不同类型甘蓝型油菜耐迟播生长能力差异分析

Growth ability of rapeseed(Brassica napus L.)seedlings under late-sowing condition

利用双季稻、再生稻和迟熟粳稻茬口种植油菜,会遇到播期推迟后营养生长期气温较低,秋冬季发育缓慢的问题,产量因此偏低。为选育耐迟播油菜品种,选择不同熟期类型的48份甘蓝型油菜资源,设计迟播(11月11日)条件下的室外营养液水培和田间直播试验,测定秋冬季的生物量及田间产量等指标,比较其迟播条件下的生长能力。室外营养液水培结果表明:它们的低温生长量存在丰富的遗传变异,移植后30 d、60 d、90 d的生物量积累均与成熟期单株产量显著正相关。早熟、中熟型30 d、90 d生物量显著少于晚熟型;早熟型60 d生物量显著少于晚熟型;晚熟型30 d叶片SPAD值显著大于早熟、中熟型。为选育耐迟播油菜品种,油菜育种上可以在移植后30 d对植株生物量积累能力进行重点选择,以提高育种效率。田间直播结果表明:早熟型单株产量显著低于中熟型。通过比较不同生态类型油菜在迟播条件下的苗期生物量积累规律,为油菜迟播高产栽培和品种选育提供了理论指导。

Planting winter rapeseed after double cropping rice,ratooning rice or/and late-maturing japonica rice,might encounter problems of delayed sowing,lower temperature,and delayed growth in late autumn and winter,resulting in decrease yields.In order to select rapeseed varieties that tolerant to late sowing,48 breeding lines of Brassica napus with different maturity periods were selected,and outdoor nutrient solution hydroponics and field direct seeding were designed under late sowing(Nov.11).Biomass and field yield in autumn and winter were measured,and their growth ability to tolerate late sowing was compared.Results of outdoor nutrient solution hydroponic cultivation showed that there were rich genetic variations in their low-temperature growth,and biomass accumulation at 30,60,and 90 days after transplantation was significantly positively correlated with yield per plant at maturity.The biomass of early and middle maturing types at 30 and 90 days was significantly less than that of late maturing type.The 60-day biomass of early maturing type was significantly less than that of late maturing type.The SPAD value of leaves of late maturing type was significantly higher than those of early and middle maturing type at 30 days.In order to select rapeseed varieties tolerant to late sowing,the 30-day biomass accumulation capacity of plants could be an index in the early stage of rapeseed breeding to improve breeding efficiency.Results of field direct seeding showed that yield per plant of the early maturing type was significantly lower than that of middle maturing type.By comparing the biomass accumulation rules of different ecological types of rapeseed at seedling stage under the late sowing,it provides theoretical guidance for the late sowing and high yield cultivation of rapeseed and variety selection.