Screening and comprehensive evaluation of drought resistance indices of rice at germination stage

Objective To study the effect of drought stress on rice growth at germination stage and screen rice drought resistance indicators quickly and efficiently.

Method Sixty-two rice varieties (lines), including indicia and japonica rice and space-induced mutants, were studied under drought artificially created by PEG-6000. Eight indicators such as shoot length, maximum root length, coleoptile length, root number and shoot dry mass etc. were tested under stressed and control conditions.

Result and conclusion Rice germination, especially the root length, was seriously affected by drought stress, and the impact of drought stress on root dry matter accumulation was much greater than that of shoot dry matter accumulation. Two indicators of maximum root length and coleoptile length significantly correlated with the comprehensive drought capability which were suitable for drought resistance screening at rice germination stage. Fourteen out of 62 materials have been identified to be highly drought resistant through dynamic clustering statistics, which will be promising for rice drought resistance breeding.