继代培养对六妹羊肚菌氧化损伤的影响OA

To investigate the impact of subculturing on oxidative damage in the mycelia of Morchella sextelata,continuous multi-generational cultivation of its mycelia was conducted,followed by systematic comparisons of morphological traits,physiological parameters,and other relevant characteristics across different generations.The findings revealed that with increasing subculture generations,notable alterations in mycelial morphology emerged beginning at the fifth generation(F5),characterized by diminished branching and a sparser apical mycelial structure.The quantity of sclerotia produced by the strains progressively declined,culminating in the absence of sclerotia formation by the twelfth generation(F12).No loss of mating-type gene was detected up to the twentieth generation(F20).Additionally,mycelial germination was delayed,and growth rates significantly decreased from the ninth generation(F9)onward.A marked reduction in the number of nuclei within apical mycelia was observed starting at the eleventh generation(F1 1).Regarding physiological indices,mycelial electrical conductivity(EC)exhibited a significant increase correlating with subculture progression,with the EC of the nineteenth generation(F19)approximately 25.6 times greater than that of the first generation(F1).Malondialdehyde(MDA)content showed no significant difference between F1 and F5;however,strains from generations F7 to F19 demonstrated significantly lower MDA levels compared to the original strain.Reactive oxygen species(ROS),specifically hydrogen peroxide and superoxide anion,accumulated progressively,while the activities of antioxidant enzymes,including superoxide dismutase and catalase,declined steadily.These results suggest that subculturing induces the accumulation of reactive oxygen species within the mycelia,thereby eliciting oxidative stress damage.This study offers empirical evidence elucidating the relationship between M.sextelata strain degeneration and the accumulation of reactive oxygen species.