scholarly journals Genetic Resources and Vulnerabilities of Major Cucurbit Crops

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1222
Author(s):  
Rebecca Grumet ◽  
James D. McCreight ◽  
Cecilia McGregor ◽  
Yiqun Weng ◽  
Michael Mazourek ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Citrullus Lanatus ◽  
Genetic Relationships ◽  
Crop Improvement ◽  
Ex Situ ◽  
Conservation Policies ◽  
Historical Collections ◽  
Technological Advances ◽  
Cucurbitaceae Family

The Cucurbitaceae family provides numerous important crops including watermelons (Citrullus lanatus), melons (Cucumis melo), cucumbers (Cucumis sativus), and pumpkins and squashes (Cucurbita spp.). Centers of domestication in Africa, Asia, and the Americas were followed by distribution throughout the world and the evolution of secondary centers of diversity. Each of these crops is challenged by multiple fungal, oomycete, bacterial, and viral diseases and insects that vector disease and cause feeding damage. Cultivated varieties are constrained by market demands, the necessity for climatic adaptations, domestication bottlenecks, and in most cases, limited capacity for interspecific hybridization, creating narrow genetic bases for crop improvement. This analysis of crop vulnerabilities examines the four major cucurbit crops, their uses, challenges, and genetic resources. ex situ germplasm banks, the primary strategy to preserve genetic diversity, have been extensively utilized by cucurbit breeders, especially for resistances to biotic and abiotic stresses. Recent genomic efforts have documented genetic diversity, population structure, and genetic relationships among accessions within collections. Collection size and accessibility are impacted by historical collections, current ability to collect, and ability to store and maintain collections. The biology of cucurbits, with insect-pollinated, outcrossing plants, and large, spreading vines, pose additional challenges for regeneration and maintenance. Our ability to address ongoing and future cucurbit crop vulnerabilities will require a combination of investment, agricultural, and conservation policies, and technological advances to facilitate collection, preservation, and access to critical Cucurbitaceae diversity.

scholarly journals Cross Species/Genera Transferability of SSR Markers, Genetic Diversity and Population Structure Analysis in Gladiolus (Gladiolus × grandiflorus L.) Genotypes

2021 ◽  
Author(s):  
Varun Hiremath ◽  
Kanwar Pal Singh ◽  
Neelu Jain ◽  
Kishan Swaroop ◽  
Pradeep Kumar Jain ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Ssr Markers ◽  
Structure Analysis ◽  
Genetic Relationships ◽  
Crop Improvement ◽  
Test Analysis ◽  
Average Value ◽  
Population Structure Analysis ◽  
Genetic Diversity And Structure

Abstract Genetic diversity and structure analysis using molecular markers is necessary for efficient utilization and sustainable management of gladiolus germplasm. Genetic analysis of gladiolus germplasm using SSR markers is largely missing due to scarce genomic information. In the present investigation, we report 66.66% cross transferability of Gladiolus palustris SSRs whereas 48% of Iris EST-SSRs were cross transferable across the gladiolus genotypes used in the study. A total of 17 highly polymorphic SSRs revealed a total 58 polymorphic loci ranging from two to six in each locus with an average of 3.41 alleles per marker. PIC values ranged from 0.11 to 0.71 with an average value of 0.48. Four SSRs were selectively neutral based on Ewens-Watterson test. Analysis of genetic structure of 84 gladiolus genotypes divided whole germplasm into two subpopulations. 35 genotypes were assigned to subpopulation 1 whereas 37 to subpopulation 2 and rest of the genotypes recorded as admixture. Analysis of molecular variance indicated maximum variance (53.59%) among individuals within subpopulations whereas 36.55% of variation observed among individuals within total population. Least variation (9.86%) was noticed between two subpopulations. Moderate (FST = 0.10) genetic differentiation of two subpopulations was observed. Grouping pattern of population structure was consistent with UPGMA dendrogram based on simple matching dissimilarity coefficient (ranged from 01.6 to 0.89) and PCoA. Genetic relationships assessed among the genotypes of respective clusters assist the breeders in selecting desirable parents for crossing. SSR markers from present study can be utilized for cultivar identification, conservation and sustainable utilization of gladiolus genotypes for crop improvement.

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.

The use of ex situ conserved plant genetic resources

2003 ◽  
Vol 1 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Toby Hodgkin ◽  
V. Ramanatha Rao ◽  
Angélica Cibrian-Jaramillo ◽  
Samy Gaiji
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Agricultural Production ◽  
Production Systems ◽  
Plant Genetic Resources ◽  
Ex Situ ◽  
Recent Information ◽  
Wide Range ◽  
Barriers To Use ◽  
The Many

AbstractPlant genetic resources are conserved so that they can be used to improve crop plant pro- duction and in other ways. However, it is often asserted that use of ex situ conserved germplasm is inadequate and that genetic diversity maintained in genebanks is underutilized. In part, this reflects an incomplete recognition of what constitutes use of plant genetic resources, and of the many different ways in which material from genebanks contributes to improved agricultural production. Based on recent information from surveys of distribution of germplasm from genebanks, and from surveys of users, we suggest that the evidence indicates that there is substantial use of ex situ conserved materials for a wide range of different uses. We suggest that barriers to use of ex situ conserved germplasm may often result from a lack in numbers of users, and from limitations in capacity to effectively utilize the genetic diversity present in genebanks to reduce genetic vulnerability and increase sustainability in modern production systems.

Some recent issues on the conservation of crop genetic resources in developing countries

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 562-569 ◽  
Author(s):  
S Jana
Keyword(s):  
Genetic Diversity ◽  
Developing Countries ◽  
Plant Breeding ◽  
Genetic Resources ◽  
Core Collection ◽  
Ex Situ ◽  
Crop Genetic Resources ◽  
Core Collections ◽  
Global Food Security ◽  
Crop Genetic Diversity

Crop genetic resources (CGRs) are renewable resources. These resources are enriched rather than depleted by their use in research and plant breeding. Both at the time of Vavilov and, later, in the early 1970s, when concerted international efforts to collect and preserve CGRs started with the initiatives of the International Board for Plant Genetic Resources (IBPGR), CGRs were considered to be the common heritage of humankind. Now, they are widely accepted as "national heritage." Possible impacts of this nationalization on the utilization and enrichment of global crop genetic diversity and, consequently, on global food security are issues of great significance. At present, efficient management and adequate use of CGRs are more important concerns than their further exploration and collection. To increase the use of preserved CGRs in plant breeding, the formation of core collections, by selecting representative subsets from large ex situ collections of CGRs, was recommended in 1984. Since then, the core-collection strategy has been further justified as a practical approach to genetic resources management, as well as to their conservation. As a cost-saving germplasm-management strategy, the core-collection concept has considerable merit. However, the rapidly increasing popularity of core collections may undermine the genetic wealth stored in national gene banks of both developed and developing countries. Distinction is made between subsets of working collections and core collections. When a small number of CGRs is required for specific plant breeding purposes, a properly formed working collection is more useful than a representative collection. Despite the relative abundance of genetic diversity in crop plants in traditional agroecosystems, maintenance of these agroecosystems is not a realistic long-term alternative for preserving crop genetic diversity and ensuring global food security. What is needed in the "gene-rich" developing countries is the adoption of "biodiversity friendly" plant breeding and agricultural practices.Key words: crop genetic resources, core collection, germplasm conservation, in situ conservation, ex situ conservation, modern landraces.

GENETIC DIVERSITY OF EXTRA-EARLY YELLOW MAIZE HYBRIDS UNDER STRIGA ENVIRONMENTS

2021 ◽  
Vol 5 (1) ◽  
pp. 302-308
Author(s):  
Abdulwahab Saliu Shaibu
Keyword(s):  
Genetic Diversity ◽  
Genetic Relationships ◽  
Block Design ◽  
Crop Improvement ◽  
Principal Component ◽  
Environment Interaction ◽  
Maize Hybrids ◽  
Group I ◽  
Significant Difference ◽  
And Cluster Analysis

The success of any breeding program depends on the ability to determine germplasm diversity and genetic relationships among breeding materials. Genetic diversity is an invaluable aid in crop improvement. This study was carried out to determine the genetic diversity among 70 extra-early yellow maize hybrids under Striga environments. Cluster and principal component (PC) analyses were used to determine the genetic diversity of the hybrids. Data on morphological and agronomical data were collected. The experiment was set up in two locations (Abuja and Mokwa) in a randomized incomplete block design experiment with two replications. A significant difference was observed among the hybrids in all the traits studied and a significant genotype × environment interaction was observed for all traits except for plant height, anthesis silking interval and Striga count at 8 and 10 WAP. The principal component reveals that the first three components account for 86% variability. PC1 gave maximum variability (43%) and was loaded with PC1 and the first four PCs can be utilized in hybridization programs. The principal component biplot reveals the relationship among traits and the distance of each variable in determining variability among hybrids. The cluster diagram reveals five distinct groups. Group IV consisted of Striga tolerant hybrids and group I consisted of susceptible hybrids. Both principal component and cluster analysis revealed the genetic diversity among the hybrids and identified genotypes that were Striga tolerant and could be selected as choice of parental materials to develop Striga resistant materials

High genetic diversity of in situ and ex situ populations of Madagascan coffee species: further implications for the management of coffee genetic resources

2013 ◽  
Vol 9 (5) ◽  
pp. 1295-1312 ◽  
Author(s):  
Domohina N. Andrianasolo ◽  
Aaron P. Davis ◽  
Norosoa J. Razafinarivo ◽  
Serge Hamon ◽  
Jean-Jacques Rakotomalala ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Ex Situ ◽  
High Genetic Diversity ◽  
Coffee Species

scholarly journals Genetic diversity and population structure of core watermelon (Citrullus lanatus) genotypes using DArTseq-based SNPs

2016 ◽  
Vol 14 (3) ◽  
pp. 226-233 ◽  
Author(s):  
Xingping Yang ◽  
Runsheng Ren ◽  
Rumiana Ray ◽  
Jinhua Xu ◽  
Pingfang Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Diversity ◽  
Citrullus Lanatus ◽  
Genetic Relationships ◽  
Snp Markers ◽  
Phenotypic Characterization ◽  
Breeding Lines ◽  
I 11 ◽  
Genome Level

Watermelon [Citrullus lanatus(Thunb.) Matsum. & Nakai var.lanatus] is an economically important vegetable belonging to theCucurbitaceaefamily. Genotypes that exhibit agronomically important traits are selected for the development of elite cultivars. Understanding the genetic diversity and the genotype population structure based on molecular markers at the genome level can speed up the utilization of diverse genetic resources for varietal improvement. In the present study, we carried out an analysis of genetic diversity based on 3882 SNP markers across 37 core watermelon genotypes, including the most widely used watermelon varieties and wild watermelon. Based on the SNP genotyping data of the 37 watermelon genotypes screened, gene diversity and polymorphism information content values across chromosomes varied between 0.03–0.5 and 0.02–0.38, with averages of 0.14 and 0.13, respectively. The two wild watermelon genotypes were distinct from cultivated varieties and the remaining 35 cultivated genotypes were differentiated into three major clusters: 20 genotypes were grouped in cluster I; 11 genotypes were grouped in cluster II; three advanced breeding lines of yellow fruit flesh and genotype SW043 were grouped in cluster III. The results from neighbour-joining dendrogram, principal coordinate analysis and STRUCTURE analysis approaches were consistent, and the grouping of genotypes was generally in agreement with their origins. Here we reveal the genetic relationships among the core watermelon genotypes maintained at the Jiangsu Academy of Agricultural Sciences, China. The molecular and phenotypic characterization of the existing core watermelon genotypes, together with specific agronomic characteristics, can be utilized by researchers and breeders for future watermelon improvement.

scholarly journals Genetic diversity and population structure analyses in the Alpine plum (Prunus brigantina Vill.) confirm its affiliation to the Armeniaca section

2020 ◽  
Author(s):  
Liu Shuo ◽  
Decroocq Stephane ◽  
Harte Elodie ◽  
Tricon David ◽  
Chague Aurelie ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Core Collection ◽  
Genetic Relationships ◽  
Allelic Diversity ◽  
Wild Relatives ◽  
Ex Situ ◽  
Conservation Measures ◽  
Geographical Regions

AbstractIn-depth characterization of the genetic diversity and population structure of wild relatives of crops is of paramount importance for genetic improvement and biodiversity conservation, and is particularly crucial when the wild relatives of crops are endangered. In this study, we therefore sampled the Alpine plum (Briançon apricot) Prunus brigantina Vill. across its natural distribution in the French Alps, where its populations are severely fragmented and its population size strongly impacted by humans. We analysed 71 wild P. brigantina samples with 34 nuclear markers and studied their genetic diversity and population structure, with the aim to inform in situ conservation measures and build a core collection for long-term ex-situ conservation. We also examined the genetic relationships of P. brigantina with other species in the Prunophora subgenus, encompassing the Prunus (Eurasian plums), Prunocerasus (North-American plums) and Armeniaca (apricots) sections, to check its current taxonomy. We detected a moderate genetic diversity in P. brigantina and a Bayesian model-based clustering approach revealed the existence of three genetically differentiated clusters, endemic to three geographical regions in the Alps, which will be important for in situ conservation measures. Based on genetic diversity and population structure analyses, a subset of 36 accessions were selected for ex-situ conservation in a core collection that encompasses the whole detected P. brigantina allelic diversity. Using a dataset of cultivated apricots and wild cherry plums (P. cerasifera) genotyped with the same markers, we detected gene flow neither with European P. armeniaca cultivars nor with diploid plums. In contrast with previous studies, dendrograms and networks placed P. brigantina closer to Armeniaca species than to Prunus species. Our results thus confirm the classification of P. brigantina within the Armeniaca section; it also illustrates the importance of the sampling size and design in phylogenetic studies.

scholarly journals Unbalanced historical phenotypic data from seed regeneration of a barley ex situ collection

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Maria Y. Gonzalez ◽  
Stephan Weise ◽  
Yusheng Zhao ◽  
Norman Philipp ◽  
Daniel Arend ◽  
...  
Keyword(s):  
Genetic Resources ◽  
Phenotypic Diversity ◽  
Spring Barley ◽  
Plant Genetic Resources ◽  
Crop Improvement ◽  
Model Organism ◽  
Ex Situ ◽  
Phenotypic Characterization ◽  
Phenotypic Data ◽  
Seed Regeneration

Abstract The scarce knowledge on phenotypic characterization restricts the usage of genetic diversity of plant genetic resources in research and breeding. We describe original and ready-to-use processed data for approximately 60% of ~22,000 barley accessions hosted at the Federal ex situ Genebank for Agricultural and Horticultural Plant Species. The dataset gathers records for three traits with agronomic relevance: flowering time, plant height and thousand grain weight. This information was collected for seven decades for winter and spring barley during the seed regeneration routine. The curated data represent a source for research on genetics and genomics of adaptive and yield related traits in cereals due to the importance of barley as model organism. This data could be used to predict the performance of non-phenotyped individuals in other collections through genomic prediction. Moreover, the dataset empowers the utilization of phenotypic diversity of genetic resources for crop improvement.

scholarly journals Efficient curation of genebanks using next generation sequencing reveals substantial duplication of germplasm accessions

2018 ◽  
Author(s):  
Narinder Singh ◽  
Shuangye Wu ◽  
W. John Raupp ◽  
Sunish Sehgal ◽  
Sanu Arora ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Next Generation Sequencing ◽  
Crop Improvement ◽  
Aegilops Tauschii ◽  
Cost Effective ◽  
Ex Situ ◽  
Next Generation ◽  
Sequencing Platform ◽  
Efficient Management ◽  
Generation Sequencing

ABSTRACTGenebanks are valuable resources for crop improvement through the acquisition, ex-situ conservation and sharing of unique germplasm among plant breeders and geneticists. With over seven million existing accessions and increasing storage demands and costs, genebanks need efficient characterization and curation to make them more accessible and usable and to reduce operating costs, so that the crop improvement community can most effectively leverage this vast resource of untapped novel genetic diversity. However, the sharing and inconsistent documentation of germplasm often results in unintentionally duplicated collections with poor characterization and many identical accessions that can be hard or impossible to identify without passport information and unmatched accession identifiers. Here we demonstrate the use of genotypic information from these accessions using a cost-effective next generation sequencing platform to find and remove duplications. We identify and characterize over 50% duplicated accessions both within and across genebank collections of Aegilops tauschii, an important wild relative of wheat and source of genetic diversity for wheat improvement. We present a pipeline to identify and remove identical accessions within and among genebanks and curate globally unique accessions. We also show how this approach can also be applied to future collection efforts to avoid the accumulation of identical material. When coordinated across global genebanks, this approach will ultimately allow for cost effective and efficient management of germplasm and better stewarding of these valuable resources.

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