Development And Application Of Phenotype Specific Molecular Markers Of White Jiaobai And Grey Jiaobai

Jiaobai(Zizania latifolia)is the second largest aquatic vegetable in China,and its planting area is all over the country.It is difficult to avoid the emergence of a kind of inedible Jiaobai during the cultivation,which is an important reason for the reduction of yield and quality of Jiaobai.Ustilago esculenta is a kind of fungus that infects Z.latifolia.It has been interacting with Z.latifolia for thousands of years.And The U.esculenta of grey Jiaobai and white Jiaobai are quite different,so it is a feasible and convenient way to develop phenotype specific molecular markers of Z.latifolia based on the genome of U.esculenta.This study developed a molecular marker method which can be used to identify the seedlings of Z.latifolia,and proved that this method can reduce the number of grey Jiaobai to a certain extent in field.In this study,we collected the white Jiaobai and grey Jiaobai varieties in Jiangsu and Zhejiang Province,obtained the U.esculenta of each variety by isolation and culture,and obtained the SNP(single nucleoside acid base polymorphism)site information of each variety by re-sequencing the genome of U.esculenta and mapping it on the genome of MT type U.esculenta in ‘Suozijiao’.The total number of SNPs was214 695,129 494 effective sites were left after one screening,and 648 SNPs were obtained by screening the SNP sites related to T-type U.esculenta.Based on this,48 pairs of AS-PCR(Allele specific PCR)primers were designed.The accuracy of these sites was verified by the known phenotypes of Z.latifolia.The results showed that there were 8 pairs of primers with high specificity,which could be used to identify T-type U.esculenta.The 8 sites with higher accuracy were used to determine their detection limits by mixture of T type and wild plant.The results showed that the detection limit of grey Jiaobai was between 0.001～0.0001(fungus/plants).The phenotype of Jiaobai in the field was predicted by detecting the seedlings and bolting tube of the unknown phenotype,and combined with the observation and statistics of the phenotype in the field,the reliability of the eight molecular markers was evaluated.The results showed that the proportion of grey Jiaobai could be reduced by 37.86% by using the prediction of these 8 sites.