بررسي برخي خصوصيات مرفولوژيك و فيزيولوژيك موثر بر علكرد و اجزاءعملكرد ژنوتيپ هاي گندم تحت شرايط كم آبياري

Study of some morphological and physiological characteristics affecting grain yield and yield components in bread wheat genotypes under reduced irrigation

In order to determine the most important morphological and physiological traits associated with wheat grain yield. The study was conducted during 1999 and 2000 growing season in Koohdasht, with 10 spring bread wheat (Trtticum aestivum L.) genotypes. A Complete Randomized Block Design with four replications was used. The results showed that varieties were different in grain yield , straw yield , biological yield . spike weight.. l00() kernal weight and ODD needed to complete their phenological stages. However. there was significant difference in no. of spike. m6-2. The Zagros with 560 and the Pi.k/Opata with 360 g/m^ 2 produced the highest and lowest dry matter among genotypes, respectively .The Kasyan / Genaro8l line with maximum LAI (3.26) at anthesis produced the maximum grain yield (1583 kgha^-1), but Maya74"sʹʹ and Seri 82/lVeeʹʹs genotypes with minimum LAI (2.4) at anthesis stage produced lowest grain yield. Crop Growth Rate pattern was low in initial stage, then increased after receiving 500 GDD and maximum the CGR achieved after receiving 800-900 GDD at athesis stage. The maximum CGR belonged to Descenocido-7 and Davin-1 genotypes (1.3 gm-2, GDD^-1) an.d minimum CGR was related to Kvz/Bjy"s" and Maya 74"s" genotypes (0.89 gm^-2, GDD^-1) at anthesis stage. Strong relationship (r-90**) was established between maximum CGR and grain yield. The results showed that genotypes No.3, 4 and 10 performed better than the other in some physiological and agronomical charactristics.