Overlapping quantitative trait loci indication of similarity of rice response to various stresses

Abstract

Combing stresses tolerance and grain yield is key for rice breeding to cope with the effect of climate change. The objective of this study was identify; lines resistant to multiple stresses and chromosomal segments containing QTLs conferring tolerance to both abiotic and biotic stresses Results revealed that, ratio of trait value under stress to normal conditions indicated that grain yield (GY) was the most affected trait by the stresses while grain size related traits were the least affected. Within the 29 regions harboring 50 overlapping QTLs, 39 QTLs were detected under drought, cold and bacterial blight stresses and 11 QTLs were stress specific. Overlapping regions harboring QTLs controlling multiples traits in different genetic backgrounds and in four environments (drought, cold, bacterial blight and normal condition (DCBN) were detected. Several lines offering resistance to both abiotic and biotic stresses were also observed. The study indicated that to some degree, plants respond to various stresses in a similar way. It also indicated that drought, BB and low temperature tolerance can be improved simulteniously, while retaining economical yield under stress; and at the same time higher yield during favorable conditions.

Key words: Bacterial blight, cold stress, Oryza sativa