بررسی روند تغییرات عملکرد، اجزای آن و انتقال مجدد مواد فتوسنتزی در ژنوتیپ های اصلاح شده گندم نان در اقلیم سرد

In order to study the trend yield, yield components and assimillate remobilization in bread wheat genotypes developed for cold climate regions , the present investigation was caaried out in randomized complete block design with 20 treatments and three replications at Torogh agricultural research station during 2012-2013 growing seasons. The tested genotypes include 4 groups: group 1 consits bread wheat cultivars released before 1960s (cv. Omid, Roshan and Bezostaya), group 2 consits the cultivars released in 1990s (cv. Alamout and Alvand), group 3 consits the cultivars released in 2000s (cv. Toos, Orum, Zareh and Mihan) and group 4 consits 11 promissing lines from the EWYT-90. The results showed that the highest and the lowest grain yeild were belong to genotype 11 with 8 t/ha and the genotype Omid with 3.806 t/ha respectively. Grain yeild were increased from 4.510 t/ha in old varities (group 1) to 7.415 t/ha in promissing lines (group 4). The number of fertile spikes per/m2, kernels per spike and harvest index significantly increased in new varities compared to the old varities. Our results indicated there was no significant difference between old and new varities in TKW, so the improvment trend of kernel weight per spike( from 0.86 to 1.09 g) is related to increasing of kernels per spike. The results showed that the assimillate remobilization trend decreased and remobilization efficiency incresed from old to new varities. Aassimillate remobilization significantly decreased from 11.3% in group 1(cv. Omid, Roshan and Bezostaya) to 8.5% in group 4 (promissing lines). Remobilization efficiency showed an increased trend from 10.8% in old varities (group 1) 17.8% in group 4 (promissing lines).