Abstract:

The study explored the development trend of oilseed rape variety selection and breeding, aiming to provide reference for breeding direction of rape. This study was conducted by compiling information on 594 registered kale type winter oilseed rape varieties in China from 2017—2021 to comprehensively analyze the change patterns and correlations of relevant traits of registered varieties. The results showed that: the growth period of the registered varieties presented a shortening trend, with an average annual shortening of 2.3 days; the yield of the varieties had an increasing trend, with an average annual increase of 60.90 kg/hm²; the main traits of plant height, thousand-seed weight and oil content showed an increasing trend with an average annual increase of 2.83 cm, 0.07% and 0.67%, respectively; the changes of the remaining traits were relatively stable. Correlation analysis showed that the growth period was highly significantly and positively correlated with the number of siliques per plant, seeds per silique, and yield; the yield was closely correlated with seeds per silique and thousand-seed weight; and the different synergistic effects among the remaining traits together constituted variety specificity, consistency and stability. Principal component analysis (PCA) screened out five principal components with a cumulative contribution of 71.44% to the overall variance, of which effective number of branches, the number of siliques per plant, seeds per silique, thousand-seed weight and erucic acid were the main factors responsible for the differences among these varieties. In general, the Brassicanapus varieties bred in recent years are more early maturing and have steadily improved yield and oil content. Future breeding objectives should focus on improving traits such as thousand-seed weight, seeds per silique and oil content.

Key words: Brassicanapus, yield, trait evolution, genetic improvement, PCA analysis