Identification of drought tolerance indices and evaluation of spring soybean varieties (lines) in Guangxi

[Objective] The objective of this study was to evaluate the drought resistance in 13 Guangxi spring soybean varieties (lines), to provide a suitable drought tolerant variety in spring drought affected areas of Guangxi, and to make a criteria for drought resistance breeding using simple but highly efficient morphological indices. [Method] The soil-pot experiment was performed and drought was simulated by withholding the water to evaluate drought resistance in 13 soybean varieties (lines) using indices of degree of leaf wilting, drought coefficient, and average subordinate function values. [Result]The varieties, viz., Guichun 8, Guichun 10 and Guichun 11 were evaluated as gradeⅠ for the degree of leaf wilting. The drought coefficient of four materials were all found to be over 0.7, and the average subordinate function values of them were all found more than 0.65. [Conclusion] The four tested materials were found highly resistant to drought, which may be extended for cultivation in areas of Guangxi suffering from spring droughts, and may also be used as resources for drought resistance breeding. The drought tolerant indices used in our experiment have been found to be the simple and most efficient for the evaluation of drought and may be used in further evaluation experiments.