Abstract:

The paper aims to promote the development of rapeseed industry and to increase the self-sufficiency rate of vegetable oil in China. Early-maturing oilseed rape varieties with excellent resistance were screened in this study, and physiological and agronomic traits of 24 early-maturing kale-type oilseed rape varieties (materials) were analyzed at the seedling stage, 5-6 leaf stage, 7-8 leaf stage, bud and shoot stage, and harvesting stage, to clarify the relationship between early-maturing traits and physiological traits. The results showed that the agronomic characteristics of ‘Fanming youtai’ in the pre-winter seedling stage had a smaller gap with other early-maturing rapeseed, which was better than that of the parent ‘WH23’, and had a good growth performance; the plant height was higher than that of 95% of the reference materials, and number of seeds per pods was higher than that of 83% of the reference materials; the rapeseed oil content was the highest, and the content of sulfur glycosides was lower than that of 83% of the reference materials; the time of shoot extraction and the time of maturity were earlier than that of 86% of the reference materials; and the oilseed rape oil content was the highest. The CAT activity of 24 early-maturing kale-type oilseed rape in the 7-8 leaf stage was on a decreasing trend; leaf MDA content increased in the 5-6 leaf stage and decreased in the 7-8 leaf stage, and the overall change of MDA content in the leaves of ‘Fanming youtai’ was small; leaf POD activity was continuously enhanced, and the activity of carex as a whole was higher than the leaf; leaf SOD activity increased in the 5-6 leaf stage and decreased in the 7-8 leaf stage. The leaf POD activity was growing, and the overall activity of carex was higher than that of leaves; the leaf SOD activity showed a decreasing trend in the 7-8 leaf stage. The early shoots, early maturity, and low-temperature tolerance of ‘Fanming youtai’, with excellent traits, can be used as high-yield and high oil early maturity breeding materials, and there is a significant correlation between the early shoots characteristics and maturity stage; 7-8 leaves may be the critical period for the growth and development of early maturing oilseed rape.

Key words: Brassica napus, early carex, early maturity, ‘Fanming youtai’, 7-8 leaf stage, catalase, malondialdehyde, peroxidase, superoxide dismutase