Monoamines have been known to mediate cellular immune responses such as hemocyte nodulation and phagocytosis in some insects. Eicosanoids also mediate the cellular immune reactions responsible for clearing bacterial infection from hemolymph circulation in various insects. In this study, we investigated a functional relationship of both mediators in expressing hemocyte nodulation and phagocytosis of fifth instar larvae of the beet armyworm, Spodoptera exigua. Addition of octopamine or serotonin along with bacteria enhanced hemocyte nodulation and phagocytosis of S. exigua larvae. Phentolamine (octopamine inhibitor) and ketanserin (serotonin inhibitor) suppressed hemocyte nodulation and phagocytosis of S. exigua in response to a bacterial challenge. Each inhibitory effect of both monoamine inhibitors was recovered by addition of either octopamine or serotonin, suggesting their independent signaling pathways. Both inhibitor effects were also recovered by addition of arachidonic acid (a precursor of eicosanoid biosynthesis). Furthermore, the stimulatory effects of monoamines on the cellular immune responses were prevented by addition of dexamethasone (a specific phospholipase A2). However, the inhibitory effect of dexamethasone was not recovered by excess amounts of monoamines. These results suggest that monoamines mediate hemocyte nodulation and phagocytosis through a downstream eicosanoid signal pathway in S. exigua.

This experiment was carried out to investigate the effects of liming, manure application, and inoculation with Rhizobium on the early growth, nodulation, seedling establishment, winter survival, and forage yield and quality of alfalfa(Medicago sativa L.)

영양액을 사용한 고온하의 Growth chamber에서 근류균을 접종한 Alfalfa의 수양시기별 작물명부위에 대한 실표시비의 영향에 관한여 미국 University of Nevada에서 실험한 결과들을 요약하면 다음과 같다. 초장과 그장에 대한 실표시비의 효과는 높이 인정되었으나 근장에 있어서는 유의성이 없는 다소의 증가을 보였다. 실표시비의 작물의 용접과 건물수량은 무실표구에 비하여 2배이상의 증가를 보여 실표시비의 높은 효과를 나타냈다. 근류의 착

저온하(低溫下)의 Growth chamber에서 근유균(根瘤菌)(R-12)를 접종(接種)한 Alfalfa의 수확시기별(收穫時期別) 작물(作物) 각부위(各部位)의 질소시비(窒素施肥)의 효과에 관하여 미국(美國) University of Nevada에서 실험(實驗)한 결과(結果)들을 요약(要略)하면 다음과 같다. 초장(草長), 근장(根長) 및 전장(全長)에 있어서는 질소시비(窒素施肥)의 효과가 나타나지 아니하였으며 작물(作物)의 용적(容積)과 건물수량(乾物

β-carotene hydroxylase (BCH) has been implicated as a key enzyme conferring a stress tolerant mechanism in plants by production of carotenoids, which serve as protectants against photoinhibition and precursor of ABA biosynthesis. We previously cloned a gene encoding a novel cytosolic form of BCH (GmBCH1) from soybean (Glycine max) whose expression increased during nodulation with Bradyrhizobium japonicum. In the present work we extended our study to three GmBCHs as soybean is an allotetraploid, and examined their possible role(s) in nodule development. In situ hybridization revealed the expression of three GmBCHs (GmBCH1, GmBCH2, and GmBCH3) in the infected cells of root nodules, and their enzymatic activities were confirmed by functional assays in E. coli. Localization of GmBCHs by transfecting Arabidopsis protoplasts with GFP fusions and by EM immunogold detection in soybean nodules indicated that GmBCH2 and GmBCH3 were present in plastids while GmBCH1 appeared to be cytosolic. RNAi of the GmBCHs severely impaired nitrogen fixation as well as nodule development. Surprisingly, we failed to detect zeaxanthin, a product of GmBCH, or any other carotenoids, in nodules. We therefore examined the possibility that most of the carotenoids in nodules are converted or cleaved to other compounds. We detected the expression of some carotenoid cleavage dioxygenases (GmCCDs) in wild-type nodules, and also a reduced amount of zeaxanthin in GmCCD8-expressing E. coli, suggesting cleavage of the carotenoid. In view of these findings we propose that carotenoids such as zeaxanthin synthesized in root nodules are cleaved by GmCCDs, and we discuss the possible roles of the carotenoid cleavage products in nodulation.

The effects of Rhizobium inoculant, compost, and nitrogen on nodulation, growth, dry matter production, yield attributes, and yield of pea (Pisum sativum) var, IPSA Motorshuti-3 were assessed by a field experiment. Among the treatments Rhizobium inoculant alone performed best in recording number and dry weight of nodules/plant. The highest green seed yield of 8.38 ton/ha (36.9% increase over control) and mature seed yield of 2.97 ton/ha (73.7% increase over control) were obtained by the application of 90 kg N/ha. The effects of 60 kg N/ha, Rhizobium inoculant alone and Rhizobium inoculant along with 5 ton compost/ha were same as the effect of 90 kg N/ha in recording plant height, root length, dry weight of shoot, and root both at preflowering and pod filling stages, number of mature pods/plant, number of mature seeds/pod, 1000-seed weight, green, and mature seed yields of pea.

Study on effectiveness of Bradyrhizobium japonicum on soybean [Glycine max (L.) Merr.], local cultivar 'Sathiya' were carried out in the garden soil of Trib-huvan University. Different parameters like nodulation, chlorophyll content in fresh leaves and growth of plant in inoculated and uninoculated plant was studied. Pot experiment was conducted in the green house to evaluate the effectiveness of B. japonicum on soybean. It was observed that B. japonicum inoculation increased the number of nodules, shoot length of plant and total chlorophyll content in fresh leaves of soybean plant. However, root length was decreased in all inoculated plants.

The effects of Rhizobium inoculant, nitrogen, phosphorus, and molybdenum on nodulation, dry matter production, yield attributes, pod and seed yields, protein and phosphorus contents in seed of pea (pisum sativum) var. IPSA Motorshuti-3 were assessed by a field experiment. Among the treatments Rhizobium inoculant in combination with 25kg P and 1.5kg Mo/ha performed best in recording number of nodules/plant, total dry matter yield, number of pods/plant, number of seeds/pod, 1000-seed weight, green pod yield, green and mature seed yields of pea. The highest green pod yield of 15.37 t/ha (97.05~% increase over control) and green seed yield of 9.6t/ha (69.31~% increase over control) were obtained by inoculating pea with Rhizobium inoculant in association with 25kg P and 1.5 Mo/ha. The effects of 60 or 120kg N/ha were comparable to Rhizobium inoculant in most cases. There were positive correlations among yield attributes, yield, protein and phosphorus contents in seeds of pea. From the viewpoint of yield attributes, yield, and seed quality, application of Rhizobium inoculant along with 25kg P and 1.5kg Mo/ha was considered to be the balanced combination of nutrients for achieving the maximum output from cultivation of pea in Shallow-Red Brown Terrace Soil of Bangladesh.

The responses of six mungbean [Vigna radiata (L.) Wilczek] varieties to Rhizobium inoculation on number and dry weight of nodules, nitrogenase activity of root nodule bacteria, dry weight of shoot and root, nitrogen content, and uptake by shoot were investigated. The mungbean varieties were BARI Mung-2, BARI Mung-3, BARI Mung-4, BARI Mung-5, BINA Moog-2, and BU Mung-1. Two-third seeds of each variety were inoculated with Rhizobium inoculant and the remaining one-third seeds were kept uninoculated. Rhizobium strains TAL 169 and TAL 441 were used for inoculation of seeds. Inoculation of seeds with Rhizobium strains significantly increased nodulation, nitrogenases activity, dry matter production, nitrogen content, and uptake by shoot of the crop compared to uninoculated control. There was positive correlation among the number and dry weight of nodules, nitrogenase activity, dry weight of shoot and root, nitrogen content, and uptake by shoot of the crop. It was concluded that BARI Mung-4 in association with Rhizobium strain TAL 169 performed best in recording nodulation, nitrogenase activity, dry matter production, and nitrogen uptake by shoot of mungbean.

An experiment was conducted to determine N₂-fixation efficiency using 5 soybean genotypes, viz. 'Chiang Mai (CM) 60', 'SJ1', 'Santa Maria', 'KUSL 20004', 'AGS 292' and 40 rhizobium strains from the Soil Microbiology Group, Soil Science Division

This study was performed to evaluate the growth and nodulation characters of hypernodulating soy-bean mutant, SS2-2, and to know the growth and yield performance of the mutant in infertile soil. Soil fertility was adjusted by mixing the different ratios of soil components including clay, river sand, and horticultural bed, which resulted in fertile and infertile soil. Dry weight, nitrogen concentration, and leaf nitrate reductase of each plant were measured around V6 stage (47 days after planting) and around R3 stage (82 days after planting). There were significant effects of soil fertility and soybean genotype on the total dry weights including root, nodule, stem, leaf, and pod dry weight at V6 and R3 stages. Total dry weight of hypernodulating mutant, SS2-2, was clearly less than that of its wild type, Sinpaldalkong 2. However, nodule development on the roots of SS2-2 was much greater than that of Sinpaldalkong 2, regardless of soil fertility. Though SS2-2 was smaller in plant size than Sinpaldalkong 2, genotypic difference in total nitrogen content was not significant at both V6 and R3 stages because SS2-2 fixed more nitrogen biologically than its wild type in the root nodule. The SS2-2 mutant showed lower plant yield in both infertile and fertile soil. The SS2-2 contained more crude seed protein than Sinpaldalkong 2, and was characterized with reduced top and root growth.

황금콩과 백운콩에 30mM 및 50mM EMS를 각각 종자 1립 당 1ml 수준으로 실온에서 6시 간 처리하여 얻은 M1 종자를 파종한 다음, 포장출현율 및 M1 개체들의 형태적 특성의 분포 양상을 검토하고,M2 세대에서 근류착생 및 기타 돌연변이 출현 양상을 조사한 결과를 요약하면 다음과 같다. 1.M1 종자의 포장출현율은 백운콩이 황금콩보다 비교적 높았으나 EMS 농도 처리간 차이는 없었으며, 엽록소 결핍 개체 발생율은 평균 0.7%였다. 2. 수확시 M1 개체들의 경장, 개체당 협수 및 립수는 무처리개체에 비하여 감소되는 경향이었으며, EMS 처리 농도간 분포차이는 크지 않았다. 3. M2 세대에서 엽록소 결핍 개체 출현율에 의하여 판별된 돌연변이 유기율은 평균 2.2%이었으며, 돌연변이가 유기된 M1 종자는 chimera 현상을 나타내었으며 돌연변이 세포의 비율은 5.3～84.2%로 나타났다. 4. EMS 처리에 의하여 근류착생이 많은 MA48계통과 근류착생이 거의 안되는 MD69계통을 선발하였는데 MA48계통은 엽연소함량이 많았고 MD69 계통은 엽록소 결핍 현상을 나타내었다.

알팔파 방목형 품종 Victoria와 건초형 품종 Vernal을 공시하여 실산태 새소 농도 0,2,4,8, 12mM의 다섯 수준으로 급여하여 파종 6주후 초기 생육시기에 지상부 부위별과 뿌리혹 건물증, 엽중 질산태 질소 환원 능력 및 축적 정도를 조사하였으며, 그 결과는 다음과 같이 요약된다. 1. NO3 ￣ 수준이 높아짐에 따라 지상부 건물중이 증가하였으나 NO(NO3 ) ￣ 의 8mM과 12mM간의 차이는 없었다. 2. 두 품종 모두 8mM 이상의 NO3 ￣ 수준에서 뿌리혹 착생이 현저히 억제되었다. 3. 엽 생체중당 nitrate reductase 활성은 NO3 ￣ 수준이 증가함에 따라 높아졌으나 4mM이상에서는 차이가 크지 않았다. 4. 엽중 질산태 질소축적은NO3 ￣ 의 12mM 처리시 크게 증가하였다.

초다 근류착생성 콩 nts 382 및 nts 246와 wild-type인 Bragg의 초기생육, 뿌리혹 형성 및 질소고정능력을 조사하였으며, 그 결과는 다음과 같이 요약된다. 1. nts 계통은 뿌리혹건물중이 현저히 높아서 파종후 31일째에는 Bragg에 비하여 2.5내지 3.5배에 달하였다. 2. nts 계통은 과도한 뿌리혹 형성 때문에 지상부 광합성산물을 많이 소모하여 지상부의 생육이 저해되었다.