DOI:10.3390/agronomy11102054

Yi Limei;Dong Zhixiao;Lei Yu;Zhao Junming;Xiong Yanli; Yang Jian; Xiong Yi; Gou Wenlong;Ma Xiao

Abstract：

Background:Prairie grass (Bromus catharticus Vahl) is an important grass species that could be used in the production systems of certified seed and high-quality forage for grazing ruminants. In the present research, a sequence-related amplified polymorphism (SRAP) marker was employed to detect the genetic variability and structure of 80 prairie grass accessions from all over the world.

Results:Altogether, 460 reliable bands were amplified from 47 SRAP primer pairs with 345 (75%) polymorphic bands. The average values of discrimination power (DP) and polymorphic information content (PIC) were 0.753 and 0.317, respectively. Both the UPGMA clustering and PCoA analyses grouped the 80 accessions into five clusters, whereas the STRUCTURE analysis showed that 80 prairie grass accessions possessed three genetic memberships (K = 3). The results of the Mantel test showed that the distance matrix has a moderately positive correlation between the morphological and molecular data sets (r = 0.524). A poor genetic differentiation (Fst = 0.045) was discovered among the six geo-groups of accessions. Besides, the highest intragroup genetic diversity was found in the North America group (He = 0.335). This study provides a genetic structure and diversity case for prairie grass, and supplies new clues for the study and utilization of prairie grass.

Conclusions:In the present study, we evaluated the genetic diversity and molecular characterization of worldwide prairie grass accessions using SRAP markers. Cluster analysis based on DICE similarity coefficients grouped all 80 prairie grass accessions intofive main clusters.The results of PCoA, SplitsTree and UPGMA cluster analysis were consistent with each other. The AMOVA suggested that most of the generality variance existed within geo-groups, and the Fst among geo-groups was 5%. The genetic diversity indices of the accessions from South America and North America were the highest, which could be considered as the excellent germplasms and should be further protected and utilized. In summary, our study provided a comprehensive insight of the diversity in prairie grass from the perspective of SRAP markers, which could further promote its utilization and breeding process.