宁南霉素等药剂对番茄黄化曲叶病毒病的田间防效

[目的]评价宁南霉素、艾德拉和碧护3种药剂混合使用防治番茄黄花曲叶病毒病的效果。[方法]通过田间试验研究8%宁南霉素、艾德拉绿(花、果)与碧护组成的药剂对番茄黄化曲叶病毒病的防治效果。[结果]8%宁南霉素、艾德拉绿(花、果)与碧护组成的试验药剂对番茄黄化曲叶病毒病具有很好的田间防治效果,第3次施药后10、20、30 d防效均在82%以上,与对照药剂番茄黄化曲叶病毒灵差异达极显著水平,且其产量比清水对照增加25 747.5 kg/hm~2,保产率为103.90%。[结论]宁南霉素、艾德拉和碧护混合使用对番茄黄花曲叶病毒病具有较好的防治效果,为番茄黄花曲叶病毒病的有效防治提供了理论依据。     

异硫氰酸丙烯酯毒杀松材线虫作用机制初步研究

对异硫氰酸丙烯酯毒杀松材线虫作用机制进行了初步研究。测定了其对线虫虫体形态、运动行为、体内总糖和蛋白质含量的影响,以及处理前后线虫体内过氧化氢酶(CAT)、乙酰胆碱酯酶(AChE)和谷胱甘肽-S-转移酶(GST)活性变化。结果表明:经异硫氰酸丙烯酯处理后的松材线虫虫体形态严重扭曲,运动形态出现由正常的S形变化为多节弯曲和螺旋状卷曲等异常状况,线虫行动随时间的推移变得迟缓,最终呈C形、新月形或直接死亡。随着异硫氰酸丙烯酯处理质量浓度的增大,线虫体内总糖和蛋白质含量显著上升,糖和蛋白质的代谢发生紊乱;线虫体内CAT、AChE和GST活性显著降低,且均低于对照组,表明线虫体内氧化和抗氧化作用失衡;细胞受到极大的影响,神经系统遭到破坏,解毒能力明显降低。研究结果可为研究利用异硫氰酸丙烯酯作为植物源杀线虫剂提供依据。     

Effect of Heat Stress on Grain Growth, Starch Synthesis and Protein Synthesis in Grains of Wheat (Triticum aestivum L.) Varieties Differing in Grain Weight Stability

The effect of heat stress on the components of grain weight was analysed in wheat ( Triticum aestivum L.) varieties differing in grain weight stability. The wheat varieties PBW154, Sonalika and Hindi62 were raised in the field (New Delhi, India; 77°12' E, 28°40' N, 228.6 m a.s.l.) at three dates of sowing: 19 November 1992 (DOS I), 14 December 1992 (DOS II) and 18 January 1993 (DOS III). The late-sown crop (DOS III) experienced 6–8 °C warmer temperatures during grain development than the crop sown at the normal time (DOS I). The heat susceptibility index (S) revealed that grain weight was less susceptible to heat in Sonalika and PBW154 than in Hindi62. Heat stress reduced both the grain growth duration (GGD) and the grain growth rate (GGR). The grain weight reduction in PBW154 and Sonalika was mainly due to a reduction in GGR, while that of Hindi62 was due to a reduction in GGD. In vivo studies on starch and protein synthesis in excised endosperm at 15, 25 and 35 °C revealed that both processes were more thermotolerant in Hindi62 than in PBW154. The grain starch content was stable in Hindi62 while that in PBW154 was significantly reduced under heat stress. The grain nitrogen content at maturity increased in both varieties under heat stress. It was concluded that the heat susceptibility of grain weight in Hindi62 was mainly due to a reduction in GGD, although GGR, starch and protein synthesis were more thermotolerant in developing grains of Hindi62 than in those of PBW154.     

棉花不同时期去叶源对库源关系影响的初步研究

通过对棉花不同时期去主茎叶、叶枝叶、果枝叶和全部叶片的研究,初步探讨了棉花叶源对库的影响.结果表明:无论蕾期还是盛铃期,叶片是棉花光合产物的主要来源,没有叶片棉花就不能正常生长,也很难保证其产量;不同部位的叶片中,主茎叶的作用显著,蕾期去主茎叶后株高日增长量减少0.5 cm以上,干物质积累明显下降,盛铃期则导致棉铃大量脱落,成铃平均减少2个以上;去果枝叶的作用相对较小,去叶枝叶几乎无影响.     

猪肺炎支原体及其生物学研究进展

猪肺炎支原体是引起猪支气管肺炎的主要病原 ,严重危害着养猪事业的发展。虽然猪肺炎支原体的结构简单 ,但由于它对营养要求较高 ,故培养难度大 ,也是人们不能对其深入研究的一个主要原因。近年来利用克隆技术 ,对猪肺炎支原体从基因水平上进行了多种研究 ,已经取得了一些可喜成果。文章从它的生物学特性、荚膜结构、膜蛋白研究以及基因水平的研究等方面进行了综合性论述 ,并简明地指出了目前研究中存在的问题以及未来展望     

苜蓿褐斑病抗性与几种同工酶的关系

以苜蓿5个品种在褐斑病抗性上存在差异的抗、感单株为材料，研究了接种病菌后苜蓿褐斑病抗性与多酚氧化酶(PPO)、过氧化物酶(POD)和超氧化物歧化酶(SOD)及其酶活性的关系。研究结果表明，褐斑病侵染后，苜蓿抗病株系和感病株系叶片中PPO、POD和SOD同工酶谱带多少和强弱存在明显的差异，即大部分抗病株系PPO、POD和SOD酶活性高于感病株系，并有新的同工酶带出现。PPO、POD和SOD在苜蓿抗褐斑病上可能起到重要作用，其同工酶谱带和酶活性的差异有可能做为鉴定苜蓿抗褐斑病的一种同工酶标记。     

Narbon Vetch (Vicia narbonensis L.): A Potential Feed Legume Crop for Dry Areas in West Asia

Provision of feed supplies for the rapidly growing livestock population is essential in West Asia. Shortages can be alleviated by growing forage crops in the existing fallow lands.
Narbon vetch (Vicia narbonensis L.) is a leguminous species with high yield potential, drought tolerance and cold resistance. It could be used for grain and straw production as source for animal feed in dry areas. It is good source of protein with seeds contain 28 % protein yielding 364 kg per hectare protein, whilst straw contains 9 % protein and yields a similar amounts of digestible protein per hectare.
Nine promising lines of Narbon vetch developed at ICARDA were tested at two sites over four years under rainfed conditions. Since climatic conditions were considered to be of considerable importance, each site in each year was treated as a separate environment to give eight environments with annual rainfall varied from 195 to 504 mm.
Narbon vetch possessed high seedling vigour with rapid winter growth and negligible cold damage. Grain yield varied form 0.47 to 1.90 t/ha, with a harvest index varying from 30 to 40 %. The data indicated that below 300 mm rainfall the grain yield varied from 0.47 t/ha when rain fall was 195 mm to 1.4 t/ha when rainfall was 245 mm. Most of the lines had wide adaptation to dry areas in terms of both grain yield and stability. Climate, except early spring rains had little effect on biological and grain yields.     

糖槭叶枯病发病规律及防治

糖槭叶枯病 Phyllosticta negundinis病菌孢子放散开始期和高峰期与每年的温、湿度变化有关。病害发生严重程度与降雨量关系密切 ,降雨早且量大时病害严重。病菌以分生孢子器和分生孢子在病叶上越冬 ,通过气流传播成为翌年初侵染源。喷洒 70 %甲基托布津可湿性粉剂 10 0 0倍液和 75%百菌清可湿性粉剂 80 0倍液均能收到较好的效果     

春小麦蛋白质、脂肪、淀粉含量间的相关与回归分析

本文通过对20个春小麦品种(或品系)蛋白质、脂肪、淀粉百分含量间的相关、回归、协方差分析,表明蛋白质百分含量与淀粉百分含量间为极显著的负相关;脂肪百分含量与淀粉百分含量间为极显著的负相关;蛋白质百分含量与脂肪百分含量间为极显著的正相关。并建立了淀粉、脂肪、蛋白质百分含量间的回归方程。在同一试验条件下,各品种(或品系)蛋白质、脂肪、淀粉百分含量变异系数的大小,在一定程度上反映出各品种在品质性状上的纯合程度。变异系数愈小,表明纯合程度愈高;变异系数愈大,表明纯合程度愈低。因此,在那些变异系数较大的品种(或品系)中,可选出表型性状与原品种(或品系)基本相似,而在品质性状上却有较大提高的优质新品系。     

采用现代食品加工技术开发蛋白质食物资源

本文分析了现阶段我国人民的食物结构以及食品加工在开发蛋白质食物开源中的地位和作用，并从五个方面进行了论述。