Regional Adaptability Test (RAT) was conducted to select promising breeding lines of rice for cultivation in specif ic regions. Analysis of genotype (G) and genotype by environment (G×E) interaction observed in RAT was carried out to test their adaptabili

The purpose of this study was to evaluate the effect of pesticides on insect pest control of Rhophalosiphum nymphaeae, growth characteristies and dry root yield from the cultivated after early maturing rice cropping. All pesticides treated had no effect on the growh period, flowering rate of Alisma plantago. The major pesticides were methomyl-Lf, 24.1 %, imidacloprid-Wp, 10%, carbosulfan-Wp, 20%, and methomyl-Wp, 45%. Dry yield of root were increased largely with imidacloprid-Wp, 10% (10g/20~ell ), pesticide than the other pesticides and control. All pesticides were had no injury with recommended concentration. On the other hand all pesticides were slightly harmful in the double dosage level for the Alisma plantago.

In spite water direct seeding cultivation of rice has advantages in terms of laborsaving and cost-down, it demonstrates uneven seedling establishment and difficult weed management. To select an applicable mat for mulching system of water seeded rice, weed occurrence, growth and yield performances of rice, and soil temperature were evaluated in several kinds of biodegradable mulching material. Field studies were conducted at the experimental farm of National Crop Experiment Station in 1999 and 2000. Among the mats tested in 1999, Safer-mat had the greatest effect on inhibiting weed occurrence and Lawn-mat demonstrated the least efficacy of weed control (EWC) value. In Safer-mat treatment, Ludwigia prostrata was the dominant weed species but Echinochloa crus-galli was not observed. Different kinds of mulching material from the mats studied in 1999 were tested in 2000. Biodegradable polyester (PES) coated on the recycled paper for newspaper press (RP) treatments showed similar or higher EWC values than non-mulched broadcast seed rice with 2 times of herbicide application (BC-herbicide) and Safer-mat that was the most effective mat on preventing weed appearance in 1999. Immediately after mat mulching on the surface of paddy soil, five pregerminated rice seeds were manually sown in each 3cm-hole formerly punctured at 30~times 14 cm spacing in 2000. All the 3 kinds of mulching material tested in 2000 had better seedling stand than BC-herbicide treatment. Rice yield in PES coated with 10 thickness on RP (PES10 ~mu~textrmm ＋RP) was a little higher than in BC-herbicide treatment but the former produced less panicles in unit land area than the latter. PES10 ~mu~textrmm ＋RP demonstrated a great effect on raising soil surface temperature than non-mulching treatment throughout the period of seedling establishment.

포유동물의 혈중 프로락틴 농도는 일주기와 연주기의 변화를 나타내며 송과체에서 분비되는 멜라토닌이 조절인자로 관여한다. 인위적인 송과체의 기능 억제는 혈중 프로락틴 농도를 증가시킨다. 임신 후반기에 태반에서는 수종의 프로락틴군 호르몬들이 분비되어 태반기능 및 배아발생에 중요한 역할을 한다. 그러나 이들 호르몬 유전자들의 발현 조절기작과 조절 인자들에 관한 연구 결과는 미비하다. 본 연구에서는 RT-PCR과, in situ hybridization 방법으로

Blast severity data of 39 rice varieties at 11 sites in Korea from 1997 to 1999 were analyzed using AMMI model and pattern analysis. Genotype x Environment (G~times E) interaction sum of squares (SS) accounted for 12 % of the total SS. Eight genotype groups and seven location groups were identified based on blast reaction pattern. The data obtained from over 21 sites with 44 test varieties from 1981 to 1996 were also considered. These were compared with the 1997-1999 data using the G~times E analysis results. Majority of the variability in the Korean Rice Blast Nursery (KRBN) were attributable to variations due to genotypes. Variations of G~times E interaction were maintained though test sites were reduced from 21 to 11 sites. Broadly compatible biological discriminative varieties identified were Nagdongbyeo and Akibare while broadly incompatible biological discriminative varieties identified were Hangangchalbyeo and Seogwangbyeo. Key sites for future evaluation work could be selected from location groups. Each location group should be represented by the site with the strongest interaction pattern. Blast responses in Cheolwon, Gyehwa, Suwon, Iksan, and Icheon showed different patterns from other locations.

To investigate the effects of planting density and nitrogen level on growth and yield potential of newly bred heavy panicle japonica rice with large grain (Iksan 435 and Iksan 438) or many spikelets per panicle(HR14022-21-8-4 and HR14022-21-8-6), four heavy panicle type rices and two many panicle type rices(Dongjinbyeo and Donganbyeo) as the checks were planted under standard planting density (30~times 15 cm) and dense planting density (15~times 15 cm) with two nitrogen levels of standard nitrogen level(110 kg h a-1 ) and heavy nitrogen level(165 kg h a-1 ). Effective tiller rate decreased in dense planting or heavy nitrogen, when compared to standard nitrogen and planting, while leaf area index and to dry weight increased in dense planting or heavy nitrogen. Tiller numbers and panicle numbers were more increased by dense planting than heavy nitrogen, whereas spikelet numbers were more increased by heavy nitrogen than dense planting. Ripened grain ratio was slightly lower only in dense planting. 1,000 grain weight in brown rice was not significantly different in dense planting or heavy nitrogen. Milled rice yield was highest in heavy nitrogen with standard planting for heavy panicle type rice, while yield for many panicle type rice was highest in heavy nitrogen with dense planting, suggesting that many panicle type rice possesses higher adapt-ability for dense planting than heavy panicle type rice. Path coefficient analysis revealed that top dry weight, spikelet number and grain weight were the greatest positive contributors to yield, whereas tiller number was negative to yield.d.

1. Polyacrylamide gel electrophoresis를 이용하여 국내외 재래종과 야생종 대두 계통들의 trypsin inhibitor의 변이를 규명하기 위하여 본 시험이 시도되었으며 1706계통의 한국산 재래종과 103계통의 한국 야생종콩, 그리고 167계통의 외래 재배종과 71계통의 외국 야생종 대두가 공시되었다. 2. Trypsin inhibitor를 함유하지 않은 ti/ti형과 Ti c/c형은 한국 재래종에서만 발견되었으며, Ti* c형을 Hymowitz도 일본 대두품종에서 보고한 바 있으나 그도 이 계통은 한국 도래종일 가능성이 크다고 보고 한 바 있다. 3. 한국기원의 콩에서 trypsin inhibitor에 관한 이형접합형의 출현빈도가 외국 기원 콩 계통에서 보다 비교적 높았으며, 재래종에서 3.6%(N=61)와 야생종에서 9.7%(N=10)이었으며 종합적으로 보아 중국, 일본 등의 대두에 비해 한국 기원의 콩이 가장 큰 변이를 나타내고 있음을 확인하였다.