Study on the Rooting Culture and Hardened-seedling Transplanting of Cotoneaster hjelmqvistii Plantlets on the Medium Supported by Vermiculite

[Objective] The study aimed to discuss the effect of vermiculite used the supporting of medium on rooting culture,acclimatizing and transplanting of Cotoneaster hjelmqvistii test-tube plantlets.[Method] The micro stem of C.hjelmqvistii was put in the vermiculite supporting medium for rooting culture.After acclimatized on opened cultural bottles for two weeks the plantlets rooted on the vermiculite supporting medium were transplanted with a lump of vermiculite into the nutrition pots,and the survival rate of the plantlets was observed,and the stoma closing state of C.hjelmqvistii test-tube plantlets was also observed during opening bottle and acclimatizing the plantlets.[Result] The micro stem of C.hjelmqvistii cultured on the vermiculite supporting medium could get into normal test-tube plantlets and the rooting rate was 88.3%,which was obviously higher than the rooting rate(66.7%) of the micro stem cultured in agar supporting medium.The stoma closing function of C.hjelmqvistii plantlets could be obviously recovered by opening the bottle and acclimatizing the plantlets for two weeks before transplanting.After C.hjelmqvistii test-tube plantlets were acclimatized and transplanted with a lump of vermiculite,the survival rate of the plantlets was 86.7% under the condition of no-spraying,no-covering and low air humidity of 60% in afternoon,being obvious higher than the survival rate(31.7%) of the plantlets transplanted with normal method.[Conclusion] This study provided the basis for improving the tissue culture propagation techniques of C.hjelmqvistii.