Enhanced regenerative capacity in Rhipsalidopsis and Schlumbergera explants by in vitro manipulations.

摘要

Several plant species are recalcitrant when considering regeneration through adventitious organs. Establishment of regeneration systems for the plants of interest is a pre-requisite for further work such as genetic transformation and induced mutation. The cactus plants belonging to species Schlumbergera and Rhipsalidopsis were found to be recalcitrant. In addition to this problem, they were very slow to grow. However, it was possible to achieve high regenerative ability in explants of in vitro cultures of these cacti. The initial phylloclade explants established from adult plants grown in greenhouse were found to be recalcitrant. These explants produced only axillary shoots from the pre-formed shoot primodia when treated with exogenous plant hormones, but they failed to produce any adventitious shoots. There was a significant improvement in adventitious shoot formation in phylloclade explants, more particularly, of Rhipsalidopsis in long-term cultures. After the first subculture, sporadic adventitious shoot formation began, and after the third subculture 87% explants of one of the cultivars of Rhipsalidopsis produced adventitious shoots. There was an increase in the regenerative capacity in the explants of Schlumbergera, however, the efficiency was not to the same extent as for the other species. Callus cultures were found to be more regenerative compared to the phylloclade explants. The results clearly indicated that the in vitro manipulations helped in increasing the capacity to regenerate..