Genetic Diversity of Waxy Gene in Chinese Glutinous Maize

Abstract

Waxy (wx) gene is a key gene for glutinous trait in many waxy crops including waxy maize. wx diversity investigation in maize population has important significance for quality breeding and germplasm utility of Chinese waxy maize. In this study, 325 waxy maize germplasm accessions (309 from China, 11 from Thailand and five from South Korea) were used to investigate their wx genotypes and determine their apparent amylose content (AAC). the results demonstrated that genetic diversity of wx gene in Chinese waxy maize was low, and two mutation types, wx-D7 and wx-D10, accounted for 96.9% of the 325 accessions. Among these accessions, those from North of China and South Korea were the type of wx-D7 while others from South of China and Thailand were the type of wx-D10; most of landraces were the type of wx-D10 (78.9%) while most commercial hybrids and inbred lines were the type of wx-D7 (88.7% and 86.6%, respectively). AAC estimations indicated that mean values of AAC in commercial hybrids and inbred lines in China were lower than 2.2% while that in landraces was relatively high. Comparing with wx-D7, wx-D10 waxy maize had higher AAC with larger changing range. Geographical distribution and origins of two main wx genotypes and other wx genotypes were discussed also.