QTL analysis for resistance to preharvest sprouting in rice (Oryza sativa)

• Published in: Plant breeding Vol. 127; no. 3; pp. 268 - 273
• Main Authors: Gao, F.Y, Ren, G.J, Lu, X.J, Sun, S.X, Li, H.J, Gao, Y.M, Luo, H, Yan, W.G, Zhang, Y.Z
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-06-2008; Blackwell Publishing Ltd; Blackwell
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; F2 population; Fundamental and applied biological sciences. Psychology; F₂ population; Genetics and breeding of economic plants; linkage disequilibrium; Oryza sativa; preharvest sprouting; quantitative trait loci; Varietal selection. Specialized plant breeding, plant breeding aims; Monocotyledones; Cereal crop; Preharvest sprouting; Quantitative trait loci; Resistance; Oryza sativa; Gramineae; Angiospermae; Genetic improvement; Genetic linkage; Population; Spermatophyta; F2 population; linkage disequilibrium
• ISSN: 0179-9541; 1439-0523
• DOI: 10.1111/j.1439-0523.2007.01450.x

Preharvest sprouting (PHS) is caused by early breaking of seed dormancy. In Sichuan, a major hybrid rice seed production area of China, PHS in hybrid seeds originated from 'G46A' parent may lead to severe yield loss, causing serious damage to agricultural production. To detect quantitative trait loci (QTLs) governing PHS, we developed an F₂ population of 164 plants derived from 'G46B' and 'K81', a near-isogenic introgression line of G46B, with high level of resistance to PHS. PHS was evaluated under controlled field and laboratory conditions. Using simple sequence repeat markers, we constructed a linkage map from this population and identified three QTLs for PHS, namely qPSR2, qPSR5 and qPSR8, which were located on chromosomes 2, 5 and 8, respectively. Among these QTLs, qPSR8, residing in the interval between RM447 and RM3754 on chromosome 8, was the major QTL controlling PHS, for it had a relative 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 (ELGP) using linkage and linkage disequilibrium. At all loci, 'K81' was responsible for enhancing the resistance to PHS.