云南松毛虫为害湿地松调查及其防治研究

云南松毛虫是福建省沿海地区湿地松的重要害虫之一。该虫一年发生1代,以卵越冬,卵于翌年2月下旬孵化,幼虫7龄,历期158d～195d,以取食嫩针叶为主,幼虫老熟时下树,藏于草丛里或树干基部,在枯枝落叶中结茧化蛹,预蛹期50d～70d,成虫寿命5d～10d.其发生与林分的林木组成、气候、天敌等因子密切相关.试验表明：用25%灭幼脲3号,白僵菌与0.4%氰戊菊酯粉剂按4︰1混合制成的粉炮防治幼虫,有良好效果。     

松阳县古松树的松材线虫病现状调查与分析

古松树是历史的见证,是文化的承载,其保护工作具有重要意义,但因松材线虫的传播侵染,其生存状况不容乐观。本研究以松阳古松树为对象,基于分子检测技术,对其松材线虫病现状进行了调查与分析。结果表明,有12个乡镇近60%的古松树均已感病,疫情较为严重,需及时开展抗病保护工作。     

松材线虫自然侵染后对不同松树组织结构的影响

 利用滑走切片技术从显微水平研究松材线虫（Bursaphelenchus xylophilus）在自然状态下入侵,对马尾松（Pinus massoniana）和黑松（Pinus thunbergii）显微结构的影响。结果表明,马尾松和黑松的组织结构在感病初期即表现出病变特征,并随感病时间推移病变加剧。马尾松在感病初期皮层薄壁细胞开始木质化,伴有细胞破裂并融合成空腔;至感病中期周皮的栓内层细胞、皮层薄壁细胞以及韧皮部薄壁细胞均发生木质化,细胞内含物增多,甚至形成层细胞也发生一定程度的木质化现象,树脂道因周围细胞破裂而变形;至感病晚期,木材以外所有部分完全被木质化、大量细胞破裂。黑松发病症状与马尾松大致相同但发病时间稍晚,发病程度也较轻,这可能是因为两者对松材线虫病的抗性强弱有差异。同一时期的组织病理学特征在空间上也存有差异,这与松材线虫入侵的位置及其在树体内的分布有关。     

马尾松松材线虫病与松材蓝变相关性研究

 研究表明:松材线虫引起的马尾松(Pinus massoniana)病树死亡后期,必然有蓝变(Blue-stain)现象。松材蓝变程度与松树树干部位相关性不大。但是,对于同一棵树,若蓝变程度高,则每一部位的蓝变程度都比较高;若蓝变程度低,则每部位的蓝变程度可能都比较低。蓝变程度与松材线虫(Bursaphelenchus xylophilus)的含量也没有正相关关系。在松材线虫病木的检疫过程中,松木蓝变仅可以作为松材线虫病的参考指标。     

Enhancement of sphaeropsis canker of aleppo pine by the Israeli pine bast scale

An interaction between the fungal pathogenSphaeropsis sapinea (Fr.) Dyko & Sutton, causal organism of Sphaeropsis canker, and the Israeli pine bast scaleMatsucoccus josephi (Homoptera: Margarodidae), causal agent of pine decline, was studied, since both were prevalent on Aleppo pine (Pinus halepensis) stands.Sphaeropsis sapinea was isolated from larvae (stage II) and molts of the Israeli pine bast scale collected in four Aleppo pine stands. When Aleppo pine saplings were infested with pine bast scale and subsequently inoculated withS. sapinea most plants died, whereas mortality of seedlings inoculated withS. sapinea alone without previous scale infestation was negligible. Scale infestation of saplings without subsequent fungal inoculation caused the death of one third of the plants. Wounding of pine shoot apices by removal of needle fascicles enhanced infection byS. sapinea. The results support the assumption thatM. josephi can play an important role in transmitting the fungal inoculum to the host tree as well as enabling its penetration to the shoots through wounds in the bark. http://www.phytoparasitica.org posting Dec. 20, 2004.     

Relationship between resistance to pine wilt disease and the migration or proliferation of pine wood nematodes

To study the relationship between resistance to pine wilt disease and the migration or proliferation of pine wood nematodes (PWN) (Bursaphelenchus xylophilus), we conducted experiments using clonally-propagated Japanese black pines (Pinus thunbergii) with pre-evaluated individual resistance levels. Bark including the cortical resin canals—one of the main migration pathways of PWN—was removed by girdling, but neither the migration of PWN nor symptom development of pine wilt disease were inhibited by this treatment in non-resistant clones. Histological observations showed no significant differences in the lumen area or the number of cortical- and xylem- axial resin canals between resistant and susceptible clone groups from a half-sib family. A bioassay using methanol extracts from resistant and susceptible clones showed that extracts from both clones showed similar attractant effects to PWN, but neither had repellent effects. The resistant clones were multi-inoculated with PWN into three split points to mimic migration in the stem. The proportion of damaged plants was not significantly different from that in single-inoculated plants (control). In this experiment, the number of PWN detected from partially-damaged plants was much higher than that from non-damaged plants. An inoculation test using stem cuttings showed that the population of PWN increased in susceptible cuttings at 1–20 days after inoculation (dai), while it remained unchanged or gradually decreased in resistant cuttings. These findings suggested that the factors contributing to resistance were associated with inhibiting the proliferation of PWN, rather than inhibiting their migration.     

Induction of resistance against pine wilt disease caused by Bursaphelenchus xylophilus using selected pine endophytic bacteria

Pine wilt disease (PWD) is the most destructive disease threatening pine worldwide. The disease is mainly caused by the pine wood nematode, Bursaphelenchus xylophilus, which is vectored by pine sawyer longhorn-beetles, Monochamus spp. This study aimed to select resistance-inducing pine endophytic bacteria for management of PWD. To set up a defence-related genes expression pattern for screening, four chemical inducers (salicylic acid, γ-aminobutyric acid (GABA), β-aminobutyric acid and α-aminobutyric acid) were tested in vitro on pine calli and in vivo on pine seedlings. Treatment with GABA had the greatest reduction in PWD severity on pine seedlings. The pattern of defence-related gene expression in calli treated with GABA was used to select potential resistance-inducing bacterial strains. In addition, 92 bacterial strains were isolated from pine tree needles and stems and were tested for expression of defence-related genes in pine calli in vitro. Among the tested strains, 13 showed a similar pattern to GABA treatment in at least four tested defence-related genes and were selected for the seedling assay. From the seedling assay, three bacterial strains (16YSM-E48, 16YSM-P180 and 16YSM-P39) showed significant reduction in PWD severity compared to the untreated control. Moreover, among the selected strains, cell-free culture supernatant of strain 16YSM-P180 significantly reduced PWD severity in inoculated pine seedlings. The selected strains were identified based on the 16S rRNA sequence as Pseudomonas putida 16YSM-E48, Curtobacterium pusillum 16YSM-P180 and Stenotrophomonas rhizophila 16YSM-P39. These selected strains are suggested as potential alternatives for management of PWD by induction of systemic resistance.     

松材线虫病取样部位及检测技术初探

本文介绍了从松材线虫病疫木的不同高度进行取样和分离,通过传统病原形态学方法进行检测和计数的技术,探讨松材线虫在松树体内的数量分布情况,从而提高松材线虫的检出率和缩短检疫时间.     

Temporal variation in contamination of pine engraver beetles with Fusarium circinatum in native Monterey pine forests in California

The relative importance of beetle species associated with Fusarium circinatum‐infected Monterey pines was investigated in three Monterey pine forests along the coast of central California, USA from April to November in 2004 and 2005. Fusarium circinatum was frequently isolated from Ips mexicanus and I. plastographus. The mean percentage isolation based upon numbers of I. mexicanus and I. plastographus carrying propagules of F. circinatum was 17·7 and 10·9% in 2004 and 16·7 and 17·3% in 2005, respectively. The mean percentage isolation was high in the spring and early summer and low in late summer and autumn in all three locations for both species. Isolation was higher from beetles emerging from harvested F. circinatum‐infected pine‐stems than for trapped beetles, 42·4% for I. mexicanus and 45·9% for I. plastographus. The mean (± SE) propagule load of trapped I. mexicanus was 269·5 (± 14·1) in 2004 and 281·7 (± 35·7) in 2005 and was 216·1 (± 28·9) in 2004 and 251·9 (± 28·4) in 2005 for I. plastographus. Mean propagule loads decreased from May to November in all locations for both species. Propagule loads of beetles emerged from infected stems were lower than that of trapped beetles, with means of 89·4 (± 23·2) and 93·0 (± 23·2) for I. mexicanus and I. plastographus, respectively. Thus beetles must acquire fungal propagules from more than one infected host. These results also suggest that higher contamination rates and propagule loads in spring and early summer may indicate a higher risk of pitch canker transmission, relative to late summer or autumn.     

两种分子技术检测松木中松材线虫的效果评价

为更好地解决当前松材线虫Bursaphelenchus xylophilus检测工作中频现的假阴性问题,通过不同分子技术检测效果的比较评价,摸索出了一套可提高松材线虫检测准确性的技术体系。针对早期感病松木的低线虫量,建立了线虫的最大量分离方法和基于rDNA ITS序列的分子检测体系,该体系可高效检测出单条松材线虫,准确率达93.75%。以来自浙江省不同疫区的96份松木样品为检测材料,比较了SCAR标记和ITS序列2种分子检测技术的阳性率。结果显示,通过首次PCR,ITS_Ⅰ和ITS_Ⅱ序列的检测阳性率分别为52.08%和55.21%,SCAR标记的检测阳性率为30.21%;通过第二次或巢式PCR,ITS_Ⅰ和ITS_Ⅱ序列的检测阳性率提高到了97.92%和100.00%,SCAR标记的检测阳性率提高到了59.38%,表明基于ITS序列的检测阳性率明显高于SCAR标记,且通过第二次或巢式PCR方法可进一步提高检测灵敏度,降低假阴性率。因此,通过线虫的最大量分离并基于rDNA ITS序列的分子检测可明显提高检测准确性,更适用于松材线虫的常规检测。     

A major gene for resistance to white pine blister rust in Western white pine from the Western cascade range

ABSTRACT A dominant gene for resistance to white pine blister was indicated by Mendelian segregation in full-sib families of western white pine parent trees selected for phenotypic resistance in six heavily infected stands in the Western Cascades of Oregon and Washington. Seedlings were artificially inoculated three times between 1959 and 1964 and observed for development of stem infection. Segregation at this locus (Cr2) occurred in only two of the six parent populations sampled: one a natural stand, Champion Mine (CM), and the other a plantation of unknown seed origin. At CM, reduced penetrance of this gene was expressed by altered Mendelian ratios (mostly less-than-expected resistant phenotypes) in families of specific combinations of certain parents, indicating the presence of modifier genes with effects that ranged from mild to almost complete suppression of Cr2. Between 1968 and 1994, an apparent shift in virulence at CM caused all of the resistant selections to become infected and die. Recent inoculations of many of the same or related families from these parents, made from grafted ramets in a seed orchard, showed that Cr2 conditions a classical hypersensitive reaction (HR) in needle tissues, the primary infection courts. In the latter tests, seedlings were challenged with wild-type and four other sources of inoculum at and near CM that were also suspected of having wider virulence than wild type. No seedlings segregating for HR that were inoculated with wild type subsequently developed stem symptoms, but the other inocula induced both susceptible and HR needle spots on Cr2- genotypes, and many of these seedlings did develop stem infections. This implied that spore genotypes with specific virulence to Cr2 are carried in these inocula.     

松材线虫对黑松一些生理生化指标的影响（英文）

 松材线虫病是松树的一种毁灭性病害。本文对接种松材线虫后3~4年生黑松茎部的一些生理生化指标的变化进行了研究。结果显示,接种线虫后,松苗的可溶性糖含量降低,在病情发展中期和后期比早期降低更显著。松苗的可溶性蛋白质和抗坏血酸含量逐渐降低,游离氨基酸含量也降低。松树茎部的可溶性蛋白质含量可用于病害的早期诊断。此外,对这4个生理生化指标在病害致病机理中的作用进行了讨论。     

Environmentally friendly methods for controlling pine pitch canker

Fusarium circinatum is a highly virulent invasive pathogen that causes the disease commonly known as pine pitch canker (PPC). On mature trees, the most common symptoms of PPC include resin bleeding, resinous cankers, wilting of needles and dieback. In nurseries the main symptoms are yellowish needles, and wilting of foliage and shoots. PPC is considered one of the most important diseases of conifers globally and at least 60 species of Pinus along with Pseudotsuga menziesii are known to be susceptible. Quarantine regulations are crucial to minimize the risk of new introductions into disease-free countries. However, if these measures fail, implementation of environmentally friendly control methods is currently encouraged in an integrated management approach that minimizes the use of chemicals in forests. This review therefore summarizes current knowledge of biological control using endophytic fungi, bacteria and viruses, and other environmentally friendly methods to control PPC, including thermotherapy, natural products with fungicidal effects, promoters of innate host resistance mechanisms and breeding for resistance. Key research gaps to be addressed for improvement of effective management of this disease are discussed.     

Detection of Diplodia sapinea in Corsican pine seeds

Diplodia sapinea is one of the major pathogens of pines worldwide. Despite the putative critical importance of seed infection in the epidemiology of the disease, this aspect of the biology of the fungus is poorly known. Here, biological and molecular methods were developed for the detection of the fungus and applied to assess D. sapinea infection in Corsican pine seeds. A buffered medium containing tannic acid and malt extract as a nutrient base was the most efficient and selective for D. sapinea recovery. A molecular method based on DNA extraction with a commercial kit and specific amplification, including an internal amplification control, was developed. A high percentage of infection (57% positive isolations) was observed in seeds obtained from fallen cones in a Corsican pine stand with no apparent symptoms of D. sapinea. Seeds collected from trees in a seed orchard showing severe symptoms of dieback caused by D. sapinea had comparatively lower infection (38%). Moreover, very low infection levels (1–5%) were observed after the standard treatment used for seed extraction, which included heating at 40°C. Diplodia sapinea was not recovered from seedlings grown from infected seed lots submitted to water stress. Overall, results suggest that the risk of disease transmission by commercial seeds is probably low, but could be further reduced by thermotherapy.     

Host selection by the pine processionary caterpillarthaumetopoea wilkinsoni

The occurrence of nests of the pine processionary caterpillar (PPC),Thaumetopoea wilkinsoni Tarns (Lepidoptera: Thaumetopoeidae), was recorded in two 9-year-old plots planted withPinus halepensis, P. brutia andP. eldarica in a randomized block design. Nest density was highest inP. eldarica and lowest inP. halepensis. The mean number of nests per tree and their frequency distribution indicate that the preference of the PPC is in the order P.eldarica >P brutia >P. halepensis;it is believed to be related to shape of the tree. Planting ofP. eldarica in camping sites is not recommended, due to its high susceptibility to colonization by the PPC.     

不同种松树对松树蜂毒素抗性的初步研究

松树蜂(Sirex noctilio Fabricius)是一种重要的国际检疫性蛀干害虫。目前在我国松树蜂潜在寄主范围内,不同树种对松树蜂毒素抗性之间的差异尚不明确。本文以室内栽培的2~3 a生油松、樟子松、红松、湿地松、马尾松及雪松这6种树种为供试寄主,培育3个月后分别接种毒素、毒素真菌混合液并测定每株枝条针叶的RGB值以及叶绿素含量。结果表明,形态上油松和樟子松幼苗接种毒素、毒素真菌混合液后一段时间内,均出现了比较明显的针叶枯黄、脱落的现象,且混合组长势萎蔫,脱落严重,对照组无明显变化。马尾松幼苗只有接种混合液后变化明显,雪松、红松、湿地松接种后长势强劲,长出新芽。从数值化的角度,油松和樟子松幼苗接种毒素、毒素和真菌混合液后,针叶的RGB值减小及叶绿素含量值显著降低。马尾松幼苗只有接种混合液后,RGB值和叶绿素含量才减小。雪松、红松、湿地松接种毒素以及毒素真菌混合液后,RGB值及叶绿素含量均没有明显变化。以上可以看出樟子松和油松对于松树蜂毒素、毒素真菌混合液的抗性较弱,马尾松对松树蜂毒素具有一定的抗性,对毒素真菌混合液的抗性较弱,红松、湿地松、雪松对两者都具有一定的抗性。该结果可为明确松树蜂在我国潜在的寄主范围及寄主选择性提供科学依据。     

Management of phytophthora root rot in radiata pine seedlings

Chemical and biological agents were evaluated for their ability to suppress root rot, caused by Phytophthora cactorum , in field-grown radiata pine seedlings in New Zealand. Trials were conducted over two seasons in an area of a forest nursery with a natural infestation of P. cactorum , and a history of root rot. In each season, symptoms of root rot developed during April, one month after root pruning, when seedlings were approximately six months old. In trial one, root rot incidence by mid July 2007 was 9·1% in untreated plots and 8·4% in plots that had been treated with metalaxyl-M/mancozeb (14 kg ha⁻¹) at seedling emergence. Disease incidence was lowest (2·1%) in plots that received seven monthly applications of phosphorous acid (6·5 L ha⁻¹). Other treatments, including seed coating with thiram or Trichoderma spp., and foliar applications of methyl jasmonate, did not control disease. In trial two, effects of treatment timing relative to root pruning were investigated. By late June 2008, three months after root pruning, root rot incidence was 22·2% in the untreated plots. Phosphorous acid was the most effective treatment and almost completely suppressed disease (0·1% incidence) when applied fortnightly from February until May (seven applications). Metalaxyl-M/mancozeb (15 kg ha⁻¹) was not effective (21·4% incidence) when applied five months before root pruning. However, disease incidence was reduced when the chemical was applied one week after root pruning (14·9% incidence) and greater control was achieved (8·2% incidence) when the application rate was increased to 50 kg ha⁻¹.     

Mating disruption of the pine processionary caterpillar by pityolure

Mating disruption obtained by the release of pityolure at 1 or 3.6 g/ha from rubber and cardboard dispensers, largely prevented oviposition by the moths of the pine processionary caterpillar (Thaumetopoea wilkinsoni Tarns). However, as the prolonged flight period of the moths necessitates repeated pheromone application, it is doubtful whether mating disruption can replace conventional control methods.     

Plant-parasitic nematodes associated with pine trees in Bulgaria1

Literature data on the nematode fauna of Pinus spp. in Bulgaria are summarized. 48 plant-parasitic nematodes have been reported so far associated with six pine species and a variety of one of these species. In the course of the present study of pine nematode fauna in Rila and Rhodope mountains, Crossonema menzeli, Criconemella xenoplax, Bursaphelenchus sp., Longidorus vineacola, L. leptocephalus, Longidorus sp. and Trichodorus similis were found. Morphological data on some of the species studied are given. The males of L. leptocephalus was more common than the females. L. leptocephalus and Bursaphelenchus sp. are new geographical records. Pinus sylvestris is a new plant host for C. menzeli and L. leptocephalus.