Drought-resistance index in rice backcross lines after anthesis

In this study, many indexes correlated with drought resistance including yield components, chlorophyll content, the content of proline, the content of malondiadehyde (MDA), the activity of superoxide dismatase (SOD), the content of peroxides (POD) and catalase (CAT) activity soluble protein content and leaf area in flag leaves were measured under water stress after flowering in five rice backcross combinations. The indexes for drought resistance were screened by the correlation and the gray relationship analysis, under water stress after flowering. The results indicated that after flowering, rate of seeds fertilization was significantly correlated with yield remarkably. And proline content, MDA content in flag leaf and leaf areas were significantly influenced with drought resistance in rice, which indicated that it is feasible to predict the drought resistance in rice after flowering. According to the gray relationship analysis, ability of drought resistance in five rice backcross combinations is the following, the combination 5 > combination 1 > combination 4 > combination 3 > combination 2. Results were generally consistent with the performance in field, which indicated that it is reasonable to predict the drought resistance in rice after flowering with the four indexes screened out in this study.