Preliminary Studies On Polyploidy Creation In Non-Astringent Persimmon

Ployploidy is widely acknowledged as a major channel of evolution and breeding in plants, and ploidy breeding is an effective means to create large and seedless fruit germplasm. In this experiment, treaments were made with colchicine on the shoot-tips of Luotiantianshi' persimmon and leaves of 'Qiuyantianshi' persimmon to search effective methods for chromosomes doubling. The endosperm of 'Luotiantianshi' persimmon was also cultured for seeking another way to get polyploid persimmon. The main results are as follows:1. Studies were carried out about the effect of chromosomes doubling with colchicine on in vitro shoot-tips of ' Luotiantianshi' persimmon. The treatments were designed with colchicine 0%^ 0.03 %. 0.05 % , 0.08 % and 0.1 % for 2 and 4 days respectively. When treated with 0.08% colchicine for 4 days, shoot-tips all died; but when the concentration was lower than 0.05%, it won't produce doubling of chromosomes. In this experiment, when treated with 0.05% 2 days, 0.08% 2 days and 0.1% 2 days, we got mutated plantlets, in the same time, the chimeric plantlets occurred in the treatment of 0.08% 2 days and 0.1% 2 days. The results indicated that the concentration of colchicine 0.08% with treatment-time 2 days was better.2. Studies were carried out about the effect of chromosomes doubling with colchicine on in vitro leaves of ' Qiuyantianshi' persimmon. The treatments were designed with colchicine 0.1 %, 0.3 % > 0.5 % and 1.0 % for 2, 4 and 6 days respectively.When the concentration of colchicine was higher than 1.0%. the leaves treated become yellow and die; the concentration of colchicine 0.1% was ineffective in this experiment; so we believed that the doubled generated plantlets could be obtained by treating leaves with 0.5% of colchicine for 4 days.3. A result was discovered by endosperm culture in 'Luotiantianshi" persimmon(90-1-37) . The effect of cytokine ZT was better than BA, all endosperm in the medium containing ZT produced callus; but in the medium with BA, only when the concentration of 2,4-D reached 2.0mg/L, they could produce callus, but in this experiment, the callus induced from the medium added 2,4-D 2.0mg/L couldn't regenerate plantlets; from this experiment, the medium constitute of ZT1.1mg/L+ 2,4-D1.0mg/L+CH1000mg/L was adaptive for callus induction, and later the callus was easily to differentiate for plant regeneration.