S. Ohki, K. Nasuda, Y. Mori, H. Katsuta
To create new varieties of vegetable crops, it takes many years and it is almost impossible to accumulate recessive characteristics even using the F1 breeding system. We tried to create a breeding=in vitro nursery system using favorable plants which appeared in F2-F3 generations in the course of the hybridization.

For the tomato, we had resistance to bacterial wilt as a breeding objective. In vitro propagated plantlets from the nodal tissue of selected plants grew without developing any bacterial wilt symptom and produced high quality fruits, in contrast to the other F1 varieties which were all killed by this disease. For the melon, high sugar content and high quality fruits associated with disease resistance was the main breeding objective. The plants showing the favorable characteristics mentioned above were obtained at the rate of 6 to 8% in F2-F3 generations. The in vitro propagating system was established using nodal tissue as an explant excised from lateral branches of the selected plants. The plantlets obtained were cultured in the field and we could harvest fruits with excellent appearance and high sugar content, although the weight of the fruits was inferior to the mother plant. Thus, the superiority of the in vitro nursery system combined with classical breeding was proved.

Ohki, S., Nasuda, K., Mori, Y. and Katsuta, H. (1988). ESTABLISHMENT OF BREEDING=IN VITRO NURSERY SYSTEM FOR VEGETABLE CROPS. Acta Hortic. 230, 89-96
DOI: 10.17660/ActaHortic.1988.230.8

Acta Horticulturae