1. 생산지에 따라 벼 종자의 수발아립률 차이가 컸던 호 품벼의 출아율과 발아율을 조사한 결과, 수발아율 8% 인 시료는 수발아율이 1%인 시료에 비해 발아율과 출 아율, 종자활력이 30% 낮았다. 2. 수발아율이 높은 시료는 수발아립의 변색 정도가 심 하고 미발아율과 부패율이 높았다. 수발아립은 배가 돌출하고, 변색된 배유와 곰팡이 감염이 관찰되었으며 배유의 1/2이상이 변색된 종자는 발아율이 매우 낮았다. 3. 종자의 발아 진행정도에 따라 현미의 변색이 심해졌 는데, 싹이 3 mm이상일 경우 배유의 1/2정도가 변색 되었다. 4. 발아 종자는 싹이 3 mm이상일 때부터 재발아율이 크 게 떨어졌으며 퇴화촉진처리 후 발아율의 감소가 더 컸다. 특히 퇴화촉진처리한 발아 종자는 싹이 2 mm부 터 종자활력이 크게 감소하였다. 결론적으로 수발아 발생이 심할수록 파종기 발아율과 출 아율의 감소가 크고, 수발아가 3 mm이상 발생하면 발아율 이 크게 저하될 것으로 생각된다. 또한 수발아는 동일 품종 과 동일 지역에서도 포장 간 차이가 크게 발생할 수 있으므 로 재배관리에 주의해야 한다.
This study aimed to investigate the effects of pre-harvest sprouting (PHS)-damaged grains of rice on seed viability, germination percentage and seedling emergence rate. As comparing the seed lots of same cultivar ‘Hopum’ with different PHS percentages, seed lot with 8% PHS (high PHS percentage) showed 30% lower germination than that with 1% PHS (low PHS percentage). The difference of seedling emergence rate and seed viability percentages between the two seed lots was consistent with that of germination percentage. PHS-damaged brown rice was observed protruded embryo, discolored endosperm and fungi infected grains. PHS grains were classified into two groups, PHS-I showing endosperm discoloration in one third of a grain and PHS-II in more than half of a grain. The seed lot with high PHS percentage had much more PHS-II grains than that of low PHS percentage. PHS-II grains showed remarkably lower germination percentage than PHS-I grains and got severely moldy during germination test. In laboratory experiment, morphological changes and re-germination ability of seeds which dried after germination by soaking were tested. Sprouted seeds of 3mm shoot length showed half discolored endosperm and had a strong resemblance with PHS-II grains. Re-germination percentage of 3mm sprouted seeds sharply decreased than 2 mm sprouted seeds. Sprouted seeds which were treated for accelerated-aging (AA) for 24hr at 45℃ were significantly reduced in re-germination percentage compared to that of non-AA-treated sprouted seeds. These results indicate that PHS with over 3mm shoot length can severely damage not only grain appearance but also seed viability, germination percentage and seedling emergence rate. Therefore, we conclude that larger difference of germination percentage or seedling emergence rate between seed lots having smaller difference of PHS percentage might be caused by accelerated seed deterioration in PHS-damaged rice grains.