Duplication assessments in Nordic Avena sativa accessions at the Canadian national genebank

Abstract

This study applied two methods to assess intra-collection duplication within 339 Nordic oat (Avena sativa L.) accessions preserved by Plant Gene Resources of Canada (PGRC). Putative duplicates, that is accessions carrying a similar accession name, were grouped into 52 duplication groups and included 230 of the 339 Nordic oat accessions. A field assessment based on visual inspection of field plots was conducted during two growing seasons to detect distinct phenotypes within each duplication group. Simultaneously, a descriptor assessment using seven characters with altogether sixteen character states was used in both years for the same purpose. The combined results of both assessments and both years indicated that among the 230 accessions in duplication groups only 118 could be identified as distinct. This would allow for a reduction of 33% of the Nordic oat accessions at PGRC. The field assessment method detected fewer (75%) distinct accessions than the descriptor assessment (84%), when considering all accessions identified as distinct as 100%. Repeatability between years was higher in the field assessment (70%) than in the descriptor assessment (64%). The field assessment requires an experienced germplasm evaluator, but allows for handling large numbers of germplasm accessions and for detecting functional, fitness related, and user-relevant diversity. Combining field assessment with descriptor assessment and more sophisticated methods on selected subgroups may be the most efficient method for determination of internal duplication in genebank collections. Bulking phenotypically similar accessions within duplication groups is preferable to eliminating duplicate accessions when collection rationalization is required, as it reduces the risk of loosing diversity.

Genetic relationships among improved varieties of rice (Oryza sativa L.) in Indonesia over the last 60 years as revealed by morphological traits and DNA markers

“…However, the correlation between these two markers and the phenotypic distance among varieties were slightly different. The slightly positive correlation caused by morphological traits in this study are associated with a relatively small number of loci, thus the potential difference could be lost in the analysis of large amounts of molecular data as suggested by Diederichsen (2009).…”

Genetic diversity among Polish landraces of common oat (Avena sativa L.)

“…On the other hand, the AFLP analysis indicated that most of the variation was located within the country (Fu et al 2005). The difference of opinion may be due to the fact that the morphological traits are controlled by several loci, which in the vastness of information generated by molecular markers are unnoticeable (Diederichsen 2009). Results of both Fu et al (2003) and Leisova et al (2007) indicated that breeding programs have had a significant impact on the decrease of common oat genetic diversity.…”

“…Due to an intensive exchange of breeding materials for over the century, currently it is almost impossible to refer unambiguously genetic differentiation to the place of accession origin (Diederichsen 2009). However, the author pointed out, that the differences in the morphological traits between countries were observed.…”

Assessing genetic diversity in 23 early Polish oat cultivars based on molecular and morphological studies

“…Therefore differences could be expected in the compilation of molecular and morphological data. Morphological traits are associated with a relatively small number of loci, thus the potential difference could be lost in the analysis of large amounts of molecular data (Diederichsen 2009). In order to determine the degree of correlation of the morphological and molecular results Mantel test was performed.…”