The Establishment Of Regeneration System And Mutants' Selection Of Turf Grass (Zoysia. Spp)

Zoysiagrass(Zoysia.spp.) commonly was used as warm～season turfgrass.The 3 species(Zoysia japonica cv.lanyin3,Zoysia japonica cv.Qingdao and Z.matrella(L.)Mer) chosen in this experiment had many good characters such as:Strong adaptability, drought～resistance,wear～tolerance elasticity and et al.they were widely used in the following fields:landscaping,ecological restoration,water and soil conservation and so on. However,their shortages also existed,such as the relatively short green period and the weak ability of endure cold.So how to improve their turf characters(such as:dwarfism for decrease cut times,changing leaf color and leaf shape for improve the ornamentals of turf),stress resistance(cold tolerance,drought tolerance,salt and alkali resistance),disease and insect resistance,selecting high quality turf grass were the main target of Zoysiagrass(Zoysia.spp.) breeding work for all the time.With the breeding techniques of radiation mutation combined with tissue culture became hotter and hotter.In this experiment,we combined low～temperature,radiation mutation with tissue culture,that turned out very useful,the frequency of embryonic callus induction increased obviously, some mutants were screened out successfully,which strongly supported the new variety breeding work of Zoysiagrass(Zoysia.spp.).The main results as follow:1.The best conditions of regeneration system estabishment(1) The best explant was caudex.(2) The feasible medium for callus induction from caudex was MS+2,4-D(2.0 mg/L).(3) The feasible subculture medium for callus was MS+2,4-D(0.05mg/L)+ 6-BA(2.0mg/L),the frequency of embryogenesis callus induction were 9.09%(QJ), 15.63%(YJ),10.34%(BJ).(4) The best differentiation medium for embryogenesis callus was MS medium;the differentiation ratio was up to 100%.2.The feasible temperature and time of low～temperature treatment.5℃was the feasible temperature,7d was the feasible time of treatment,the frequency of callus induction were 93.33%(QJ),94%(YJ),90%(BJ),the frequency of embryogenesis callus induction were 50%(QJ),65.96%(YJ),60%(BJ).3.20Gy was the feasible dose,15Gy was the second,30Gy was the LD50,when treated caudex only with ⁶⁰Co-γray.4.The combinenation treatment of ⁶⁰Co-γray and low-temperature(1) Combined radiation treatment of ⁶⁰Co-γray with low-temperature treatment of (5℃,7d)on the receptor material of the callus induced from caudex,the results Showed: 20Gy was the optimum dose,once low-temperature treatment before or after the radiation induction was the best treatment after that the frequency of embryogenesis callus induction were 51.72%(QJ),88.89%(YJ),83.33%(BJ).(2) Some mutants had been selected out,they presented as leaf color changing and plant height changing,et al.