[Evaluation of pre-harvest sprouting resistance of wheat varieties from different ecological regions.]

The pre-harvest sprouting (PHS) resistance of 137 wheat varieties from different regions was evaluated and the relative germination index (RGI) was calculated. The relationships between PHS and grain quality traits, amylase activity and related gene expression level of these varieties were analyzed. The results showed that wheat varieties from the middle and lower reaches of Yangtze River Valley winter wheat region had the lowest RGI value and the highest ratio of resistant pre-harvest sprouting wheat varieties, followed by the varieties from the upper reach of Yangtze River Valley winter wheat region and from the Yellow and Huai River Valley. Red-grain wheat had lower RGI than white-grain wheat. RGI was positively correlated with seed length, seed width, and spikelet number, but not correlated with other grain traits (panicle type, ear color, ear length, and spikelet density, grain per spike and 1000-grain weight). RGI was negatively associated with the test weight, dough development time, and flour yield, but not with other quality indices (protein content, wet gluten content, water absorption, stability time, sedimentation, extension area, extensibility and max resistance). Amylase activity of different varieties increased with seed imbibition time. RGI was positively associated with α-amylase activity after germinating for 24-72 hours. The cluster analysis results of resistant varieties were consistent with the PHS resistance evaluation after 48 hours. RGI was positively associated with the related gene expression with seed imbibition time.