Endosperm Culture and the Regeneration of Triploid Rice Plants

Abstract

Triploid and hexaploid plants are more vigorous than diploids (Morinaga and Fukushima 1935), and their foremost use is in hybridization programs, especially for the augmentation of reservoirs of germplasm. Hybrid selection can then be made for desirable agronomic traits; however, in rice these are difficult to obtain. Triploids are sometimes spontaneously found in the field (Watanabe et al. 1969). Some rice triploids were obtained by crossing 2n with 4n (Morinaga and Kuriyama 1959) or 4n with 2n plants (Nagamatsu et al. 1964). Such conventional practices are timeconsuming and unpredictable. However, by the in vitro culture of endosperm they can be obtained in a matter of weeks (Bajaj et al. 1980). Moreover, endosperm-derived plants would generate somaclonal variation and will add to the genetic variability in this important cereal crop (Bajaj and Bidani 1986).