EVALUATION OF WHEAT GENOTYPES IN RESPONSE TO SALINITY

Abstract

Two experiments (Germination test & seedling growth, and pot experiment for yield) were carried out at laboratory and shade house, Department of Agronomy, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during Nobember 2013 to March 2014. For germination and seedling growth 22 wheat genotypes were tested in three salinity levels (0, 100 and 200 mM) for 10 days in sand culture in small plastic pot. Speed of germination as expressed by germination percentage (GP), rate of germination (GR), germination co-efficient (GC) and germination vigor index (GVI) of all wheat genotypes were delayed and germination percentage was reduced due to salinization compared to control. The lower reduction of GP, GR, GC and VI due to salinity was observed in BARI Gom 25, BARI Gom 27, Shatabdi, Sonora, and Akbar whereas higher reduction was recorded in BARI Gom 26, Duram, Triticale, Sufi and Kheri. Shoot and root lengths, fresh and dry weights were found to be affected due to salinization and shoot was more affected than root. Under saline conditions, longer shoot and root length was recorded in BARI Gom 25, BARI Gom 27, Akbar, and Shatabdi, i.e. less reduction of shoot and root lengths was observed, on the other hand, BARI Gom 26, Duram, Prodip and Triticale produced shorter shoot and root length. In this study, genotypes BARI Gom 25, BARI Gom 27, Shatabdi, Sonora and Aghrani showed better performance in terms shoot and root growth (fresh and dry weights) and proved to be tolerant genotypes to salinity. On the other hand, Duram, BARI Gom 26, Triticale, Kheri and Prodip were affected seriously in terms of fresh and dry weights by the saline environment. BARI Gom 25, BARI Gom 27, Shatabdi, Sonora and Aghrani showed more salt tolerance index (STI) based on shoot dry weight while BARI Gom 26, Triticale, Durum, Sufi, Prodip and Kalyanson demonstrated lower STI value under saline conditions. Results on germination and seedling growth indicate that BARI Gom 25 and BARI Gom 27 performed well but BARI Gom 26 and Durum were affected more than other genotypes under salinity stress. After screening from experiment-1, BARI Gom 25 appeared as the most salt tolerant and BARI Gom 26 as the most salt sensitive genotype. Therefore, the yield performance of these two genotypes BARI Gom 25 and BARI Gom 26 was evaluated in three saline conditions (0, 75 and 150 mM NaCl). With the increase in salinity level, days to first heading and maturity were reduced and BARI Gom 25 showed lesser reduction than BARI Gom 26 at 150 mM NaCl. BARI Gom 26 was affected more in its plant height, tiller production, spike length, spike plant’, spikelet spike”, grain dry weight spike", 100 grain weight, and finally grain yield plant under saline condition than BARI Gom 25. Considering the results of both experiments, it can be concluded that the BARI Gom 25 could be treated as the most salt tolerant and BARI Gom 26 as the most salt sensitive genotypes.