Yield stability of selected rice breeding lines and donors across conditions of mild to moderately severe drought stress

Abstract

Although mild to moderately severe drought stress may have less of an effect on rice grain yield than severe drought stress during reproductive stage, its prevalence across rice farmers’ fields at the global level may be more economically significant. In this study, field experiments were conducted on selected genotypes with known tolerance to severe reproductive-stage drought in order to identify those that would produce high and stable grain yield across seasons and soil moisture conditions varying from well-watered to mild and moderately severe drought stress. Mild stress generally occurred during wet seasons and moderate stress happened during dry seasons. The drought stress was mild enough such that the time to flowering was similar under drought stress and well-watered conditions in either season. However, significant grain yield reductions were incurred even at mild drought levels. Using an AMMI1 biplot analysis, IR83142-B-7-B-B, Binuhangin, IR77298-14-1-2-13, IR70215-70-CPA-3-4-1-3 and IR77298-14-1-2 were identified as the genotypes with the highest and most stable grain yields in both well-watered and mild to moderately severe drought stress environments. In a characterization of traits conferring drought tolerance among the highest yielding genotypes under mild to moderate drought stress, genotypes Binuhangin and IR70215-70-CPA-3-4-1-3 stood out for multiple physiological traits under drought. However, no direct correlations among genotypes between stomatal conductance, normalized difference vegetation index (NDVI) or root dry weight with grain or total dry matter yield were observed under any soil moisture level. These results reflect the complex interaction of drought response traits contributing to grain yield. The genotypic variation and physiological responses observed in this study point to the potential of developing varieties targeted to mild and moderate drought stress using yield as the selection criterion.

Phenological, Physiological and yield markers as efficient tools to identify drought tolerant rice genotypes in Eastern India

“…Soil moisture tension during the stress was -47.83 kPa and -54.55 kPa in 2017 and 2018. Torres et al (2018) reported similar results of occurring moderate to severe stress when soil moisture tension drops below -50 kPa. Drought stress at vegetative stage reduces water content and lower leaf water potential, leading to reduce turgor, stomatal conductance, and photosynthesis, and ultimately reduce grain yield (Akbarian et al, 2011;Amini et al, 2014).…”

l-tryptophan-assisted PGPR-mediated induction of drought tolerance in maize (Zea maysL.)

“…The decrease in rainfall, increase in atmospheric CO 2 and more extreme weather events accompanied by a 1.5-4.5°C increase in temperature are expected in the next 100 years (Torres and Henry, 2016). Agriculture sector is severely affected by drought stress widespread in the arid and semi-arid area resulting in prominent loss of yield and production of agricultural crops.…”

Ratooning as a management strategy for lodged or drought‐damaged rice crops

“…However, it should be noted that the observed differences in postharvest ratoon tillering ability do not necessarily reflect differences in ratoon crop yield. Genotypes showing the highest levels of ratoon crop productivity included both relatively drought-susceptible as well as drought-tolerant released varieties based on previous evaluations (Torres & Henry, 2018). Interestingly, genotypes Binuhangin and IR87707-445-B-B-B (released as the variety DRR 42 in India) have both stood out as having high grain yield under drought in previous reports (Swamy et al, 2013;Torres, McNally, Vera Cruz, Serraj, & Henry, 2013) and have shown some similarities in their physiology in terms of low canopy temperature and deep root growth compared with other genotypes (Henry et al, 2015;Torres & Henry, 2018).…”

“…To characterize postharvest ratooning, two sets of genotypes ( Supplemental Table S1) were selected from drought screening trials in the 2012 dry season (DS) (reported by Torres & Henry, 2018) based on their contrasting yield under drought (the "drought resistance" set) or their contrasting ratooning ability (the "ratooner" set), which was assessed after harvest of the trial. Separate experiments on postharvest ratooning were conducted on these two sets of genotypes in two consecutive dry seasons and wet seasons (WS) from 2013WS to 2015DS.…”