Sugar and starch in leaf-sheaths and internode of Jinheung and IR667 rice under various ripening environments

진흥(振興)과 IR 667의 엽초(葉鞘) 및 절간(節間)의 당(糖) 및 전분함량(澱粉含量)과 등숙환경(登熟環境)

According to the content of sugar and starch of each positional leaf sheath and internode at heading and 4 weeks after it using IR667-Suwon 214 (high yielding var. having tropical Indica parantage) and Jinheung (local leading var. temperate Japonica) rice grown in various cultivation seasons the suitability of grouping into the high sugar type (sugar>starch), sugar, tendency (increasing tendency in sugar content), high starh type (starch>sugar) and starch tendency (increasing tendency in starch) in carbohydrate metabolism was reexamined as follows. 1. Sugar tendency appeared strongly in IR667 than Jinheung, internode than leaf sheath, late season cultivation than early season, 4 weeks after than heading and high temperature than low temperature. Thus at heading, leaf sheath and internode of Jinheung in early and late season cultivation were high starch type, and lower internode in early season cultiattion and leaf sheath and internode in late season for IR667 were high sugar type. In very late season all internodes of both varieties except 1st internode of Jinheung at heading were high starch type. At four week after heading all leaf sheaths except 1st and 4th one of Jinheung and all internodes were high sugar type. High sugar type was intensified 4 weeks after heading in leaf sheaths than in internodes of IR667 in early season and of both varieties in late season. 2. The upper three leaf sheaths and internodes seem to work in the same way for carbohydrate translocation. Among them upper ones showed sugar tendency at heading and starch tendency 4 weeks after heading and it was clear in Jinheung. 3. The later the cultivation season, the higher the carbohydrate content (sugar+starch), and such tendency was clear 4 weeks after heading and in IR667, suggesting teanslocation inhibition by low temperature. 4. Grain filling rate (weight increase per day) was more rapid in early season cultivation and IR667 took shorter days to reach maximum rate. 5. The later the cultivation season, the greater the percent contribution of carbohydrate before heading to yield and it was always greater in IR667, a leaf sheath type. 6. Sugar and starch ratio appears to be determined principally by metabolic characteristics of variety according to growth process and secondly but considerably by environmental factors.

진흥(振興)과 IR667-수원(水原) 214의 작기이동재배(作期移動栽培)에서 출수기(出穗期)와 출수(出穗)4주후(週後)에 절위별(節位別) 엽초(葉鞘) 및 절간(節間)의 당(糖) 및 전분함량(澱粉含量)에 따라 탄수화물대사(炭水化物代謝)에 있어 고당형(高糖形)(당(糖)>전분(澱粉)), 당경향(糖傾向)(당함량증가경향(糖含量增加傾向)), 고전분형(高澱粉形)(전분(澱粉)>당(糖)), 전분경향등(澱粉傾向等) 분류(分類)의 타당성(妥當性)을 재검토(再檢討)한 결과(結果) 다음과 같다. 1) 진흥(振興)보다 IR667이, 엽초(葉鞘)보다 절간(節間)이, 조기(早期)보다 만기(晩期)가 출수기(出穗期)보다 4주후(週後)가 저온(低溫)에서보다 고온(高溫)에서 당경향(糖傾向)이었다. 따라서 출수기(出穗期)에는 조기(早期) 및 만기재배(晩期栽培)의 진흥엽초(振興葉鞘)와 절간(節間)이 고전분형(高澱粉形)이고 조기(早期) IR667의 하위절간(下位節間) 및 만기(晩期) IR667의 엽초(葉鞘)와 절간(節間)은 고당형(高糖形)이었다. 극만기(極晩期)에서는 진흥출수기제(振興出穗期第)1절간(節間)을 제(除)한 두 품종의 모두 절간(節間)이 고전분형(高澱粉形)이었다. 출수(出穗)4주후(週後)에는 진흥(振興)의 제1(第) 및 4위엽초(位葉鞘)를 제외(除外)한 두품종의 모든 엽초(葉鞘)와 절간(節間)이 고당형(高糖形)이었다. 조기(早期) IR667과 만기(晩期) 두품종이 출수(出穗)4주후(週後)에 절간(節間) 보다 엽초(葉鞘)에서 고당형(高糖形)이 강화(强化)되었다. 2) 상위(上位)3절위(節位) 엽초(葉鞘) 및 간(稈)이 탄수화물전류(炭水化物轉流)에서 같은 방향(方向)으로 작용(作用)하는 것 같다. 그들간엔 상위(上位)로 갈수록 출수기(出穗期)에는 당경향(糖傾向)을, 4주후(週後)에는 전분경향(澱粉傾向)을 보이며 이러한 현상은 진흥(振興)에서 뚜렷하였다. 3) 작기(作期)가 늦을수록 탄수화물함량(炭水化物含量)(당(糖)+전분(澱粉))이 높고 이 경향(傾向)은 출수(出穗)4주후(週後)와 IR667에서 뚜렷하여 저온(低溫)에 의(依)한 전류조해(轉流阻害)를 나타내는것 같다. 4) 수(穗)로의 전류속도(轉流速度)(일당입중증가(日當粒重增加))는 단기재배(單期栽培)에서 빠르고 진흥(振興)보다 IR667이 빨리 최고속도(最高速度)에 도달(到達)하였다. 5) 작기(作期)가 늦을수록 수량(收量)에 대(對)한 출수전(出穗前) 탄수화물(炭水化物)의 기여율(奇與率)은 커지며 엽초중심형(葉鞘中心形)인 IR667이 언제나 컸다. 6) 당(糖)/전분비(澱粉比)는 주(主)로 품종(品種)의 대사특성(代謝特性)으로, 이차적(二次的)으로 그러나 상당한 정도로 환경요인(環境要因)에 의하여 결정(決定)되는것 같다.