Effect of Grain Size of Rice Seeds on the Initial Growth of Seedlings

법씨알의 크기가 모의 초기생육에 미치는 영향

The effect of differences in grain size on the initial growth of seedlings was studied in rice with two leading varieties of Jaekun and Nongkwang. The grains were classified into three classes of large, medium and small size by their specific gravity. The results observed at seedling stage are summarized as follows. 1. Higher percentage of seeds with larger size was observed to be normally developed into sound seedlings comparing with those with small seeds. This suggests the more effective maintainance of seedings. 2. Seedlings from larger seeds also showed higher values in the number of roots, leaves and tillerings where no varietal difference was observed. 3. Varietal speciality led to the lorger coleoptile of Nongkwang variety, with rather longer plant, than that of Jaekun, while higher value in coleoptile length was observed at the seedlings from larger seeds. 4. Thus larger seeds and the Aariety Nongkwang yielded heavier dry matter of upper part. These trends appeared more clearly at the late seedling stage. 5. There was constant decrease in the dry matter weight per unit coleoptile length until the seedling-selfsupportingstage while after this stage abrupt increase was observed. Seedlings from larger seeds showed higher value in the dry matter weight per unit coleoptile until this stage, thought the differences became insignificant after this stage. And no varietal difference was found.

종자의 대소가 묘의 초기생육에 미치는 영향을 알고저 재건, 농광의 2개 수도품종을 공시하고 종자를 크기에 따라 대립, 중립, 소립으로 구별하여 묘대기의 생육을 관찰한 결과는 다음과 같았다. 1. 종자가 클수록 성묘율은 높아 대립이 묘수 확보에 유리함을 알 수 있었다. 2. 발근수, 출엽수 및 분얼수 역시 대립일수록 많았으며 품종간 차는 나타나지 않았다. 자엽장은 품종적 특성에 따라 농광이 길었으며 대립일수록 역시 길었다. 4. 따라서 지상부 건물중은 대립일수록 크게 나타났으며 품종별로는 농광이 높았다. 이러한 차는 생육이 진전될수록 현저하였다. 5. 단위 자엽길이 당건물중은 이난기까지는 감소하고 그 이후부터 증가하여쓴데 종자크기에 따른 건물중은 이 시기까지는 대립이 높았으나 그 후는 곧 차를 보이지 않았고 품종간 차는 전반적으로 나타나지 않았다.