Root system plasticity to drought influences grain yield in bread wheat

Abstract

Crop productivity in semiarid regions is mainly limited by water availability. Root characteristics and plasticity to drought may reduce the negative impact of drought on crop yield. A set of near-isogenic wheat-rye translocation lines was used to test the hypothesis that root system plasticity to drought influences grain yield in wheat. Bread wheat Pavon 76 and 1RS translocation lines, namely Pavon 1RS.1AL, Pavon 1RS.1BL, and Pavon 1RS.1DL were evaluated for root allocation and plasticity in sandtube experiments under well-watered and droughted conditions across 2 years using factorial treatments in a randomized complete block design with four replicates. The 1RS translocation lines had greater root biomass per plant ranging from 7.37 to 8.6 compared to 5.81 g for Pavon 76. Only Pavon 76 showed a positive response to drought by producing more shallow roots (roots developed between 0 and 30 cm) and deep roots (roots developed below 30 cm) in droughted conditions than in well-watered conditions. Thus at drought intensity of 19% (measured as overall reduction in grain yield), grain yield in Pavon 76 was reduced only by 11% compared to the other genotypes with yield reductions ranging from 18 to 24%. However, at drought intensity of 36%, grain yield in Pavon 76 showed maximum reduction indicating that greater root production under drought is advantageous only when plant-available water is enough to support grain production. Grain yield was positively correlated with shallow and deep root weight and root biomass under terminal drought. Correlation coefficients between root system components (shallow and deep root weight and root biomass) and phenological periods were not significant. Our study indicated that genes influencing adaptive phenotypic plasticity of the root system to drought in Pavon 76 are located on chromosome 1BS.

Effect of Deficit Irrigation on Raised Bed Wheat Cultivation

“…Crop productivity in semi-arid regions is mainly limited by water availability (Ehdaie et al, 2011). Wheat, being the second cereal crop of Bangladesh, faces periods of water stress/drought due to shortage of water during the months of December to second decade of February.…”

Polyethylene Glycol (PEG)-Treated Hydroponic Culture Reduces Length and Diameter of Root Hairs of Wheat Varieties

“…Extensive research efforts over the last five decades revealed physiological mechanisms relevant to osmotic stress response of crop plants [8][9][10][11][12][13]. Awareness related to root morphology of annual crop plants, such as wheat, barley, or perennial forage grasses under limited water supply, has developed within the last 20 years [14][15][16][17][18][19][20][21][22][23]. However, little awareness has been created as to how root hairs get modified, and are possibly associated with crop yield under different levels of osmotic potential.…”

Root trait characteristics and genotypic response in wheat under different water regimes

“…Waines and Ehdaie (2007) also reported that root characters may be integrated in to components of yield analysis in wheat. Ehdaie et al (2012) observed that genotypes with increased root biomass had higher grain yields under terminal drought due to the greater root system plasticity in response to drought. Our studies corroborates with these hypothesis that the genotypic variability on the basis of their root system response to well watered and water deficit conditions can be used to identify superior genotypes with high yield potential.…”

“…Phenotypic plasticity of roots influences the response of genotypes to drought conditions (Ehdaie et al 2012). Root biomass and its component traits had positive correlations with Cereal Research Communications 42, 2014 grain yield under drought.…”

“…Genotypic differences have been observed among wheat cultivars for root length density (Mian et al 1994), root distribution, post-anthesis root growth (Ford et al 2006), root angle and seminal root number (Manschadi et al 2006(Manschadi et al , 2008, and partitioning of assimilate to deep roots (Lopes and Reynolds 2010). Ehdaie et al (2012) observed the phenotypic plasticity response of root system on grain yields in wheat and its translocation lines under drought conditions and found positive correlations between root system components and grain yields. Genomic associations with quantitative trait loci for better root systems for higher productivity and water use efficiency have recently been reported in wheat (Sharma et al 2011;Kadam et al 2012).…”