Genetic diversity and heterotic grouping of Philippine inbred rice germplasm : implications to Philippine hybrid rice breeding

Date

6-2017

Abstract

In order to determine the possible contribution of the genetic diversity of Philippine inbred lines in hybrid rice breeding, SNP data of the 182 PhilRice inbred lines and the 372 hybrid parental germplasm of the International Rice Research Institute (IRRI) was merged. Results showed that merging the two groups of lines increased genetic diversity. Mean genetic distances obtained likewise increased from 0. 19 for the PhilRice lines to 0.31 for the merged PhilRice and IRRI lines. The STRUCTURE analysis performed for the combined PhilRice and IRRI lines generated five major groups, clustering together he lines according to line classification and breeding group that developed the lines. The grouping derived was used in choosing parents for the determination of heterotic groups among Philippine inbred and IRRI hybrid parental lines

From the groupings generated, 26 parents representing the identified groups were used for the combining ability test using the line tester analysis Twenty-six parents from PhilRice and IRRI hybrid lines, 135 derived hybrids, and a hybrid and an inbred check were evaluated in 5 environments. Results showed that hybrid yield, heterosis and combining ability were statistically significant among the parents and hybrids. Mean yield advantage of hybrids was 32%, 20% and 9% against the means of the parents, inbred check and hybrid check respectively. For this set of lines, three IRRI groups formed heterotic hybrids with the PhilRice inbred lines and four promising hybridization patterns were identified based on the marker grouping and the field testing done. The study confirmed that the grouping identified in the PhilRice and IRRI lines by SNP markers represents heterotic groups and is useful in selecting parents in hybrid rice breeding. Results likewise showed the high potential of the SNP markers used in grouping the germplasm materials. The information generated in the study will be useful in developing heterotic groups in the PhilRice germplasm and gives a guide on how to possibly attain high yield heterosis in Philippine hybrid rice varieties.

Document Type

Dissertation

Degree

Doctor of Philosophy in Plant Breeding

College

Graduate School (GS)

Adviser/Committee Chair

Jose E. Hernandez, Ph.D.

Committee Member

Teresita H. Borromeo, Pompe C. Sta Cruz, Fangming Xie

Language

English

LC Subject

Rice, Germplasm resources, Plant, Hybrid rice, Rice

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 996 2017 A42 E93

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