猕猴桃溃疡病综合防治方法

溃疡病是一种为害猕猴桃生产的细菌性病害,造成果实品质降低,树势衰弱。为害严重时,造成果园毁灭,损失严重。介绍猕猴桃溃疡病在城固县的发病原因和传播途径,并提出防控措施。     

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。     

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。     

猕猴桃品种对细菌性溃疡病的抗性机制

研究了安徽省猕猴桃主栽品种金魁(高抗)、早鲜(中抗)、魁蜜(抗病)、华美2号(感病)、秦美(中感)和金丰(高感)对细菌性溃疡病的抗性机制.结果表明:形态结构抗性方面,感病品种的皮孔密度和长度及气孔密度、长度和宽度都明显高于抗病品种,抗、感品种间皮孔、气孔的排列方式也存在一定差异.相关分析表明,皮孔密度和长度及气孔密度、长度和宽度与品种发病率都有较高的相关性,尤其以皮孔长度和气孔长度相关性最高,r分别为0.9278和0.9794;生理生化抗性方面,品种未感染溃疡病菌前,芽中的POD酶活性与品种抗性存在规律性不强,一年生枝条、叶片中的POD酶活性与品种抗性有密切关系.品种感染溃疡病菌后,POD酶活性均升高,但抗病品种中酶活提高倍数高于感病品种.一年生枝条上病斑越大,POD酶活性越高.POD同工酶谱带表现出与酶活相一致的规律.     

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。     

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。     

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...     

不同猕猴桃品种RAPD分析及其与抗溃疡病的关系

对不同猕猴桃品种的分子生物学试验表明：猕猴桃的DNA浓度在920 μg/mL符合RAPD分析的要求。通过60个随机引物的PCR扩增,报道了6个不同品种和类型猕猴桃种质资源的RAPD多态性,计算了它们之间的遗传距离,构建了聚类图,并讨论了其亲缘关系。聚类分析图反映出来源于安徽省主要猕猴桃产区的6个样品可以分为3组,其中抗病与感病的相对较为集中,由此可推断出现这种聚类的原因可能是由于它们基因组中有相同的DNA片段。抗病品系都有一条1 458 bp DNA片段,而感病品系均没有该带。故该片段可能与猕猴桃植株抗溃疡病相关。RAPD多态性从分子水平上反映出了猕猴桃种质资源不同品种及不同类型间复杂的遗传背景,为抗病育种的亲本选配提供了依据,也为合成猕猴桃抗溃疡病探针并用于检测猕猴桃抗溃疡病种质和分子标记辅助育种奠定了基础。     

猕猴桃品种中糖分及木质素含量 与抗溃疡病的关系

以安徽省猕猴桃主栽品种金魁、早鲜、魁蜜和金丰为研究对象，于展叶孕蕾期分别取发病的枝条、叶片，以未发病的健株相应组织为对照，采用生理生化的方法，分析枝条、叶片中木质素和可溶性糖的含量变化以及与抗溃疡病的关系。结果表明：抗病品种金魁健株枝条、叶片中可溶性糖及木质素含量显著高于感病品种金丰。自然发病后，抗感病品种枝条、叶片中可溶性糖含量都降低，感病品种降低更多，金魁叶片可溶性糖含量下降4．20％，金丰叶片可溶性糖含量下降55.35％；木质素含量都升高，且抗病品种金魁叶片中的木质素含量比感病品种金丰高得多，其变化率分别为7．17％、3．01％，枝条中的木质素含量变化率分别为110．39％、68．98％，其差异达到显著水平。相关分析表明，枝条中木质素、可溶性糖含量与品种发病率也呈负相关，γ分别为-0．9583和-0．9282；叶片中木质素、可溶性糖含量与品种发病率呈负相关，γ分别为-0．8099和-0、8266。从而说明枝条、叶片中可溶性糖及木质素含量与品种抗性呈正相关。抗感品种淀粉含量无明显规律性变化，与品种抗性关系不大。     

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.     

植物内生放线菌活性物质防治猕猴桃溃疡病

以供试内生放线菌发酵液的皿内抑菌活性为指标,得到对猕猴桃细菌性溃疡病菌有抑制活性的菌株76株,其中35株的发酵液对猕猴桃溃疡菌的抑菌圈直径≥20mm,5株对猕猴桃溃疡病菌均具有显著的抑制活性.其中gCLA4菌株发酵液抑菌谱最广,不仅对4种靶标细菌具有抑制活性,还对10种植物病原真菌有较强的抑制活性.通过发酵液制备及大孔吸附树脂D101处理得到gCLA4菌粗提活性物质.田间防治结果表明,gCLA4菌株粗提活性物质100倍稀释液对猕猴桃溃疡病28d的相对防效达64.9%,明显优于化学药剂施那宁.     

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。     

Evaluation of the wild Actinidia germplasm for resistance to Pseudomonas syringae pv. actinidiae

Bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is a catastrophic disease that threatens the global kiwifruit industry. As yet, no cure has been developed. Planting resistant cultivars is considered as one of the most effective ways to control Psa. However, most existing cultivars lack Psa-resistance genes. Wild Actinidia resources contain rich genetic diversity and may have powerful disease-resistance genes under long-term natural selection, but lack of knowledge about the resistance to Psa for most Actinidia species results in some excellent wild resistant genotypes being underutilized. In this study, the response to Psa of 104 wild genotypes of 30 Actinidia species (including 37 taxa) was tested with an in vitro bioassay, and a considerable number of individuals from different species with tolerance or high resistance to Psa were identified. The results showed high consistency between years. This is the first large-scale evaluation of diverse Actinidia species with resistance to Psa through an in vitro bioassay. The resistant genotypes of A. chinensis identified could be used in future kiwifruit improvement programmes. The findings should help provide an understanding of the resistance to Psa.     

Molecular and phenotypic features of Pseudomonas syringae pv. actinidiae isolated during recent epidemics of bacterial canker on yellow kiwifruit (Actinidia chinensis) in central Italy

Pseudomonas syringae pv. actinidiae (Psa) was identified as the causal agent of severe epidemics of bacterial canker on Actinidia chinensis (yellow kiwifruit) in central Italy occurring during 2008–9. A total of 101 strains were obtained from infected leaves, twigs, branches and trunks of cvs Hort16A, Jin Tao and CK3. Outbreaks were also found on A. deliciosa cv. Hayward. A representative set of 21 strains were compared with other Psa strains isolated from previous outbreaks in Japan and Italy as well as with P. s. pv. syringae strains obtained from A. chinensis and with strains of genomospecies 8. Repetitive‐sequence PCR (rep‐PCR) typing using BOX and ERIC primer sets revealed that all Psa strains obtained during 2008–9 showed the same fingerprinting profile. This profile, however, was different from those of strains previously isolated in Japan and Italy. Multilocus sequence typing (MLST) of gapA, gltA, gyrB and rpoD revealed a higher genetic variability among the strains than rep‐PCR, with some of them showing the same sequence pattern although isolated from different areas, cultivars and years. None of the recently obtained strains possessed genes coding for phaseolotoxin or coronatine, and all had an effector protein, namely hopA1, differentiating them from the strains causing past outbreaks in Japan and Italy. All isolates were inhibited in vitro by copper‐based compounds, antibiotics, geraniol, citronellol and by a chitin‐based organic compound. The recent epidemics found in central Italy on yellow kiwifruit appear to have been caused by a different Psa population than those previously recorded in Japan, South Korea and Italy.     

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。     

猕猴桃细菌性叶枯病生防芽孢杆菌筛选及田间防效

从猕猴桃大田根际土壤和青海牦牛粪中分离到86株芽孢杆菌。平板对峙试验发现其中8个菌株对猕猴桃细菌性叶枯病病原菌Pseudomonas syringae var. syringae的拮抗性能明显。经管碟法复筛,得到2株对病原菌具有显著拮抗作用的芽孢杆菌M24和Q13。田间试验表明,发酵液（109cfu/ml）稀释100倍时喷施,菌株M24和Q13对猕猴桃细菌性叶枯病的防效分别达到85.9%和80.6%,均显著高于95%CT杀菌剂的60.5%防效。2个菌株均具有良好的田间应用潜力。     

Characterization of Pseudomonas syringae pv. actinidiae (Psa) isolated from France and assignment of Psa biovar 4 to a de novo pathovar: Pseudomonas syringae pv. actinidifoliorum pv. nov.

Since 2008, bacterial canker of kiwifruit (Actinidia deliciosa and A. chinensis) caused by Pseudomonas syringae pv. actinidiae (Psa) has resulted in severe economic losses worldwide. Four biovars of Psa can be distinguished based on their biochemical, pathogenicity and molecular characteristics. Using a range of biochemical, molecular and pathogenicity assays, strains collected in France since the beginning of the outbreak in 2010 were found to be genotypically and phenotypically diverse, and to belong to biovar 3 or biovar 4. This is the first time that strains of biovar 4 have been isolated outside New Zealand or Australia. A multilocus sequence analysis based on four housekeeping genes (gapA, gltA, gyrB and rpoD) was performed on 72 strains representative of the French outbreak. All the strains fell into two phylogenetic groups: one clonal corresponding to biovar 3, and the other corresponding to biovar 4. This second phylogenetic group was polymorphic and could be divided into four lineages. A clonal genealogy performed with a coalescent approach did not reveal any common ancestor for the 72 Psa strains. Strains of biovar 4 are substantially different from those of the other biovars: they are less aggressive and cause only leaf spots whereas Psa biovars 1, 2 and 3 also cause canker and shoot die‐back. Because of these pathogenic differences, which were supported by phenotypic, genetic and phylogenetic differences, it is proposed that Psa biovar 4 be renamed Pseudomonas syringae pv. actinidifoliorum pv. nov. Strain CFBP 8039 is designated as the pathotype strain.     

Frost promotes the pathogenicity of Pseudomonas syringae pv. actinidiae in Actinidia chinensis and A. deliciosa plants

Frost occurs in all major areas of cultivation, presenting a threat for the production of kiwifruit crops worldwide. A series of experiments were performed on 1‐year‐old, potted plants or excised twigs of Actinidia chinensis and A. deliciosa to verify whether strict relationships exist between bacterial canker outbreaks from Pseudomonas syringae pv. actinidiae (Psa) attacks and the occurrence of autumn and winter frost events. The association between the occurrence of autumn frost and the sudden outbreak of bacterial canker in A. chinensis in central Italy has been confirmed. Both autumn and winter frosts promote Psa multiplication in the inoculated twigs of both species. The day after the frost, reddish exudates oozing from the inoculation sites were consistently observed in both species, and Psa was re‐isolated in some cases. During the thawing of both A. deliciosa and A. chinensis twigs, the 2‐cm upward and downward migration of Psa from the inoculation site was observed within 3 min, and the leaves were consistently colonized with the pathogen. A consistent brown discoloration, accompanied with a sour‐sap odour, was observed throughout the length of the excised twigs of both Actinidia species after Psa inoculation and winter frost. Psa inoculation induced a remarkably higher necrosis in excised twigs that were not frozen compared with P. s. pv. syringae inoculation. Antifreeze protection using irrigation sprinklers did not influence the short‐term period of Psa and P. s. pv. syringae multiplication in both A. deliciosa and A. chinensis twigs. Thus, the damage from frost, freeze thawing and the accumulation of Psa in Actinidia twigs promotes the migration of the pathogen within and between the orchards. Taken together, the results obtained in this study confirmed that A. deliciosa is more frost tolerant than A. chinensis, autumn frosts are more dangerous to these crops than winter frosts, and in the absence of Psa, young kiwifruit plants remain sensitive to frost.