How do we address the disconnect between genetic and morphological diversity in germplasm collections?

This study of genetic diversity in a wild ancestor of the cultivated strawberry was undertaken to describe patterns of variation in nature, assess worth of existing germplasm collections, and identify promising locations for future collection. Previous work reported a similar study of octaploid strawberry ranging east to west across North America. This complementary study focused on variation from north to south in the Rocky Mountains. The morphological diversity of 16 populations of Fragaria virgininia were characterized for morphological and molecular traits. Two clones of each of 133 genotypes from these populations were grown in a common environment in a greenhouse. Eighteen morphological traits, such as leaf area, runner color, and days to flowering, were measured and analyzed with principal components and canonical discriminant analyses. Molecular diversity data were obtained using seven randomly amplified polymorphic DNA primers. Resulting population marker frequencies were also subjected the previously describe anlayses. Differences due to latitude, longitude, and altitude were observed. Implications of the results will be discussed.

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Comparison of AFLPs, RAPD Markers, and Isozymes for Diversity Assessment of Garlic and Detection of Putative Duplicates in Germplasm Collections

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.128.2.0246 ◽

2003 ◽

Vol 128 (2) ◽

pp. 246-252 ◽

Cited By ~ 46

Author(s):

Meryem Ipek ◽

Ahmet Ipek ◽

Philipp W. Simon

Keyword(s):

Genetic Diversity ◽

Rapd Markers ◽

Genetic Relationships ◽

Morphological Diversity ◽

Mantel Test ◽

Group Method ◽

Aflp Analysis ◽

Additional Tool ◽

Germplasm Collections ◽

Diversity Assessment

Garlic (Allium sativum L.) is an asexually propagated crop that displays much morphological diversity. Studies which have assessed garlic diversity with isozymes and randomly amplified polymorphic DNA (RAPD) markers generally agreed with the morphological observations but sometimes failed to discriminate clones. To discriminate among closely related garlic clones in more detail, we introduced amplified fragment-length polymorphism (AFLPs) to evaluate the genetic diversity and phenetic relatedness of 45 garlic clones and three A. longicuspis clones and we compared AFLP results with RAPD markers and isozymes. Three AFLP primer combinations generated a total of 183 polymorphic fragments. Although similarities between the clusters were low (≥0.30), some clones within the clusters were very similar (>0.95) with AFLP analysis. Sixteen clones represented only six different banding patterns, within which they shared 100% polymorphic AFLPs and RAPD markers, and likely are duplicates. In agreement with the results of other investigators, A. longicuspis and A. sativum clones were clustered together with no clear separation, suggesting these species are not genetically or specifically distinct. The topology of AFLP, RAPD, and isozyme dendrograms were similar, but RAPD and isozyme dendrograms reflected less and much less polymorphism, respectively. Comparison of unweighted pair group method with arithmetic averaging (UPGMA) dendrograms of AFLP, RAPD, and isozyme cluster analyses using the Mantel test indicated a correlation of 0.96, 0.55, and 0.57 between AFLP and RAPD, AFLP and isozyme, and RAPD and isozyme, respectively. Polymorphic AFLPs are abundant in garlic and demonstrated genetic diversity among closely related clones which could not be differentiated with RAPD markers and isozymes. Therefore, AFLP is an additional tool for fingerprinting and detailed assessment of genetic relationships in garlic.

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Genetic and morphological diversity analysis of lime and acidic Citrus spp. from two germplasm collections in Thailand

Agriculture and Natural Resources ◽

10.34044/j.anres.2021.55.4.09 ◽

2021 ◽

Vol 55 (4) ◽

Keyword(s):

Morphological Diversity ◽

Diversity Analysis ◽

Germplasm Collections ◽

Citrus Spp

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Strategies for developing a core collection of bladder clover (Trifolium spumosum L.) using ecological and agro-morphological data

Australian Journal of Agricultural Research ◽

10.1071/ar08209 ◽

2008 ◽

Vol 59 (12) ◽

pp. 1103 ◽

Cited By ~ 11

Author(s):

K. Ghamkhar ◽

R. Snowball ◽

B. J. Wintle ◽

A. H. D. Brown

Keyword(s):

Core Collection ◽

Selection Process ◽

Morphological Diversity ◽

Morphological Data ◽

Systematic Evaluation ◽

Ecological Data ◽

Optimal Method ◽

Germplasm Collections ◽

Selection Strategies ◽

Morphological Evaluation

Core collections are a way to improve the functioning of germplasm collections through systematic evaluation, exploitation, and improved management of the whole collection. The published sizes of cores have ranged from 10 to 30% of the collection. The first step in developing a core collection is usually stratification of the whole collection. We adopted three approaches in the process of core designation. First, the existing ecological data and newly acquired agro-morphological (evaluation) data were analysed to determine the optimal method for capturing the ecological and morphological diversity of accessions. Second, different selection strategies were compared to identify the most powerful analysis with the greatest likelihood of covering maximum diversity. Third, the correlation between the two datasets was investigated. The annual pasture legume, bladder clover (Trifolium spumosum L.), was used for this pilot study because 80% of the existing 398 accessions have near-complete ecological data. The study found that a two-step selection process using ecological data and stratified proportional strategy followed by combined datasets and maximising strategy best represents the whole collection of T. spumosum in the core.

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