Drought resistant characters during germination of different wheat germplasm in Yunnan Province and their correlations with the index and coefficient of drought resistance

Objective To explore indicative characters for predicting drought resistance in the whole growing period of different wheat germplasm in Yunnan Province at seed germination stage by simulating drought stress.

Method Six germination characters associated with drought resistance, including germination energy, germination rate, number of radicels, length of maximal radicels, length of coleoptiles and length of embryos among 70 accession wheat materials of Yunnan with 5 subspecies in 2 species, were studied under water and hypertonic solution of polyethylene glycol (PEG-6000) described by GB/T21127-2007 treatment conditions. Moreover, the correlations between observed average values and relative values of six germination characters and indexes and coefficients of drought resistance were analyzed.

Result and conclusion Among 5 subspecies, most of the observed average values and relative values of six germination characters did not show consistently significance in the whole growing period between varieties of drought resistance and highly drought resistance and the control of Yunxuan 11-12 of highly weak resistance, between varieties of drought resistance and highly drought resistance and varieties of middle resistance or between drought resistance and highly drought resistance and weak and highly weak resistance. Accordingly, most of the observed average values and relative values did not indicate conformable significance to their relative indexes and coefficients of drought resistance in the whole growing period. These results show that it is impossible to filter out the varieties of drought resistance and highly drought resistance in the whole growing period among all subspecies just depending on a single associated germination character of drought resistance. Thus, the breeding materials of different subspecies with drought resistance and highly drought resistance should be screened out by a combination of some germination characters (relative number of radicels, relative length of maximal radicels, relative length of coleoptiles and relative length of embryos, and ratios of length of radicels- embryos) associated with drought resistance and indexes and coefficients of drought resistance.