Analysis on the mechanism of pre-harvest sprouting resistance in white grain wheat

Understanding the mechanism of pre-harvest sprouting(PHS) is very important to breed wheat cultivars with PHS resistance.The functional molecular markers Vp1B3,Vp1-b2 and Dorm-1,combining with the germination test of spike,seed,seed + awn,seed + spike-stalk,seed + glumes,and seed + awn + spike-stalk + glumes,were used in this study to find out the mechanism of PHS resistance of the 11 winter wheat cultivars(lines).The results showed that the resistance of PHS in two red-grain check cultivars Jing 9428 and Jingdong 8 was controlled by red-color and Vp-1Bc as well as glumes or their inhibitors.Nine white-grain cultivars(lines) had not only the common mechanisms of resistance called awn and glumes or their inhibitory substances,but also some different mechanisms.There were no relationships among PHS resistance of high tolerant line CA0431 with Vp1B,Dorm-1 and grain color,while its resistance was controlled by other genetic factors.High resistance of Shandong 046432 was due to Vp-1Bc and Dorm-1.Spike-stalk provided the medium resistance to cultivar Aikang 58.The effect of Vp-1Bb gene on the resistance of CA9550-2 needed further investigation.Awn and glumes or their inhibitory substances offered some resistance to the three medium susceptible lines CA9640,CA0459 and CA0493,and two high susceptible lines Shandong 928802 and CA0306.However,the genotype Vp-1Bb of Shandong 928802 and genotype Vp-1Bc of CA0306 were not associated with the PHS resistance.