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ARS Home » Southeast Area » Stuttgart, Arkansas » Dale Bumpers National Rice Research Center » Research » Publications at this Location » Publication #227821
Title: QTL analysis for resistance to pre-harvest sprouting in rice (Oryza sativa)

Author
item GAO, F - SICHUAN UNIV., PRC
item REN, G - SICHUAN UNIV., PRC
item LU, X - SICHUAN UNIV., PRC
item SUN, S - SICHUAN UNIV., PRC
item LI, H - SICHUAN UNIV., PRC
item GAO, Y - INST. CROP SCI, BEIJING
item LUO, H - CORNELL UNIVERSITY
item Yan, Wengui
item ZHANG, Y - SICHUAN UNIV., PRC

Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/17/2007
Publication Date: 6/1/2008
Citation: Gao, F.Y., Ren, G.J., Lu, X.J., Sun, S.X., Li, H.J., Gao, Y.M., Luo, H., Yan, W., Zhang, Y.Z. 2008. QTL analysis for resistance to pre-harvest sprouting in rice (Oryza sativa). Plant Breeding. 127:268-273.

Interpretive Summary: Pre-harvest sprouting (PHS) is defined as rice germination on the panicle before harvesting, which could cause severe yield losses and reduce grain quality in hybrid rice seed production, especially in Sichuan, a major producer of hybrid seed in China where PHS originated from the ‘G46A’ parent. A F2 population of 164 plants was developed from a cross of ‘G46B’ with ‘K81’, a near-isogenic introgression line of G46B selected from BC2F5 between G46B and ‘Lemont’ where G46B was the recurrent parent. The PHS varied from 0 to 99% of sprouting germination continuously with two peaks, indicating the quantitative inheritance with main gene effect in the population. A linkage map was constructed from genotyping this F2 population with 760 SSR markers. Three QTLs for PHS were identified by composite interval mapping in the population, namely qPSR2, qPSR5 and qPSR8 which were located in chromosome 2, 5 and 8, respectively. The qPSR8 residing in the interval between RM447 and RM3754 on chromosome 8 was the major QTL controlling PHS because it had high logarithm of the odds (LOD) score and explained 43.04% of the phenotypic variation. These results were correspondent to those identified in extreme low germination rate plants in the population using linkage and linkage disequilibrium. At all loci, K81 was responsible for enhancing the resistance to PHS.

Technical Abstract: Pre-harvest sprouting (PHS) is caused by early breaking of seed dormancy. In Sichuan, a major producer of hybrid rice seed production in China, PHS in hybrid seeds originated from ‘G46A’ parent may result in severe yield loss and cause serious damage to agricultural production. We developed an F2 population of 164 plants from a cross of ‘G46B’ with ‘K81’ highly resistant to PHS selected from BC2F5 between G46B and ‘Lemont’ where G46B was the recurrent parent. K81 is a near-isogenic introgression line of G46B. The PHS varied from 0 to 99% of sprouting germination continuously with two peaks, indicating the quantitative inheritance with main gene effect in the population. A linkage map was constructed from genotyping this F2 population with 760 SSR markers. Three QTLs for PHS were identified by composite interval mapping in the population, namely qPSR2, qPSR5 and qPSR8 which were located in chromosome 2, 5 and 8, respectively. The qPSR8 residing in the interval between RM447 and RM3754 on chromosome 8 was the major QTL controlling PHS because it had high logarithm of the odds (LOD) score and explained 43.04% of the phenotypic variation. These results were correspondent to those identified in extreme low germination rate plants in the population using linkage and linkage disequilibrium. At all loci, K81 was responsible for enhancing the resistance to PHS.