Abstract: Seedling survival percentage after a repeated drought stress has been extensively used as an evaluation index for seedling drought resistance in many crops. This paper aimed at improving the method for identifying seedling survival percentage after a repeated drought stress for seedling drought resistance evaluation in maize crop.A new type experiment design,termed here as double randomized block with single planting,was proposed and used to identify seedling survival percentage after a repeated drought stress in 32 varieties in maize. The experiment was conducted in separated plots compartted by concrete walls on sides and bottom. Maize seedling was germinated in sand medium and transplanted into the plot to ensure uniformly vigorous seedlings. It has been proved that the experiment design has assured uniform soil moisture for seedlings of all varieties,and that sand cultures technique effectively improved the seedling vigor uniformity. Both factors have contributed to the satisfactory identification results with acceptable variations among replications. The experiment revealed a significant linear positive correlation (r =0. 913^＊＊,n = 32) between seedling survival percentage after the first drought-rehydrtion circle and that after the second drought-rehydration circle. A new type experiment design -double randomized block with single planting-in maize was proposed,with a draft of rules for drought resistance identification technique,which greatly reduced the variations in soil moisture among different varieties resulted from difference in plant leaf area of seedlings. It has also been suggested that seedling survival percentage after the first drought-rehydration cycle can be used as an effective and practical method for identification and evaluation of maize seedlings.

Key words: Maize, Seedling drought-resistance identification, Seedling survival after repeated drought, Single planting patterns with double randomized block design

CLC Number: 

• S513.01