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ARS Home » Southeast Area » Stuttgart, Arkansas » Dale Bumpers National Rice Research Center » Research » Publications at this Location » Publication #420483
Research Project: Broadening and Strengthening the Genetic Base of Rice for Adaptation to a Changing Climate, Crop Production Systems, and Markets

Location: Dale Bumpers National Rice Research Center

Title: Mining the diversity in rice and it’s ancestral species for rice improvement

Author
item Eizenga, Georgia

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/8/2024
Publication Date: 11/14/2024
Citation: Eizenga, G.C. 2024. Mining the diversity in rice and it’s ancestral species for rice improvement. Abstract. ASA,CSSA,SSSA International Annual Meeting, San Antonio, Texas. November 10-13, 2024. https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/156032

Interpretive Summary:

Technical Abstract: Cultivated rice, Oryza sativa divides into the varietal groups Indica and Japonica based on sterility barriers and nine genotypic subpopulations. Most US rice is Japonica with cultivars grown in the Midsouth classified as tropical japonica (TRJ) and California as temperate japonica. The Rice Diversity Panel 1 (RDP1) was developed for genome-wide association (GWA) mapping and evaluated for over 30 traits. To validate the RDP1 GWA QTL, mapping populations were developed from RDP1 Japonica accessions. The Estrela x NSFTV199 population was phenotyped for 23 yield-related traits and 52 of the 92 QTL overlapped with RDP1 QTL. Two TRJ germplasms were derived from these progeny, SC14_072 with extra-long kernels and SC14_166 with increased panicle branching and seeds per panicle. The L-202 x Trembese population was phenotyped for 20 yield component traits, 16 of which were measured in RDP1 and 37 of the 43 RIL QTL overlapped with RDP1 GWAS QTL. O. rufipogon and O. nivara are the ancestral species of O. sativa, collectively identified as the Oryza rufipogon Species Complex (ORSC). Six genotypic subpopulations were disclosed in a collection of 286 ORSC accessions, and phenotyping 240 accessions for 44 traits revealed three phenotypic groups roughly corresponding to the O. rufipogon, O. nivara and Oryza spp. designations. A subset of about 110 ORSC accessions was screened for tolerance to the major rice fungal diseases sheath blight and blast with four accessions identified as resistant to one or both diseases. O. sativa x ORSC advanced backcross populations were developed with each accession to identify resistance QTL. Three diverse ORSC accessions originating from China, Laos and Indonesia were backcrossed into IR64, an indica cultivar and Cybonnet, a TRJ cultivar. Six chromosome segment substitution libraries were assembled from these progeny, evaluated for yield-related traits and substitution mapping applied to identify candidate genes.