Evaluation of Agronomic and Phenological Traits of Promising Rapeseed Lines in the Sistan Region

Extended abstract Introduction and Objective: In order to increase the motivation of farmers to cultivate open pollinated oilseed rape cultivars, new cultivars with appropriate yields should be introduced. Also, due to the effects of climate change, increase in temperature, early arrival of heat and intensification of drought stress at the end of the season in the warm and dry regions, it is also necessary to pay attention to traits such as early maturity in identifying oilseed rape genotypes. Accordingly, the purpose of this study is to identify the most desirable lines compatible with warm and dry climates. Materials and Methods: In order to investigate agronomic characteristics of the promising oilseed rape spring lines, an experiment was conducted with 21 spring genotypes in the Sistan region in a randomized complete block design with three replications during cropping season 2020-2021. Results: Analysis of variance showed that there are significant differences for traits including day to end of flowering, plant height, number of branches per plant, number of pods in sub-branches, number of pods per main stem, total number of pods per plant, main stem length, yield and biological yield among the studied genotypes. The study of broad sence heritability showed that phenological traits were more influenced by environmental factors; while quantitative traits of yield and its components were more influenced by genetic factors. Also, the number of branches per plant, the number of pods per main stem and grain yield had the highest values of genetic coefficients of variance, respectively. In addition, the number of pods per main stem, plant height, length of main stem, number of pods per plant, number of branches per plant, seed yield, day to end of flowering and biological yield, had the highest broad sense heritability among the studied traits, respectively. In terms of grain yield, G9 line (SRL-99-1) had the highest yield with a value of 2992 kg/ha. This genotype showed a significant difference with the control cultivar RGS003. Also, G11 (SRL-99-9), G2 (SRL-99-2), G1 (SRL-99-1), Dalgan,G18 ( SRL-99-16),  G20 (SRL-99-18), G21 (SRL-99-19)  and  G13 (SRL-99-11) lines were in the next ranks in terms of yield, respectively. Additionally, using various statistical methods such as mean comparison, principal component analysis and cluster analysis, lines were grouped based on the studied traits in this study. Conclusion:  In this study, 8 lines with desirable characteristics were identified. The superior lines which were identified in terms of yield and its components in this study, could be introduced as new lines compatible with the warm regions if the trend of superiority continues in adaptability tests.