Abstract
These experiments were conducted to investigate the :actors influencing the systemic action of Dimethoate (O,O-dimethyl-S-(N-methylcarhamoylmethyl) photphorodithioate) to rice seeds and the phytotoxic effects on the seed germination. Dimethoate $(Roxion^{(R)})$ $40\%$ emulsion was used. The varieties tested were Jinheung. Nongkwang,Suwon #82, Norm #6, Paltal, Shirogane, Suseong, Pungkwang, Shin #2, Fujisaka #5, Kwanok, and Jaekeun. The permeated Dimethoate was extracted from the treated seeds by chloroform and quantities were determined by Spectrophotometer. The phytotoxicity was evaluated from the effects on the germination of the treated seeds which were kept in an incubator. The oxygen consumption was measured by Warburg Manometer at $30^{\circ}C$ for 60 minutes. Indices of KOH disintegration of seeds and chemical composition of the seeds were also determined. The results obtained were as followings; 1) The amount of permeated Dimethoate in the seeds showed remarkable differences with varieties. The amount of Dimethoate per 100 grains was greater as in the ascending order of Suseong, Kwanok, Nongkwang, Jinheung, Paltal, Fujisaka #5, Suwon #82, Norm #6, Shirogane, Shin #2, Pungkwang and Jaekeun. 2) It was observed that the total amount of Dimethoate in the seeds(mg./100 grains) were greater among the varieties with large grain than those with small grains, while reverse cases were true in the amount of Dimethoate in a gramme of seeds, probably because of the greater surface areas In a small grains for a gramme weight. 3) There was no significant correlation between the permeated amount of Dimethoate and amount of absorbed water by the seeds when the seeds were treated with $0.1\%$ Dimethoate for 24 and 48 hours. 4) The permeability of Dimethoate to seeds significantly increased in the prolonged soaking periods, higher concentration, and higher temperature. 5) When the seeds were treated with $0.1\%$ Dimethoate for 24 and 48 hours at $15^{\circ},\;20^{\circ},\; 20^{\circ},\; and \;30^{\circ}C$, the permeated amount of Dimethoate were increased at higher temperature. It seems to be that the more active penetration of Dimethoate was involved at the higher temperature. 6) The phytotoxic effects of Dinethoate on the seed germination varied with the varieties. An descending order of varietal tolerance of seeds was as followings: Jinheung, Fujisaka #5, Suwon #82, Paltal, Nongkwang, Jaekeun, Shin #2, Kwanok, Shirogane, Pungkwang, Suseong, and Norm #6. 7) There was a positive correlation between the amount of Dimethoate permeated into the seeds (mg./gram. of seeds) and phytotoxicity of seeds. 8) The Phytotoxic effects of Dimethoate showed close correlation with the degree of KOH disintegration of seeds, average germination periods, and oxygen respiration of seeds. 9) It was observed that higher protein contents of the seeds decreased the phytotoxic effects of Dimethoate. 10) Relatively high negative correlation between the degree of KOH disintegration of seeds and crude protein content of the seeds was observed. 11) The average germination period was delayed for about 2 days when the seeds were treated with $0.2\%$ Dimethoate for 24 hours at $30^{\circ}C$. 12) The oxygen consumption of the seeds treated with $0.2\%$ Dimethoate for 24 hours at $30^{\circ}C$ was greatly decreased when compared with that of the normal seeds. 13) The amount of oxygen consumption of the seeds (in 24 hours after 24 hours water soaking) was negatively correlated with the average germination periods of the seeds.
본 실험은 볍씨를 Dimethoate 액에 침지처리하였을 경우 약제의 침투량 및 볍씨의 발아생리에 미치는 여러 가지 요인의 영향을 추정하기 위해 수도품종 12개를 공시하여 침지시간, 농도 및 온도에 따르는 약제침투량 그리고 처리에 의한 볍씨의 발아생리에 미치는 영향에 관하여 실험하여 다음과 같은 결과를 얻었다. 1) Dimethoate 침투량은 공시품종에 따라 현저한 차이가 있으며 볍씨 100입당 약제침투량은 수성>관옥>농광>진흥>팔달>승판 5호>수원 82호>농림 6 호>시로가네>신 2호>풍광>재원의 순서 이었고 종자당 약제 침투량은 대립종에서 많았고 소립종에서 적었으며 1g당 약제침투량은 그와 반대로 소립종에서 많았다. 약제침투량과 볍씨의 흡수율과의 상관은 $\gamma=+0.35$로 낮았다. 2) 약제침투량은 침지시간, 농도 및 온도에 따라 차이가 있었으며 특히 처리온도의 영향이 컸다. $0.1\%$ Dimethoate에 48시간 침지처리하였을때 볍씨 1g당 약제 침투량은 $15^{\circ}C$에서는 0.174mg, $20^{\circ}C$술에서는 0.208mg 및 $30^{\circ}C$에서는 0.397mg이었다. 3) Dimethoate처리가 볍씨의 발아에 미치는 영향은 품종에 따라 현저한 차이가 있었는데 발아저해도의 순위는 $0.1\%$ Dimethoate액에서 24시간 처리의 경우 팔달>수원 82 호>진흥>풍광>재건>시로가네>농광> 농림 6 호>신 2호>수성>승판 5호>관옥이었고 48시간 처리의 경우 진흥>승판 5호>수원 82호>팔달>농광>재건>신 2호>관옥>시로가네>풍광>수성>농림 6호이었으며 발아저해도와 약제침투량간의 상관은 $\gamma=0.683$로 유의하였다. 4) Dimethoate처리$(30^{\circ}C,\;0.2\%$액에서 24시간)에 의하여 볍씨의 발아가 억제되었으며 평균발아속도는 약 2일 지연되었고 그 정도는 품종에 따라 차이가 있었다. 5) 공시품종의 발아속도와 발아저해율과는 정의 정관$(\gamma=+0.78$을 나타내었으며 발아속도가 빠른 품종에서 발아저해율이 낮았고 딴대로 발아속도가 늦은 품종에서 발아저해가 심하였다. 6) 공시품종의 화학적조성중 단백질이 발아저해도와 가장 관계가 깊었는데 단백질의 함량이 낮은 품종은 Dimethoate에 의한 발아저해가 높은 경향을 보였다. 7) 공시품종의 KOH 붕괴도는 품종간에 현저한 차이가 있었으며 KOH 붕괴도가 큰 품종이 발아저해가 심하고 작은 품종은 덜한 경향을 보였다. 또한 KOH 붕괴도와 단백질 함량과는 $\gamma=-0.422$의 높은 상관을보였다. 8) 공시품종의 산소호흡량은 품종에 따라 현저한 차이가 있었으며 Dimethoate처리$(30^{\circ}C,\; 0.2\%$액에서 24시간)에 의하여 볍씨의 호흡량이 감소되었다. 9) 산소호흡량과 평균발아소요일수와는 $\gamma=-0.945$로 부의 유의한 상관을 보였는데 산소호흡량이 많은 품종은 평균발아소요일수가 짧은 경향을 보였다. 10) 볍씨의 산소호흡량과 Dimethoate 처리에 의한 볍씨의 발아저해도와는 $\gamma=-0,771$의 높은 부의 상관을 보였으며 산색호흡량이 많은 품종이 발아저해도가 낮고 적은 품종에서는 높았다.