سهم انتقال مجدد در پرشدن دانه ژنوتیپ‌های گندم نان

To determine the contribution of stem components on grain filling of bread wheat genotypes under source restriction Condition, an experiment was conducted at Agricultural Research Station of Islamabad-e-Garb on 2012-13 cropping cycle. Four bread-wheat cultivars (Karim, Orum, Pishgam, and Sivand) and two lines (DN-11 and Cross of Sabalan) and also Sardari (as check) were planted as Randomized Complete Block Design with three replicates on two separate sites as source restriction versus normal conditions. Grain yield, biological yield, harvest index, seed number per spike, grain weight, plant height, peduncle dry weight, Penultimate internode dry weight and remobilization of reserved substrates from stem internodes to main sink (grain) were measured. Results showed that stem reserved substrate of genotypes at normal and also source restriction had a high impact on grain weight. Thousand kernel weight was significantly reduced at source limitation, Sivand and DN-11 cultivars had the most and least thousand kernel weight, respectively. Peduncle and Penultimate Internode allocations on grain filling were 32.17% and 22.89% respectively. It seems that by induction of source restriction the remobilization allocation on grin weight was increased (10%). The results of this study indicated that thousand kernel weight is highly correlated with yield and can be used on selection of superior genotypes for grain yield improvement.