Change of sugar and starch content in unripened grain of Jinheung and IR667 rice during ripening

진흥(振興)과 IR667벼의 미등숙립중(未登熟粒中) 당(糖) 및 전분(澱粉)의 시기별(時期別) 변화(變化)

  • 박훈 (농촌진흥청 농업기술연구소) ;
  • 권항광 (미성농약실험실)
  • Received : 1975.01.20
  • Published : 1975.03.20

Abstract

The weekly change of sugar and starch content in unfilled grain of Jinheung (temperate rice var.) and IR667-Suweon 214 (tropical rice var.) and of filled grain ratio (less than specific gravity 1.06 for Jinheung and 1.03 for IR667), filled grain weight and unfilled grain weight from flowering and the relationship among them were as fallows. 1. Total sugar content in unfilled grain was twice in Jinheung than in IR667 and starch content was higher (about 2.5 to 3.5%) in Jinheung but starch/sugar ratio was greater in IR667. Thus IR667 that was classified as high sugar type in leaf sheath and internode appears to be high starch type in sink (grain). 2. Under the favorable condition the weight of unfilled grain reached to minimum value and followed by maximum filled grain ratio and lastly by maximum weight of filled grains per ear. 3. Sugar and starch content gradually increased and then decreased during ripening and the maximum values reached prior to maximum filled grain ratio (6 weeks). Sugar content reached to maximum much earlier than starch content did and increased again from 8 weeks later. 4. Starch/sugar ratio reached to maximum value earlier than maximum starch content and earlier in IR667 than in Jinheung. 5. Maximum starch content of unfilled grain in Jinheung was 51.1%.

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