甘蓝型油菜耐低温生长生理生化响应机制

Physiological and biochemical response of growth in rapeseed(Brassica napus L.)under low temperature

为提高甘蓝型油菜耐寒育种过程中的筛选效率,研究甘蓝型油菜耐低温机理,以8个不同抗寒性的甘蓝型油菜为材料,对低温条件下各材料的生物量、叶绿素、脯氨酸和相对电导率进行测定,发现在室外平均气温2.75℃时,抗性材料的生物量、叶绿素和脯氨酸的累积量都显著高于敏感材料,相对电导率没有显著差异;当平均气温7.52℃回升至12.39℃,抗性材料和敏感材料生物量的累积量无显著差异;在恒定低温10℃/4℃处理下抗性材料和敏感材料在处理前3周生物量均持续累积,但从第4周开始敏感材料新叶出现白斑,生物量减少,抗性材料老叶出现白斑,生物量维持不变。结果表明,耐低温材料在低温条件下叶绿素含量受到的影响较小,脯氨酸的积累量持续上升,具有较强的快速适应能力,在低温下具有显著的持续生长优势。

To improve cold tolerance breeding of rapeseed(Brassica napus L.),effect of low temperature on rapeseed growth was studied using 8 cultivars.In natural temperature(falling with 2.75℃mean temperature),the content of proline and chlorophyll in cold tolerant varieties were higher than those in cold sensitive ones,and the rel⁃ative conductivity had no significant differences.When the natural temperature rising to the mean temperature of 7.52℃to 12.39℃,no difference was found of the biomass for the recovery growth in these varieties.Under 10℃/4℃,biomass of all varieties was increased in the first 3 weeks.But from the fourth week,the biomass of cold sensi⁃tive varieties decreased with white spots in new leaves.While,the biomass of cold tolerant varieties remained un⁃changed with white spots appeared in old leaves.Under low temperature,proline continued to increase,and chloro⁃phyll became significantly higher,which resulted in significant growth advantage in cold tolerant rapeseed varieties.