Identification and introgression of QTLs implicated in resistance to sorghum downy mildew (Peronosclerospora sorghi (Weston and Uppal) C. G. Shaw) in maize through marker-assisted selection

Journal of genetics

H. C. Lohithaswa1²  Puttaramanaik¹  Shailaja Hittalmani³  K. R. Sunil Kumar³  K. Jyothi³ 

[1] All India Coordinated Research Project on Maize, ZARS, V. C. Farm, Mandya 571 405, India$$;Department of Genetics and Plant Breeding, College of Agriculture, V. C. Farm, Mandya 571 405, India$$;Marker Assisted Selection Laboratory, Department of Genetics and Plant Breeding, GKVK, University of Agricultural Sciences, Bengaluru 560 065, India$$

关键词: maize;    sorghum downy mildew;    linkage map;    marker-assisted introgression;    Peronosclerospora sorghi.;   

DOI  :  

学科分类：生物科学（综合）

来源: Indian Academy of Sciences

【 摘 要 】

Sorghum downy mildew caused by Peronosclerospora sorghi is a major disease of maize and resistance is under the control of polygenes which necessitated identification of quantitative-trait loci (QTLs) for initiating marker-assisted introgression of resistant QTLs in elite susceptible inbred lines. In the present study, QTLs for sorghum downy mildew (SDM) resistance in maize were identified based on cosegregation with linked simple sequence repeats in 185 F2 progeny from a cross between susceptible (CM500-19) and resistant (MAI105) parents. F3 families were screened in the National Sorghum Downy Mildew Screening Nursery during 2010 and 2011. High heritability was observed for the disease reaction. The final map generated using 87 SSR markers had 10 linkage groups, spanning a length of 1210.3 cM. Although, we used only 87 SSR markers for mapping, the per cent of genome within 20 cM to the nearest marker was 88.5. Three putative QTLs for SDM resistance were located on chromosomes 3 (bin 3.01), 6 (bin 6.01) and 2 (bin 2.02) using composite interval mapping. The locus on chromosome 3 had a major effect and explained up to 12.6% of the phenotypic variation. The other two QTLs on chromosomes 6 and 2 had minor effects with phenotypic variation of 7.1 and 2%. The three QTLs appeared to have additive effects on resistance. The QTLs on chromosomes 3 and 6 were successfully used in the marker-assisted selection programme for introgression of resistance to SDM in eight susceptible maize lines.

【 授权许可】

Unknown