بررسي برخي خصوصيات مرفولوژيك موثر بر عملكرد و اجزاء عملكرد ژنوتيپ هاي لوبيا تحت شرايط كم آبياري

A Study of Some Morphological Characteristics Affecting Grain Yield and Yield Components in Bean under Reduced Irrigation

In order to study the phenotypic and genotypic variation of important agronomic traits associated with yield, 45 genotypes of White, Red and Chiti beans were evaluated. A group balanced randomized complete block design of 3 replications in two environments of under water stress, and non stress conditions wa carried out in Mashad Agricultural Research Station in 2003. Fourteen morphological traits related to yield were considered. Analysis of variance showed that there were significant differences among genotypes, indicating the existence of genetic variation. The results indicated that seed yield, number of seeds per plant, number of pods, and biological yield were reduced in stress conditions. In non-stress conditions, yield was highly correlated with biological yield and the number of seeds per plant, whereas in stress conditions it was highly correlated with harvest index. Factor analysis was accomplished in non stress and water stress conditions. There were 4 factors that explained 67 percent of variance in non stress conditions and there were 5 factors that explained 66 percent of total variations in stress conditions. Results of stepwise regression and path analysis showed that, selection can be done based on harvest index, biological yield, number of seeds per plant, number of seeds per pod, and 100-seed weight. Results of path analysis showed that the highest direct effect, being positive, was related to biological yield, number of seeds per plant in non stress and to harvest index in stress conditions. In classification of genotypes based on phenotypic characteristics, using cluster analysis (UPGMA), all of the 45 genotypes were classified in 8 separate groups in non stress and 7 separate groups in stress conditions.