湖南白菜和红菜薹根肿病菌生理小种鉴定

为了弄清湖南省白菜和红菜薹根肿病菌生理小种组成和分布,2013年采集长沙、湘潭、益阳、怀化4个地区的十字花科作物白菜、红菜薹根肿病株27个,用Williams根肿病鉴别品种对其进行生理小种鉴定。初步鉴定出5个生理小种,即1号、5号、8号、9号和11号,它们在湖南病区中出现的频率分别为22.3%、18.5%、14.8%、33.3%和11.1%。按寄主生理小种组成,湖南白菜根肿病菌生理小种有1号、5号、9号、11号,红菜薹根肿病菌为8号、9号和11号;按地区生理小种分布,长沙白菜根肿病菌生理小种为5号和9号,湘潭白菜和红菜薹根肿病菌生理小种分别1号、8号和11号,怀化白菜根肿病菌为生理小种9号;益阳白菜和红菜薹根肿病菌分别为生理小种1号、11号、8号和9号。目前,在湖南4个市白菜和红菜薹根肿病菌生理小种是9号。     

黑龙江省稻瘟病菌生理小种的鉴定

应用３个籼稻、４个粳稻组成的中国鉴别品种将黑龙江省１１０个稻瘟病菌菌株划分为４群７个生理小种。用日本清泽的１２个单基因抗性鉴别品种将上述菌株划分为７７个生理小种。对＋、ｔｉ－ａ、Ｐｉ－ｋ、Ｐｉ－ｚ基因致病频率高（７０．４％～８９％）的生理小种遍布全省各稻区；对Ｐｉ－ｔ、Ｐｉ－ｂ、Ｐｉ－ｚｔ基因致病频率低（０～１９．３％）的生理小种分布窄，这３个基因可用于抗病育种。试验表明应用日本清泽的１２个粳稻单基因抗性鉴别品种更适宜黑龙江省稻瘟病菌生理小种的鉴定     

2002年黑龙江省部分稻区稻瘟病菌生理小种鉴定

用中国7个统一鉴别品种对2002年在黑龙江省部分地区采集的57个单孢分离菌株进行了生理小种鉴定。共鉴定出6群10个生理小种,即ZA17、ZA49、ZB1、ZB19、ZB25、ZC9、ZD1、ZD5、ZE1和ZF1生理小种,其中ZD1为优势小种,出现频率为36.8%。生理小种的组成由1996年商世吉报导的4群7个生理小种发展到6群10个生理小种,优势小种也由ZE1转变为ZD1。其中ZA17、ZA49强致病型的生理小种开始出现。所鉴定出的10个生理小种对4个粳稻鉴别品种有较强的致病力。地域较近的地区稻瘟病菌的生理小种群体组成也有较大差异。     

小麦叶锈菌生理小种MFR的分子鉴定研究

 用AFLP方法对来自中国和墨西哥的23个小麦叶锈菌生理小种进行分析,共筛选了64对引物,获得一对引物(M₀₅/E₀₃)可在MFR小种中扩增出一条特异性DNA片段,进行回收、克隆、测序,结果表明该片段具有325个碱基。根据特异性片段序列设计出SCAR标记引物,对60个叶锈菌生理小种分离物进行回检结果表明,研制的SCAR标记能够准确区分MFR生理小种。本实验结果为小麦锈菌生理小种分子检测体系的建立奠定了基础     

东北春玉米区大斑病菌生理小种鉴定

对2005年采自东北玉米主产区的大斑病叶标样进行分离,经单孢纯化后获得56个菌株。通过Ht单基因鉴别寄主接种鉴定,结果表明:东北地区玉米大斑病菌生理分化已呈现复杂化,0号生理小种和1号生理小种分别占35.7%和17.9%,为优势小种,其次为123号生理小种,占12.5%,另外还存在2、3、23、123N、12和23N号生理小种。     

向日葵霜霉病菌生理小种鉴定初报

 由Plasmopara halstedii (Farl) Berl and de Toni引起的向日葵(Helianthus annuus I.)霜霉病是一种毁灭性的种子和土传病害,到目前国际上已经鉴定出8个生理小种,在我国仅吉林省1989年吴天平等人鉴定并报导了吉林白城地区霜霉菌为1号生理小种(欧洲小种)。     

黑龙江省稻瘟病菌生理小种鉴定与分析

2006年,应用日本清泽鉴别寄主共分离测定了黑龙江省稻瘟病菌单孢菌株178个,结果共划分为104个生理小种。其中77.7号小种为黑龙江省的优势小种,比例为4.49%;677.7、377.7号小种为强毒力小种,能侵染91.67%的鉴别品种,从基因角度来说,Pi-ta2、Pi-zt可在黑龙江省的优势小种区利用,Pi-ks,Pi-t不可在黑龙江省大规模利用,此外,地域较近地区的稻瘟病菌的生理小种群体也有较大的差异。     

小麦白粉病菌生理小种鉴定结果初报

 近年来,我们对小麦白粉病菌生理小种的鉴定方法及我国部分麦区生理小种进行了初步的研究。现将情况简报如下。     

天津市番茄晚疫病菌生理小种的鉴定

从天津市9个区县的20份番茄晚疫病样上分离纯化出15个菌株。利用含有不同单显性抗番茄晚疫病基因的番茄材料TS19、TS33、W．Va．700、L3708和LA1033作为鉴别寄主,确定其生理小种。结果表明,天津市番茄晚疫病菌生理小种有3种类型,即T0、T1、T1,2其中T0小种占所测菌株的6．67％,分布在北部新菜区;T1小种占60．00％,各个区县均有分布;T1,2小种占33．33％,主要分布在近郊的老菜区。     

向日葵锈病菌生理小种国际统一的鉴定方法

向日葵锈病菌生理小种国际统一的鉴定方法张建平，李子钦（内蒙古农科院植保所呼和浩特０１００３０）向日葵锈病（ＰｕｃｃｉｎｉａｈｅｌｉａｎｔｈｉＳｃｈｗ）是向日葵的重要病害之一，各国对病原菌生理小种都作了大量研究，但各地学者所用鉴别寄主、小种命名法和分级...     

北京地区西瓜枯萎病生理小种分化研究

对在北京大兴、顺义、通县等西瓜主产区采集，经单孢分离得到的８个西瓜枯萎病菌株进行了生理小种分化研究。应用国际通用的３个鉴别寄主ＳｕｇａｒＢａｂｙ、ｃｈａｒｌｅｓｔｏｎＧｒａｙ、ｃａｌｈｏｕｒＧｒａｙ和国内京欣１号、苏蜜１号２个品种，采用全国协作组统一的苗期抗病鉴定方法，进行人工接种鉴定。结果表明北京地区西瓜枯萎病菌株均系同一生理型，为西瓜枯萎病生理小种１号。     

我国小麦秆锈菌种群动态分析

１９９５～１９９６年间,在我国７省区６２个县点共收集标样２８３份,涉及品种１１７个,分离到菌株４５５份,鉴定出１５个致病类型,其出现类型的发生频率分别是２１Ｃ３ＣＫＲ为１７．５％,２１Ｃ３ＣＦＨ９．６％,２１Ｃ３ＣＫＨ８．８％,２１Ｃ３ＣＦＲ６．０％,２１Ｃ３ＣＴＲ２２．０％,２１Ｃ３ＣＰＲ９．４％,２１Ｃ３ＣＴＨ８．８％,２１Ｃ３ＣＰＨ１１．９％,３４ＭＫＧ１．３％,３４Ｃ２ＭＫＨ０．２％,３４Ｃ２ＭＫＫ０．１％,３４Ｃ２ＭＦＨ３．６％,３４Ｃ２ＭＦＫ０．４％,３４Ｃ１ＭＫＲ和３４Ｃ１ＭＦＲ为０．２％。１９９６年２１Ｃ３ＣＫＲ的出现频率上升为第１位,对Ｓｒ１１有毒力的致病类型出现频率有所下降。     

Occurrence of Fusarium oxysporum f. sp. melonis Race 1 in Japan

In 1994, Fusarium wilt of melon cultivars which are resistant to races 0 and 2 of Fusarium oxysporum f. sp. melonis was observed in southern area of the Lake Biwa region, Shiga prefecture. In commercial fields, mature plants of cv. Amus which were grafted onto cv. Enken Daigi 2, and of cv. FR Amus showed yellowing, wilting and finally death before harvesting of fruits. Diseased plants had vascular and root discolorations, and their stem sections yielded typical colonies of F. oxysporum. When the Shiga strains were tested for their pathogenicity to 12 species of cucurbits, they caused wilts only on melon. Using race differential cultivars of melon, the Shiga strains were classified as race 1 of F. oxysporum f. sp. melonis, which has not been reported in Japan. To further characterize their pathogenicity, the strains were used to inoculate 46 additional cultivars of melon, oriental melon and oriental pickling melon. All the race 1 strains were pathogenic to the cultivars tested, and their host range was apparently different from those of strains belonging to other races (races 0, 2 and 1,2y). DNA fingerprinting with a repetitive DNA sequence, FOLR3, differentiated race 1 strains from strains of races 0 and 2, but not from race 1,2y strains. Received 2 July 1999/ Accepted in revised form 30 September 1999     

Evidence for the Preemptive Nature of Tomato Race 3 of Xanthomonas campestris pv. vesicatoria in Florida

ABSTRACT Until recently, tomato race 1 (T1) of Xanthomonas campestris pv. vesicatoria was the only race causing bacterial spot of tomato in Florida. In 1991, tomato race 3 (T3) was first identified in 3 of 13 tomato production fields surveyed. By 1994, T3 was observed in 21 of 28 fields and was the only race identified in 14 fields. In field studies, tomato genotypes with resistance to either T1 or T3 or susceptibility to both were co-inoculated with strains of both races. Lesions on 10 plants in each of three replications for each genotype were sampled three times during the experiment; bacterial isolations were made from each lesion, and tomato race identifications were made for each strain. At the third sampling date, T3 was isolated from 97% of the lesions on the susceptible genotype Walter and the T1-resistant genotype Hawaii 7998, while T3 was isolated from 23% of the lesions and T1 from the remaining 77% on the T3-resistant genotypes PI 128216 and PI 126932. In surface population studies done in growth rooms, suspensions of T1 and T3 were applied alone and in combination to the leaf surfaces of susceptible and resistant genotypes. T1 populations were reduced more than 10-fold when applied in combination with T3, compared with populations that developed when T1 was applied alone. T3 populations were not affected when applied in combination with a T1 strain. In greenhouse studies with the T3-resistant genotype Hawaii 7981, disease was significantly reduced in plants inoculated with T3 in combination with T1, compared with plants inoculated with T1 alone. These results clearly demonstrate the competitive nature of T3 in the presence of T1 and help explain the emergence of T3 as a prevalent race in Florida.     

Bacteriocin-Like Substances from Tomato Race 3 Strains of Xanthomonas campestris pv. vesicatoria

ABSTRACT Tomato race 3 (T3) strains of Xanthomonas campestris pv. vesicatoria are antagonistic in vitro to tomato race 1 (T1) strains of the bacterium. All T1 strains and 11 strains of other X. campestris pathovars tested were inhibited by T3 strains. Sensitivity of tomato race 2 (T2) strains was variable. No strains from other bacterial genera tested were inhibited. Cell-free filtrates from T3 strains were inhibitory to sensitive strains. The inhibitory activity of these filtrates was lost after treatment at temperatures above 80 degrees C and with selected protease enzymes. However, treatment with trypsin or DNase had no effect on their activity. Seven cosmid clones from a genomic library of a T3 strain were selected for their ability to consistently inhibit a sensitive indicator strain in plate assays. Southern hybridization analysis placed these into three bacteriocin (BCN)-producing groups designated BCN-A, BCN-B, and BCN-C. The BCN-like groups could be differentiated by variations in inhibitory spectra and levels of activity in plate assays. Mutations that inactivated expression of each BCN group individually in a wild-type T3 strain had inhibitory activity confirming that multiple BCNs are present in the T3 strain. T3 strains were inhibitory to a sensitive indicator strain in tomato leaf tissue, but this effect was observed only when T3 strains were applied in advance of the sensitive strain. BCN-A was the major BCN-like substance involved in the suppression of the sensitive indicator strain in tomato leaf tissues.     

广东省稻瘟病菌生理小种的消长动态

１９９０～１９９７年,用中国稻瘟病菌鉴别寄主鉴定了广东省稻瘟病菌单孢菌株１５７４份,共鉴定出８群４３个生理小种。其中ＺＣ群一直是广东省的优势种群,其出现频率平均为５０.２％;ＺＣ_１３一直是优势小种,其出现频率平均为２７.４％,其次是ＺＧ_１（１８.８％）、ＺＣ_１５（１４.５％）和ＺＢ_１３（９.１％）小种。不同地区不同年份优势小种的类型及其组成不同。     

广东省稻瘟病菌生理小种的消长动态

１９９０～１９９７年,用中国稻瘟病菌鉴别寄主鉴定了广东省稻瘟病菌单孢菌株１５７４份,共鉴定出８群４３个生理小种。其中ＺＣ群一直是广东省的优势种群,其出现频率平均为５０２％;ＺＣ１３一直是优势小种,其出现频率平均为２７４％,其次是ＺＧ１（１８８％）、ＺＣ１５（１４５％）和ＺＢ１３（９１％）小种。不同地区不同年份优势小种的类型及其组成不同。     

香蕉枯萎病菌生理小种鉴定及其SCAR标记

 通过室内人工接种蕉类鉴别寄主,对采集于广东蕉区的18个蕉类枯萎病菌菌株进行鉴定,KP021、KP022、GZ981和JL021 4个菌株属Racel,其余14个菌株属Race4,说明广东蕉区同时存在尖孢镰刀菌古巴专化型Race1和Race4。用RAPD技术对上述18个菌株进行分析,从200条随机引物中筛选出8条引物可产生生理小种RAPD标记12个,其中标记Racel的8个,标记Race4的4个。对这些RAPD标记带分别进行回收、克隆、测序,根据这些特异片段序列分别设计相应的SCAR引物,通过对18个菌株的PCR扩增检验,有4个RAPD标记成功地转化为SCAR标记,其中Race1-SCAR标记1个、Race4-SCAR标记2个、同时能鉴定出2个小种的SCAR标记1个。应用这4个SCAR标记同时对采自田间的9个病菌分离物进行检测,能够准确地鉴定出广东蕉区的尖孢镰刀菌古巴专化型Racel和Race4,这为下一步开展香蕉枯萎病菌生理小种的分子鉴定及各生理小种田间流行动态监测奠定了基础。     

Polygenic Inheritance of Partial Resistance to Fusarium oxysporum f. sp. melonis Race 1.2 in Melon

ABSTRACT Fusarium oxysporum f. sp. melonis is responsible for Fusarium wilt of melon. Race 1.2 strains overcome two dominant resistance genes (Fom-1 and Fom-2) and are further divided into two types depending on the symptoms they cause, yellowing or wilting. Partial resistance to F. oxysporum f. sp. melonis race 1.2 was studied by using a recombinant inbred line (RIL) population that was developed by single seed descent from an F(1) hybrid between 'Isabelle', a partially resistant line, and a susceptible line, 'Védrantais'. Artificial inoculations were performed with a yellowing strain (TST) and a wilting strain (D'Oléon 8) and replicated in six locations. Disease reactions of the parental lines, controls, and RILs were scored using a 1-to-5 scale and by using the area under the disease progress curve (AUDPC). Phenotypic correlations were highly significant between the different locations and experiments. The heritability of the resistance was high, from 0.72 to 0.96, and 4 to 14 genetic factors were estimated to confer resistance to F. oxysporum f. sp. melonis race 1.2. Thirteen other strains were tested with an RILs subset. Some small strainspecific effects may be involved. These results contribute to a better understanding of the polygenic inheritance of the partial resistance to F. oxysporum f. sp. melonis race 1.2.