几种甘蓝型油菜幼苗抗旱性特征的比较研究

以EV1、EV2、EV3、EV4、EV5、EV66个抗旱性不同的油菜品种为试验材料，通过不同浓度PEG-6000渗透溶液模拟干旱胁迫处理，研究油菜幼苗的抗旱指数、根长、苗高和根冠比等性状变化，探索在大田环境条件下的苗期生长特征。结果表明，水分胁迫下EV2的抗旱指数最大，EV6的抗旱指数最小；不同浓度PEG胁迫下，各品种差异显著, EV1、EV2、和EV3的根长、苗高和根冠比较大，而EV5和EV6的表现较差。在大田油菜五叶期时，EV2的冠层覆盖面积最大，与其它品种之间存在极显著性差异；总生物量以EV2、EV3和EV1较大，根系干重以EV2较大，而且三者之间存在显著相关性；与抗旱指数进行通径分析，冠层覆盖面积对抗旱性的直接通径系数最大，达到0.5975。冠层覆盖面积的大小反映了早期活力的强弱，早期活力强，相应的品种抗旱指数高，抗旱性强。

Comparative study on drought resistance characteristic of Brassica napus L. seedling

An experiment was conducted to investigate drought index, root length, seeding height and the ratio of root to shoot of 6 rapeseed cultivars (EV1, EV2, EV3, EV4, EV5, EV6) with different drought resistance under different concentrations of PEG-6000 osmotic solution simulated drought in field. The result showed that drought index of EV2 was the highest, while EV6 was the lowest under water stress. There were significant differences among cultivars under different concentration of PEG, that root length, with seeding height and ratio of root to shoot of EV1, EV2 and EV3 being larger than those of EV5 and EV6. Canopy cover area of EV2 was the larger as compared with other cultivars dur ing five-leaf stage. Path analysis of drought resistance index showed that direct path coefficient of canopy cover area to drought resistance was as high as 0.5975. Canopy cover area reflected strength of vigor during early stage at early stage when the drought resistance index of cultivars and drought resistance being stronge.