scholarly journals Maximizing genetic representation in seed collections from populations of self and cross-pollinated banana wild relatives

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Simon Kallow ◽  
Bart Panis ◽  
Dang Toan Vu ◽  
Tuong Dang Vu ◽  
Janet Paofa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Papua New Guinea ◽  
Mating Systems ◽  
Plant Genetic Resources ◽  
Genetic Material ◽  
New Guinea ◽  
Wild Relatives ◽  
Ex Situ ◽  
Conservation Targets ◽  
Seed Collections

Abstract Background Conservation of plant genetic resources, including the wild relatives of crops, plays an important and well recognised role in addressing some of the key challenges faced by humanity and the planet including ending hunger and biodiversity loss. However, the genetic diversity and representativeness of ex situ collections, especially that contained in seed collections, is often unknown. This limits meaningful assessments against conservation targets, impairs targeting of future collecting and limits their use. We assessed genetic representation of seed collections compared to source populations for three wild relatives of bananas and plantains. Focal species and sampling regions were M. acuminata subsp. banksii (Papua New Guinea), M. balbisiana (Viet Nam) and M. maclayi s.l. (Bougainville, Papua New Guinea). We sequenced 445 samples using suites of 16–20 existing and newly developed taxon-specific polymorphic microsatellite markers. Samples of each species were from five populations in a region; 15 leaf samples from different individuals and 16 seed samples from one infructescence (‘bunch’) were analysed for each population. Results Allelic richness of seeds compared to populations was 51, 81 and 93% (M. acuminata, M. balbisiana and M. maclayi respectively). Seed samples represented all common alleles in populations but omitted some rarer alleles. The number of collections required to achieve the 70% target of the Global Strategy for Plant Conservation was species dependent, relating to mating systems. Musa acuminata populations had low heterozygosity and diversity, indicating self-fertilization; many bunches were needed (> 15) to represent regional alleles to 70%; over 90% of the alleles from a bunch are included in only two seeds. Musa maclayi was characteristically cross-fertilizing; only three bunches were needed to represent regional alleles; within a bunch, 16 seeds represent alleles. Musa balbisiana, considered cross-fertilized, had low genetic diversity; seeds of four bunches are needed to represent regional alleles; only two seeds represent alleles in a bunch. Conclusions We demonstrate empirical measurement of representation of genetic material in seeds collections in ex situ conservation towards conservation targets. Species mating systems profoundly affected genetic representation in seed collections and therefore should be a primary consideration to maximize genetic representation. Results are applicable to sampling strategies for other wild species.

scholarly journals Maximizing genetic representation in seed collections from populations of self and cross-pollinated banana wild relatives

2021 ◽  
Author(s):  
Simon Kallow ◽  
Bart Panis ◽  
Toan Vu Dang ◽  
Tuong Vu Dang ◽  
Janet Paofa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Papua New Guinea ◽  
Mating Systems ◽  
Plant Genetic Resources ◽  
New Guinea ◽  
Musa Acuminata ◽  
Wild Relatives ◽  
Ex Situ ◽  
Conservation Targets ◽  
Seed Collections

Background: Conservation of plant genetic resources, including the wild relatives of crops, plays an important and well recognised role in addressing some of the key challenges faced by humanity and the planet including ending hunger and biodiversity loss. However, the genetic diversity and representativeness of ex situ collections, especially that contained in seed collections, is often unknown. This limits meaningful assessments against conservation targets, impairs targeting of future collecting and limits their use. We assessed genetic representation of seed collections compared to source populations for three wild relatives of bananas and plantains. Focal species and sampling regions were Musa acuminata subsp. banksii (Papua New Guinea), M. balbisiana (Viet Nam) and M. maclayi s.l. (Bougainville, Papua New Guinea). We sequenced 445 samples using suites of 16-20 existing and newly developed taxon-specific polymorphic microsatellite markers. Samples of each species were from five populations in a region; 15 leaf samples and 16 seed samples from one infructescence ('bunch') for each population. Results: Allelic richness of seeds compared to populations was 51%, 81% and 93% (M. acuminata, M. balbisiana and M. maclayi respectively). Seed samples represented all common alleles in populations but omitted some rarer alleles. The number of collections required to achieve the 70% target of the Global Strategy for Plant Conservation was species dependent, relating to mating systems. Musa acuminata populations had low heterozygosity and diversity, indicating self-fertilization; many bunches were needed (>15) to represent regional alleles to 70%; over 90% of the alleles from a bunch are included in only two seeds. Musa maclayi was characteristically cross-fertilizing; only three bunches were needed to represent regional alleles; within a bunch, 16 seeds represent alleles. Musa balbisiana, considered cross-fertilized, had low genetic diversity; seeds of four bunches are needed to represent regional alleles; only two seeds represent alleles in a bunch. Conclusions: We demonstrate empirical measurement of representation of genetic material in seeds collections in ex situ conservation towards conservation targets. Species mating systems profoundly affected genetic representation in seed collections and therefore should be a primary consideration to maximize genetic representation. Results are applicable to sampling strategies for other wild species.

scholarly journals Challenges for Ex Situ Conservation of Wild Bananas: Seeds Collected in Papua New Guinea Have Variable Levels of Desiccation Tolerance

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1243 ◽  
Author(s):  
Simon Kallow ◽  
Kevin Longin ◽  
Natalia Fanega Sleziak ◽  
Steven B. Janssens ◽  
Filip Vandelook ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Papua New Guinea ◽  
Embryo Rescue ◽  
New Guinea ◽  
Crop Wild Relatives ◽  
Wild Relatives ◽  
Ex Situ ◽  
Wild Populations ◽  
Seed Collections

Ex situ seed conservation of banana crop wild relatives (Musa spp. L.), is constrained by critical knowledge gaps in their storage and germination behaviour. Additionally, challenges in collecting seeds from wild populations impact the quality of seed collections. It is, therefore, crucial to evaluate the viability of seeds from such collecting missions in order to improve the value of future seed collections. We evaluate the seed viability of 37 accessions of seven Musa species, collected from wild populations in Papua New Guinea, during two collecting missions. Seeds from one mission had already been stored in conventional storage (dried for four months at 15% relative humidity, 20 °C and stored for two months at 15% relative humdity, −20 °C), so a post-storage test was carried out. Seeds from the second mission were assessed freshly extracted and following desiccation. We used embryo rescue techniques to overcome the barrier of germinating in vivo Musa seeds. Seeds from the first mission had low viability (19 ± 27% mean and standard deviation) after storage for two months at 15% relative humidity and −20 °C. Musa balbisiana Colla seeds had significantly higher post-storage germination than other species (p < 0.01). Desiccation reduced germination of the seeds from the second collecting mission, from 84 ± 22% (at 16.7 ± 2.4% moisture content) to 36 ± 30% (at 2.4 ± 0.8% moisture content). There was considerable variation between and (to a lesser extent) within accessions, a proportion of individual seeds of all but one species (Musa ingens N.W.Simmonds) survived desiccation and sub-zero temperature storage. We identified that seeds from the basal end of the infructescence were less likely to be viable after storage (p < 0.001); and made morphological observations that identify seeds and infructescences with higher viability in relation to their developmental maturity. We highlight the need for research into seed eco-physiology of crop wild relatives in order to improve future collecting missions.

Key issues facing genebanks in preserving crop genetic diversity ex situ: overview of the range of challenges

2021 ◽  
pp. 139-154
Author(s):  
Paula Bramel ◽  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Plant Genetic Resources ◽  
Cost Effective ◽  
Ex Situ ◽  
Crop Genetic Diversity ◽  
Ex Situ Collections ◽  
Key Issues ◽  
Market Preference ◽  
The Impact

This chapter reviews the key issues and challenges facing genebanks in preserving crop genetic diversity ex situ. Local crop genetic diversity is challenged with changes in land use, urbanization, land degradation, changes in agricultural practises, availability of improved varieties, changes in market preference, and the impact of climate change. Efforts have been made to secure plant genetic resources ex situ for future use but there are significant issues related to cost effective, efficient, secure, rational, and sustainable long-term ex situ conservation. It begins by addressing issues for the composition of ex situ collections and moves on to discuss issues for routine operations for conservation. The chapter also highlights issues for the use of conserved genetic resources, before concluding with a summary of why the development of sustainable genebank systems is so important.

Techniques and key issues in collecting crop wild relatives

2021 ◽  
pp. 155-184
Author(s):  
Michael Way ◽  
Keyword(s):  
Genetic Diversity ◽  
Best Practice ◽  
Seed Quality ◽  
Crop Wild Relatives ◽  
Wild Relatives ◽  
Wild Plant ◽  
Genetic Sampling ◽  
Key Issues ◽  
Essential Resource ◽  
Seed Collections

The genetic diversity found in populations of crop wild relatives is an essential resource for future crop breeding, but populations are at risk of loss before germplasm has been fully conserved in genebanks. This chapter describes best practice for targeting and identifying species, and review knowledge about the variation in wild plant populations to guide the timing of collecting and approaches for genetic sampling. Indicators are presented for seed quality, ripeness and dispersal. Techniques for collection of seed, herbarium vouchers and associated data are reviewed with examples drawn from the Adapting Agriculture to Climate Change (Crop Wild Relative) project. Further research is needed to find optimal approaches for handling of seed to ensure high longevity of seed collections, and improved tools are needed to guide sampling of genetic diversity of crop wild relatives.

scholarly journals The Genetic Diversity of Cranberry Crop Wild Relatives, Vaccinium macrocarpon Aiton and V. oxycoccos L., in the US, with Special Emphasis on National Forests

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1446
Author(s):  
Lorraine Rodriguez-Bonilla ◽  
Karen A. Williams ◽  
Fabian Rodríguez Bonilla ◽  
Daniel Matusinec ◽  
Andrew Maule ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
The United States ◽  
Crop Wild Relatives ◽  
Wild Relatives ◽  
Vaccinium Macrocarpon ◽  
Ex Situ ◽  
National Forests ◽  
United States Department ◽  
The Us

Knowledge of the genetic diversity in populations of crop wild relatives (CWR) can inform effective strategies for their conservation and facilitate utilization to solve agricultural challenges. Two crop wild relatives of the cultivated cranberry are widely distributed in the US. We studied 21 populations of Vaccinium macrocarpon Aiton and 24 populations of Vaccinium oxycoccos L. across much of their native ranges in the US using 32 simple sequence repeat (SSR) markers. We observed high levels of heterozygosity for both species across populations with private alleles ranging from 0 to 26. For V. macrocarpon, we found a total of 613 alleles and high levels of heterozygosity (HO = 0.99, HT = 0.75). We also observed high numbers of alleles (881) and levels of heterozygosity (HO = 0.71, HT = 0.80) in V. oxycoccos (4x). Our genetic analyses confirmed the field identification of a native population of V. macrocarpon on the Okanogan-Wenatchee National Forest in the state of Washington, far outside the previously reported range for the species. Our results will help to inform efforts of the United States Department of Agriculture Agricultural Research Service (USDA-ARS) and the United States Forest Service (USFS) to conserve the most diverse and unique wild cranberry populations through ex situ preservation of germplasm and in situ conservation in designated sites on National Forests.

scholarly journals In situ and ex situ conservation gap analyses of crop wild relatives from Malawi

2020 ◽  
Author(s):  
Nolipher Khaki Mponya ◽  
Tembo Chanyenga ◽  
Joana Magos Brehm ◽  
Nigel Maxted
Keyword(s):  
Ex Situ Conservation ◽  
Plant Genetic Resources ◽  
Crop Wild Relatives ◽  
Wild Relatives ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Grid Cells ◽  
Ex Situ Collections ◽  
Minimum Number

Abstract The study analysed the conservation gaps of the priority crop wild relatives (CWR) taxa for Malawi in order to contribute to the development of a harmonized conservation strategy that helps secure the priority CWR under in situ and ex situ. We used taxa distribution modelling, complementarity analysis and ecogeographic land characterization map to analyse spatial diversity and distribution of 123 priority taxa across different adaptive scenarios. We identified areas of observed and predicted richness, the minimum number of protected areas (PAs) that conserve the broadest ecogeographic diversity in situ and the minimum number of grid cells that capture highest diversity outside PAs to recommend the establishment of genetic reserves. We then analysed the representativeness of the conserved ecogeographic diversity of target taxa in ex situ collections to identify ex situ conservation gaps and advise for priority areas for ex situ collections. For the 123 taxa, 70.7% of the total diversity occurs in 36 PAs with 66.8% of the diversity captured in only 10 complementary PAs. Outside PAs, the broadest diversity was conserved in three grid cells of size 5 × 5 km. Fifty-three of 123 taxa have ex situ collections with only three taxa having ex situ collections at the Malawi Plant Genetic Resources Centre. The findings of this study will guide formulation of conservation actions for the priority taxa as well as lobbying for active conservation of the same under in situ and ex situ.

scholarly journals Importance of Genetic Diversity Assessment in Crop Plants and Its Recent Advances: An Overview of Its Analytical Perspectives

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
M. Govindaraj ◽  
M. Vetriventhan ◽  
M. Srinivasan
Keyword(s):  
Genetic Diversity ◽  
Food Production ◽  
Genetic Manipulation ◽  
Plant Genetic Resources ◽  
Crop Improvement ◽  
Genetic Material ◽  
Easy Access ◽  
Production Network ◽  
Gene Banks ◽  
Diversity Assessment

The importance of plant genetic diversity (PGD) is now being recognized as a specific area since exploding population with urbanization and decreasing cultivable lands are the critical factors contributing to food insecurity in developing world. Agricultural scientists realized that PGD can be captured and stored in the form of plant genetic resources (PGR) such as gene bank, DNA library, and so forth, in the biorepository which preserve genetic material for long period. However, conserved PGR must be utilized for crop improvement in order to meet future global challenges in relation to food and nutritional security. This paper comprehensively reviews four important areas; (i) the significance of plant genetic diversity (PGD) and PGR especially on agriculturally important crops (mostly field crops); (ii) risk associated with narrowing the genetic base of current commercial cultivars and climate change; (iii) analysis of existing PGD analytical methods in pregenomic and genomic era; and (iv) modern tools available for PGD analysis in postgenomic era. This discussion benefits the plant scientist community in order to use the new methods and technology for better and rapid assessment, for utilization of germplasm from gene banks to their applied breeding programs. With the advent of new biotechnological techniques, this process of genetic manipulation is now being accelerated and carried out with more precision (neglecting environmental effects) and fast-track manner than the classical breeding techniques. It is also to note that gene banks look into several issues in order to improve levels of germplasm distribution and its utilization, duplication of plant identity, and access to database, for prebreeding activities. Since plant breeding research and cultivar development are integral components of improving food production, therefore, availability of and access to diverse genetic sources will ensure that the global food production network becomes more sustainable. The pros and cons of the basic and advanced statistical tools available for measuring genetic diversity are briefly discussed and their source links (mostly) were provided to get easy access; thus, it improves the understanding of tools and its practical applicability to the researchers.

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