Pestalotiopsis canker of cypress in Israel

The occurrence of a new type of canker on stems and branches of cypress trees(Cupressus sempervirens L.) in Israel is reported.Pestalotiopsis funerea (Desm.) Steyaert was isolated from the cankers. Its pathogenicity was confirmed by formation of typical disease symptoms in inoculated plants and reisolation of that fungus from the cankers. Canker development was significantly enhanced when extreme water stress (water potential of -4.7 MPa) was imposed prior to inoculation.     

Comparative genomics‐informed design of two LAMP assays for detection of the kiwifruit pathogen Pseudomonas syringae pv. actinidiae and discrimination of isolates belonging to the pandemic biovar 3

The aim of this study was to develop a rapid, sensitive and reliable field‐based assay for detection of the quarantine pathogen Pseudomonas syringae pv. actinidiae (Psa), the causal agent of the most destructive and economically important bacterial disease of kiwifruit. A comparative genomic approach was used on the publicly available Psa genomic data to select unique target regions for the development of two loop‐mediated isothermal amplification (LAMP) assays able to detect Psa and to discriminate strains belonging to the highly virulent and globally spreading Psa biovar 3. Both LAMP assays showed specificity in accordance with their target and were able to detect reliably 125 CFU per reaction in less than 30 min. The developed assays were able to detect the presence of Psa in naturally infected kiwifruit material with and without symptoms, thus increasing the potential of the LAMP assays for phytosanitary use.     

BACTERIAL SWOLLEN STEM CANKER ON POPLAR:THE DISEASE AND ITS CAUSES

The bacterial swollen stem canker of poplar is prevalent in planted poplars ofnortheast China.Serious damage occurs in the form of necrosis,putridity,cankers,swollen stemsand discolored wood of trunks and branches of young and mature trees.Tests of allergic reaction,pathogenicity,culture characteristic,Gram stain and anaerobic culture revealed that the pathogen isErwinia sp.Its occurrence depends mainly on the predisposing factors of the disease among whichthe susceptibility of poplars is the most important one.The disease becomes widespread in associa-tion with low-lying and high-humidity terrain,frost injury,node wounds,insect damage,and prun-ing and other mechanical wounds.Harmful factors promote the disease.     

用螺旋毛壳(Chaetomium spirale) ND35菌防治果树腐烂病的试验研究

报道了在离体和田间条件下螺旋毛壳(C. spirale) ND35菌株对苹果树腐烂病的初步抑菌试验结果.PDA平板对峙培养的结果显示在毛壳ND35和苹果树腐烂病菌的两菌落间出现明显的抑菌带;毛壳ND35培养液粗提液比麦芽浸膏培养液的粗提液有更强的抑制病菌菌丝生长的作用.温室和田间生防试验表明用接种毛壳ND35的处理,其苹果树腐烂病发病率明显低于其它处理,包括直接种苹果树腐烂病菌和烫伤处理,及健康对照.再分离试验表明毛壳ND35可成功地在苹果树枝干部位定殖,而且固体麦麸菌剂的定殖率高于玉米粉液体菌剂的定殖率.但是玉米粉液体菌剂在田间的生防效率较好.     

树木溃疡病菌主要类群系统地位及茶蔗子葡萄座腔菌的种内一致性

报道利用微卫星引物[（GT）n、（CGA）n、（CCA）n、（GAA）n、（CAA）n、（GA）n]和小卫星引物M13进行的葡萄座腔菌属、盾壳霉属和疡壳孢属真菌的随机扩增微卫星多态性PCR（RAMs-PCR）遗传多样性结果：42个参试菌株被分为4个RAMs分类群；其中22个葡萄座腔菌属菌株和6个小穴壳菌属菌株分布于这4个类群中；RAMs分类群Ⅰ，Ⅱ，Ⅳ仅仅由葡萄座腔菌属和小穴壳菌属菌株构成，部分茶蔗子葡萄座腔菌，4个贝伦格葡萄座腔菌和所有的盾壳霉属和疡壳孢属菌株构成了RAMs分类群Ⅲ。研究结果显示通过形态学确定的茶蔗子葡萄座腔菌种内具有遗传不一致性．形态学上一致的28个茶蔗子葡萄座腔菌菌株识别为4个不同的表观群；造成苹果轮纹病菌和苹果干腐病菌的贝伦格葡萄座腔菌菌株与部分茶蔗子葡萄座腔菌在分子水平上非常相似；研究结果亦显示盾壳霉属与疡壳孢属真菌有着较近的系统关系。     

杨树上的冰核细菌及其在引起杨树冻害和诱发真菌溃疡病过程中的作用

在黑龙江、吉林和辽宁省的杨树上普遍存在着冰核活性（ＩＮＡ）细菌,经测定它们能在－４℃～－６℃温度下产生冰核活性。它们分属于３个属５个种或变种,即：菠萝泛生氏菌（ＰａｎｔｏｅａａｎａｎａｓＳｅｒａｎｏ１９２８）、噬夏孢子欧文氏菌（Ｅｒｗｉｎｉａｕｒｅｄｏｖｏｒａ（Ｐｏｎｅｔａｌ．）Ｄｙｅ１９６３）、丁香假单胞菌（Ｐｓｅｕｄｏｍｏｎａｓｓｙｒｉｎｇａｅｐｖ．ｓｙｒｉｎｇａｅＶａｎＨａｌ１９０２）、丁香假单胞菌流泪致病变种（Ｐ．ｓｙｒｉｎｇａｅｐｖ．ｌａｃｈｒｙｍａｎｓ（Ｓｍｉｔｈ＆Ｂｒｙａｎ）Ｄｙｅ１９７８）和丁香假单胞菌未定变种（Ｐ．ｓｙｒｉｎｇａｅｐｖｓ．）。自然条件下ＩＮＡ细菌增加了杨树的冻害;冻害的主要时期是在早春杨树萌芽阶段。在由真菌ＤｏｔｈｉｏｒｅｌａｇｒｅｇａｒｉａＳａｃｃ．引起的大斑型溃疡病病斑中分离到的ＩＮＡ细菌数量最多;而同一真菌引起的水泡型溃疡病病斑中分离到的ＩＮＡ细菌数量最少。在杨树干上接种ＩＮＡ细菌并经冷冻处理后,增加了Ｄ．ｇｒｅｇａｒｉａ的侵染,形成大斑型溃疡。证明冻伤和其它伤口是Ｄ．ｇｒｅｇａｒｉａ形成大斑型溃疡病斑的主要原因。提出了对ＩＮＡ细菌造成的杨树冻害和真菌性溃疡病进行综合     

Differential responses of Central American and Mexican pine species and Pinus radiata to infection by the pitch canker fungus

Seedlings from a wide array of 23 species, varieties,and geographic races were screened for resistance topitch canker using artificial inoculation in agreenhouse. Seed to represent these taxa weregenerally collected in natural stands. In addition,seedlings from 79 families of P. radiata fromcommercial populations from Chile and New Zealand werescreened in a separate experiment. There was littlevariation in resistance among the commercial P.radiata families, with over 98% mortality. Similarresults were obtained with native P. radiatapopulations. All close relatives of P. radiata(sub-section Patula) were very susceptible. However,a number of closed-cone pine species (specifically,from sub-section Oocarpa) were generally veryresistant, with survival approaching 100%. Inaddition, in P. oocarpa, P. jaliscana, and P. tecunumanii from low elevation provenances anextremely high frequency of trees suffered no apparentdamage from the pathogen (92%, 85% and 80%,respectively).     

基于气象因子的杨树溃疡病发生率空间格局研究

根据全国范围内2002—2012年杨树溃疡病逐年发生数据,选取发生杨树溃疡病地级行政区的平均发生率作为杨树溃疡病的预测指标,在ClimateChina v4.40气候模拟软件中,计算出发生地区的气象数据。利用偏最小二乘回归,得到杨树溃疡病平均发生率与气象因子的回归方程,即杨树溃疡病平均发生率空间格局模型,并结合地理空间数据和属性数据,预测未来我国杨树溃疡病的潜在变化趋势。结果显示：结合5月平均气温、5月平均最高气温、1月平均最低气温、3月平均最低气温、4月平均最低气温、6月平均最低气温、8月平均最低气温、11月平均降水量、春季平均最低气温、夏季平均最低气温、大于5 ℃的有效积温度日和大于18 ℃的有效积温度日12个气象因子建立的杨树溃疡病平均发生率空间格局模型,具有较强的可靠性,据此预测杨树溃疡病平均发生率在2020s、2050s、2080s的空间格局与2002—2012年相比主要呈现出华北、华中和华东地区整体发生面积减少,但局部地区发生程度加重,东北地区发生程度普遍加重且总体北移的趋势。     

桐庐县板栗溃疡病发生现状及防治对策

介绍了板栗溃疡病的病害种类、病原、症状和发生规律,提出了适地适树、良种壮苗造林、加强栗园管理、增强树势、及时清除病原、抓好防治的防治对策。     

杨树溃疡病测报方法的初步研究

根据杨树溃疡病的发生规律,在测报期间内,病情指数(Dis)与相应时期的菌量(F_1、F_2、F_3)、积温(CT)、温湿比(TH)、温雨比(TR)及湿雨比(HR)有着密切的相关关系。应用多元统计方法建立的多元线性回归预测模型:Dis=19.0-2.8(F_3)~(1/2)+0.1F_1+0.0015(F_2)~3+4.15TH-0.042(CT)~(1/2)-0.4HR+3.5TR,可以预测一个月后的发病情况,模型经实际病情验证,有较高的准确性。