Studies On Stem Segment In Vitro Culture Of Chinese Plum (Prunus Salicina Lindl.cv.Gulf-ruby)

Prunus salicina, a centuries-old cultivated history tree, is one kind of important fruit trees in China, and its fruits have good color, sweet-smelling and sapor. However, plum possesses not only longer juvenility but also higher pistil sterile and heterozygosity. Plum is often infected by virus. Advances in tissue culture and genetic transformation of plum have offered the opportunity to acquire the new germplasm resources, shorten the breeding cycle and produce the seedings free from the viruses.The objective of the present study was to establish the regeneration systems of Chinese plum (Prunus salicina Lindl. cv. Gulf-ruby). The important factors such as sampling season, methods of sterilization, components of medium used were investigated. The main results were as follows:1. During the annual sterilization of explants, using the stem segments of gulf-ruby as the explant for initial culture, the best season for collecting samples was from April to May, in which germination rate was high with less pollution. The optimal method was 70 %alc 30 s+(0.5%NaC10+Tween-20 2-3 drops) 12 min.2. Different methods were adopted for samples harvesting of different phases. At the early stage of growth from April to May, the optimal method was 70%alc 30 s+(0.5% NaClO+Tween-20 2—3 drops) 12 min. At the late stage of growth from June to November, the optimal method was 70% alc 30 s+(1%NaClO+Tween-20 2—3 drops) 15 min. During the dormancy from December to March, the optimal method was 70% alc 30 s+(5%NaClO+Tween-20 2—3 drops) 15 min.3. During initial culture, the optimal medium was WPM+IBA 0.05—0.1 mg/L+BA 0.5—1.0 mg/L+glucose 30 g/L+agar 5 g/L+Vc 1.0 g/L. The explants were cultured in darkness or were covered with newspapers for 5 d before transferred to white light.4. During subculture, the optimal multiplication medium was WPM+IBA 0.05—0.1 mg/L+BA 0.2 mg/L+KT 0.3 mg/L+glucose 30 g/L+agar 5 g/L+Vc 1.0 g/L+CH 1.0 g/L. The optimal strong seedling medium was WPM+IBA 0.05—0.1 mg/L+BA 0.3 mg/L+glucose 30 g/L+agar 5 g/L+Vc 1.0 g/L+CH 1.0 g/L.5. The optimal medium of rooting was 1/2MS+IBA 0.2—0.5 mg/L+sucrose 15 g/L +PG 20—40 mg/L. They were cultured in darkness for 7 d before transferred to white light.6. The acclimated method of seedlingd was to open middle bottleneck for 2 d and then opened all bottleneck for another 3 d with adding some distilled water in medium. The seedlings were transplanted in mixture made of soil, vermiculite and perlite (1:1:1).