Variation of grain yield and agronomic traits of Brassica napus L. cultivars under salt stress

Salt stress is one of the most critical factors impacting plant growth and yield. The aims of this study were to assess the effect of salt stress on grain yield and some agronomic traits of canola (Brassica napus L.). Five spring canola cultivars including Sarigol, Delgan, Zaffar, Zarfam and RGS003 were selected and treated with 6% and 20% sodium chloride. A factorial experiment based on randomized complete block design (RCBD) with three replications was performed. Main effects of cultivar, NaCl stress and interaction of NaCl stress × cultivar in all agronomic traits were significant at 0.01 probability level. The highest and the lowest seed yield was found in Delgan and Zarfam, respectively. The highest thousand-seed weight of Sarigol, Delgan, Zaffar and RGS003 was found in the control condition while in Zarfam cultivar was found under 6% NaCl treatment. In Sarigol and Zarfam cultivars the largest number of pods were found under 20% and %6 of NaCl treatments. Stepwise multiple linear regression analysis showed that grain weight per pod and number of pods per plant had the highest effect on grain yield and explained 95% of grain yield variations. Factor analysis based on principal component analysis showed that four factors explained 80.81% of total variations. The first factor explained 36.07% of total variance and was named as an effective factor on vegetation growth. The second factor explained 16.28% of the variation and was identified as the grain yield and its components factor. In this research, Sarigol cultivar was introduced as the most tolerant cultivar due to the highest grain yield under NaCl stress conditions.