A study on source-sink relationship, photosynthetic ratio of different organs on Yield and Yield Components in bread wheat (Triticum aestivum L.)

ABSTRACT: Wheat is an important crop whose research in this aspect is highly noticeable related to food quality. In order to determine, effect of yield components position on wheat and the effect of each part of these components on increasing seed yield, A farm experiment was conducted at Agriculture Research station of Firoz Abad ,Fars, in Iran during autumn 2008-2009 (located at 52°, 15´N & 52°, 40S) and 1876 m altitude to evaluate source-sink relationship, photosynthetic ratio of different organs on Yield and Yield Components in bread wheat (Triticum aestivum L). the Experiment was done to split plot and randomized complete blocks (RCB) in three replications and consisted of 20 treatments. In addition, main plots were consisted of four wheat cultivars (V1: PISHTAZ, V2: SHIRZ, V3:DARAB2 and V4: NIKNEJAD) and sub plots included five phonotypical manipulation treatment (P1: Control, P2: Awns cutting, P3: flag cutting, P4: Cutting of the leaves which is below the flag leaf and P5: Spike covering), respectively. The results demonstrate the maximum number of spike and number grain per spike and 1000- kernel weight were regarding to DARAB2 and NIKNEJAD cultivars, respectively. At finally this fact cause dry matter and seed yield were increased. There was significant difference between mainpluting treatment and control. Conclusively, Darab 2 and Niknejad cultivars are the best cultivars for achieve to high yield. Results of analysis of variance (ANOVA) showed that was excelsior than others in all traits. In this study result indicate awn cutting, flag leaf and spike covering cause1000-kernel weight, grain yield, biological yield and harvest index were decreased. The ratio of different organs on Yield and Yield Components in bread wheat cultivars was illustrated that maximum 1000- kernel weight and seed yield relating to spike photosynthetic which covering spike minimum 1000-kernel was obtained Minimum ratio in this trait was relating to cutting of the leaves which is below the flag leaf treatment. In present study, evaluation cultivars sink limitation was emphasized that none of cultivars sink limitation, but all of them were source limitation.