Fine mapping and marker-assisted selection (MAS) of a low glutelin content gene in rice

Abstract

Rice with low glutelin content is suitable as functional food for patients affected with diabetes and kidney failure. The fine mapping of the gene(s) responsible for low glutelin content will provide information regarding the distribution of glutelin related genes in rice genome and will generate markers for the selection of low glutelin rice varieties. Following an SDS-PAGE screen of rice germplasm from Taihu Valley of China, Japonica selection W3660 is identified to be a novel mutant characterized with low glutelin content. For fine mapping the mutant gene for low glutelin content, F 2 and F 3 populations were derived from a cross between W3660 and Jingrennuo. SDS-PAGE analysis of the total endosperm protein showed that the low glutelin content trait was controlled by a single dominant nuclear gene. Genetic mapping, using SSRs, located this gene to chromosome 2, in the region between SSR2-001/SSR2-004 and RM1358. The distances of the two markers to the target gene were 1.1 cM and 3.8 cM respectively. By semi-quantitative RT-PCR analysis, the transcripts of GluB4/GluB5 genes located within the region do not change. However, GluB5 gene located proximal to SSR2-001/SSR2-004 was specifically reduced. SSR profiles of seven Japonica varieties were compared with that of W3660 for loci in the relevant genetic region. The markers SSR2-004 and RM1358 were used for markerassisted selection. The selection efficiencies of SSR2-004 and RM1358 were 96.8% and 92.7% respectively. This provides a standard starting point for the breeding of low glutelin content rice varieties in China.

SSR markers linked to mite (Polyphagotarsonemus latus Banks) resistance in jute (Corchorus olitorius L.)

“…This suggests that they are closely linked to the mite resistant genes. Similar findings were also observed by Wang et al (2005). They reported that the selection efficiencies of SSR2-004 and RM1358 were 96.8% and 92.7%, respectively, and 99.8% in combination.…”

Evaluation of Antioxidant, Lipid, and Protein Fractions of Accessions of Oryza Species

“…Rice breeders across the globe have worked to increase the protein content of some cultivars and decrease the levels in others (Wang et al 2005. Low protein is desired for those that must curtail their protein intake, such as those with renal disease and for use in sake production to reduce off-flavor creation.…”

Development of gene-tagged markers for quantitative trait loci underlying rice yield components

“…Therefore, in the past decade, the inheritance of many agricultural traits, resistance to pests/disease, stress tolerance, and quality of crops have been widely studied using molecular markers (e.g., RFLP, SSR, RAPD, and AFLP), consequently providing molecular markers for MAS as well. On the basis of genetic information, several successful examples of MAS combined with phenotype measurement have been accomplished, and these mainly focus on the improvement of discontinuous traits such as resistance to pests/disease, stress tolerance, and grain quality in crops (Davierwala et al 2001;Huang et al 2003;Zhou et al 2003;Chen et al 2004;He et al 2004;Joseph et al 2004;Sharma et al 2004;Yi et al 2004;Tan et al 2005;Wang et al 2005;Liu et al 2006;Miyata et al 2007). However, there have been only a few reports on quantitative trait improvements by MAS in rice thus far, especially on the yield-related traits, although a larger number of QTLs associated with yield and yield components have been identified in rice.…”

“…Further, the property of relatively small effects of an individual QTL possibly leads to the failure of QTL-MAS (Ashikari and Matsuoka 2006). Therefore, up to date, there are only a few reports on successfully developing a rice cultivar with an improved yield level by MAS, although improvements on resistance to pests/ disease, grain quality, and stress tolerance traits, which are controlled by major genes, have been successfully achieved (Davierwala et al 2001;Huang et al 2003;Zhou et al 2003;Chen et al 2004;He et al 2004;Joseph et al 2004;Sharma et al 2004;Yi et al 2004;Tan et al 2005;Wang et al 2005;Liu et al 2006;Miyata et al 2007;Neeraja et al 2007).…”