Development of an in vitro pod culture technique for young pods ofPhaseolus vulgaris L.

摘要

A research program to develop an in vitro culture technique adapted to very immature Phaseolus zygotic embryos indicated that osmolality within young pods in vivo ranged from 580 to 350 mosm during the first 10 d after pollination. Different culture techniques for 2-d-old Phaseolus pods are described using a modified Phillips medium for maturation. The application of high and variable osmolality conditions, similar to what is observed in vivo, during pod culture (1 wk) and before extracting the embryos, gave the best results in terms of ovule and embryo development. To solve contamination problems affecting pod development during these investigations, a sterilizing technique was tested combining various concentrations of polpoxyethylenesorbitan monolaurate (Tween 20) and a broad-spectrum industrial biocide, Plant preservative Mixture (PPM). The PPM sterilizing method totally eliminated pod contamination and did not affect ovule growth, but significantly reduced the embryo germination rate.