parameters were used to calculate three aspect ratios, geometric mean diameter, sphericity index and specific mass of each seed. The average values of the basic physical properties of the analyzed seeds were determined in the following range: terminal velocity – 5.25 to 8.34 m s-1, thickness – 1.10 to 2.32 mm, width – 1.43 to 3.19 mm, length – 2.76 to 5.52 mm, the angle of external friction – 23.1 to 30.0°, and mass – 2.29 to 18.57 mg. The seeds of Jezo spruce and Meyer's spruce were most similar to the seeds of other spruce species, whereas oriental spruce seeds differed most considerably from the remaining seeds. Our findings indicate that spruce seeds should be sorted primarily with the use of mesh sieves with longitudinal openings to obtain fractions with similar seed mass and to promote even germination.
... Na kiełkowanie nasion wpływa przede wszystkim ich masa [Mikola 1980;Khan 2004;Parker i in. 2006;Shankar 2006;Upadhaya i in. 2007;Norden i in. ...
The objective of this study was to determine the influence of the age of parent tree stand on selected physical properties of Norway spruce seeds to improve the efficiency of seed separation processes. Seeds were harvested in a forest complex located in the seed zone No. 202, in the municipality of Kruklanki in the Borki Forest District (N Poland) during mast years (1999, 2004, 2007 and 2012). The experimental material comprised of Norway spruce seeds from three differently aged tree stands (86, 119 and 129 years old in the first harvest year). The following measurements were performed for each seed: terminal velocity – with a pneumatic classifier; length and width – with a laboratory microscope; thickness – with a thickness gauge; angle of external friction – on an inclined plane, in two positions on a steel friction plate, and mass – with a laboratory scale. The results were used to calculate the arithmetic and geometric mean diameters, aspect ratio, sphericity index and density of seeds. The values of the analyzed properties were compared with ANOVA for factorial designs and linear correlation analysis. The results of the study indicate that Norway spruce seeds obtained from cones harvested in 2012 are characterized by the highest thickness and, consequently, by the highest values of the aspect ratio and sphericity index. The age of parent trees significantly influences the majority of physical properties of seeds. However, the patterns of observed changes are difficult to interpret due to the impact of weather conditions and the genetic potential of parent trees, which perform differently in response to changing climate and geomorphological conditions. Over the analyzed 13−year period a gradual increase was noted in the width, geometric mean diameter, aspect ratio and sphericity index of seeds, whereas the length and density of seeds decreased. Therefore, Norway spruce seeds should be separated mostly with the use of mesh screens with longitudinal openings, pneumatic separators and graders. The use of those devices, separately or in combination, for sorting Norway spruce seeds into mass fractions could contribute to more uniform seedling emergence when every seed fraction is sown separately.
... In the case of belowground conditions, the emergence, establishment and early growth of seedlings are affected by various physico-chemical properties, including soil water content (Shankar 2006), nutrient availability (Roberts et al. 2005), organic matter thickness (Lafleur et al. 2015) and soil compaction (Jordan et al. 2003), which in turn affect soil biological characteristics (Closa and Goicoechea 2010). In addition, seedlings that are established near canopy trees can benefit from different communities of root symbionts and, thus, increase nutrient uptake compared with seedlings that have established in openings (Simard and Durall 2004). ...
In seasonally dry environments such as the Zagros woodlands (Iran), severe drought stress and lack of appropriate management practices can cause failure of oak afforestation or reforestation. We investigated the effect of soil properties and burial depth on Persian oak (Quercus brantii Lindl.) establishment in different microhabitats resulting from traditional forest practices. Four microhabitats that were based on forest structure were considered for oak acorn seeding: (1) inside old sprout clumps (ISPC); (2) under the canopy of tall trees (UCTT); (3) outside the canopy of tall trees and sprout clumps; and (4) near recent stumps or sprout clumps. Acorns were seeded at two depths (2 and 5 cm), and seedling survival and growth variables were recorded for 4 years, together with soil chemical and biological attributes. Stepwise discriminant analysis showed that a combination of total soil nitrogen, cation exchange capacity, available phosphorus and potassium, litter depth, microbial quotient, metabolic coefficient, substrate-induced respiration and earthworm abundance was the best variables to characterise the microhabitats. With the exception of pH, bulk density and soil texture, these variables were higher in UCTT and ISPC than in the other microhabitats. Seedling emergence and survival were greater at a seed depth of 5 cm than at 2 cm. Seedling
height and shoot, root and leaf biomasses were higher in the UCTT microhabitat compared to the other microhabitats and correlated positively with soil nutrients contents and most of the soil biological variables but negatively with soil bulk density. This study emphasised the role of microhabitats in creating a ‘‘canopy effect’’ producing favourable physical, chemic al and biological soil conditions. In particular, large oak trees form islands of fertility and therefore are of key importance for successful seedling establishment in forests subjected to intense human
activities.
... Na kiełkowanie nasion wpływa przede wszystkim ich masa [Mikola 1980;Khan 2004;Parker i in. 2006;Shankar 2006;Upadhaya i in. 2007;Norden i in. ...
The objective of this study was to determine the influence of the age of parent tree stand on selected physical properties of Norway spruce seeds to improve the efficiency of seed separation processes. Seeds were harvested in a forest complex located in the seed zone No. 202, in the municipality of Krukianki in the Borki Forest District (N Poland) during mast years (1999, 2004,2007 and 2012). The experimental material comprised of Norway spruce seeds from three differently aged tree stands (86, 119 and 129 years old in the first harvest year). The following measurements were performed for each seed: terminal velocity - with a pneumatic classifier; length and width - with a laboratory microscope; thickness - with a thickness gauge; angle of external friction - on an inclined plane, in two positions on a steel friction plate, and mass - with a laboratory scale. The results were used to calculate the arithmetic and geometric mean diameters, aspect ratio, sphericity index and density of seeds. The values of the analyzed properties were compared with ANOVA for factorial designs and linear correlation analysis. The results of the study indicate that Norway spruce seeds obtained from cones harvested in 2012 are characterized by the highest thickness and, consequently, by the highest values of the aspect ratio and sphericity index. The age of parent trees significantly influences the majority of physical properties of seeds. However, the patterns of observed changes are difficult to interpret due to the impact of weather conditions and the genetic potential of parent trees, which perform differently in response to changing climate and geomorphological conditions. Over the analyzed 13-ycar period a gradual increase was noted in the width, geometric mean diameter, aspect ratio and sphericity index of seeds, whereas the length and density of seeds decreased. Therefore, Norway spruce seeds should be separated mostly with the use of mesh screens with longitudinal openings, pneumatic separators and graders. The use of those devices, separately or in combination, for sorting Norway spruce seeds into mass fractions could contribute to more uniform seedling emergence when every seed fraction is sown separately.
