Molecular mapping of QTLs for yield and its components under two water supply conditions in rice (Oryza sativa L.)

Abstract

Moisture stress is the major constraint to rice production and its stability in rainfed, mainly irrigated, and aerobic environments. Identification of genomic regions conferring tolerance to stress would improve our understanding of the genetics of stress response and result in the development of drought tolerant cultivars. In the present study, quantitative trait loci for drought response related traits and as well as grain yield were identified using a set of 140 recombinant inbred lines derived from a cross between the popular high-yielding variety, IR64 and the landrace, INRC10192. A total of 36 QTL were identified for grain yield and its components under control and stress conditions. Strikingly, a QTL cluster flanked by the markers RM38 and RM331 on chromosome 8 was found to be associated with grain yield, plant height, no. of productive tillers, chaffy grains, and spikelet fertility on secondary rachis and biomass under stress treatment. The genomic regions associated with these QTL under drought stress will be useful for the development of marker-based breeding for drought tolerant, high-yielding varieties suited to drought-prone areas.Drought is the most devastating among abiotic stresses and it depresses yield by 15 -50% depending on the vigor and period of stress in rice. In the course of origin, domestication, and further evolution of rice, natural selection has been in favor of retaining traits of adaptability for its survival, whereas breeding by man has been towards selective improvement of traits of agronomic value such as higher yield, duration of choice, plant type, etc. Detailed studies of drought tolerance have enabled us to understand the physiological responses of plants, although our understanding of its genetic basis remains poor. Like yield and its components, traits that confer tolerance to the stress, directly or indirectly, are controlled by many genes, with each contributing a relatively small effect on the overall phenotype.Most of the past efforts to combine drought tolerance in highyield backgrounds have been a futile exercise, largely because of its genetically complex nature and lack of precise screening or selection protocols. Availability of high density marker linkage maps, annotated genome sequence, and powerful biometric methods has enabled identification and use of trait-specific genes/QTL for directed improvement of rice. It started with the pioneering discovery of yield QTL in wild/weedy species in rice by Xiao et al. (1998) closely followed by Brondani et al. (2002)

Development of Drought Resistance in Rice

“…Drought stress during the vegetative stage greatly reduced the plant growth and development (Farooq et al, 2009). Yield losses ranging from 15 to 50% has been reported (Srividhya et al, 2011). Chronic dry spells even for a short period affects the crop and it becomes more severe when flowering period coincides with the drought period (Boonjung and Fukai, 1996;Saini and Westgate, 2000;Pantuwan et al, 2002;Lanceras et al, 2004;Venuprasad et al, 2008;Sellamuthu et al, 2011;He and Serraj, 2012;Yadaw et al, 2013;Ha et al, 2016).…”

Evaluation of Recombinant Inbreed Lines (RIL) population of upland rice under stress and non stress conditions for grain yield and drought tolerance

“…Drought is a major abiotic stress that limits rice productivity in rainfed and upland ecosystems (Bimpong et al, 2011) and worldwide, drought affects approximately 27 million ha of rainfed. Drought reduces yield by 15-50 per cent depending on the stress intensity and crop growth period at which the stress occurs in rice (Srividhya et al, 2011). Eastern India, comprising Jharkhand, Orissa, and Chhattisgarh alone accounts loss of about 40 per cent of the total rice production due to severe drought (Pandey and Bhandari, 2009).…”

Screening of some rice varieties and landraces cultivated in Nigeria for drought tolerance based on phenotypic traits and their association with SSR polymorphism

“…Rice is most sensitive to drought stress during reproductive development at which time moderate water shortages can result in a significant reduction in grain yield (O'Toole, 1982;Venuprasad et al, 2008). The extent to which drought affects yield varies depending on the intensity and the time of occurrence of the stress within the crop growth cycle (Srividhya et al, 2011). Yield losses ranging from 15 to 50% have been reported (Pandey and Bhandari, 2009;Srividhya et al, 2011).…”

“…The extent to which drought affects yield varies depending on the intensity and the time of occurrence of the stress within the crop growth cycle (Srividhya et al, 2011). Yield losses ranging from 15 to 50% have been reported (Pandey and Bhandari, 2009;Srividhya et al, 2011). The situation becomes more serious with increasing global climate change.…”