Molecular diversity and relationships among elite maize inbreds from US and CIMMYT populations and current heterotic groups in China

Abstract

Exploring extensive maize germplasms from diverse origins is helpful to broaden the genetic base of maize. This study was performed to assess genetic diversity and genetic distance among representative inbreds from known heterotic groups in China and broadly based American populations. A total of 36 maize inbreds, 18 each from America and China, were evaluated at 109 simple sequence repeat (SSR) loci. SSR data revealed greater genetic diversity with an overall mean polymorphic information content (PIC) of 0.66 and mean number of 6 alleles per locus. Among the alleles, 25.5 and 19.8% were inbred-specific to Chinese and American inbreds, respectively. The inbreds were clustered into five groups, Reid Yellow Dent (RYD), Iowa Corn Borer Synthetic No. 1 (BSCB1), Luda Red Cob (LDRC), Lancaster Surecrop (LSC) and Tangshan Sipingtou (TSSPT). Most of the inbreds released from US hybrids and their derivatives clustered with BSSS inbreds, enhancing the RYD heterotic group. However, the inbreds from two-ear composite (BS11) and CIMMYT population (Pool41) were not clustered as independent groups. Two inbreds, B109 and B73, and those from BSCB1 could be promising for the exploitation of heterosis and broadening germplasm sources for Chinese maize improvement programs.