Method of Constructing Core Collection for Malus sieversii in Xinjiang,China Using Molecular Markers

The method for constructing core collection ofMalus sieversii based on molecular marker data was proposed. According to 128 SSR allele of 109 M. sieversii, an allele preferred sampling strategy was used to construct M. sieversii core collection, using the UPGMA （unweighted pair-group average method） cluster method according to Nei ＆ Li, SM, and Jaccard genetic distances, by stepwise clustering, and compared with the random sampling strategy. The number of lost allele and t-test of Nei＇s gene diversity and Shannon＇s information index were used to evaluate the representative core collections. The results showed that compared with the random sampling strategy, allele preferred sampling strategy could construct more representative core collections. SM, difference for construction of M. sieversii core collection. Jaccard, and Nei ＆ Li genetic distances had no significant SRAP （sequence-related amplified polymorphism） data and morphological data showed that allele preferred sampling strategy was a good sampling strategy for constructing core collection of M. sieversii. Allele preferred sampling strategy combined with SM, Jaccard, and Nei ＆ Li genetic distances using stepwise clustering was the suitable method for constructing M. sieversii core collection.

The comparative analysis and identification of secondary metabolites between Tibet wild and cultivated pomegranates(Punica granatum L.)in China

Secondary metabolites are closely related to the nutritional quality and health functions of plants.We investigated the secondary metabolites of both wild(n=23)and cultivated(n=27)pomegranate plants(Punica granatum L.)growing in China.The total flavonoid(TF)and tannin(TT)contents from the peel and juice were determined and the secondary metabolites in the peel(ZLP)and juice(ZLZ)of‘Zela 4’were identified using liquid chromatography–electrospray ionization tandem mass spectrometry(LC–ESI-MS/MS).Analysis of variance(P<0.05)showed that there were significant differences in the TF content of peel(TF(P))and juice(TF(J)),and the TT content of peel(TT(P))and juice(TT(J))among different pomegranate accessions.Pearson correlation analysis showed that latitude and altitude might be the main environmental factors affecting TF and TT contents in pomegranates.In this study,279 secondary metabolites were identified in the ZLP and ZLZ.In addition,we report for the first time 227 secondary metabolites in pomegranates.Using orthogonal partial least squares discriminant analysis,90 differential metabolites were identified in ZLP and ZLZ.In addition,we screened eight specific germplasms(high-TF(P),‘Junyong 3’;low-TF(P),‘Yanzhihong’;high-TF(J),‘Zela 4’;low-TF(J),‘Yudazi’,high-TT(P),‘Junyong 4’;low-TT(P),‘Anba 1’;high-TT(J),‘Yeba 1’;and low-TT(J),‘Baihuayushizi’).The results of our study provide a reference for the development and utilization of wild pomegranate resources and pomegranate breeding in China.