Evaluation of Bitter Vetch Lines Under Irrigated and Rainfed Conditions

In order to determine the most promising lines of bitter vetch regarding drought tolerance in rainfed areas، an experiment was conducted with 16 lines، under irrigated and rainfed conditions at Dryland Agriculture Research Institute، Maragheh. A randomized complete block design with three replications was used for each experiment. Analysis of variance for both rainfed and irrigated conditions showed that there were significant differences between lines for all studied traits. Combined analysis of variance indicated significant differences between two environments for all traits except plant height. Genotype × environment interaction was significant for all traits، except for plant height، pod number per plant and seed number per pod. Comparing means under irrigated and rainfed conditions showed that Sel 2518 had the lowest number of days to flowering and Sel 2515 and Sel 2516 had shorter period of grain filling. Local bitter vetch possessed the highest plant height، biomass، number of pods per plant and seed yield. Biomass، number of pods per plant and plant height had highest correlations with seed yield in both conditions. According to three drought tolerance indices (STI، GMO and MP)، the local landrace was recognized as the most drought tolerant line with ability to produce highest yield in both rainfed and irrigated environments. This landrace was separated from other lines in the cluster analysis. In some cases، lines Sel 2644 and Sel 2647، originated from Bulgaria، were grouped with the local landrace. The results indicate that the local landrace was more productive than other lines under study and therefore، it is possible to identify suitable varieties for cultivation by evaluating different landraces of bitter vetch.