The response of dissolved oxygen (DO) concentrations caused significant change in root number, root length, coleoptile length, shoot length and leaf age of seedlings. The genotypic difference in the effect of DO also highly significant (P<0.01) for all of the seedling traits. The number and length of root were extremely inhibited at the condition of 0.39~pm0.09 DO concentration. While the coleoptile elongated markedly in the lowest DO concentrations, the shoot did not develop. The root growth was improved slightly at the 1.39~pm0.27mg L-1 , however, there were no difference among genotypes at these two low DO concentrations. As the DO concentration become higher, the growth of root and shoot was improved remarkably. Root number, root length and shoot length was significantly different between 20~;and~;30~circC in DO rich and normal conditions, the development of those traits were apparently accelerated in high water temperature, however those traits of seedlings in DO deficiency were not different between the two temperatures except for shoot length. On the other hand the coleoptile length was not affected by the stagnant water temperature; it was stimulated by the low DO concentration. The competition of DO was greater as the seedling density was increased in the stagnant water, therefore the seedlings grown under high density have long and white coleoptiles, and the growth of roots and shoots was retarded severely.

벼 약배양에 있어서 배양약의 viability의 변화를 관찰하고자 밀양 2003, 대청벼, 치악벼를 재료로 품종 및 저온전처리, 약의 갈변에 따른 호흡율의 변화를 2~3일 간격으로 조사하였다. 화분의 발육시기에 따른 배양전 약의 호흡활성은 개화직전에 가장 높았으며, 배양적기인 stage 3~4에서의 호흡율은 12.46 O2 n mode/ml/h/another이었다. 배양약의 호흡활성의 변화는 3~9일경에 1차 정점을, 9~11일경에 2차 정점을 나타냈으며, Callus 형성능이 높은 대청벼에서 가장 높게 나타났다. 저온전처리는 배양 초기의 호흡활성을 저하시켰으나 15일경부터는 무처리구 보다 높은 경향이었다. 또한 저온전처리는 약의 갈변을 촉진하였으며, 갈변약에서 호흡활성이 높았다.