CRYPTIC USEFULNESS OF ORYZA LONGISTAMINATA, AFRICAN WILD SPECIES OF RICE

Abstract

In the 21st century, several novel traits in crops should be possibly needed. Genetic resource is a jewel box for crop improvement. Oryza longistaminata, African wild species of rice is the most distantly related species from O. sativa within the Sativa group. Some characters of this species, long anther, large biomass and rhizomatous trait will be potentially useful in Next New Ideal Rice irrespective of high cross-incompatibility and hybrid sterility between two species. Long anther trait of O. longistaminata had been introduced into Shiokari, a variety in Hokkaido, Japan, through backcrossing. Segregants selected by long anther trait from O. longistaminata showed cool weather tolerance under cool summer condition, suggesting that long anther trait of O. longistaminata might be effective to cool weather injury at the booting stage. Large biomass trait was introgressed through selfing of selected lines derived from the cross between O. longistaminata and T-65. The selected lines showed stiff and long culm, large number of spikelets and relatively small number of panicles under non-fertilized conditions. Although global cultivars of rice are probably incompatible with O. longistaminata, some novel traits will be useful in the near future breeding program. Thus, these breeding materials derived from O. longistaminata are expected to be effective for new ideal rice.