Studies on White-Belly Rice Kernel : I. Varietal differences in the occurrence of white-belly kernel

[摘要] Varietal differences were investigated on the occurrence of white-belly kernel with reference to weight and size of kernel and a panicle character. Occurrence of white-belly ranged from small to large degree depending upon varieties. But no essential difference was recognized in the occurrence among japonica and indica varieties. White-belly abundantly occrred in upland and late-lowland varieties of japonica type and Chinese Sen type of indica variety. Percentage of white-belly kernel considerably differed with cropping year, except for varieties of two extremes on white-belly occurrence. External type of white-belly occured more frequently in japonica lowland varieties. External and internal white-belly was abundantly found in varieties of high white-belly percent. A close relationship between the length·width/thickness and the occurrence of white-belly was observed. But no correlation was found between length-width ratio and white-belly occurrence. Relation between kernel weight and white-belly occurence was possitive and highly significant. Density of spikelet born on panicle and white-belly occurrence were negatively correlated. From these results, it could be said that white-belly may occur more frequently in the well-developed but slightly flat kernel. And furthermore, it can be assumed that vigorous growth of kernel in early stage and declining accumulation of carbohydrates in later stage may lead to the occurrence of opaque tissue in the outer-ventral part of kernel which might be very susceptible to ill ripening.

[学科分类] 农业科学（综合）