Promotion of the population growth of pinewood nematode in 4-month-old Japanese black pine seedlings by pretreatment with simulated acid rain

Simulated acid rain (SAR) at three pH levels (pH 4, 3, 2) was applied to only the top or both the top and roots of 4-month-old Japanese black pine seedlings repeatedly for two months. Then the seedlings were inoculated with a virulent isolate (S10) of pinewood nematode,Bursaphelenchus xylophilus. The exposure to SAR at any level did not kill the seedlings. When inoculated with nematodes, however, the nematode population build-up was significantly higher in the seedlings pretreated with SAR at any level than in the control at the 7th and 17th day after inoculation, and subsequent disease symptom development was also significantly accelerated by the exposure to SAR at pH 2 and 3. This result indicates that even acid rain at pH 4 has the potential for promoting population growth of pinewood nematodes in 4-month-old Japanese black pine seedlings.     

白云山森林植物病害的调查

1998-2000年期间对白云山风景区主要森林植物病害进行了调查，发现病害共计59种，分布于44种寄主植物中，病害类型比较丰富，其中以叶部病害为主，病原涉及真菌、细菌、植物菌原体等多种寄生物及非侵染性病原，其中又以真菌为主，病害发生普遍，但为害较轻，没有发现严重的危害性病害。     

Genetic improvement in pine wilt disease resistance inPinus thunbergii: The effectiveness of pre-screening with an artificial inoculation at the nursery

Open pollinated progenies from 15 clones of Japanese black pine (Pinus thunbergii), that had been selected for their tolerance to pine wilt disease, were tested by artificial inoculation with pine wood nematode for six years at a nursery of Kyushu Regional Breeding Office. Family variations in the respective year were all significant. An analysis of variance across the six years’ tests confirmed highly significant effect of year and of families; however, the year by family interaction was significant also. Phenotypic and genetic variances estimated from each year’s result were fitted to a quadratic regression using their mean survival ratio as an independent variable. The variances were greatest at around 0.5 of the mean survival ratio. Estimated heritability showed a similar trend of change, whereas the peak of the expected amount of improvement shifted toward the lower survival range: around 0.4, where a greater selection differential was anticipated. It was concluded that a useful amount of genetic improvement that may be reduced by 30% due to the interaction, would be expected by prescreening seedlings where the mean survival ratio after inoculation was around 0.25 to 0.6.     

臭椿花叶病病原病毒的研究

从出现花叶症状的臭椿上分离到一种线条状病毒,经过生物学特性、病毒粒体形态、血清学及超薄切片等方面的研究,确定为马铃薯Y病毒组病毒。     

Blight of conifer seedlings caused by Colletotrichum gloeosporioides

In a growth chamber experiment, 70-day-old seedlings of 10 conifer species were inoculated with Colletotrichum gloeosporioides conidia to determine the host range of the fungus. Based on the percentage of seedlings affected and the disease severity on individual seedlings, the order of most to least susceptibility was: western hemlock (WH), mountain hemlock, western larch, Sitka spruce, Engelmann spruce, Douglas-fir (coastal form, then interior form), white spruce and ponderosa pine; lodgepole pine and western red cedar remained unaffected. Inoculation of WH needles showed that within 24 h C. gloeosporioides conidia germinate and appressoria (penetration structures) form. A growth chamber study demonstrated that the pathogen can infect WH at needle wetness periods as short as 15 min; number of needles affected was higher at 0.5 h, but did not increase further even when wetness was extended up to 8 h. The results are discussed in relation to blight management of greenhouse-grown conifer seedlings.Portion of a Bachelor of Science (Honors) thesis, Department of Biology, University of Victoria, Victoria, British Columbia.     

香椿栽培技术

作者根据多年的实践经验，总结了香椿的栽培技术，包括采种、播种、育苗、种植、管理、病虫害防治及菜用林培育等技术。     

银中杨抗病虫性研究

用室内外接种及自然感病的方法，对银中杨抗烂皮病进行测定，采用系统聚类方法进行分析，结果证明银中杨为感病最轻品种，聚在第一类，并对鉴定林中　１６个品系的病情指数作方差分析，结果表明各品系间感病指数有极度显著差异。同时对银中杨及对照品种的虫害按五级分类标准进行调查并计算受害指数，结果表明银中杨是抗杨干象、白杨透翅蛾等虫害的优良树种。     

杨梅主要病虫害的防治技术

介绍了杨梅病虫害综合防治技术、无公害防治简历、主要病虫害防治要点和植物生长调节剂的使用技术。通过健康栽培、调节生态和科学用药实现病虫害的综合治理；无公害防治简历抓住主要物候期提出技术规程，力求简洁实用；对主要病虫害提出关键防治时期和防治方法；植物生长调节剂则提倡适树使用。     

几丁质酶在植物抗真菌病害中的作用

几丁质酶对于植物抗真菌病害有重要作用,它可水解真菌细胞壁的重要组成成分———几丁质。正常情况下,植物体内几丁质酶的含量很低,如果将外源几丁质酶基因导入植物,可增强植物抗真菌病害的能力,而将几丁质酶基因与其他防卫蛋白基因一同导入植物,植物抗真菌病害的能力将会大大提高。     

福建省森林病虫害监测预警现状及发展对策

对福建省森林病虫害监测预警工作的现状进行深入分析的基础上,从网络建设、资金投入、机构队伍、管理机制、技术研究等方面,提出了今后加强监测预警工作的发展对策。