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. [ABSTRACT FROM AUTHOR]