Quantitative trait loci (qtls) associated with drought Tolerance in rice (Oryza sativa L.)

N.T. LANG¹*, C.T. NHA¹, P.T.T. HA¹ and B.C. BUU²

¹CuuLong Delta Rice Research Institute, Viet Nam

²Institute of Agricultural Science of Southern Viet Nam, Viet Nam

*Corresponding author’s email: ntlang@hcm.vnn.vn

SUMMARY

SSR  genotyping was  combined with selective genotyping to map quantitative trait loci (QTLs) associated with drought tolerance in rice. A total of 229lines (BC2F2) derived from the cross of OM1490/WAB880-1-38-18-20-P1-HB was evaluated for drought at flowering (DRF), root dry weight (RDW), and root length (RL).Amicrosatellite map of this population was constructed with 232 markers to detect the linkage to the target traits. The map covered 2,553.7 cM with an average interval of 10.97 cM between marker loci. Markers associated with drought tolerance were located on chromosomes 2, 3, 4, 8, 9, 10 and 12. QTL mapping was used to determine effects of loci associated with drought tolerance traits. We also mapped QTLs for morphological attributes related to drought tolerance. Chi-square tests (χ2), single maker analysis (SMA), interval mapping (IM) were combined in the QTL analysis. All approaches used for QTL detection obtained similar results. QTLs were identified for drought tolerance with the emphasis on 2 QTLs for RL, and 2 QTLs for RDW. The proportion of phenotypic variation explained by each QTL ranged from 20.7% to 30.8% for dry root weight (DRW) and from 6.2 to 3.4% for morphological characters related to drought at flowering. This study  has provides  detailed information on the  potential of using marker-assisted selection for drought tolerance. 

Keywords:Drought,  interval mapping (IM), single marker analysis (SMA), QTL, chi-square tests (χ2), rice

From: SABRAO Journal of Breeding and Genetics

45 (3) 409-421, 2013 .