Dry Weight, Nitrogen Absorption and Survival of Wheat Tillers

[摘要] Relationship between tiller top growth at the initial stage of internode elongation and the heading ratio was investigated using two wheat cultivars of West Japan, Shinchunaga and Omasekomugi, and one spring cultivar of Hokkaido, Norin 29. The heading ratio of tillers was lower in Shinchunaga than in Omasekomugi. The top dry weight increment (ΔD) for one week and total nitrogen content (N content) one week after transfer to greenhouse-longday, condition were larger in vigorous tillers of Shinchunaga than in those of Omasekomugi, and larger in weak tillers of Omasekomugi than in those of Shinchunaga. The thresholds of ΔD and N content of the tillers where the heading ratio dropped below 100% were higher in Shinchunaga than in Omasekomugi. Two weeks after transfer to greenhouse-longday condition, when tillers clearly belonged to one of the two types, namely, heading and non-heading, the tillers of heading type had larger dry weight, higher N content and higher nitrogen absorption ability than the other. In Norin 29, the ΔD of the vigorous tillers for one week after the daylength treatment started was larger in the longday plot and that of the weak tillers was larger in the shortday plof N content was higher in the heading tillers than in the non-heading tillers. There was no difference in N content in the heading tillers between those of the longday plot and the shortday plot. Until the tillers started to grow independently with their elongated roots, their growth and nitrogen absorption ability proportionately declined to their heading ratio.

[学科分类] 农业科学（综合）

[关键词] Dry weight;乾物重;Heading ratio;コムキ;Nitrogen absorption ability;出穂率;Stem elongation stage;節間伸長期;Tiller;全窒素含有量;Total nitrogen content;窒素吸収能力;Wheat;分げつ