Evaluation for adaptive thermo-tolerance in spring wheat ( Triticum aestivum L.) genotypes under natural stress

摘要

Fifteen genotypes of spring wheat ( Triticum aestivum L.) including eleven commercial cultivars, three landraces, and one Mexican variety were evaluated in an entirely different mega-environment with harsh natural stress. The plants experienced a hot and humid climate during the vegetative and reproductive stages. Three different sowing dates one-month apart were employed to all the genotypes to experience, in replications, three different regimes of harsh environmental conditions that would allow all the developmental and reproductive stages to experience high-temperature stress. It was hypothesized that all the genotypes do not have the same strategy to cope with the conditions and some must do better than others though none of them had been developed for this typical climate. Though all the genotypes were adversely affected due to delayed sowings, few showed some stability in the yield and yield components whereas others managed their green leaf status for a relatively longer duration. It has been learned that spring wheat has adaptive potential to be cultivated in warm-dry tropical weather with irrigation and certain genotypes may be used for a breeding program of wheat with abiotic stress tolerance for such geographical zone.