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Seed germination percentage (a) and speed germination index (b) of Diospyros hispida. Control (c), rub scarification (T1), seeds immersed in sulfuric acid (H2SO4) for 1 and 5 min (T2 and T3, respectively), seeds immersed in water at 25 °C over a period of 24, 48, and 72 h (T4, T5, and T6, respectively), seeds immersed in water at 70 °C for 1 and 5 min (T7 and T8, respectively) and seeds immersed in water at 80 °C for 1 and 5 min (T9 and T10, respectively)
Source publication
Diospyros lasiocalyx (Mart.) B. Wall. is a dioecious tree species found in the threatened and fragmented Brazilian Cerrado. Its fleshy fruits, which are consumed extensively by wildlife, make the species ideal for use in restoration. This study includes a ten-year phenological observation, germination tests, and analysis of molecular markers to und...
Citations
... Other than the pollinator attraction strategies, D. sericea also seems to have adapted to the environmental conditions towards maximizing the success of its reproductive cycle until its final stage, which is seed dispersal. Female individuals have the highest flower production at the end of the dry season, as also described in D. lasiocalyx [73]. This phenological behavior does not seem ideal for these individuals, given that female reproduction is costly, and water is limited during this period. ...
Diospyros sericea is a tree/shrub species considered dioecious and broadly distributed in Brazil. Despite its importance for niche composition in a range of ecosystems, there is little knowledge about this species, and so far no study has analyzed its sexual system. We aimed to investigate dioecy expression in D. sericea through sexual dimorphisms in its phenology and floral biology. We analyzed the phenological events over a year and studied floral biology traits (mor-phology, flower development, floral resource, floral attractants supply, viability of pollen, and stigma receptivity) in both male and female plants. D. sericea presents typical features of dioecious plants like well-established primary and secondary dimorphisms that contribute to its reproductive success. However, we also identified fruit development in what should be structurally male individuals. We suggest that the evolutionary pathway leading to the observed phenomenon may be the existence of subdioecious populations with "inconstant males". Although our data prevented us from making further assumptions about the origin of this trait, the study contributes to future analyses towards unraveling the enigma of dioecy not only in D. sericea but in other Diospyros species .
... B. Walln. [9], also reproduce asexually, ensuring population persistence. ...
Allocasuarina verticillata (Lam.) L.A.S. Johnson is a widespread species in southeastern Australia providing vegetation cover, protecting fragile soils and providing food for birds. Understanding the effects of gene flow on the recruitment patterns, genetic differentiation and structure of fragmented populations provides fundamental guidelines to underpin plant conservation strategies and activities. In this study, four spatially disjunct populations of A. verticillata were sampled to explore the effects of population size, reproductive patterns and pollen and seed dispersal on among-population genetic diversity, genetic differentiation and structure, using field survey and microsatellite marker techniques. It was found that stands of A. verticillata were predominantly sexually reproductive, but asexual reproduction through root suckering was an additional mode of reproduction. The reproductive success of A. verticillata is positively correlated with the effective population size rather than actual population size. The reduction in effective population size and increment of spatial isolation resulted in lower genetic diversity and higher inbreeding coefficient of progenies. Moderate pairwise genetic differentiation and weak genetic structure were identified. The results suggest that exogenous, wind-mediated pollen flow provides some maintenance of genetic diversity in the isolated stands. Seed dispersal appears mainly to be over short distances (i.e., within populations), but the infrequent transport of seeds between disjunct locations cannot be ruled out as another factor that may help maintain genetic diversity.
... The distance between AS and PE is 334 km, AS and IT 264 km, and between PE and IT 116 km. AS covers 4,480 ha on two types of acidic low fertility soils (Oxisol and Ultisol typical Dystrophic), with high aluminum content, but is species rich and diverse, with about 200 species of trees, shrubs and herbs (Aguiar et al. 2019). The PE site covers a total area of 2069 ha with a high floral and faunal diversity and is the only protected area in the northeast of the state (Sasaki and Mello-Silva 2008). ...
... Moreover, the nutritionally poor soil (Silva 2005), fire and severe frosts at IT may have caused die back or reduced growth, resulting in the small and homogeneous size in height and diameter, compared to the larger and more heterogeneous AS population. The maximum sizes for DBH (20.4 cm) and total height (H = 5.7 m) at IT were lower than the species mean (DBH = 50 cm, H = 20 m, Carvalho 2007), with similar results observed for Diospyros hispida at IT (Aguiar et al. 2019). ...
Key message
Although all populations show extensive pollen immigration, the occurrence of spatial genetic structure and biparental inbreeding decreased genetic diversity and effective population size.
Abstract
The Brazilian savanna is the second largest Neotropical biome, and a globally important biodiversity hotspot. Basic knowledge of the ecology and genetics of its species can help conserve this important biome. We investigated genetic diversity, spatial genetic structure (SGS), pollen dispersal, and mating system in three Hymenaea stigonocarpa populations (AS, PE, IT) in the Brazilian savanna, using microsatellite loci and samples of adult trees from all populations and seeds from the IT population. As a result of the long geographic distance between populations, the genetic differentiation among them was high (0.397). Individuals of the IT population presented a grouped distribution due to root propagation, resulting in low genotypic richness (GR\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm{GR}$$\end{document} = 0.194) and allelic richness (R\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$R$$\end{document} = 4), and high SGS (Sp\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm{Sp}$$\end{document} = 0.064) compared to AS and PE (GR\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm{GR}$$\end{document} > 0.98, R > 5, Sp\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathrm{Sp}$$\end{document} < 0.026) populations. The IT population showed high pollen immigration (46.4%), pollen dispersal distance (up to 3.57 km), and outcrossing rate (0.934–1.0), but matings were correlated (0.01–1), and some occurred among relatives (up to 0.098), resulting in some inbred seeds (0.140), a lower variance effective population size (Ne\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${N}_{e}$$\end{document} = 3.02) than expected with random mating, and an estimate of 50 seed-trees required to retain an Ne\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${N}_{e}$$\end{document} of 150 in samples of maternal progeny. The estimated minimum viable area to retain a reference (Ner\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${N}_{\mathrm{er}}$$\end{document}) of 1000 indicates that the current AS and IT population areas are insufficient to maintain viable populations in the long-term, demonstrating the importance of maintaining surrounding areas for conservation of these H. stigonocarpa populations.
... This has been observed in other species. A 10-year phenological study in Brazil found that Diospyros lasiocalyx trees in three forests reproduced mainly through vegetative propagation, and widespread senescence in the D. lasiocalyx populations was not observed (Aguiar et al. 2020). Pyrenean saxifrage is a monocarpic perennial species that escapes monocarpic senescence at high altitudes by clonally producing lateral rosettes that share the same root, which results in the plant becoming polycarpic (Cotado and Munné-Bosch 2020). ...
Background
The relationship between physiological age of parental trees and lifespan of clonal offspring is unclear. White oak ( Quercus fabri Hance) has a high sprouting capability after harvest, with the regenerated sprouts being typical clonal individuals. To determine whether regenerated sprouts undergo rapid senescence compared with the parent, the senescence levels of 5-, 10-, 20- and 40-year-old regenerated stump sprouts in a natural forest were evaluated. The antioxidative abilities and transcriptomes in these leaves and shoots were compared.
Results
Older regenerated sprouts still had robust antioxidative systems, with 40-year-old sprouts having lower peroxidation product levels but similar antioxidative enzyme activity levels compared with 5-year-old sprouts. Older leaves had greater transcriptional activities in pathways related to cell growth and division than younger leaves. However, older sprouts had some unhealthy characteristics, such as increased base excision repair levels and upregulated phagosome, proteasome and glycerophospholipid metabolism pathways in 40-year-old leaves, which indicates that DNA damage and tissue remodeling occurred more frequently than in younger leaves. Additionally, plant-pathogen interactions and MAPK signals pathways were upregulated in older shoots, which indicates that older shoots suffered from more pathogen-related biotic stress.
Conclusions
The 40-year-old sprouts still had the same vitality level as the 5-year-old sprouts, although the former had some unhealthy characteristics. We conclude that during their first 40 years of growth, regenerated stump sprouts do not begin to senesce, and that physiological age of parental trees does not significantly affect the lifespan of its clonal offspring.
... This has been observed in other species. A 10-year phenological study in Brazil found that Diospyros lasiocalyx trees in three forests reproduced mainly through vegetative propagation, and widespread senescence in the D. lasiocalyx populations was not observed (Aguiar et al. 2020). Pyrenean saxifrage is a monocarpic perennial species that escapes monocarpic senescence at high altitudes by clonally producing lateral rosettes that share the same root, resulting in the plant becoming polycarpic (Cotado and Munné-Bosch 2020). ...
Background: The relationship between the parental tree’ physiological age and the clonal offspring’s lifespan is unclear. White oak (Quercus fabri Hance) has a high sprouting capability after harvest, with the regenerated sprouts being typical clonal individuals. To determine whether regenerated sprouts undergo rapid senescence compared with the parent, the senescence levels of 5-, 10-, 20- and 40-year-old regenerated stump sprouts in a natural forest were evaluated. The antioxidative abilities and transcriptomes in these leaves and shoots were compared.
Results: Older regenerated sprouts still had robust antioxidative systems, with 40-year-old sprouts having lower peroxidation product levels but similar antioxidative enzyme activity levels compared with 5-year-old sprouts. Older leaves had greater transcriptional activities in pathways related to cell growth and division than younger leaves. However, older sprouts had a few unhealthy characteristics, such as increased base excision repair levels and upregulated phagosome, proteasome and glycerophospholipid metabolism pathways in 40-year-old leaves, indicating that DNA damage and tissue remodeling occurred more frequently than in younger leaves. Additionally, plant–pathogen interactions and MAPK signals pathways were upregulated in older shoots, indicating that older shoots suffered from more pathogen-related biotic stress.
Conclusions: The 40-year-old sprouts still had the same vitality level as the 5-year-old sprouts, although the former had some unhealthy characteristics. We conclude that during their first 40 years of growth regenerated stump sprouts do not begin to senesce, and that the parental tree’s physiological age does not significantly affect its clonal offspring’s lifespan.
Sexual systems in tree crop species is often an important determinant of stable and efficient fruit production, and harnessing them is a key for both cultivation and breeding aspects. In contrast to animals, plants have various sexual systems to maintain their genetic diversities to fit new environments and to expand their habitats. Most of the Diospyros species are classified as dioecy (separated male and female individuals) controlled by the Y-encoded putatively single sex-determining gene, OGI, which encodes small-RNA repressing its autosomal target gene, MeGI. This mechanism would be specific to the Diospyros lineage, as these two sex-determining factors were derived from lineage-specific paleo-duplications, and thereafter, neofunctionalizations. Furthermore, some polyploid Diospyros species exhibit plastic sexuality mixed with male and female flowers or with occasional conversion from male to hermaphrodite flowers, which are determined by internal environmental conditions and epigenetic layers on the sex determinants. Although recent findings made some achievements for understanding the evolutionary paths into dioecy and the escape from that into plastic sexuality, many unclarified mechanisms have still remained. In this chapter, we introduce the sexual systems and their evolution in Diospyros species.KeywordsDioecyMonoecyHermaphroditismSexual plasticityPolyploidization
Background: The relationship between the parental tree’s physiological age and the clonal offspring’s lifespan is unclear. White oak (Quercus fabri Hance) has a high sprouting capability after harvest, with the regenerated sprouts being typical clonal individuals. To determine whether regenerated sprouts undergo rapid senescence compared with the parent, the senescence levels of 5-, 10-, 20- and 40-year-old regenerated stump sprouts in a natural forest were evaluated. The antioxidative abilities and transcriptomes in these leaves and shoots were compared.
Results: Older regenerated sprouts still had robust antioxidative systems, with 40-year-old sprouts having lower peroxidation product levels but similar antioxidative enzyme activity levels compared with 5-year-old sprouts. Older leaves had greater transcriptional activities in pathways related to cell growth and division than younger leaves. However, older sprouts had some unhealthy characteristics, such as increased base excision repair levels and upregulated phagosome, proteasome and glycerophospholipid metabolism pathways in 40-year-old leaves, which indicates that DNA damage and tissue remodeling occurred more frequently than in younger leaves. Additionally, plant–pathogen interactions and MAPK signals pathways were upregulated in older shoots, which indicates that older shoots suffered from more pathogen-related biotic stress.
Conclusions: The 40-year-old sprouts still had the same vitality level as the 5-year-old sprouts, although the former had some unhealthy characteristics. We conclude that during their first 40 years of growth, regenerated stump sprouts do not begin to senesce, and that the parental tree’s physiological age does not significantly affect its clonal offspring’s lifespan.
