نشریه پژوهشهای زراعی ایران
سال دهم شماره 3 (پیاپی 27، پاییز 1391)

Jujube (Ziziphus jujuba Mill.) is a valuable medicinal plant which is important in Iranian traditional medicines. Although the regional plants such as jujube play an important role in our economy، but they are forgotten in research and technology. Considering the economic and medicinal importance of jujube، the first step in breeding programs is determination of the genetic diversity among the individuals. 34 ecotypes of jujube، which have been collected from eight provinces of Iran، were used in this study. The genetic relationships of Iranian jujube ecotypes were analyzed using Random Amplified Polymorphic DNA (RAPD) marker. Six out of 15 random decamer primers applied for RAPD analysis، showed an informative polymorphism. According to clustering analysis using UPGMA''s methods، the ecotypes were classified into two major groups at the 0. 81 level of genetic similarity. The highest value of similarity coefficient (0. 92) was detected between Mazandaran and Golestan ecotypes and the most genetic diversity was observed in ecotypes of Khorasan-Jonoubi. The affinity of Khorasan-Jonoubi and Esfahan ecotypes indicated a possible common origin for the variation in these areas. Results indicated that RAPD analysis could be successfully used for the estimation of genetic diversity among Ziziphus ecotypes and it can be useful for further investigations.

Plant photosynthetate partitioning is important in seed yield formation. In this research، in order to study grain filling procedure of chickpea in the presense of drought stress and nitrogen (N) fertilizer on remobilization rate، final grain weight and grain yield were measured. Experiment was performed in an split-factorial using randomized complete block design with three replications. Drought stress treatment stand in main plots in three levels consist of no drought stress (complete irrigation)، moderate drought stress (irrigation at planting and early flowering) and severe drought stress (no irrigation). Nitrogen fertilizer in two levels (0kg N/ha and 25kg N/ha) and four chickpea cultivars (Azad، Hashem، ILC482 genotype and endemic mass of Bivanij) stand in sub plots. The results showed that that drought stress had significant effect on all the characters and all the characters except the remobilization and its efficiency was significant. Also، with increasing drought stress، remobilization amount، share and efficiency and rate of grain filling rate increased but duration of grain filling، final grain weight and grain yield was decreased and dry matter accumulation was lessIn non stress condition، during the growing season of chickpea was higher and Assimilate accumulation in it was higher، ultimately lead to increasing in final grain weight and grain yield per unit area. Effect of nitrogen fertilizer on stem dry weight and remobilization of it was significant and with application of N fertilizer these traits were reduced.