Pollen Tube Growth, Fertilization and Embryo Development of Camellia japonica L. × C. chrysantha (Hu) Tuyama

Abstract

A study of reproductive barriers limiting interspecific hybridization between Camellia japonica L. and C. chrysantha (Hu) Tuyama was undertaken in intra- and interspecific crosses using two different lines of each species. Prezygotic barriers were unimportant; pollen tube growth and penetration was good in all combination. Zygote formation and early embryo development were similar in intra- and interspecific crosses. Intraspecific embryos grew smoothly and filled the ovules about 150 days after pollination; whereas in interspecific crosses, aborting hybrid embryos were found in various stages of decline 120 days after pollination. Full-sized but empty ovules in mature capsules resulted from embryo abortion.