甘蓝型油菜DH群体苗期抗旱性的评价

Evaluation of Drought Resistance in Rapeseed (Brassica napus L.) DH Lines at Seedling Stage

中国油菜主产区常常受到秋冬旱和春旱危害而影响产量及品质。本文通过盆栽试验,以株高、根长、地上部干重、根干重、根冠比、总干重6个性状的抗旱系数作为抗旱性评价指标,对甘蓝型油菜DH(doubled haploid)群体的118个株系及其亲本进行苗期抗旱性评价,筛选极端抗旱DH系。结果表明,与对照相比,干旱严重抑制了甘蓝型油菜苗期的生长,6个评价指标均表现出显著差异,其中根干重的变异系数最大;在对照和干旱条件下,群体各株系各性状均表现出超亲连续分离,大部分呈正态分布,抗旱条件下的分离更为明显;相关性分析表明,地上部干重、根干重和总干重抗旱系数可作为甘蓝型油菜苗期抗旱性的主要评价指标;综合应用这3个评价指标,筛选出032、034、035为候选的极端抗旱基因型,006、091、104等为候选的极端不抗旱基因型,为抗旱相关研究及育种提供了材料。

Drought stress in autumn, winter and spring has endangered the production and quality of rapeseed in China. The ob- jective of the study was to evaluate drought resistance of the rapeseed （Brassica napus L.） DH （doubled haploid） population and screen the most drought-resistant DH lines. For phenotyping, the rapeseed lines from DH population [（Huyou 15x5900） F4 x （No2127-17x275B） F4] were grown in plastic pots. Six traits including plant height, root length, shoot dry weight （SDW）, root dry weight （RDW）, root/shoot ratio and total dry weight （TDW） together with DRC （drought resistance coefficient） of all the traits were used to evaluate the drought resistance of the 118 DH lines and their parents. The results showed that the six responsive traits changed significantly under the drought conditions compared with the control in the experiment and the effects of drought were much more severe on RDW than on other traits. All traits showed transgressive and continuous distribution under both drought and control conditions. The correlation among all the traits investigated in the study indicated that DRC of SDW, RDW and TDW could be used as available evaluation indices for drought resistance. Lines 032, 034, and 035 screened from the population were the most drought-resistant lines and 006, 091, and 104 were the most drought-sensitive lines.