Chinese Cornus officinalis: genetic resources, genetic diversity and core collection

Worldwide, there are cuurently more than 60 germplasm banks that contain tomato (Lycopersicon esculentum) collections ranging is size from a few dozen to several thousands of accessions. In the utilization of these genetic resources sampling from only one germplasm bank may result in limiting available genetic diversity, whereas sampling from several germplasm banks may result in unnecessary redundancy. The current lack of knowledge regarding the relative magnitudes of genetic diversity contained within different collections makes it difficult to develop a core collection that maximizes genetic diversity. Two large tomato collections are housed at the Asian Vegetable Research and Development Center (AVRDC), Sanhua, Taiwan, R.O.C., and the Centro Agronomico Tropical de Investigacion y Enseoanza (CATIE), Turrialba, Costa Rica. Ninety-six accessions from CATIE and 102 accessions from AVRDC were randomly sampled from each base collection. The total of 198 accessions were charcterized for 103 polymorphic RAPD molecular marker bands. The results indicated that the two germplam banks sampled different genetic diversity. In addition, the magnitude of genetic diversity was greater in the AVRDC collection compared to CATIE.

Download Full-text

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

Genome ◽

10.1139/g99-051 ◽

1999 ◽

Vol 42 (4) ◽

pp. 562-569 ◽

Cited By ~ 11

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.

Download Full-text

Establishment of a cryopreserved gene bank of European elms

Canadian Journal of Forest Research ◽

10.1139/x03-193 ◽

2004 ◽

Vol 34 (1) ◽

pp. 43-55 ◽

Cited By ~ 51

Author(s):

L Harvengt ◽

A Meier-Dinkel ◽

E Dumas ◽

E Collin

Keyword(s):

Genetic Diversity ◽

Genetic Resources ◽

Liquid Nitrogen ◽

Random Sample ◽

Plant Material ◽

Core Collection ◽

Gene Bank ◽

Ulmus Glabra ◽

Negative Effect ◽

Ulmus Laevis

Cryopreservation of a core collection of 444 elm (Ulmus spp.) clones in liquid nitrogen was carried out by two laboratories participating in a European project of conservation of elm genetic resources. Plant material, collected in nine European countries, represented a large sample of the genetic diversity within three European elm species and their hybrids. The cryopreservation technique used in both laboratories involved the stepwise freezing of cryotubes containing dormant buds. Comparisons with fresh buds showed that the cryopreservation treatment had no negative effect on the viability and regrowth potential of frozen buds. Tests on a random sample of 26 clones showed that direct regrowth of cryopreserved buds (i.e., through propagation by microcuttings) of Ulmus minor and Ulmus laevis was possible; conversely, Ulmus glabra could only be regrown through micrografting. Most thawed explants from all 26 clones survived through the whole cultivation phase and were successfully transferred to the field. A calculation of costs indicates that cryopreservation of elm buds is economically competitive to field clonal archives.

Download Full-text

Genetic diversity and construction of core collection in Chinese wheat genetic resources

Science Bulletin ◽

10.1007/s11434-008-0212-x ◽

2008 ◽

Vol 53 (10) ◽

pp. 1518-1526 ◽

Cited By ~ 26

Author(s):

ChenYang Hao ◽

YuChen Dong ◽

LanFen Wang ◽

GuangXia You ◽

HongNa Zhang ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Resources ◽

Core Collection ◽

Chinese Wheat

Download Full-text

Common Vetch, Valuable Germplasm for Resilient Agriculture: Genetic Characterization and Spanish Core Collection Development

Frontiers in Plant Science ◽

10.3389/fpls.2021.617873 ◽

2021 ◽

Vol 12 ◽

Author(s):

Lucía De la Rosa ◽

María Isabel López-Román ◽

Juan M. González ◽

Encarnación Zambrana ◽

Teresa Marcos-Prado ◽

...

Keyword(s):

Genetic Diversity ◽

Genetic Resources ◽

Core Collection ◽

Animal Feed ◽

Plant Genetic Resources ◽

Wild Relatives ◽

Agricultural System ◽

Protein Profiles ◽

Common Vetch ◽

Breeding Programs

Common vetch (Vicia sativa L.) is a legume used for animal feed because of its high protein content and great capacity for nitrogen fixation, making this crop relevant in sustainable agriculture. The Spanish vetch collection, conserved at the Spanish Plant Genetic Resources Center (CRF), is one of the largest collections of this species worldwide, including landraces, wild relatives mainly collected in Spain, and commercial cultivars, but also accessions of international origin. The analysis of the genetic diversity of this material, whose genome has not been sequenced yet, and the assembly of a representative collection could play a pivotal role in conserving and exploiting these genetic resources in breeding programs mainly in those focused on consequences and demands of climate change. In this work, a set of 14 simple sequence repeat (SSR) reference alleles for genetic diversity analysis of the CRF vetch collection has been developed, used for genotyping more than 545 common vetch accessions from all over the world and validated. All the tested markers were polymorphic for the analyzed accessions. Overall, at least 86 different loci were identified with 2–11 alleles per locus with an average of 6.1 alleles per locus. Also, the analyses of the generated SSR database support that most of these SSR markers are transferable across closely related species of Vicia genus. Analysis of molecular variance revealed that wild relatives have a higher genetic diversity than landraces. However, cultivars have similar diversity than landraces, indicating that genetic variability has been barely lost due to the breeding of this legume. Low differences of genetic variations between Spanish and non-Spanish accessions have been observed, suggesting a high degree of diversity within Spanish genotypes, which provide 95% of the total genetic variation, so we have focused our efforts on characterizing genotypes of Spanish origin that were further studied using storage protein profiles. Based on SSR, seed protein profiles, and agromorphological and passport data, a vetch core collection (VCC) containing 47 V. sativa accessions of Spanish origin has been established. In this collection, the characterization has been expanded using ISSR markers, and it has been reevaluated with new agromorphological data, including drought tolerance characters. This VCC presents a minimum loss of genetic diversity concerning the total collection and constitutes an invaluable material that can be used in future breeding programs for direct use in a resilient agricultural system.

Download Full-text

Genetic Diversity and Population Structure Analysis of Dalbergia Odorifera Germplasm and Development of a Core Collection Using Microsatellite Markers

Genes ◽

10.3390/genes10040281 ◽

2019 ◽

Vol 10 (4) ◽

pp. 281 ◽

Cited By ~ 5

Author(s):

Fu-Mei Liu ◽

Ning-Nan Zhang ◽

Xiao-Jin Liu ◽

Zeng-Jiang Yang ◽

Hong-Yan Jia ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Microsatellite Markers ◽

Genetic Resources ◽

Tree Species ◽

Core Collection ◽

Southern China ◽

Breeding Programs ◽

Expected Heterozygosity ◽

Dalbergia Odorifera

Dalbergia odorifera T. Chen (Fabaceae) is a woody tree species indigenous to Hainan Island in China. Due to its high medicinal and commercial value, this tree species has been planted over 3500 ha2 in southern China. There is an urgent need for improvement of the D. odorifera germplasm, however, limited information on germplasm collection, conservation, and assessment of genetic resources is available. Therefore, we have built a database of 251 individuals collected across the whole of southern China, which included 42 wild trees and 210 cultivated trees, with the following objectives. (1) Evaluate genetic diversity and population structure of the database using 19 microsatellite markers and (2) develop a core collection for improvement and breeding programs. Totally, the 19 microsatellite markers harbored 77 alleles across the database with the polymorphic information content (PIC) ranging from 0.03 to 0.66. Medium genetic diversity level was inferred by Nei’s gene diversity (0.38), Shannon’s information index (0.65), and observed (0.33) and expected heterozygosity (0.38). Structure analysis showed that four was the optimum cluster size using the model-based Bayesian procedure, and the 251 D. odorifera individuals were grouped into five populations including four pure ones (RP1-4) and one mixed one (MIX) based on their maximum membership coefficients. Among these populations, the expected heterozygosity varied from 0.30 (RP3) to 0.38 (RP4). Analysis of molecular variance (AMOVA) showed 11% genetic variation existed among populations, and moderate population differentiation was inferred by the matrix of pairwise Fst (genetic differentiation among populations), which was in the range of 0.031 to 0.095. Moreover, a core collection of 31 D. odorifera individuals including six wild and 25 cultivated trees was developed, which was only 12.4% of the database but conserved the whole genetic diversity. The results of this study provided additional insight into the genetic structure of the large D. odorifera germplasm, and the core collection will be useful for the efficient and sustainable utilization of genetic resources, as well as efficient improvement in breeding programs.

Download Full-text

Analysis of genetic diversity of rapeseed genetic resources in Japan and core collection construction

Breeding Science ◽

10.1270/jsbbs.16192 ◽

2017 ◽

Vol 67 (3) ◽

pp. 239-247 ◽

Cited By ~ 1

Author(s):

Ruikun Chen ◽

Takashi Hara ◽

Ryo Ohsawa ◽

Yosuke Yoshioka

Keyword(s):

Genetic Diversity ◽

Genetic Resources ◽

Core Collection

Download Full-text

Genetic diversity and establishment of a core collection of oil palm (Elaeis guineensisJacq.) based on molecular data

Plant Genetic Resources ◽

10.1017/s1479262114001026 ◽

2014 ◽

Vol 13 (3) ◽

pp. 256-265 ◽

Cited By ~ 2

Author(s):

Diana Arias ◽

Maria González ◽

Hernán Romero

Keyword(s):

Genetic Diversity ◽

Genetic Differentiation ◽

Genetic Resources ◽

Oil Palm ◽

Core Collection ◽

Molecular Data ◽

Core Collections ◽

Mini Core Collection ◽

Entire Collection ◽

Breeding Programmes

Understanding of genetic diversity and its distribution is essential for promoting the use of genetic resources. The development of core collections using molecular tools has been proposed as a strategy for increasing the economical use and conservation of genetic resources. In this study, we investigated the genetic variation among different geographical origins and potential entries that constituted a core collection of oil palm, using 29 microsatellite markers and by evaluating 788 oil palm accessions. Our results revealed important genetic diversity (HT= 0.759) between oil palm accessions from Angola and Cameroon, which exhibited a low coefficient of genetic differentiation between populations (GST= 0.022). However, the inclusion of oil palm accessions from Indonesia in the analysis resulted in a high coefficient of genetic differentiation between populations (GST= 0.251). We found that the combination of stratified sampling based on a sorting method and a heuristic algorithm was the most effective method for the development of an oil palm core collection set. Using this method, two core collections were identified. The first core collection, comprising 289 entries, contained 271 retained alleles in a sample representing 37% of the entire collection. The second one is a mini core collection, comprising 91 entries, that contained 271 retained alleles with a totalHevalue of 0.72 in a sample representing 11% of the entire collection. The information reported in this study will be of great interest to oil palm researchers because new strategies for breeding programmes can be developed based on these advances.

Download Full-text