Ethyl methanesulfonate mutagenesis and mutant screening of two cold-season turfgrasses

This study aimed to determine the optimal mutagenesis conditions for ethyl methane sulfonate (EMS) mutagenesis treatment of Lolium perenne ‘Accent’ and Festuca arundinacea ‘Equator’ seeds and to obtain mutant material and progeny with stable traits. Seeds of both turfgrasses were mutagenized using different EMS concentrations and treatment times, and mutagenesis combinations were determined according to the semi-lethal concentration. The best mutagenic effect was achieved by treating two turfgrass seeds with 0.8% EMS solution for 36 h and then sowing them with germination rates close to 50%. After large-scale mutagenesis with these parameters, 933 mutant plants of two M₁ generation turfgrass species were transplanted and survived, and a series of 18 drought-tolerant monocultures were screened after short-term drought stress. Morphological analysis of the M₂ generation mutant plants revealed two mutation types: foliar narrowing and root length growth. Amplification of 20 turfgrass samples with five SCoT marker primers showed a polymorphism ratio of 84.09%. Among them, the SCoT-35 primer amplification product had the clearest and most stable bands, and the difference between the mutant and wild type was obvious. After the M₂ generation of three-leaf stage mutant plants was treated with drought and high temperature stress, the malondialdehyde content, proline content, and relative conductivity all tended to increase, and the chlorophyll content tended to decrease. Two L. perenne drought-tolerant mutants A5 and A8; one F. arundinacea drought-tolerant mutant B9; two heat-tolerant mutants A8 and B9; and one drought and heat-tolerant mutant B-9 were finally obtained. The results of this study provide help for the breeding of resistant turfgrass varieties.