Desiccation Tolerance and Its Relationship to Assimilate Partitioning in Winter Wheat

Abstract

Winter wheat (Triticum aestivum L.) is frequently subjected to stress that causes early senescence of plants and cessation of grain filling. This research evaluated chemical desiccation for selecting genotypes for tolerance to postanthesis stress and determined the relationship of chemical desiccation tolerance to carbohydrate and N partitioning. Twenty‐eight cultivars with a wide range of stress tolerance and yield potential were treated with 0 and 0.19 mol L‐1 NaCIO3 14 d after anthesis. The 2‐yr study was on a Eudora silt loam (coarse‐silty, mixed, mesic Fluventic Hapludoll); treatments were in randomized‐complete blocks with four replications. Ten cultivars representing a range of treatment responses were evaluated further at two locations on dryland and irrigated Eudora silt loam and Pratt loamy fine sand (sandy, mixed thermic Psammentic Haplustalf) in split plots with three replications. Cultivars that had high kernel weights and early release dates were generally more tolerant of chemical desiccation than cultivars with low kernel weights and recent release dates. Grain yields of chemically desiccated plants under irrigation correlated significantly with yields of untreated plants at one location but not at another location. Losses of dry matter and soluble carbohydrates, but not of N, from stems were related to grain yield response to chemical desiccation. We concluded that chemical desiccation effectively selects for postanthesis stress resistance, and that combining high carbohydrate reserves with efficient translocation to the grain should improve wheat performance in unfavorable environments.

Application of photochemical parameters and several indices based on phenotypical traits to assess intraspecific variation of oat (Avena sativa L.) tolerance to drought

“…Indices of sensitivity to drought stress (SI stress index, DSI drought susceptibility index) were calculated from the grain weight based on the yield per plant and D conditions (Y C and Y D ), both according to FAO reports Fischer and Maurer (1978) and Golbashy et al (2010). TOL-stress tolerance index according to Hossain et al (1990) and MP-mean productivity index according to Rosielle and Hamblin (1981).…”

Efficiency of Triple-SCoT Primer in Characterization of Genetic Diversity and Genotype-Specific Markers against SSR Fingerprint in Some Egyptian Barley Genotypes

“…These indices were calculated as mentioned in previous studies as follow; stress susceptibility index (SSI) [11], mean productivity (MP) [12], stress tolerance index (STI) and geometric mean productivity (GMP) [13], yield index (YI) [14], yield stability index (YSI) [15] and tolerance (TOL) [16].…”

Response of bread wheat genotypes to drought simulation under a mobile rain shelter in Kenya

“…Drought stress from heading to maturity gives greater reduction in grain yield than from emergence to tillering (Imityaz et al, 1990). However, post anthesis grain yield loss is associated with kernel abortion or reduction in kernel growth leading to fewer grains per head and low kernel weights (Hossain et al, 1990). Drought stress at seedling and flowering stages of maize is estimated to cause annual yield losses of about 17% in the tropics (Edmeades et al, 1997).…”