Source-sink relationship between photosynthetic organs and grain yield attributes during grain filling stage in spring wheat (Triticum aestivum)

Five spring wheat varieties were utilized to estimate the contribution of flag leaf and awns towards grain yield and its attributes. The characters associated with the photosynthetic activity were investigated in relation to the grain yield and its attributes. The present study revealed significant variation among different varieties, treatments and varieties × treatment. The treatments (removal of flag leaf, awns & both) caused considerable decrease in grain yield and its related characters. Flag leaf removal had less effect on yield and related components than awns detachment. Nonetheless the detachment of flag leaf + awns revealed greater effects than individual treatment. Flag leaf area, awn length, number of grains per spike and 1000 grain weight demonstrated positive and significant association with grain yield per plant. Number of grains per spike, grain weight per spike and 1000 grain weight exhibited the maximum heritability and genetic advance over different treatments. This study advocated the presence of strong source-sink association of both flag leaf and awns with grain yield hence these traits could be used as morphological markers for selection of wheat genotypes having superior photosynthetic activity and higher grain yield. © 2010 Friends Science Publishers