Molecular marker systems for profiling and diversity analysis of rice germplasm in Philippine Genebank

Issue Date

8-2009

Abstract

Rice breeding programs require a wide gene pool from which to assemble outstanding gene combinations. Germplasm diversity can be accurately evaluated through DNA fingerprinting. In this study, genetic variability and relationships among 265 rice germplasm accessions from the PhilRice Genebank were established from DNA fingerprints generated using two resistance gene analogue (RGA) markers: carboxy-terminal leucine-rich repeat (CLRR) and ribonuclease inhibitor leucine-rich repeat (RLRR), and two Uniprimers: Seoulin Research Institute Life Science-6 (SRILS6) and Seoulin Research Institute Life Science-8 (SRILS8). The DNA fingerprints showed that CLRR was the most discriminating marker, generating 48 polymorphic bands in the germplasm samples with an average of 29 bands per accession, and hence the most efficient marker for rapid DNA fingerprinting. On the average, however, the RGA and Uniprimer markers showed similar power in detecting polymorphism within the population for the entire germplasm population level. The average percentage of polymorphic bands generated by RGA and Uniprimer markers were 60.6 and 60.5%, respectively. Seven dendrograms were generated based on banding profiles generated by RGA and SRILS primers and their combinations, featuring two nearly even major groups: Group I and II. Dendrogram analysis showed that both RGA and SRILS primers distinguished all 265 accessions, and revealed a high level of diversity among the accessions. The clustering patterns and the compositions of the groups were remarkably similar among the seven dendrograms ranging 88-97% match. This indicates that these particular RGA and SRILS markers amplify genomic regions that may have undergone mutations at comparative rates so as to manifest highly congruent genetic trees. The two DNA marker systems studied could be ideal tools for rapid DNA fingerprinting and diversity analysis of rice germplasm varieties, and hence, can be an important adjunct in rice germplasm management such as in germplasm identification, diversity analysis and assembly of core collections.

Source or Periodical Title

Philippine Journal of Crop Science

ISSN

0115-463x

Volume

34

Issue

2

Page

1-11

Document Type

Article

Frequency

tri-quarterly

Physical Description

tables, pictures, dendrogram

Language

English

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