A spatio-temporal multi-scale fusion algorithm for pine wood nematode disease tree detection

Pine wood nematode infection is a devastating disease.Unmanned aerial vehicle(UAV)remote sensing enables timely and precise monitoring.However,UAV aerial images are challenged by small target size and complex sur-face backgrounds which hinder their effectiveness in moni-toring.To address these challenges,based on the analysis and optimization of UAV remote sensing images,this study developed a spatio-temporal multi-scale fusion algorithm for disease detection.The multi-head,self-attention mechanism is incorporated to address the issue of excessive features generated by complex surface backgrounds in UAV images.This enables adaptive feature control to suppress redundant information and boost the model’s feature extraction capa-bilities.The SPD-Conv module was introduced to address the problem of loss of small target feature information dur-ing feature extraction,enhancing the preservation of key features.Additionally,the gather-and-distribute mechanism was implemented to augment the model’s multi-scale feature fusion capacity,preventing the loss of local details during fusion and enriching small target feature information.This study established a dataset of pine wood nematode disease in the Huangshan area using DJI(DJ-Innovations)UAVs.The results show that the accuracy of the proposed model with spatio-temporal multi-scale fusion reached 78.5%,6.6%higher than that of the benchmark model.Building upon the timeliness and flexibility of UAV remote sensing,the pro-posed model effectively addressed the challenges of detect-ing small and medium-size targets in complex backgrounds,thereby enhancing the detection efficiency for pine wood nematode disease.This facilitates early preemptive preser-vation of diseased trees,augments the overall monitoring proficiency of pine wood nematode diseases,and supplies technical aid for proficient monitoring.

Pine wilt disease: a short review of worldwide research

This article summarizes the results of the research papers presented at the International Symposium on pine wilt disease （IUFRO Working Party Meeting 4.04.03） held in July 2009, at Nanjing, China. The general topics covered were on pine wilt disease （PWD）, its causal organism, the pinewood nematode （PWN） Bursaphelenchus xylophilus, plus other PWN-associated microorganisms that play a significant role in PWD such as bacteria （e.g. Pseudomonasfluorescens）. Most of the papers that are reviewed are based on work on PWD-PWN in East Asia and Russia. Specific topics covered include： 1） the fundamental conceptions of PWD development, 2） pathogenicity, 3） host-parasite relationships including the histopathology of diseased conifers and the role of toxins from bacteria-nematode ecto-symbionts, 4） PWN life cycle and transmission, 5） B. xylophilus dissemination models, 6） associations （with other nematodes）, 7） diagnostics, 8） quarantine and control of the PWN and 9） biocontrol of the PWN.

Theory and Practice of Controlling and Extinguishing Pine Wilt Disease

[Objective] This study was aimed to review the controlling experience of pine wilt disease in the past 25 years, explore the theories and methods of controlling pine wilt disease, and improve the scientific level of controlling techniques and the protection capacity of healthy pine trees. [Method] Eleven items of effects were used to refine the theory of clearing dead pine trees affected by pine wilt disease, namely, ＂1 priority＂, ＂2 objections＂, ＂3 principles＂, ＂4 measures＂, and ＂5 manage- ments＂. On the basis of comprehensive control and complete removal of the infect- ed pine trees, a variety of comprehensive and efficient controlling methods were developed to carry out targeted chemical ecology trapping, bionic pesticide killing and releasing natural enemies of Sclerodermus guani, Dastarcus helophoroides. High ef- ficient emamectin benzoate immune injection was developed to inject the healthy pine trees for prevention, so as to extinguish the pine wilt disease. [Result] The pine wilt disease dropped from the peak of 3.5 million dead trees with an infecting area of 28 273 hectares in 1999 to 0.068 million with an area of 4 333 hectares in 2012 gradually, reducing by 98.06% in number and 84.84% in area, respectively. On the basis of removal, Dastarcus helophoroides was also released, which could make the number of dead pines decrease more significantly than the control, and af- ter releasing for 5 consecutive years, the dead pine trees dropped to 0.511 plant/hm2 in 2012, with a mortality rate of 0.022 7%, which achieved the control effect, reaching extremely significant level. ＂Forest land removal＋infected trees isolation＋natural enemy release＂ could extinguish the pine wilt disease. The test of isolating 24 heaps of infected pine trees showed that there were 9 heaps of pine trees extinguished the pine wilt disease, which controlled the occurrence of pine wilt disease for 100%, accounting for 37.5% of the total, in which the number of those isolated using iron netting and nylon net were 4 for each, accounting for 88.9%, and there was one heap using polypropylene net, accounting for 11.1%. The invention of em- amectin benzoate immune injection laid the foundation for extinguishing pine wilt disease. The follow checking of the effects of emamectin benzoate immune injection on pine wilt disease found that the number of dead trees caused by pine wilt dis- ease decreased significantly after injecting, and became very small in October of the next year, and the disease was completely extinguished in the third year. [Conclusionl Pine wilt disease could be controlled and extinguished with positive control by using ＂comprehensive cleaning＋industrialized removal＂, ＂comprehensive cleaning＋ natural enemy release＂, ＂comprehensive cleaning＋infected trees isolation＋natural ene- my release＂ and ＂comprehensive cleaning＋emamectin benzoate immune＂.

Analysis of Influencing Factors of Pine Wood Nematode Disease in Lu an City Based on GIS

[Objectives]The paper was to figure out the distribution of Monochamus alternatus in the stumps of pine wood nematode infected wood in Lu'an City and to provide a theoretical and practical basis for differentiated prevention and control of pine wood nematode disease in the future.[Methods]The factors influencing the number of epidemic small classes and infected plants in all counties and districts of Lu'an City were analyzed by GIS method,and the number of worms and wormholes of M.alternatus inside and outside the stumps of pine wood nematode infected wood in Lu'an City were investigated on the spot.[Results]There were 98,40,54,781,193,268 and 34 epidemic small classes of pine wood nematode disease,and 7241,6099,9532,39161,11079,49876 and 4853 infected plants in Yu'an District,Jin'an District,Yeji District,Shucheng County,Huoshan County,Jinzhai County and Huoqiu County,respectively.Pine wood nematode disease in Lu'an City mostly occurred in Huoshan County,Shucheng County and Jinzhai County,with relatively high altitude,paddy soil,the annual precipitation higher than 2062 mm,and the annual average temperature lower than 16.2℃.The number of diseased plants of pine wood nematode disease was positively correlated with altitude and annual precipitation,and was negatively correlated with annual average temperature.The number of worms and wormholes in pine wood nematode infected wood was very small at different altitudes,stump heights and stump diameters.[Conclusions]The pine wood nematode infected wood can be differentially processed after stump treatment,and stumps can be peeled.The results will provide a theoretical and practical basis for differentiated prevention and control of pine wood nematode disease in the future.

Investigation of beetle species that carry the pine wood nematode,Bursaphelenchus xylophilus(Steiner and Buhrer)Nickle,in China

In order to found new carriers of pine wood nematode(PWN),Bursaphelenchus xylophilus,beetles were collected from pine wilt disease-affected areas in six provinces in China.A total of 8830 beetles of 29 species was collected and examined to determine whether they were PWN carriers.Eight species were identified as carriers.Results included the first worldwide report of Monochamus uigromaculatus,Semanotus siuoauster,and Uraecha angusta being carriers of PWN,and the first report from China of A rhopalus rusticus carrying PWN.Monochamus alternatus was commonly collected in all six provinces and was the dominant species in four inland affected areas and A.rusticus was dominant in two coastal affected areas.The species varied between different neighboring regions in the same province.The distribution of the same species varied considerably over different regions.

Review of Pathogen Identification and Diagnosis Technology of Pinewood Nematode Disease

This article briefly introduced the disease incidence and disservice situation in China. The disease is regarded as cancer in pines for its higher spread and death speed and the difficulty in prevention. Strict quarantine is the main measure on countrol of the disease, for there are many difficulties in the prevention. The most important part of the disease study is the early diagnosis and detection.

2%甲维盐乳油对松材线虫病的防效测定

[目的]为测试2%甲维盐乳油(商品名:松高飞)对松材线虫病的防治效果。[方法]首先通过室内浸渍法比较了2%甲维盐乳油和2%甲维盐微乳剂(商品名:林源松韵)的杀线活性,然后在温室和林间通过树干注射测试了2%甲维盐乳油对松材线虫病的防治效果,最后通过高效液相色谱法测定了不同时间、不同松树体内甲维盐的含量变化。[结果]室内浸渍法结果显示,2%甲维盐乳油具有更强的杀线活性,LC_(50)为41.808 mg·L^(-1),显著低于2%甲维盐微乳剂的75.959 mg·L^(-1)(p<0.05)。温室预防组结果显示,2%甲维盐乳油的预防效果显著,2 a后松树无死亡。温室治疗组结果显示,2%甲维盐乳油治疗时间越早,治疗效果越好;2 a后,接种线虫后7 d注药治疗组,松树无死亡;而30 d后注药治疗组,白皮松、无死亡,油松死亡率为20%,华山松死亡率为40%。林间的试验显示2%甲维盐乳油在两块林地的防治效果显著,其试验组马尾松林2 a累计死亡率分别为2%和5%,远低于对照组马尾松死亡率20%和25%。随着时间变化,不同松树体内甲维盐变化有所差异,华山松体内平均甲维盐含量最高(36.59 mg·kg^(-1)),油松最低(27.11 mg·kg^(-1))。注射后15 d内,所有松树体内甲维盐含量均上升;15 d后,华山松树干中部甲维盐含量逐渐升高,60 d的含量最高;而油松、白皮松树干内甲维盐含量逐渐降低并趋平。[结论]2%甲维盐乳油对松材线虫具有显著的杀线活性,温室和林间防治效果显著,在不同松树体内传输和存留效果良好,无明显药害,可以进一步推广使用。

基于无人机高光谱的川南疫木林区早期监测研究

为探明马尾松感染松材线虫病早期地理位置及发病率。2021年7月上旬,利用无人机搭载高光谱成像仪采集遥感影像,选用支持向量机进行监督分类,在早期感病反演模型基础上,顺利提取了感病早期的马尾松地理位置及相关信息。结果表明:(1)利用460 nm、525 nm和635 nm的3波段组合真彩色影像进行ROI勾绘,马尾松与其他地被物分离度较高;(2)基于支持向量机的监督分类,顺利获取741株马尾松地理位置及高光谱反射率数据;(3)结合监测模型提取64株疑似感病马尾松,通过随机采样及镜检,马尾松聚类范围感病植株提取准确率86.67%,即马尾松林间发病率7.49%。综上,初步揭示川南地区马尾松林自然状态下松材线虫发病率,有利于今后指导松材线虫病早期精准防治。

松材线虫病防治措施分析

本文从清理病死松树、媒介昆虫药物防治、健康松树打孔注药和林分改造4个方面对松材线虫病防治措施进行了分析。从保护松木资源、形成综合防治体系和积累防控工作经验3个方面对其防治效果进行了评价。提出从优化防治措施、强化检疫管理、完善防治方式、加强精准监测和促进联防联治等方面强化松材线虫病防治策略。目的在于为松材线虫病防治工作提供参考。

基于U-Net网络和无人机影像的松材线虫病变色木识别

松材线虫病是由松墨天牛等媒介昆虫快速传播的一种针对松树的毁灭性流行病。及时对染病变色木进行识别、定位,并砍伐清除是当前控制该病扩散蔓延的主要手段。该研究使用无人机航拍获取大区域染病松林可见光影像,结合深度学习分割网络U-Net开展染病松材变色木图像分割研究。使用制作的样本数据训练U-Net网络,得到训练精度和验证精度分别为98.74%和97.76%。使用混淆矩阵评估U-Net网络分割精度,表明变色木图像分割的用户精度和生产者精度分别达到93.51%和97.30%,误报率6.49%,漏报率2.70%。总体上,U-Net网络变色木识别精度95.17%,Kappa系数0.90,达到较高精度。U-Net分割网络运用于松材线虫病变色木图像识别较随机森林方法能更有效地降低误报,减少分割噪音。

细菌分离物B619与松材线虫病关系的初步研究

在无菌条件下 ,用从松材线虫虫体上分离到的细菌分离物B61 9、无菌线虫以及它们的混合物对无菌黑松苗进行了接种试验。结果发现 ,用无菌线虫或细菌分离物B61 9接种的无菌苗不发病 ,而把二者混合后接种则使无菌苗发生萎蔫。这表明松材线虫携带的细菌与松材线虫的致病性有关 ,二者在致病性上极可能存在着协同作用关系。因此 。

抗生素对松材线虫病的影响

利用某些抗生素的内吸性 ,筛选出可使黑松幼苗组织抑制B61 9菌的抗生素溶液浓度 ;进行了抗生素对松材线虫病影响的试验 ,在非无菌条件下 ,用松材线虫对幼苗接种 ,结果表明用抗生素溶液培养的幼苗未发生萎蔫 ,而用无菌水培养的幼苗均出现萎蔫病状 ;同时试验后检查抗生素溶液培养的幼苗 ,发现其组织内均有活线虫存在。这一结果不仅进一步说明了松材线虫病是一种由松材线虫和细菌共同侵染引起的复合侵染病害 ,而且首次用试验证明了通过控制致病细菌的方法可以控制松材线虫病。该结果为开发防治松材线虫病及早期诊断的新方法、培育抗松材线虫病的转基因松树新品种。

松材线虫入侵的黑松内栖真菌区系初步研究

44 isolates of fungi were isolated from the xylem of the Pinus thunbergii samples(healthy stem,weak stem and withered stem)infected by the pine wilt disease caused by pine wood nematode,Bursaphelenchus xylophilus,from infected trees at Zhoushan and Pinghu of Zhejiang Province in China,and these isolates were identified as:Trichoderma spp.,Penicillium spp.,Pestalotia spp.These identified isolates took 70.62% of total isolates of the fungi.Among the 12 isolates unidentified,one sporiferous fungus was found,the other 11 isolates were nonsporiferous.Trichoderma spp.was the dominant fungus in P.thunbergii,the total rate was 53.34%,followed by Penicillium spp.,18.89%.

松材线虫病感病松树中致萎毒性物质的研究

本研究用我国自然感染松材线虫病的 15年生以上黑松和马尾松以及人工感染松材线虫病的 3年生黑松的木质组织进行萃取和粗提纯 ,方法为高压蒸煮法和氯仿碱法。生物测定结果显示 ,有致萎活性的毒性物质仅存在于自然感病未死的黑松和马尾松以及人工感病未死的黑松木质组织中。自然感病死后 1年的黑松和马尾松以及健康松树中不含有这些毒性物质。通过气相色谱—质谱联用仪 (GC MSSystem)对上述木质组织萃取物作定性分析发现 ,自然感病未死的黑松、马尾松和人工感病未死的黑松有致萎活性的萃取物中均含苯乙酸和 2 甲氧基肉桂酸 ,自然感病死后 1年的松树和健康松树中则无。而在健康松树和感病松树中都发现有苯甲醛存在。表明毒性物质与苯乙酸和 2 甲氧基肉桂酸有关 ,苯甲醛则是松树正常的代谢产物。苯乙酸和 2 甲氧基肉桂酸均为酚类化合物 ,是植物体内重要的次生物质。说明感病松树中的毒性物质是松树组织由于松材线虫侵染而产生的异常代谢产物 ,应称之为致萎毒性物质。

松材线虫病致病机理和防治技术研究进展

在松材线虫病的研究方面,目前比较一致的观点是松材线虫在整个病程中起着重要作用,其中多数学者认为松材线虫是唯一病原,还有认为松材线虫携带的细菌与松材线虫一起导致发病。在致病机理的研究中,有三种主要观点:(1)松材线虫分泌的酶破坏了松树薄壁细胞的壁和膜,导致松树死亡;(2)松材线虫入侵松树后,松树体内出现了导致松树死亡的毒素;(3)松树感染松材线虫后,木质部内挥发性物质增加,管胞中形成了空洞,致使松树体内水分输导受阻,松树萎蔫死亡。在松树对松材线虫的抗性方面,树种之间抗性的差异性较显著,而同种松树不同地理种源之间抗性的差异性的显著程度因树种而异。

松材线虫对其携带的一株细菌繁殖和致病性的影响

采用黑松(Pinusthunbergii)无菌苗和愈伤组织的接种试验证明,松材线虫携带的洋葱伯克霍尔德氏菌(Burk-holderiacepacia)B619菌株的繁殖及对黑松的致病性受松材线虫的影响.进一步的研究表明,松材线虫的分泌物及死尸均可促进该菌株的生长繁殖和致病作用,且活线虫的促进作用比死尸更加显著,这可能是由于松材线虫提供给该菌株某些重要的营养物质.试验还发现,松材线虫分泌液经高温处理后对致病细菌繁殖的促进活性下降.

松材线虫病研究文献计量分析

松材线虫病是世界松林最严重的病害,引起各国学者广泛研究。以ISI Web of Science平台的Web of Science^(TM)作为数据源,采用文献计量学的方法,对2002—2016年间发表松材线虫病文献的国家、机构、作者、载文期刊、基金资助机构、学科类别和关键词进行分析。结果表明,全球56个发文国家中,以松材线虫病危害程度最高的亚洲3个国家:日本、中国和韩国,发文数量最多,影响力最高;全球排名前10的研究机构和作者也主要分布于这3个国家中;研究方向则更倾向于动物学、林学和昆虫学方向;载文期刊中,刊载中国学者论文的期刊质量与国际上排名前10的期刊质量还有一定差距;关键词共现网络表明近15年的研究热点为:松墨天牛、生物防治、黑松、鉴定、致病性、传播和拟松材线虫。

松材线虫携带的一株细菌分离及其致病性

从患松材线虫病致死的黑松和马尾松病树组织及松褐天牛虫体中分离的松材线虫虫体上均分离到同一细菌菌株 .经致病性、革兰氏染色、菌体形态、培养性状和生理生化反应等测定 ,将致病菌株鉴定为洋葱伯克霍尔德氏菌 .ATBExpression自动鉴定仪的鉴定结果与上述结果相同 .在分离过程中该菌出现频率较高 ,说明是松材线虫携带的主要细菌 .人工接种试验结果显示 ,用无菌线虫或洋葱伯克霍尔德氏菌菌株分别接种的黑松无菌苗不发病 ,而用二者混合接种则使无菌苗迅速发生褐变和萎蔫 .林间利用 6年生黑松进行的接种试验结果证明 ,用无菌松材线虫和洋葱伯克霍尔德氏菌菌株混合接种的黑松与使用野生松材线虫接种的黑松都 10 0 %的患病 .单独用无菌松材线虫接种有 4株发病 ,6株没有发病 .其中发病黑松中不仅分离到了松材线虫 ,也分离到了细菌 ,而没有患病的 6株黑松中仅分离到少量松材线虫 .这说明在野外条件下接种的松材线虫可以通过某种途径重新获得细菌 ,导致了接种的黑松患病 .而接种后无菌松材线虫没能获得细菌的那些黑松就没有患病 ,说明单独无菌松材线虫不能使黑松患病 .这些结果说明松材线虫携带的细菌与松材线虫的致病性有关 .因此 ,可以把松材线虫病看作是线虫和细菌共同侵染引起的一种植物复合侵染病害 .

松树泌脂速度对松材线虫病的抗性影响

依据松树不同树种、树龄、树势对松材线虫病的抗性差异,分别进行了树干泌脂速度的测定与分析。结果表明,在不同的树种中,松树泌脂速度为火炬松>马尾松>黑松;在马尾松不同的树龄中,幼龄林>老龄林;在马尾松不同树势中,树势强>树势中等>树势弱。依据已知的树种、树龄、树势与松材线虫病的抗性关系,泌脂速度与松材线虫病的发病程度正好呈负相关性。因此,树干泌脂速度或树脂含量可能是评价松树对松材线虫病抗性的重要性状之一。在今后的松材线虫病防治中,应注意选择树脂含量高的树种和品种;或通过栽培管理措施增加树脂含量,以提高树木的抗病性。

基于分子证据探讨松材线虫在中国的传播途径

采用11个随机引物对来自中国最早发病的5个省和日本疫区的松材线虫共10个居群进行遗传多样性分析和系统发育分析，拟从分子水平探讨松材线虫病在中国蔓延的可能途径。结果表明：中国松材线虫居群间 存在明显的遗传差异，遗传距离为0．066—0．262；除了安徽明光的居群自成一支外，其他居群均与南京居群聚成一支，其中安徽皖南和浙江岱山居群与南京中山陵居群遗传距离最近，为0．066；安徽明光居群与南京居群的遗传距离最大，为0．262。表明发生在安徽皖南和浙江岱山等地的松材线虫病可能是由最早发病的南京地区扩散的；而发生在毗邻南京的安徽明光的松材线虫病不是由南京地区扩散的。该结果揭示，松木制品的调运等人为远距离传播是松材线虫在我国蔓延的主要途径之一。