不同猕猴桃品种对细菌性溃疡病的抗病性及其聚类分析

通过田间定点抗病性调查,结合前人的研究结果得出:不同猕猴桃品种对细菌性溃疡病的抗性存在明显差异。金魁和两种雄株中华软、美味硬最为抗病,早鲜次之,魁蜜稍抗。华美2号、海沃德中感。秦美、金丰最感病。用最长距离法对安徽省9个猕猴桃品种进行抗细菌性溃疡病系统聚类,可以将9个品种划分为5类。在谱系图上,抗病性相同的品种大致划分在同一个类中,第1类中华软、美味硬(8、9)为免疫品种;第2类早鲜、金魁(6、7)为高抗品种;第3类魁蜜(5)为中抗品种;第4类为中感品种,华美2号(4)为偏抗病,海沃德(3)为感病品种;第5类则为感病品种,金丰(1)为高感品种,秦美(2)为感病品种。其结果与实际抗性调查情况基本相符。     

陕西猕猴桃细菌性溃疡病田间发生动态和规律

为有效防治猕猴桃细菌性溃疡病和明确其发生时期与规律,采用田间定点、定期系统调查的方法,对该病害在枝干和叶片上的周年发生动态、不同品种的发病情况和发病部位,以及影响发病的气候因素等进行了研究.结果显示,溃疡病在枝干上有冬末春初和秋季2个发病高峰,以冬末春初为主,发病株率占全年的80％以上;在叶片上亦有2个发病高峰,分别为春末夏初和秋末冬初.溃疡病在不同品种上的发病存在明显差异,以红阳品种发病率较高,平均病株率达37.8％,平均病叶率达21％;不同品种的主干、侧枝、结果枝均能发病,但发病率有明显差异(P＜0.05),以侧枝和结果枝发病为主;菌脓出现位点在枝干皮孔、芽眼、伤口、枝杈裂缝及落叶痕等处,以皮孔为主要出脓位点;低温有利于枝干发病,其中秋冬季日均温低于0℃的时间和出现早晚是影响枝干发病的重要因素.     

湘西地区猕猴桃细菌性溃疡病抗性资源筛选及其抗性机理研究

由Pseudomonas syringae pv.actinidiae(Psa)引起的溃疡病是猕猴桃生产中威胁最大的细菌性病害。种植抗病品种是防治猕猴桃溃疡病最有效途径,猕猴桃抗源是抗病育种的物质基础。本试验通过离体接种,在室内评价了4个不同种的7个猕猴桃资源及品种对溃疡病的抗性。结果表明:供试材料离体叶片、枝条接种溃疡病菌后,其发病时间、病斑大小、发病率差异明显。按病斑大小排序,其抗性强弱依次为毛花猕猴桃‘M9808’>对萼猕猴桃‘S9801’>美味猕猴桃‘M-06’>美味猕猴桃‘米良1号’>中华猕猴桃‘Z-12’>中华猕猴桃‘东红’>中华猕猴桃‘红阳’(CK)。其中,毛花猕猴桃‘M9808’抗病性最强,表现为发病最晚,离体叶片、枝条分别于接种后10 d、20 d发病,比对照推迟了8 d、10 d;病斑最小,为对照的1/25、1/11;发病率最低,为对照的1/28、1/10。抗病性相关酶活性比对发现,不同材料的PAL、CAT、POD酶活性差异较大,抗性材料均高于感病材料,且峰值出现时间早于感病材料。其中,毛花猕猴桃‘M9808’的PAL峰值最高,接种后5 d出现,比对照早10 d;CAT、POD峰值接种后10 d出现,比对照早5 d。说明毛花猕猴桃‘M9808’对溃疡病抗性最强,可作为今后猕猴桃抗病育种或抗性砧木的理想材料。这为猕猴桃抗病育种提供了理论依据,为猕猴桃溃疡病的防控提供了参考。     

四川省猕猴桃溃疡病发生现状及绿色防控技术体系的建立

通过调查,明确了猕猴桃溃疡病在四川的发生分布情况,以及猕猴桃品种抗性、园区管理情况,建立了猕猴桃溃疡病绿色防控体系。     

修文县猕猴桃溃疡病综合防控措施

通过对修文县猕猴桃溃疡病的调查研究,掌握猕猴桃溃疡病的发生特点、发病因素和田间消长规律,并提出综合防治措施。     

红心猕猴桃溃疡病及其防治技术

湖北省恩施自治州属亚热带季风性山地湿润气候,适宜红心猕猴桃生长。多年来,由于溃疡病频繁发生,直接影响红心猕猴桃产量和品质,制约了恩施州猕猴桃产业高质量发展。本文阐述了红心猕猴桃溃疡病的发病条件、危害症状及发病原因,并提出了避雨栽培、植物检疫、农业防治及化学防治等综合防控措施,旨在为山区红心猕猴桃溃疡病的防控提供指导服务。     

云南猕猴桃细菌性溃疡病病原菌鉴定

为明确云南省发生的猕猴桃溃疡病种类,通过田间发病症状、菌落形态、致病性测定、Biolog分析,16S rDNA序列分析比较,对疑似猕猴桃溃疡病病原菌进行鉴定。结果表明:病原菌接种可引起烟草过敏反应,同时在猕猴桃叶片表面形成带有黄色叶晕的不规则褐色斑点,将菌株测序序列与现有的丁香假单胞菌菌株的16S rDNA序列构建进化树,结果显示病原菌与丁香假单胞猕猴桃致病变种聚在同一分支上。以上表明云南省猕猴桃溃疡病病原菌为丁香假单胞猕猴桃致病变种(Pseudomonas syringae pv. actinidiae)。这是云南省首次报道由Pseudomonas syringae pv. actinidiae引起的猕猴桃细菌性溃疡病。     

猕猴桃果园冬季注意预防冻害

<正>植株伤口是猕猴桃溃疡病病菌入侵的主要途径之一,冬季低温对猕猴桃植株造成的冻伤为溃疡病入侵提供了通道,冻伤严重的果园开春后往往发生大面积流胶,并伴随溃疡病严重发生。重庆猕猴桃主产区主要集中在黔江、万州、秀山等冬季寒冷地区,容易发生冻害,因此要注意做好防寒防     

湖南猕猴桃溃疡病菌16S rDNA和16S-23S rDNA间隔区序列的克隆与分析

为明确湖南省猕猴桃溃疡病其致病菌的种类与特征,以猕猴桃主栽品种红阳、米良1号的溃疡病感病枝条为材料,采用BPA培养基、平板划线和梯度稀释法分离病原菌。利用引物27F/1492R和Psa F1/Psa R2对湖南省猕猴桃溃疡病菌16S r DNA和16S-23S r DNA间隔区序列(ITS)进行PCR扩增并进行核苷酸序列测定及相似性分析。获得Psa-JSHY株系、Psa-LXHY株系以及Psa-LXML株系的16S r DNA基因片段1 383 bp及16S-23S r DNA间隔区序列280 bp,且序列一致。经序列相似性比较表明:所分离株系的16S r DNA与法国181、新西兰ABAC9、意大利IKB4等株系的16S r DNA基因序列一致,与日本的KW11等株系存在3个碱基的差异,相似性为99.78%,与国内分离的11-830-1株系存在4个碱基的差异,相似性为99.71%;16S-23S r DNA-ITS序列与中国SXHY11-1、西班牙EFA131.1、葡萄牙PA838、韩国KBE9等株系的ITS序列一致。构建16S r DNA及16S-23S r DNA-ITS序列的进化树,可以看出所分离的株系与已报道的P.syringae pv.actinidiae各菌株聚在同一个进化枝上。以上结果表明,湖南地区分离的3个猕猴桃溃疡病菌致病株系均属于P.syringae pv.actinidiae。     

猕猴桃园区坡度和晴雨天对猕猴桃溃疡病传播的影响

猕猴桃溃疡病是由丁香假单胞菌猕猴桃致病变种(Pseudomonas syringae pv. actinidiae,Psa)引起的细菌性病害,严重影响猕猴桃产业发展。明确猕猴桃溃疡病在田间的传播对其防治具有重要意义。本研究于2020年4月16-22日和2021年3月24-30日,在湖北省赤壁市调查了半岛南猕猴桃种植园区内猕猴桃溃疡病的发病情况,通过孢子捕捉器在猕猴桃园区的不同地势(坡度为10°、30°和45°的区域)和不同天气环境下进行24 h连续病原捕集,并据猕猴桃叶片上溃疡病显症所需时长反映不同地势和天气环境对病害传播的影响。结果表明,在坡度10°区域进行病原捕集的猕猴桃叶片显症所需时间比坡度30°和45°区域晚1~2 d。雨天在孢子捕捉器内的叶片上显症所需时长仅需7 d,而晴天显症时长则需10~12 d。明确了露地栽培猕猴桃园区坡度和雨天显著促进了猕猴桃溃疡病的传播。对猕猴桃溃疡病防治技术制订和实施有一定意义。     

猕猴桃褪绿环斑相关病毒在陕西省的分布、分子变异及其2个分离物的基因组序列

为明确我国陕西省猕猴桃主产区的徐香、海沃德、华优和秦美4个猕猴桃品种上的猕猴桃褪绿环斑相关病毒(Actinidia chlorotic ringspot-associated virus,AcCRaV)的分布情况,对采集自该省4个地区的493份样品进行AcCRaV检测,基于cp基因序列对获得的AcCRaV分离物进行分子变异分析,并采用高通量测序技术对其中2份样品进行转录组测序。结果显示:AcCRaV在陕西省猕猴桃上分布广泛,且检出率较高,其中周至县秦美猕猴桃上AcCRaV的检出率最高,为45.0%,在杨凌区秦美猕猴桃上AcCRaV的检出率最低,为10.0%。测定的23个AcCRaV分离物cp基因序列全长均为945 nt。系统发育树显示AcCRaV分离物共分成2个组,存在较大的分子变异。AcCRaV的cp基因分子变异与猕猴桃品种有一定关系,而与地理位置相关性不明显。获得了2个AcCRaV分离物ZZ1和ZZ2的基因组序列,RNA1长度分别为7 049 nt和7 274 nt,RNA2长度均为2 266 nt,RNA3长度分别为1 691 nt和1 696 nt,RNA4长度分别为1 736 nt和1 683 nt,RNA5长度分别为1 460 nt和1 497 nt。分离物ZZ1和ZZ2的基因组序列与GenBank中唯一报道的我国湖北省AcCRaV分离物HN-6基因组序列比对中,分离物ZZ2与HN-6的RNA4同源率最高,为96.0%,分离物ZZ2与HN-6的RNA1同源率最低,为87.8%。表明AcCRaV在我国陕西省猕猴桃主产区分布较广泛,且其分子变异与猕猴桃品种有一定关系。     

Impact of kiwifruit bacterial canker on productivity of cv. Hayward kiwifruit using observational data and multivariable analysis

A virulent strain of Pseudomonas syringae pv. actinidiae biovar 3 (Psa), which causes bacterial canker in kiwifruit, was first recorded in New Zealand in November 2010. This strain has severely affected Actinidia chinensis var. chinensis ‘Hort16A’ kiwifruit productivity but its effect on green Actinidia chinensis var. deliciosa ‘Hayward’ kiwifruit productivity has been variable. An observational study design was used to develop explanatory models to quantify the impacts of Psa infection on productivity (tray equivalents per hectare) of Hayward kiwifruit harvested in 2012, using data captured by industry from 2599 orchards. A total of 934 orchards were Psa positive at the end of the study period. Multivariable linear regression was used to model 2012 productivity in the presence of Psa, while controlling for regional differences, elevation, 2011 productivity, harvest dates and application of agrichemicals. The model showed productivity was initially higher in the presence of Psa, and was not reduced until after 1 year of infection. The relationship between protective spray use and productivity was also quantified. It is likely that improved disease management has offset the impact of the disease and future research should consider a reassessment of the effects of disease after longer term exposure to Psa in New Zealand. The use of an observational cohort study to assess disease impacts using multivariable analysis could have wider application in the field of plant epidemiology.     

Current situation and characterization of Pseudomonas syringae pv. actinidiae on kiwifruit in Galicia (northwest Spain)

Bacterial canker of kiwifruit, caused by Pseudomonas syringae pv. actinidiae (Psa), is a disease that is spreading rapidly in several kiwifruit‐producing countries, causing significant economic losses. In 2011, it was detected for the first time in Spain, in the south of Galicia (northwest Spain). Kiwifruit orchards were therefore inspected and sampled in 2011 and 2012 to determine the pathogen distribution, and the isolates obtained were characterized by morphology, fatty acids profile, biochemical tests and molecular techniques. Isolates were obtained from Actinidia deliciosa ‘Hayward’ (from leaves, canes, flower buds, fruits and roots), from A. deliciosa ‘Summer’, from Actinidia chinensis ‘Jin Tao’ (from canes and leaves) and from A. chinensis pollinator ‘Belén’ (from canes). Results of the analysis of the cfl gene (phytotoxin production‐related), the tox–argK gene cluster and phylogenetic analysis of the cts gene demonstrated that all Psa isolates from northwest Spain correspond to the Psa3 population, which includes strains of haplotype 2. This is the first record of Psa3 and haplotype 2 in Spain.     

Field efficacy of chitosan to control <Emphasis Type="Italic">Pseudomonas syringae</Emphasis> pv. <Emphasis Type="Italic">actinidiae</Emphasis>, the causal agent of kiwifruit bacterial canker

In order to provide an alternative for controlling bacterial canker of kiwifruit, caused by Pseudomonas syringae pv. actinidiae, in case of the appearance of copper/antibiotic-resistant strains of the pathogen, the field efficacy of a chitosan-based compound was compared with a copper compound on Actinidia deliciosa cv. Hayward. The 3-year trials were carried out in central Italy, in an area heavily affected by the disease. Both compounds were sprayed on the same day according to the following schedule: every 14 days, from early April to early June (a total of seven treatments), and once a month, from mid November to mid February (a total of four treatments). Chitosan did not incite any phytotoxic effect on plant and fruit and showed an overall higher level of performance than the copper compound in reducing disease symptoms throughout the 3-year trials. Chitosan significantly reduced also the presence of exudates on trunk and leader recorded at the end of winter.     

软枣猕猴桃种质资源溃疡病抗性鉴定方法的建立与评价

以51份软枣猕猴桃Actinidia arguta种质资源为材料,以中华猕猴桃Actinidia chinensis Planch'红阳'、美味猕猴桃Actinidia chinensis var.deliciosa'徐香'为对照,利用丁香假单胞菌猕猴桃致病变种Pseudomonas syringae pv.actin...     

关中地区猕猴桃树体周年磷素需量动态规律研究

以10年生"秦美"猕猴桃树为试材,研究了猕猴桃树体生物量和各器官及茎和根的皮层、木质部的磷含量和累积动态,以期探讨猕猴桃树磷素吸收、转运和分配规律。结果表明,猕猴桃树整株生物量从萌芽期到果实生长始期增加缓慢,在整个果实生长期快速增加,果实的收获和落叶使整株生物量大幅下降,根系生物量年周期内增加较少。磷在猕猴桃树的根、茎、叶、果及皮层和木质部的分布表现为:根、叶、果实>茎;根和茎的皮层>木质部。萌芽期到果实生长始期猕猴桃叶生长所需的磷素78.89%来自于土壤,4.44%来自根的上年贮藏,16.67%来自茎的上年贮存。果实生长始期到果实迅速膨大末期猕猴桃树吸磷量为全年总吸磷的55.39%,是磷素营养最大效率期。年周期猕猴桃树体吸收磷素的总量为36.95 kg/hm2(猕猴桃产量以40.16 t/hm2计)。进入果实收获期以后和结果前共吸收磷量10.92 kg/hm2,整个果实生长期吸收26.03 kg/hm2,分别占总吸收量的29.55%和70.45%。     

Pseudomonas syringae pv. actinidiae: chemical control,resistance mechanisms and possible alternatives

Pseudomonas syringae pv. actinidiae (Psa) is a Gram‐negative bacterium that causes the bacterial canker of both green (Actinidia deliciosa) and yellow (Actinidia chinensis) fleshed kiwifruit. Since the emergence of an economically devastating Psa outbreak in Japan in the 1980s, the disease took a contagious turn causing severe economic loss to kiwifruit industries in Italy, South Korea, Spain, New Zealand and other countries. Research shows that the pathogenic strains isolated from different infected orchards vary in their virulence characteristics and have distinct genes coding for the production of different toxins. The global Psa outbreak has activated research around the world on developing efficient strategies to contain the pandemic and minimize loss to the kiwifruit industry. Chemical and biological control options, orchard management and breeding programmes are being employed in this global effort. Synergy between different disease control strategies has been recognized as important. Phytotoxicity, resistance development and regulatory measures in certain countries restrict the use of copper compounds and antibiotics, which are otherwise the mainstay chemicals against bacterial plant diseases. Therefore, because of the limitations of existing chemicals, it is important to develop novel chemical controls against Psa. Antimicrobial peptides, which are attractive alternatives to conventional antibiotics, have found promising applications in plant disease control and could contribute to expanding the chemical control tool box against Psa. This review summarizes all chemical compounds trialled so far against Psa and provides thoughts on the development of antimicrobial peptides as potential solutions for the future.     

猕猴桃品种酚类物质及可溶性蛋白含量与抗溃疡病的关系

以安徽省猕猴桃主栽品种金魁、早鲜、魁蜜、华美2号、秦美、金丰为研究对象,于展叶孕蕾期分别取发病的枝条、叶片,以未发病健株的相应组织为对照,分析枝条、叶片中酚类物质和可溶性蛋白的含量变化。结果表明：抗病品种健株枝条、叶片中可溶性蛋白含量显著高于易感病品种,说明枝条中可溶性蛋白含量与品种抗性成正相关。自然发病后,感病品种枝条中可溶性蛋白含量增加,抗病品种可溶性蛋白含量降低。抗病品种健枝条、叶片中酚类物质含量高于易感病品种的健枝、叶,发病后抗感品种酚类物质含量都增加。     

Occurrence and molecular characterization of Actinidia virus C (AcVC), a novel vitivirus infecting kiwifruit (Actinidia spp.) in China

Kiwifruit (Actinidia spp.) is an economically important fruit crop in the world. China is the largest producer of kiwifruit in terms of both acreage and yield. In this study, a novel virus, tentatively named Actinidia virus C (AcVC), was discovered in Actinidia deliciosa ‘Xuxiang’ grown in commercial kiwifruit fields in the Shaanxi province, a major kiwifruit-growing region in China. Sequencing of the complete genome showed that AcVC has 7,668 nucleotides (not including the poly-(A) sequence). Complete genome comparison and phylogenetic analysis showed that AcVC is most closely related to AcVA and then to AcVB. AcVC shares 69.2% nucleotide identity with AcVA (GenBank accession number JN427014 ). Based on these data, Actinidia virus C is assigned as a new tentative member of the genus Vitivirus in the family Betaflexiviridae. AcVC was found to infect A. deliciosa and A. chinesis, the two major cultivated kiwifruits. Infection frequency of AcVC varied with the kiwifruit-growing regions and cultivars in the Shaanxi province of China.