Natural Hybrids Okra Tissue Culture And Clonal Established

Abelmoschus esculentus, a kind of annual herbaceous cultivated plant which belongs toMalvaceae family, possesses important edible value and various medicinal value. It is nativeto India and widely planted in some southern areas of China, while, it has recently started toappear in the northern part of China. Some natural hybrid plants which grew luxuriantly andthe yield of tender fruit was high, were found from the open cultivation in Ganjingzi District（Dalian, China）. However, the advantages of the natural hybrid plants could not be preservedand applied due to the separation of hybrid plants. In order to use the advantage of the naturalhybrid plants in field application, study on tissue culture and asexual system establishmentwere investigated by researchers. In this study, the tender stem and growing point werechosen as the material. Clones of the natural hybrid plants of Abelmoschus esculentus weresuccessfully established through induction and differentiation of callus and differentiation ofgrowing point.1. Induction and differentiation of the callus（1） Induction of callus. The tender stem was chosen as the material and callus issuccessfully induced. The results showed that the optimal medium for induction and culturingof the callus contained (mg L^-1, in1/2MS):2,4-D2.1,6-BA0.75, sucrose15000and AgNO₃0.9.（2） Subculture amplified culturing of the callus. The above mentioned medium（2,4-D2.1,6-BA0.75, sucrose15000and AgNO₃0.9）is the optimal one under constant temperatureand illumination conditions. The time of one amplified culturing cycle is50d, and theamplified coefficient for one generation is13.8fold. Excluding the effects of variousdisadvantageous factors and assigning the amplified coefficient of50d-one cycle as9fold,97fold of callus could be amplified annually.（3） Differentiation culture of culturing callus. The optimal medium for differentiationculture of subculture amplified culturing callus contains (mg L^-1, in MS): AgNO₃1.0, NAA0.1, ZT1.6and sucrose30000.2. Differentiation culture of the growing pointDifferentiation culture of the growing point was investigated basing the growing point asmaterial. The results showed that the optimal medium for growing point contains (mg L^-1, in1/2MS): ZT0.2and NAA0.3. Subculture amplified culturing of the callus. The optimalmedium for differentiation culture of the bud contains (mg L^-1, in MS):6-BA0.7, NAA0.1, sucrose30000and AgNO₃0.8, under constant temperature and illumination conditions. Onecycle for subculture amplified culturing of adventitious buds was60d and the amplifiedcoefficient for one generation was5.2fold.300000adventitious buds were amplified in oneyear basing on one bottle of original material.3. Culture of plantletRooting culture of plantlet was performed using adventitious buds as material. Theresults showed that the optimal medium contains (mg L^-1, in1/2MS): sucrose10000and IAA0.4. One cycle for subculture amplified culturing was30d and50000plantlets could beamplified from1plantlet annually.4. Cultivation of seedlingsThe survival ratio of seedling cultivation, micro-cuttage and seedling transplantation are93.9%,87.5%and97.25%, respectively. The seedlings which were transplanted grew largerand more flourish, and could normally flower and bear. After colonization, the seedlingsmaintained all the advantages of hybrid Abelmoschus esculentus.5. ConclusionsClones of the natural hybrid plants of Abelmoschus esculentus were established throughinduction and differentiation of callus and differentiation of growing point, which lays atechnical foundation of germplasm conservation of the natural hybrid plants of Abelmoschusesculentus and provides the application possibility of natural hybrid plants.