Golgi/plastid‐type manganese superoxide dismutase involved in heat‐stress tolerance during grain filling of rice

AbstractAddressing the impact of heat stress during flowering and grain filling is critical to sustaining wheat productivity to meet a steadily increasing demand from a rapidly growing world population. Crop wild progenitor species of wheat possess a wealth of genetic diversity for several biotic and abiotic stresses, and morphological traits and can serve as valuable donors. The transfer of useful variation from the diploid progenitor, Aegilops tauschii, to hexaploid wheat can be done through the generation of synthetic hexaploid wheat (SHW). The present study targeted the identification of potential primary SHWs to introduce new genetic variability for heat stress tolerance. Selected SHWs were screened for different yield-associated traits along with three advanced breeding lines and durum parents as checks for assessing terminal heat stress tolerance under timely and late sown conditions for two consecutive seasons. Heat tolerance index based on the number of productive tillers and thousand grain weight indicated that three synthetics, syn9809 (64.32, 78.80), syn14128 (50.30, 78.28) and syn14135 (58.16, 76.03), were able to endure terminal heat stress better than other SHWs as well as checks. One of these synthetics, syn14128, recorded a minimum reduction in thousand kernel weight (21%), chlorophyll content (2.56%), grain width (1.07%) despite minimum grain-filling duration (36.15 d) and has been selected as a potential candidate for introducing the terminal heat stress tolerance in wheat breeding programmes. Breeding efforts using these candidate donors will help develop lines with a higher potential to express the desired heat stress-tolerant phenotype under field conditions.

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Evaluation of Spring Wheat Genotypes (Triticum Aestivum L.) for Heat Stress Tolerance Using Different Stress Tolerance Indices

Cercetari Agronomice in Moldova ◽

10.1515/cerce-2015-0004 ◽

2015 ◽

Vol 47 (4) ◽

pp. 49-63 ◽

Cited By ~ 5

Author(s):

A.A. Khan ◽

M.R. Kabir

Keyword(s):

Heat Stress ◽

Grain Yield ◽

Stress Tolerance ◽

Spring Wheat ◽

Grain Filling ◽

Filling Rate ◽

Wheat Genotypes ◽

Grain Filling Rate ◽

Heat Stress Tolerance ◽

Late Sowing

Abstract Twenty five spring wheat genotypes were evaluated for terminal heat stress tolerance in field environments in the Agro Ecological Zone-11 of Bangladesh, during 2009-2010 cropping season. The experiments were conducted at Wheat Research Centre, Bangladesh Agricultural Research Institute, using randomized block design with three replicates under non-stress (optimum sowing) and stress (late sowing) conditions. Seven selection indices for stress tolerance including mean productivity (MP), geometric mean productivity (GMP), tolerance (TOL), yield index (YI), yield stability index (YSI), stress tolerance index (STI) and stress susceptibility index (SSI) were calculated based on grain yield of wheat under optimum and late sowing conditions. The results revealed significant variations due to genotypes for all characters in two sowing conditions. Principal component analysis revealed that the first PCA explained 0.64 of the variation with MP, GMP, YI and STI. Using MP, GMP, YI and STI, the genotypes G-05 and G-22 were found to be the best genotypes with relatively high yield and suitable for both optimum and late heat stressed conditions. The indices SSI, YSI and TOL could be useful parameters in discriminating the tolerant genotypes (G-12, G-13, and G-14) that might be recommended for heat stressed conditions. It is also concluded from the present studies that biomass, grain filling rate and spikes number m-2 are suitable for selecting the best genotypes under optimum and late sowing conditions because these parameters are highly correlated with MP, GMP, YI and STI. However, high ground cover with long pre heading stage and having high grain filling rate would made a genotype tolerant to late heat to attain a high grain yield in wheat.

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