The possibility to obtain the seeds by the method of test-tube fertilization was examined using a self-incompatible plant, Petunia hybrida, and a self-compatible one, Eschscholtzia californica, as a control.
1. Pollen grains from both tested plants germinated and grew well on the sucrose-borate medium. On the basal medium (Table 1), pollens of E. californica germinated considerably, while those of P. hybrida hardly germinated. Pollen germination and tube growth of the latter were improved, however, in following two methods; (a)“style culture”or (b) culture of whole mass of bare ovules with placental tissue dusted with pollen grains.
2. With E. californica, the ovules developed normally at the early period of the culture, but well developed seeds were not obtained in spite of the subculturing. Some of well swelled ovules formed callus having bud primordia like protuberances.
With. P. hybrida ovules developed well by culturing the whole mass of bare ovules with pollen grains in both cross (fertile) or self (sterile) combinations. Some of the seedlings were obtained by subculturing the developed seeds onto basal medium in the former combination and also in the latter by employing MURASHIGE and SKOOG medium.