Evaluation of Cold Tolerance in Rice Cultivars by the Characteristics Related to Chilling Injury -II. Transition Temperature of Respiratory Activity on Rice Cultivars and Cold Tolerance

수도(水稻) 품종(品種)의 냉해관련인자(冷害關聯因子) 특성(特性)에 의(依)한 내냉성(耐冷性) 평가(評價) -II. 호흡활성(呼吸活性) 전이온도(轉移溫度)와 내냉성(耐冷性)

To evaluate cold tolerance of rice cultivars on the basis of a relationship between cold tolerance in the field test and a biochemical character, transition-temperature of respiratory activity of mitochondria(TRM) which were isolated from different parts and at different growth stages and from etiolated rice seedling was investigated, and its relationship with degree of cold tolerance(DCT) in the field experiment was studied. The results obtained were summarized as follows. 1. The transition-temperature of respiratory activity of mitochodria (TRM) isolated from etiolated seedling ($25^{\circ}C$, two week-grown in the dark) of cold tolerant cultivars tended to be low, while that of cold susceptible cultivars to be high. 2. The correlation between TRM of etiolated seedling and the degree of cold tolerance(DCT) was $r=0.8935^{**}$ in 1988 and $r=0.8236^{**}$ in 1989. The correlation coefficient between TRM of 4-leaf seedling and DCT was $0.6239^{**}$ 3. TRM of young panicle was correlated with DCT except a few varieties. 4. TRM of seedling increased with growth as $12.5^{\circ}C$, $14.5^{\circ}C$, $15.5^{\circ}C$ and $16.5^{\circ}C$ at 1, 2, 3~4 and 5weeks respectively. 5. The transition temperature of mitochondrial respiratory activity was not significantly influenced by growth stages as $15.0{\sim}16.0^{\circ}C$ in Pungsanbyeo and $17.0{\sim}18.0^{\circ}C$ in Satbyelbyeo, while it was significantly different depending upon the degree of cold tolerance(tolerant, medium, susceptible).

수도품종(水稻品種)의 내냉성(耐冷性)을 실험실내(實驗室內)에서 화학적(化學的)인 분석방법(分析方法)에 의하여 조사(調査)하기 위하여 백화묘(白化苗) 및 유묘(幼苗)와 생육시기별(生育時期別) 잎 및 유수의 mitochondria 호흡활성(呼吸活性) 전이온도(轉移溫度)를 측정(測定)하고 내냉성정도(耐冷性程度)와의 관계(關係)를 검토(檢討)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 수도(水稻) 백화묘(白化苗)($25^{\circ}C$, 암상태(暗狀態) 2주간(間) 생육(生育))에서 분리(分離)한 mitochondria의 호흡활성전이온도(呼吸活性轉移溫度)와 내냉성정도(耐冷性程度)와의 관계(關係)를 보면 내냉성(耐冷性)이 강한 품종(品種)에서 전이온도(轉移溫度)가 낮고 약(弱)한 품종(品種)에서 높은 경향(傾向)을 보였다. 2. 백화묘(白化苗)의 호흡활성(呼吸活性) 전이온도(轉移溫度)와 내냉성정도(耐冷性程度)와의 관계(關係)에서 1988년에는 상관계수(相關係數) $r=0.8935^{**}$, 1989년은 $r=0.8236^{**}$으로서 높은 상관관계(相關關係)를 보였고 유묘(幼苗)(4엽기(葉期))의 호흡활성(呼吸活性) 전이온도(轉移溫度)와는 $r=0.6239^{**}$로서 약간 낮았다. 3. 수잉기 유수의 mitochondria의 호흡활성(呼吸活性) 전이온도(轉移溫度)와 내냉성정도(耐冷性程度)와의 관계(關係)는 몇 품종(品種) 벗어나는 것도 있었으나 일치(一致)하는 경향(傾向)을 보였다. 4. 수도묘(水稻苗)의 생육시기(生育時期)에 따른 호흡활성(呼吸活性) 전이온도(轉移溫度)는 1주묘(苗) $12.5^{\circ}C$, 2주묘(苗) $14.5^{\circ}C$, 3주와 4주묘(苗) $15.5^{\circ}C$, 5주묘(苗)는 $16.5^{\circ}C$로서 어린묘(苗) 일수록 낮았다. 5. 생육시기별(生育時期別) 엽신(葉身)과 유수의 mitochondria 호흡활성(呼吸活性) 전이온도(轉移溫度)는 상풍벼 $11.5{\sim}12.5^{\circ}C$, 풍산벼 $15.0{\sim}16.0^{\circ}C$, 샛별벼 $17.0{\sim}18.0^{\circ}C$로서 시기별(時期別) 큰 차이(差異)가 없었으나 내냉성(耐冷性) 강, 중(中), 약(弱) 정도별(程度別)로는 뚜렷한 차이(差異)를 보였다.