稻瘿蚊综合防治新技术与示范

20世纪80年代后，稻瘿蚊发生危害明显回升，损失相当严重。以大田试验示范为主，系统研究了新耕作条件下稻瘿蚊综合防治，首次总结提出“喷药除草、压低虫源、抓住晚秧、做好测报、挑治本田”的综合防治新技术体系。室内外试验和大田示范表明，应用草甘膦杀死越冬寄主游草，可显著减少虫源基数；灭线磷(商品名益舒宝)、氯唑磷(商品名米乐尔)是防治稻瘿蚊的高效药剂，抗蚊青占品种高抗稻瘿蚊。此外，合理利用杀虫植物、性引诱剂和天敌等亦是防治稻瘿蚊的重要措施。在面积达12．46万hm^2的示范推广实践中，本田防治效果均达80％以上。     

对锰害敏感性不同的两个苹果品种枝条中锰的积累与分布

 以对苹果粗皮病抗性不同的两个苹果品种富士(感病) 和乔纳金(抗病) 为材料,通过田间采样、室内盆栽模拟,结合组织化学、显微鉴定和X- 射线微区分析,研究了枝条内锰的累积、分布与粗皮病抗性的关系。结果表明,锰在韧皮部的含量高于木质部,感病品种含量高于抗病品种;粗皮病病斑部位存在氧化锰沉淀,韧皮部锰的局部累积和分布与病斑的分布相一致;锰在感病品种的枝条横截面上存在局部累积现象,而在抗病品种上分布较均匀。     

黄瓜叶色突变体遗传机制的研究

 从黄瓜雌性系9110G中发现能稳定遗传的叶色突变体。该突变体子叶和第1～2片真叶最初为金黄色，叶绿素含量约为正常株的3／5，但随着叶片的生长这些叶片逐渐转绿。该突变体叶色黄主要是由叶绿素降低引起的，与类胡萝卜素无关。通过对亲本、F。、BE及F2后代观察和叶绿素测定，证明该突变体是细胞核遗传，由单一隐性基因控制，并且绿色对黄色为不完全显性。该突变性状是研究光合系统和基因定位的好材料，同时也可用来作为指示性状鉴定杂种纯度。     

香蕉分生小球体途径胚性细胞悬浮系的建立

 以7 个香蕉品种未成熟雄花为外植体均获得了分生小球体(meristematic globules) 。分生小球体的诱导率因基因组型和品种而异, 为15 %～81 % , 分生小球体的特点及开始出现的时间也受基因组型和品种的影响。以分生小球体为起始材料, 建立了‘广东2 号’、‘华农7 号’及‘河口龙牙’3 个品种的胚性细胞悬浮系, 并通过体胚发生途径获得了前两个品种的再生植株。     

Multi#ex—CAPS技术及其在番茄遗传鉴定中的应用

 ：应用Multiplex—PCR和CAPS(Cleaved amplified polymorphic sequence)原理研究建立了Mutiplex—CAPS技术。该技术包括：(1)在PCR扩增反应体系加入2对、3对或多对核苷酸引物，经30～40个扩增循环后得到每对引物的特异扩增片段；(2)应用同一种限制性内切酶消化这些不同引物经扩增后获得的特异片段；(3)琼脂糖凝胶电泳溴化乙锭染色检测酶切片段长度的多态性。利用该技术对番茄(Lycopersicon es—cdentum)TA517及其近等基因系的分析表明，Multiplex—CAPS能同时检测2个、3个或多个CAPS标记的多态性，其效果等同于每个CAPS标记的多态性的叠加，重复性好，分析效率高，降低成本数倍。     

种块大小对生姜生长及产量的影响

本试验条件下,生姜出苗期随种块的增大而提早。幼苗期,较大种块处理的植株长势较旺,但茎叶旺盛生长期后,过大或过小的种块处理都不利于生姜的生长和产量的提高。生姜产量以75 g左右的种块处理为最高,达3 572.4 kg·(667 m2)-1,而100、50、25 g种块处理的生姜产量分别为3 250.2、3 077.9、2 600.1 kg·(667 m2)-1。     

大白菜细胞核雄性不育基因向自交系97A407的转育

根据复等位基因遗传假说 ,利用大白菜核不育系 9810 9和已知基因型的甲型两用系可育株 99135 2作为不育源 ,以大白菜自交系 97A40 7为目标亲本 ,经过 5个世代的转育 ,获得了具有 97A40 7遗传基因型的新甲型两用系、临时保持系和雄性不育系。     

Comparison of an in vitro and a damping-off assay to test soils for suppressiveness to Pythium aphanidermatum

Testing of soil samples in greenhouse assays for suppressiveness to soilborne plant pathogens requires a considerable investment in time and effort as well as large numbers of soil samples. To make it possible to process large numbers of samples efficiently, we compared an in vitro growth assay with a damping-off assay using Pythium aphanidermatum as the test organism on tomato seedlings. The in vitro test compares the radial growth or relative growth of the fungus in soil to that in autoclaved soil and reflects suppressiveness of soils to the pathogen. We used soils from a field experiment that had been farmed either organically or conventionally and into which a cover crop (oats and vetch in mixture) had been incorporated 0, 10, 21, and 35 days previously. We obtained a significant, positive correlation between damping-off severities of tomato seedlings in damping-off assays and both relative and radial growth in vitro. In addition, radial and relative growth of P. aphanidermatum in the in vitro assay were positively correlated with several carbon and nitrogen variables measured for soil and incorporated debris. We did not find differences between the two farming systems for either growth measures of P. aphanidermatum or disease severities on tomato at different stages of cover crop decomposition. The in vitro assay shows potential for use with any fungus that exhibits rapid saprophytic growth, and is most suitable for routine application in suppressiveness testing.     

Studies on the potential use of Pasteuria penetrans as a biocontrol agent of root-knot nematodes (Meloidogyne spp.)

Some aspects of the interaction of the bacterial parasite Pasteuria penetrans and the root-knot nematode ( Meloidogyne spp.) were investigated in laboratory and pot experiments. The variable spore attachment on juveniles exposed to water suspensions of the bacterium is probably attributed to differential susceptibility of biotypes within a heterogeneous Meloidogyne population. The relationship between spore concentration and attachment level is not linear over a range of spore dosages, indicating that even at very high spore concentrations the number of spores capable of attachment may not be present in excess and it is difficult to ensure sufficient numbers of spores to ensure infection will attach to all nematodes. Attempts to apply the bacterium in conditions such as might occur in seedbeds did not suppress nematode multiplication after transplanting in nematode-infested soil, indicating that the only effective application method is a thorough spore distribution in the planting sites. Two major constraints were revealed: high levels of spore attachment to juveniles does not always guarantee a significant reduction of egg laying and this is greatly influenced by the Meloidogyne biotype. Furthermore, the cumulative effect of the parasite in reducing Meloidogyne populations over several crop cycles was less than expected as the bacterium reduced intra-specific competition for the food supply and the less damaged root enabled many nematodes to survive.     

The effects of ultraviolet-B (UV-B: 290–320 nm) radiation on blister blight disease of tea (Camellia sinensis)

Sunlight is known to reduce the incidence of blister blight disease of tea, caused by Exobasidium vexans . The effects of the ultraviolet-B (UV-B: 290–320 nm) component of solar radiation on the disease and the development of E. vexans were studied in the field in Sri Lanka using UV-screening filter materials held over a commercial crop. Exclusion of UV-B radiation by Polyester, which reduces fluxes in the UV-B region by approximately 75–85%, increased both the number of translucent spots (immature sites of infection) and number of sporulating blisters (mature sites of infection), but it had little or no effect on the sporulation of the pathogen. When basidiospores were artificially inoculated on leaves, and were exposed to full or filtered solar radiation, their survival and germination increased when UV-B wavelengths were removed; significant differences were found 62 h after inoculation. However, UV-B did not affect the extension of germ tubes. This study indicates that the UV-B component of solar radiation plays an important role in the natural regulation of blister blight disease in the field.