寒冷地の水稲湛水直播栽培における品質関連形質の特徴とその変動要因

日本作物学会紀事

長田 健二¹  福田 あかり¹  白土 宏之¹  吉永 悟志¹ 

[1] 東北農業研究センター

关键词: Cooler region;    寒冷地;    Direct-seeding;    ç›´æ’­;    Grain quality;    品質;    Palatability;    食味;    Rice (Oryza sativa L.);    水稲;   

DOI  :  10.1626/jcs.81.432

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

In the cool region of Japan, the grain quality of direct-seeded rice is assumed to be different from that of transplanted rice, since the heading date is dlayed by direct seeding and the climate condition during the ripening period is also different. However, the details of the effects of direct seeding on the grain quality have not been examined. We analysed the results of a 4-year field experiment with different cropping seasons in Tohoku region and examined the characteristics of the quality and their causal factors in direct-seeded rice. As compared to transplanted rice, the protein and amylose contents of direct-seeded rice, which are considered to affect taste quality, were not so different as to affect the palatability. On the other hand, grain weight and perfect grain ratio were higher and the yearly difference in the perfect grain ratio was smaller in the direct-seeded rice than in the transplanted rice. Such improvement of the quality by direct seeding was attributed to the delay of the heading date and the lower number of spikelets per panicle. The delay of the heading date lowered the temperature during the early ripening period (lower than 25°C for 20 days after heading) which in turn resulted in the decrease in chalky grains and the increase in the grain length. The lower number of spikelets per panicle in direst-seeded rice reduced the grain ratio on the secondary-rachis branches, with grain quality lower than that on the primary rachis branches.

【 授权许可】

Unknown