Morphological characteristics and SRAP analysis of bermudagrass mutants generated by 60Co-γ radiation

Abstract

Yangjiang bermudagrass is an excellent variety with high turf quality and good stress tolerance; however, the inflorescence density of Yangjiang is too high, which leads to management problems. To lower the inflorescence density of Yangjiang bermudagrass, Yangjiang bermudagrass mutants were generated using gamma-ray irradiation. Forty-two mutants were generated, and identification was performed on the basis of eight morphological characteristics and SRAP molecular markers. The results showed that significant variation occurred for all characteristics among the mutants and their parent. Most of the mutants showed reduced turf height; reduced leaf length, internode length and number of reproductive branches; and reduced leaf width. Compared with Yangjiang, some mutants showed higher turf density. The inflorescence density of all tested samples was observed in June, August and November, and the inflorescence density of some mutants was always lower than that of their Yangjiang parent. Based on the morphological characteristics, 12 mutants with low inflorescence density were selected as promising progeny, and their genetic characteristics were identified by SRAP molecular markers. The results showed that all 12 mutants presented differences in amplified polymorphic fragments compared with those of Yangjiang, indicating that mutations at the DNA level occurred in all mutants.