Morpho-physiological character association studies of seedling traits in ten wheat (Triticum aestivum L.) genotypes under osmotic stress conditions

Abstract

In the past, many environmental stress especially water stress, negatively influenced the productivity and production of wheat (Triticum aestivum L.), one of the most important cereal crop in the world. Breeding current high yielding water stress tolerant wheat genotypes is a research priority specifically for these regions where climate change is predicted to result in more water stress conditions. A strategy that evaluates genotypes for physiological responses to water stress at earlier growth stages may be more targeted to water stress. Therefore, present investigation, ten wheat genotypes were screened following a completely randomized design under controlled condition. Different concentrations of PEG-6000 were used to induce osmotic stress at the germination growth stage. The analysis of variance indicated that significant differences among treatments for all seedling traits. All genotypes also differed significantly in germination percentage, shoot and root length, fresh and dry weight of shoot and root. Significant treatment interaction revealed that genotypes responded variably to osmotic stress treatments; hence provided better opportunity to select a water stress tolerant genotype at seedling growth stages. Data revealed a decreasing trend in values for all traits with the increasing concentration of PEG-6000. The relative minimum decrease over average due to osmotic stress was 9.04 percent in seed germination, 20.58 percent in shoot length, 9.01 percent in root length, 10.04 percent in shoot fresh weight, 3.30 percent in shoot dry weight, 11.57 percent in root fresh weight and 11.01 percent in root dry weight. However, relative decrease of individual genotype for various seedling traits might be more meaningful which indicated that genotype AKAW-5017 showed minimum reduction in root length, fresh root weight, dry root weight, fresh shoot weight and dry shoot weight while the minimum decline of seed germination and shoot length observed in AKAW- 3717. However, AKAW-4842, AKAW- 4907, and AKAW-4926 gave almost equally lower reduction for seed germination, root length, and shoot length and were consider as water stress tolerant. Correlation coefficient studies revealed considerable and positive correlation among seedling traits. The result indicated that increase in one trait may cause a simultaneous an increase in other traits; hence, selection for any of these seedling attributes will lead to developing water stress tolerant wheat genotypes.