رابطه خصوصيات مورفولوژيكي ريشه با مقاومت به كمبود آب در تعدادي از ژنوتيپ هاي كلزا BRASSICANAPUS. L.( )

Association of Root Morphological Characters with Resistance to Water Deficit in Some Rapeseed Genotypes (Brassica napus L.)

Root depth and spreading have an important role in drought resistance and better use of soil moisture. This experiment was conducted to study the root characters and their impact on drought resistance. Genetic material constituted of Global, Puma, Regent, Eureka and PF 7045.91 from napus species, Sonja and Parkland from rapa species and two hybrids, Hyola308 and Hyola44l. The experiment was carried out under normal and water deficit conditions, arranged in randomized complete block design with eight replications. Water deficit was imposed by stopping the irrigation at 50% flowering. The results showed significant differences between two conditions as well as between genotypes with respect to most of the characters studied. Among cultivars Global had higher plant height, shoot dry weight and the number of silique than others, followed by Puma and PF 7045.9I. These three cultivars had the highest maximum root length, root volume and root thickness. Puma was able to modify its root system under water deficit condition and gained adaptive/ inducible characters to compensate drought. Maximum root length was highly and positively correlated with root to shoot dry weight ratio and root to shoot length ratio under water deficit condition. Canonical correlation analysis showed high correlation between root morphological traits and shoot related characters in normal as well as water deficit conditions.