甘蓝型与芥菜型油菜种间杂交后代DH系抗旱性评价

为评价和利用种间杂交的抗旱新种质,以24份甘芥(甘蓝型油菜和芥菜型油菜)种间杂交后代DH株系为材料,在全生育期降水量约60mm的情况下,设置正常灌水、苗期干旱胁迫、薹花期干旱胁迫、角果生长期干旱胁迫4个处理,考察产量及与产量相关的4个农艺性状和5个品质性状,应用抗旱指数法、灰色关联度综合分析法结合聚类分析,筛选优异的抗旱种质资源。结果表明,多数甘芥杂交后代材料抗旱性均高于常规甘蓝型品种,其中角果生长期、苗期更显著,共获得10份抗旱性较强的材料,其中2份在全生育期抗旱性均较强。3个时期抗旱性相关分析表明,苗期和薹花期抗旱性显著相关,而角果生长期和苗期、薹花期的相关性不显著。在苗期、薹花期、角果生长期的任一时期发生干旱均能严重影响油菜地上部鲜重、株高、芥酸及油酸含量,同时薹花期发生干旱对产量影响最大,其次为苗期。植株在苗期、薹花期、角果生长期的抗旱性与地上部鲜重呈极显著正相关,薹花期抗旱性与株高呈极显著正相关。

Evaluation of drought resistance of DH line from hybrid of B. napus and B. juncea

To evaluate new drought resistant germplasm, 24 DH lines from hybrid of Brassica napus and Brassica juncea were planted under 2 conditions of drought stress at 3 stages (seedling, flowering and podding stages) and normal irrigation in Kunming, Yunnan Province. In this area, the rainfall is approximately 60mm in the whole growth season for rapeseed. The identification criteria for drought-resistance were yield, 4 yield-related agronomic traits and five quality traits and different evaluation methods were compared by drought resistance index method, gray relevancy method and cluster analysis. The result showed that the drought resistance of the most hybrids was stronger than that of the conventional B. napus, especially at podding and seedling stage. 10 strong drought-resistant materials were screened, and 2 materials with both strong resistance and high yield were found. The drought-resistance correlation coefficient analysis of 3 growth stages showed that the drought resistance at seedling stage was correlated to flowering stage, and podding stage showed a poor correlation to seedling or flowering stage. Drought stress at any growth stage could seriously affect the fresh weight, plant height, oleic acid content and erucic acid content. Yield was affected by the drought stress most seriously at the flowering stage, and next at the seedling stage. The drought-resistance had significant positive correlation to fresh weight at seedling, flowering and podding stages. The drought-resistance had significant positive correlation to plant height at flowering stage.