The genetic basis of spectral reflectance indices in drought stressed wheat
Drought imposes a major constraint over the productivity of wheat, particularly in arid and semi arid production zones. Here, the genetic basis of spectral reflectance indices was investigated in drought stressed wheat by comparing, under two contrasting moisture regimes, the performance of an F6 recombinant inbred line (RIL) population bred from a cross between the drought tolerant cultivar Pavon76 and the sensitive cultivar Yecora Rojo. The parents and RILs were genotyped with respect to both a set of microsatellite (SSR) loci and a number of known drought responsive genes. In all, 28 quantitative trait loci (QTL) controlling dry weight per plant, water content of the above ground biomass, leaf water potential, canopy temperature, and spectral reflectance indices traits were identified. The loci were distributed over 11 chromosomes, belonging to each of the three wheat sub genomes. There were important location flanking markers Barc109 and Barac4 on chromosome 5B relating to dry weight per plant accumulation under the limited irrigation regime. The same region harbored QTL associated with leaf water potential, canopy temperature, and ratio index under the limited irrigation regime. Linkage between the known drought responsive genes and aspects of the drought response was established. Some of QTL were of substantial enough effect for their linked markers to be likely usable for the marker assisted breeding of drought tolerance in wheat.
Acta Physiologiae Plantarum