The potential for Fusarium oxysporum f. sp. fragariae,cause of fusarium wilt of strawberry,to colonize organic matter in soil and persist through anaerobic soil disinfestation

Fusarium wilt of strawberry, caused by Fusarium oxysporum f. sp. fragariae, is a disease of primary concern for strawberry production in many countries. Crop rotation and anaerobic soil disinfestation (ASD) have gained recent interest for their potential to contribute to management of this disease. Both techniques involve incorporation of organic matter into soil, which may be utilized by strains of Fusarium that are competitive saprophytes. We show that F. oxysporum f. sp. fragariae can colonize strawberry, lettuce, raspberry, and broccoli leaf tissues, which are sources of organic matter generated during crop rotation. This pathogen increased in soil population density during ASD treatments that did not become anaerobic, possibly as a result of growth on the organic amendment. However, significant population decreases were observed after ASD treatment when at least 100,000 cumulative reduced mV hours occurred in a 14-day experiment. Post-ASD abundance of F. oxysporum f. sp. fragariae in soil was negatively correlated with cumulative reduced mV hours. The only treatment that consistently caused disinfestation was exposed to a maximum temperature of 22 °C, which indicates there is potential for developing effective ASD treatments in the cool climates where strawberries are grown. Awareness that F. oxysporum f. sp. fragariae can act as a competitive soil saprophyte should be further investigated for its potential to alter disease outcomes where organic amendments are applied.     

草莓角斑病菌PCR检测研究

[目的]研究草莓角斑病菌的快速检测方法。[方法]根据草莓角斑病菌的hrp基因,设计了1对引物XF-F/R,进行该病菌PCR特异性扩增。[结果]该引物可特异性地扩增草莓角斑病菌的DNA、菌悬液、人工接种样品。[结论]该检测方法特异性强、灵敏度高,可适用于草莓角斑病菌的检测。     

盆钵珠兰叶斑线虫病的研究——Ⅰ.病原鉴定

珠兰叶斑病的病原线虫,经人工接种尚能诱发草莓矮缩和引起菊花、四季海棠、牡丹和及已(Chloranthus serratus)的叶斑病,用稍加改良的Christie和Crossman平板上的柑桔交链孢(Alternaria citri)或PDA平板上的灰葡萄孢(Botrytis cinerea)培养,它们可以取食平板上的菌丝而繁殖。这种病原线虫的侧带区特有4条刻线,与国内外关于草莓芽线虫(Aphelenchoides,fragariae)都是2条刻线的已有报道不同,但除此以外,这两种线虫的所有其它形态特征几乎全部相似。本文根据上述,同时参照1987年Dr.Hooper为我们在英国复查典型草莓芽线虫侧带时所获得的“是4条刻线”而不是2条刻线的新结果,鉴定珠兰上的叶斑线虫为A.fragariae。     

草莓角斑病菌传入中国的风险分析

草莓角斑病菌是一种严重为害草莓生产的细菌。本文从其分布状况、寄主、经济重要性、传入与定殖可能性和风险管理难度等方面进行了综合分析评估,结果表明该病菌属于特别危险的有害生物。并根据风险分析的结果提出了防止其传入我国的管理措施。     

草莓枯萎病菌的生物学特性及7种杀菌剂对其抑制作用

采用十字交叉法和血球计数板法测定草莓枯萎病菌的生物学特性。结果表明,PSA培养基最适合草莓枯萎病菌的生长和产孢,菌落生长的适温为5~40℃(最适温度为28℃),适宜pH值为5,菌落产孢的适宜pH值为6,且光暗交替可促进菌落的生长和产孢,同时明确了不同碳氮源对草莓菌落生长及产孢的影响。采用菌落生长速率法,测定草莓枯萎病菌对7种杀菌剂的敏感性,烯唑醇和戊唑醇对菌落生长的抑制毒力最强,EC₅₀分别为0.2072μg·mL^-1和0.2130μg·mL^-1,分别是多菌灵的238.85倍和232.35倍;腈菌唑和苯醚甲环唑的毒力次之,EC₅₀分别为0.7929μg·mL^-1和0.8513μg·mL^-1,分别是多菌灵的62.42倍和58.13倍;三唑酮和霜霉威的毒力最小。     

沼液对植物病害的防治效果及机理研究I:对植物病原真菌的抑制效果及抑菌机理初探

采用菌丝生长抑制和分生孢子萌发抑制的试验方法,以草莓枯萎病菌为靶标病原菌,研究了江苏省内运行稳定的21个大型沼气工程的沼液及其无菌滤液对草莓枯萎病菌的生长抑制特性.结果表明,所有沼气工程的沼液对草莓枯萎病菌的菌丝生长都有不同程度的抑制作用,不同运行年限的沼气池沼液以及不同发酵原料的沼液对草莓枯萎病菌的抑制效果均无显著差异,但不同贮液阶段的沼液对其抑菌效果影响显著.沼液的无菌滤液对草莓枯萎病菌菌丝的生长没有抑制作用;沼液及其无菌滤液对草莓枯萎病菌分生孢子的萌发均有不同程度的抑制作用,猪粪沼液及其无菌滤液对草莓枯萎病菌分生孢子萌发的抑制作用好于牛粪沼液.沼液对生产上常见的5种植物病原真菌的抑制效果有显著差别.沼液中的拈抗微生物是沼液抑菌防病的主要因子.     

Identification of alternatives for the management of foliar nematodes in floriculture

The foliar nematodes, Aphelenchoides spp, have emerged as important pests of ornamentals in North America during the last decade. Due to the ban on the use of potentially toxic pesticides, there are currently no nematicides registered to manage foliar nematodes on ornamentals. Therefore, we have evaluated a biological [Burkholderia cepacia (syn Pseudomonas cepacia)], two plant products [clove (Syzygium aromaticum) extract and Nimbecidine (azadirachtin)] and twelve chemical pesticides registered for the management of insects, mites, slugs or diseases of ornamentals, against Aphelenchoides fragariae on the most popular ornamental, hosta (Hosta spp), for two consecutive years. We found ZeroTol (270 g liter-1 peroxyacetic acid), currently labeled as a broad-spectrum fungicide/algicide, to be a very potent nematicide that killed 100% of the nematodes in water suspension. It also caused over 70% reduction in A fragariae population in soil and in the leaves without any phytotoxicity. B cepacia caused 67-85% reduction in A fragariae population in leaves and 50% reduction in the soil whereas insecticidal soap caused over 72% reduction in leaves and 61% reduction in the soil. Clove extract and Nimbecidine did not show any potential for the control of A fragariae on hosta. Although all twelve chemical pesticides were effective in reducing the population of A fragariae in the soil 45 days after treatment (DAT), only diazinon 475 g liter-1 EC, trichlorfon 800 g kg-1 SP, ethoprophos 100 g kg-1 GR, oxamyl 100 g kg-1 GR and ZeroTol caused over 70% reduction in nematode population compared with the control. In the leaves, only diazinon EC, trichlorfon SP, insecticidal soap, oxamyl GR and ZeroTol consistently caused over 70% nematode population reduction compared with the control at 45 DAT in both years. Thus, only diazinon EC, trichlorfon SP, oxamyl GR and ZeroTol consistently caused over 70% reduction in nematode population both in soil and leaves. Due to the recent ban by the US Environmental Protection Agency on the use of the first three of these formulations, only ZeroTol would serve as an effective tool to manage foliar nematodes in ornamentals. Although not as effective as ZeroTol in the soil, insecticidal soap is the only other alternative for foliar nematode management.     

草莓枯萎病菌的生物学特性

草莓枯萎病病原为尖孢镰刀菌草莓专化型(Fusarium oxysporumf.sp.fragariae)。生物学特性研究表明,草莓枯萎病菌在PSA上生长和产孢最好,菌丝生长和产孢的适温为25~30℃,适宜pH 4~6,全光照可促进产孢。对碳源的利用,麦芽糖最好,乳糖最差;对氮源的利用,酵母膏最好,尿素最差。孢子萌发的适温为20~30℃,最适28℃,高于40℃和低于5℃不能萌发,RH在90%~100%均能萌发,在水滴中萌发率最高,低于90%不萌发;萌发最适pH 4~6,高于pH 8不萌发,光照有利于孢子萌发,最适孢子萌发的碳源是乳糖,氮源是牛肉膏。     

草莓枯萎病菌对16种杀菌剂的敏感性检测

采用菌丝生长速率法在室内测定了16种杀菌剂对草莓枯萎病菌的毒力。结果表明,戊唑醇、烯唑醇、申嗪霉素、苯醚甲环唑、腈菌唑、氰烯菌酯、吡唑醚菌酯、三唑酮、超敏蛋白、嘧菌酯、恶霉灵、乙蒜素、氨基寡糖素、多菌灵、春雷霉素和井冈霉素对草莓枯萎病菌的EC50值分别为0.1544、0.1658、0.4455、0.7891、2.9167、3.0657、3.3535、3.4188、5.0728、6.5805、7.0021、16.6701、21.2633、24.2783、35.3456和101.1356μg/mL。供试草莓枯萎病菌对不同杀菌剂的敏感性差异较大,对其中的戊唑醇最敏感。     

草莓叶主要挥发性物质的测定及其对草莓球腔菌的抑菌效果

为探究草莓叶片中挥发性物质对草莓球腔菌的抑菌作用,本研究测定了草莓叶片中主要挥发性物质,并以草莓球腔菌为处理对象,研究草莓叶片主要挥发性物质对其孢子萌发、菌丝生长以及线粒体膜电位的影响.结果表明,草莓叶片挥发性物质中的萜类化合物主要组分为芳樟醇、桃金娘烯醇,C6醛类化合物主要组分为己醛、2-己烯醛、反式-2-己烯醛、顺...