Effect of Substrate and Nutrient Solution Supplied on Growth of Plantlets of Apple Dwarf Rootstocks in vitro

Taking apple dwarf rootstocks of SH28 and SH29 in vitro as materials,the effect of the transplantation substrate with the mix of turfy soil and vermiculite,the pre-treating ways of the turfy soil,and the watering of nutrient solutions(with formula of MS,Garden test and Hoagland) on the growth of the plantlets after transplanted were studied.The results showed that the survival rates of the plantlets were significant higher when using the mix of turfy soil and vermiculite at ratio of 1:1 or 1:2,and could reach 88.24% or 90.77%,respectively,compared to the using of the ratio of 2:1.Meanwhile,the plantlets had more growth amount when transplanted in the substrate mixed with turfy soil and vermiculite at ratio of 1:1.The turfy soil pre-treated with autoclave had an effect on the increasing of the leaf area of the plantlet and the single leaf area,and contributed to more healthy plantlets.The supplement of 0.1% Bacillus subtilis in the substrate had no significant effect on the plantlet growth.Three kinds of the nutrient solutions(MS,Hoagland,Garden test) could accelerate the plantlet growth,which could be seen 40 days after the application,and the formula of MS showed the best in general.