벼 Anaerobic 무논직파 재배시 파종깊이와 담수기간에 따른 입모(立毛)및 초기 생육 = Rice Seedling Establishment and Early Growth Affected by Seeding Depth and Flooding Duration for Anaerobic Wet Seeding

국문 초록 (Abstract)

벼 Anaerobic 무논직파시 사용종자별 파종 후 種子埋沒 깊이에 따른 限界 排水時期 구명의 기초 자료를 얻고자 催芽種子와 浸種種子를 0-2.0㎝(0.5㎝ 간격) 깊이로 파종하여 1, 3, 5, 7일간 담수한 후 排水하여 出芽日數, 立毛率, 中胚軸長, 播種 後 20日 草長 등을 조사하였던 결과를 요약하면 다음과 같다.
1. 出芽日數는 催芽種子 2.0-6.8일, 浸種種子 3.0-7.8일로 최아종자가 침종종자 보다 평균 1일이 빨랐고, 최아, 침종종자 다같이 파종깊이가 깊고 湛水日數 길수록 출아가 늦었다.
2. 立毛率은 催芽種子가 浸種種子 보다 높았고 그리고 파종깊이가 깊고 湛水日數가 길수록 떨어졌다. 입모율 40% 기준시 파종깊이별 限界湛水日數는 최아종자는 파종깊이 0㎝와 0.5㎝는 5일, 1-2.0㎝는 3일이었고, 침종종자는 모든 파종 깊이에서 3일이었다.
3. 中胚軸은 浸種, 催芽種子 다같이 파종깊이 0㎝, 0.5㎝에서는 관찰되지 않았고, 파종깊이 1-2㎝에서는 파종깊이가 깊을수록 中胚軸이 길었다. 湛水日數에 따른 中胚軸長은 모든 파종깊이에서 1일간 담수에서 가장 길었고, 3일-7일간 담수시는 파종깊이 1㎝에서는 큰 차이가 없었으나, 湛水日數가 길어질수록 中胚軸長이 파종깊이 1-1.5㎝에서는 길어졌으나 파종깊이 2.0㎝에서는 짧아졌다.
4. 파종 후 20日 草長은 催芽種子가 浸種種子보다 약간 길었고, 파종깊이간에는 파종깊이가 깊을수록 草長이 짧아졌으며, 湛水日數에 따라서는 3일간 담수에서 가장 길었고, 1일 및 5일간 담수는 비슷했으며 7일간 담수에서 가장 짧았다. 파종 깊이와 湛水日數에 따른 草長들은 파종깊이 1.0㎝ 및 1.5㎝에서는 7일간, 2.0㎝에서는 5일 및 7일간 담수시는 草長들이 15.9-19.2㎝로 짧았고, 그 외 처리에서는 草長이 20.0㎝이상으로 생육이 좋았다.

다국어 초록 (Multilingual Abstract)

The experiment was conducted to obtain the stable seedling establishment under different seed burying depths in anaerobic wet seeded rice. Pregerninated and soaked seeds of IR72(Indica) seeded to 0, 0.5, 1.5 and 2.0㎝ depth in trays, respectively and flooded with 3-4㎝ depth. The water was carefully siphoned at 1, 3, 5, or 7 days after flooding. Afterward, the trays were managed under saturated soil moisture by spraying water one or two times everyday. Days to seedling emergence with seeding depth and flooding duration ranged from 2.0 to 6.8 days for pregerminated seed(PS) and from 3.0 to 7.8 days for soaked seed(SS). For PS and SS, seedling emergence was significantly delayed with deeper seeding depth and longer flooding duration. Percent seedling establishment was very high at one day flooding in all sowing depths, with 80.3-89.0% for PS and 78.0-92.0 for SS, but decreased sharply with longer flooding duration. The degree of decrease was greater at deep seeding depth and long flooding duration. Based on about 40% of seedling establishment, the critical flooding duration was 5 days at 0 and 0.5㎝ seeding depth and 3 days at 1.0-2.0㎝ sowing depth for PS, and 3 days at all seeding depths for SS. No mesocotyl was observed at 0 and 0.5㎝ seeding depths in all flooding duration. At 1-2㎝ seeding depth, mesocotyl length was longer as seeding depth increased. And mesocotyl length with flooding duration was longest at one day flooding, and that among 3-7days flooding was no significantly difference at 1.0㎝ seeding depth but increased and decreased at 1.5㎝ and 2.0㎝ seeding depth, respectively with longer flooding duration. Plant height was significantly shortened at 1.0-1.5㎝ seeding depth of 7 days flooding, and 2.0 seeding depth of 5-7 days flooding, but not greatly significant among other treatments.