UV-B injury in rice plants: A genetic study

Application of an inhibitor of gibberellin biosynthesis alleviated the UV-B injury in rice seedlings when tested for chlorophyll content per unit fresh and dry weight. A genetic study was conducted by crossing Tan-ginbozu, a gibberellin-deficient mutant, against two floating rice cultivars that presumably contain large amounts of endogenous gibberellins. The heritabilities of plant height, and chlorophyll content per unit fresh and dry weight were high in the F2 plants in non UV-B irradiated control populations. When those plants were treated with UV-B irradiation, the F2 population tended to shift to the lower range in the chlorophyll content per unit weight, and the value of heritability fluctuated depending on the cross and characters measured. Selection of plants that are highly resistant to UV-B irradiation can be made possible by finding the range of UV-B energy that increases the difference between sensitive and resistant, while also increasing the value of the heritability.