Establishment Of Micropropagation And Shoot Regeneration System In Vitro In Plum

Progress in tissue culture and genetic transformation of plum have offered the opportunity to obtain the novel germplasm resources with shorten the breeding procedure. In order to establish high efficient plum regeneration system, different factors that effect adventitious shoot regeneration was studied on the basis of establishment of a stable and high efficient micropropagation system. Two cultivars of Chinese plum (Prunus salicina Lindl.'Xiaohuangli', 'Oshiwase') and one cultivar of European plum (Prunus domestica L. 'Grand Rose') were employed as tested materials. The results of micropropagation and regeneration were as follows:1. Using the stem segments of Prunus salicina Lindl. 'Oshiwase' as the explant for initial culture, the results showed that 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% ale 30 s + (0.5%NaClO + Tween-20 2-3 drops) 12 min. The optimal medium for shoot proliferation was modified F14 + 0.6-0.8 mg·L^-1 6-BA + 0.1-0.2 mg·L^-1 NAA + 30 g·L^-1 sugar + 6 g·L^-1 agar. The multiplication index of shoot was 6.0. The optimal medium for rooting was modified MS + 0.2 mg·L^-1 NAA + 0.1 mg·L^-1 IBA + 30 g·L^-1 sugar + 6 g·L^-1 agar. The rooting rate was 66.7%. The plantlets were transplanted into nutrition soil with vermiculite, perlite and turf (1:1:1). The survival rate was more than 70%.2. The effects of different basal media, plant growth regulators, their concentration combinations and pH value on in vitro plants were studied on micropropagation of Prunus salicina Lindl. 'Xiaohuangli'. The results showed that the optimal medium for shoot proliferation was modified F14 + 0.8 mg·L^-1 6-BA + 0.2 mg·L^-1 NAA + 30 g·L^-1 sugar + 6 g·L^-1 agar. The suitable pH in medium before disinfect was from 5.4 to 5.8. The optimal medium for rooting was modified MS + 0.1 mg·L^-1 NAA + 0.2 mg·L^-1 IBA + 30 g·L^-1 sugar + 6 g·L^-1 agar. The rooting rate was 100% and the average number of roots each plantlet was 3-4. The plantlets were transplanted into nutrition soil with vermiculite, perlite and turf (1:1:1). The survival rate was more than 80%. The micropropagation system constructed in this study will be helpful for large-scale production of 'Xiaohuangli' clonal seedling. 3. The results showed that the optimal medium for Prunus domestica L. 'Grand Rose' shoot proliferation was improved MS + 0.5 mg·L^-1 6-BA + 0.1 mg·L^-1 NAA + 0.5 mg·L^-1 GA₃ + 30 g·L^-1 sugar + 6 g·L^-1 agar. The multiplication index of shoot was 6.5. The optimal medium for rooting was improved MS + 0.2 mg·L^-1 NAA + 0.1 mg·L^-1 IBA + 30 g·L^-1 sugar + 6 g·L^-1 agar. The rooting rate was 66.7%. The plantlets were transplanted into nutrition soil with vermiculite, perlite and turf (1:1:1). The survival rate was more than 79.8%.4. Factors that effect on leaf regeneration of Prunus salicina Lindl. 'Xiaohuangli' were studied, including type of basal medium, type and content of plant growth regulators, time of darkness treatment. The results showed that WPM medium was the optimal basic medium. The optimal medium for leaf regeneration was modified WPM +1.5 mg·L^-1 6-BA + 0.8 mg·L^-1 IBA + 30 g·L^-1 sugar + 6 g·L^-1 agar. 6-BA was proved better than TDZ in the inducing adventitious bud from leaf disc. The optimal dark treatment time for explants was 21 days.5. Effect of explant types on regeneration was studied. The browning was seriously in adventitious shoot regeneration from leaf. The addition of antioxidant into the culture medium could not effectively inhibit its browning. The regeneration rates of etiolated intemode and internode were 30.42% and 18.57% respectively. The adventitious shoot regeneration from etiolated intemode and internode could grow normally and the survival rate was 100%. The better explant type was etiolated intemode which nodal position is the first and the second.