ارزيابي محدوديت مخزن و سهم نسبي اندام هاي فتوسنتز كننده گندم در انباشت ماده خشك در دانه

Assessment of sink limitation and relative shares of different photosynthetic organs of wheat in grain filling

In order to determine the relative shares of different photosynthetic wheat parts for grain dry matter accumulation and their sink limitation, this study was conducted in from of a split plot experiment with complete randomized block design with three replications in Ahvaz Agricultural Research Station in 2001-2002 growing season .In this study, 10 wheat cultivars were considered as main factor and 4 phenotypic components manipulation treatment including awns removing of the whole spikes (-A), flag leaf removing (-FL) ,removing of leaves under flag leaf (-L) and spike covering (CO) were considered as sub factors . Means comparisons for phenotypic components manipulation factor showed that spike photosynthesis had highest relative shares in grain filling (15.93%). Also, 13.9, 12.1 and 11.9 percent of mean seed dry matter relative share belonged to flag leaf, leaves under flag leaf and awns respectively. Evaluation of sink limitation of studied cultivars showed that there was no sink limitation in these cultivars. CIMMYT cross line and Star cultivar had greatest sink limitation then other cultivars, although Dove and Chamran cultivars had lowest.