بررسی اثر تنش خشکی در مرحله‌ی سنبله‌روی و رسیدگی فیزیولوژیک روی فتوسنتز جاری و انتقال مجدد مواد فتوسنتزی در لاین‌های هاپلوئید مضاعف شده‌ی جو

An experiment was carried out in Miyandoab agricultural research station with 42 barley doubled haploid lines in randomized complete blocks design with three replication and in two conditions of normal irrigation and stop irrigation at anthesis stage in 2011-2012. In order to determine the remobilized dry matter to grain, 10 full stems with leaves and spike were harvested randomly from each plot during anther appearance and physiological maturity. Then, total dry weight, dry weight of spike, leaf, first, second and the rest of internodes for both harvest stages and grain dry weight (just in physiological maturity) were measured. Results of stress condition showed non-significant difference for first, second and the rest of internodes. Dry matter remobilization, than rest of internodes, showed reduction for lines such as 3، 10، 26، 8 و 21 regard to normal condition and showed increases for lines such as 36، 4، 33، 28، 29، 34، 35، 6، 22 و 4. Increasing the proportion of transitional dry matter during remobilization process of studied sections was impressive in particular in lines number of22، 34، 33، 36، 38 and 40. This high increase is likely due to grain filling period of these lines with end-season heat stress is in addition to applied dry stress. Grouping of lines to cluster analysis procedure placed lines in four clusters in normal irrigation condition and in five clusters in drought stress condition.
Key words: carbohydrates remobilization, drought stress, physiological maturity and current photosynthesis.