Abstract
Screening of 60 wheat genotypes against drought was done in a pot experiment at the Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during 2004-2005. The wheat genotypes were grown under 50% field capacity and 100% field capacity soil moisture conditions. Based on total dry matter production, grain yield and drought indexing parameters such as dry matter stress index (DMSI), yield stability (YS) and drought susceptibility index (DSI) the genotypes V42, V16 and V60 were found to be tolerant, V6, V36, V56 and V41 moderately tolerant and V29, V28, V30, and V4 susceptible to water tress. The second year pot culture experiment was carried out for morpho-physiological studies of wheat genotypes selected from the performance of 1st year trial. A total of 7 genotypes were grown with different soil moisture regimes viz. 50% field capacity, 75% field capacity and 100% field capacity conditions. Variation among the genotypes in respect of plant height, tillers plant', leaf area, TDM plant', harvest index, root characters, CGR, RGR, NAR and yield was significant. Soil moisture stress caused significant reduction in above mentioned parameters. The extent of reduction of different plant parameters increased with the increase of drought severity and the highest reduction was found at 50% FC. Genotypes V42 and V16 appeared to be drought tolerant indicating the least grain yield reduction. Drought tolerant genotypes showed higher CGR and RGR and TDM compared to susceptible genotypes which contributed higher TDM plant under water stress condition. The drought susceptible genotypes, V29 and V47, had the highest reduction in grain yield and TDM. Genotype V56 also performed better under moderate and severe stress conditions with comparatively less reduction in grain yield and TDM. The preliminary field observation trial with 12 selected wheat genotypes grown under rainfed and irrigated condition showed that plant growth, yield and yield contributing characters were considerably reduced due to soil moisture stress. However, genotypes V42 and V16 showed better performance in respect of yield and other growth parameters under moisture stress condition. Genotypes V29 and V47 showed highest reduction in grain yield under rainfed condition. A multilocation field trial was conducted at BARI, Joydebpur, Gazipur; at ARS, BARI, Rangpur and at RWRC, Shympur, Rajshahi with promising drought tolerant wheat genotypes under rainfed condition. The genotype V42 appeared as the most promising genotype under rainfed condition in all locations showing the lowest grain yield. reduction. Similarly, V16, V60 and V56 also produced satisfactory yield in rainfed condition. whereas the genotype V29 was the most susceptible to drought followed by V47 in all locations. Overall results of screening, physio-morphological study, preliminary field observation and multilocation field trial indicate that V42, V16 and V60 are found promising wheat genotypes against drought and achieving satisfactory grain yield under drought condition.