Effect of Different High Altitudes on the Seed Oil Content and Agronomic Traits of Brassica napus L.

PurposeTo explore the effect of different high altitudes on the main agronomic traits and oil content of Brassica napus, and to provide the theoretical basis for cultivation and breeding of B. napus in the high altitude area.

MethodsFour DH lines of B. napus with different oil content were used as test materials, the pot experiment was conducted under the five high altitude of 1600, 1800, 2 000, 2200 and 2400 m and four lines of agronomic traits and oil content were tested.

ResultsIn a certain altitude gradient range (1600-2200 m), B. napus plant height, primary number of branches, number of effective pods per plant and yield per plant showed an increasing trend; when it reached an altitude of 2400 m, the agronomic traits all decreased significantly (P<0.05). The number of seeds per pod gradually decreased with the altitude increasing, and all decreased significantly at an altitude of 2400 m (except for DH0216) (P<0.05); the growth period, maturity stage of pod, 1 000-grain weight and oil content showed a gradual increase trend with the altitude. Correlation analysis showed that at high altitude, the yield of B. napus plant was significantly or extremely significantly positively correlated with plant or ectremely significantly height, primary number of branches, number of effective pods per plant, 1000-grain weight, and number of seeds per pod (P<0.05 or P<0.01); the oil content were significantly positively correlated with altitude and mature stage of pod (P<0.05), and extremely significantly positively correlated with growth stage (P<0.01).

ConclusionThe better suitable planting altitude range of B. napus is below 2200 m, and the popularized B. napus at high altitude should have the characteristics of early maturity and extremely early maturity.