马铃薯品种抗软腐病测定条件的研究

用全薯块吸头刺伤接种法测定时,较理想的测定条件为:每接种点接种0.1ml浓度为10~2～10~5CFU/ml菌悬液,随后在21±5℃～31±5℃(依所用菌株而定)下保持2～3天,以接种点腐烂斑的最大直径作记载标准。用新鲜薯片法测定时,除接种浓度为10~2～10~3CFU/ml,保持时间为1～2天及以侵染限值作评价标准外,其余条件和全薯块吸头刺伤接种法相同。当用皮孔浸渍法接种时,薯块在10_6CFU/ml菌悬液中浸5分钟,然后使薯块表面保持连续水膜,3～5天后测量薯块表面腐烂面积。上述3种方法都必须有20个以上重复,并使用大小一致、无伤无病的成熟薯块。     

大白菜软腐病苗期抗性及其与成株期抗性的关系

对６６个大白菜品种苗期抗性的测定结果表明，不同品种对细菌根系侵入和潜伏侵染的抗性存在显著差别；同一品种幼苗对侵入侵染的抗性与对潜伏侵染的抗性间没有相关性。幼苗期的组织含菌量与成株的田间软腐病发病程度有一定的相关性。并初步建立了大白菜对软腐病苗期抗性的鉴定方法。     

沉降监测在高速公路软土路基施工中的应用

在高速公路沿线土质为软弱土层时,根据控制桥头路基的工后沉降,覆盖全线软基特性的原则,选取了典型监测观测段.文章介绍了软基沉降监测所需要的仪器及其埋设方法、观测要求、数据处理等方面的内容,以便更好的指导施工.     

同步辐射软X射线对家蚕生理生化性状的影响

采用一定剂量同步辐射（ＳＲ）软Ｘ射线辐照催青卵及蚕蛹,利用ＰＡＧＥ对蚕卵及蛹子代的蛋白质和酯酶同工酶进行分析,结果发现谱带数目及活性的变化,茧质调查与对照相比也有差异。首次证明ＳＲ软Ｘ射线对家蚕的生理生化性状有一定影响     

中华猕猴桃单芽绿枝扦插试验

中华猴猕桃单芽绿枝扦插试验结果表明:1.采自组织培养的猕猴桃植株的插穗比采自嫁接植株的插穗更易生根,且发根早,根量大;2.插穗经不同浓度的吲哚丁酸(IBA)处理后可不同程度地促进生根,处理以100ppm浸泡插穗基部20小时为最佳.生根率可达100%.     

A pollen extender medium technology for seedless watermelon production by pollination with soft X-ray irradiated pollen

The inactivation of pollen by soft X-ray irradiation and subsequent artificial pollination are time-intensive practices used in the production of seedless watermelons (Citrullus lanatus L.). Watermelon generally has a lot of staminate flowers; however, they only have a small amount of pollen. Watermelon pollen cannot be used in pollination under the present situation. Therefore, the objective of this study was to determine which is the most effective pollen extender medium for cultivation of watermelon with soft X-ray irradiated pollen. In this experiment, ‘Agar,’ ‘Marriage powder,’ and ‘Sekishoshi’ (Lycopodium dyed red with safflower pigment) were used as extender media with soft X-ray irradiated pollen at equal or twice the weight of the pollen. When ‘Sekishoshi’ was used as an extender medium, fruit set was very low. A lot of deformed fruit was produced when agar was used with the pollen. On the other hand, when ‘Marriage powder’ was used in equal proportions with the pollen, fruit set was about 70% and, moreover, Brix was high. Thus, the mixture of ‘Marriage powder’ with an equal amount of pollen was the best for use in actual cultivation. We conclude, then, that soft X-ray irradiated pollen in an extender medium can be effectively adapted for producing seedless watermelons.     

在软土地区路基的施工中应采取的措施

本文阐述了在软土地路基施工过程中，各个施工环节的特点及应用采取的措施。     

Fibril angle variability in earlywood of Norway spruce using soft rot cavities and polarization confocal microscopy

The main purpose of this study was to investigate the variability of the fibril angle of tracheids in earlywood of Norway spruce (Picea abies L. Karst.). Polarization confocal microscopy was chosen and compared with the method utilizing the orientation of soft rot cavities. There was a significant correlation between the soft rot and polarization confocal microscopy methods, which showed the same trend of high fibril angles in the first part of the earlywood followed by a decrease toward the end of earlywood. This declining trend was less pronounced in annual rings containing compression wood. Moreover, large variations in fibril angle occurred between neighboring tracheids. The investigation also emphasized the differences between X-ray diffraction and microscopic methods, as the large variation seen by the latter methods is not seen by the X-ray diffraction approach because of its large area of measurement. No correlation was found between fiber morphology (i.e., average length, width, density) and the average fibril angle in the investigated annual rings.     

Soft X-ray observation of water distribution in the stem ofCryptomeria japonica D. Don II: Types found in wet-area distribution patterns in transverse sections of the stem

Using soft X-ray photography, two-dimensional observations were made of the water distribution within the green stem ofCryptomeria japonica D. Don. Variations in the distribution pattern of the wet area in the horizontal plane of the lower stem were described. The distribution patterns showed extreme variation among individual trees, with broad wet-area distribution types appearing, namely, the regularly distributed wet area and the irregularly distributed wet area. We defined five basic types of wet-area distribution patterns on the basis of their regularity or irregularity. It was concluded that the between-tree variation in the wet-area distribution causes the between-tree variation in the mean moisture content of the heartwood. The distribution patterns of the wet area were similar for individual trees within each plus-tree clone.Part of this paper was presented at 46th annual meeting of the Japan Wood Research Society at Kumamoto, April 1996