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Hideki OGISO Masashi FUJINAGA Hideki SAITO Toshiaki TAKEHARA Shigeru YAMANAKA 《Journal of General Plant Pathology》2002,68(4):292-299
One hundred and sixteen isolates of Fusarium oxysporum f. sp. lactucae obtained from 85 fields in three crisphead lettuce-producing areas in Nagano Prefecture, Japan were typed for races using
differential cultivars Patriot, Banchu Red Fire and Costa Rica No. 4. They were also grouped into vegetative compatibility
groups (VCGs) using complementation tests with nitrate non-utilizing (nit) mutants. Two California strains reported as F. oxysporum f. sp. lactucum, a type culture of F. oxysporum f. sp. lactucae, and 28 avirulent isolates of F. oxysporum obtained from crisphead lettuce were included for comparison. Among Nagano isolates, 66 isolates were identified as race 1,
and 50 as race 2. Race 1 strains derived from Shiojiri and Komoro cities and race 2 from Kawakami village and Komoro city.
All isolates of race 2 were biotin auxotrophs, and the race could be distinguished based on its requirement for biotin on
minimal nitrate agar medium (MM). Pathogenic isolates were classified into two VCGs and three heterokaryon self-incompatible
isolates. Strong correlations were found between race and VCG. All the race 1 strains were assigned to VCG 1 except self-incompatible
isolates, and all the race 2 strains to VCG 2. The 28 avirulent isolates of F. oxysporum were incompatible with VCG 1 and VCG 2. California strains was vegetatively compatible with VCG 1, and they were assigned
to race 1. Based on vegetative compatibility, these two races of F. oxysporum f. sp. lactucae may be genetically distinct, and F. oxysporum f. sp. lactucae race 1 is identical to F. oxysporum f. sp. lactucum.
Received 7 May 2002/ Accepted in revised form 6 September 2002 相似文献
2.
Laura Cobelli Marina Collina Agostino Brunelli 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(5):449-455
Control of lettuce downy mildew (Bremia lactucae) with phenylamide fungicides has failed in some intensive lettuce-producing areas in Northern Italy since Spring 1993. Before then, these chemicals and particularly metalaxyl, provided the best disease control. The sensitivity of Bremia lactucae isolates collected in such areas to metalaxyl was evaluated in the laboratory. These strains grew and sporulated profusely on lettuce seedlings treated with 100 and 200 ppm of metalaxyl, whereas sensitive control strains were completely inhibited when treated with fungicide concentrations ranging from 0.5–1 ppm. Thus in Italy occurrence of resistance to phenylamide fungicides in Bremia lactucae has also been demonstrated, as in almost all the countries where these chemicals were previously authorised. Subsequently, a demonstration of occurrence of resistance was made and the virulence pattern of several strains (resistant and sensitive to metalaxyl) was characterised using differential NL series containing the 13 DM resistant genes or R factors. The results suggest the occurrence of a new pathotype in Italy different from all the 16 NL Bremia lactucae races studied. 相似文献
3.
A. Lebeda 《Plant Breeding》1990,105(1):75-77
Thirty-one accessions of four Lactuca species (L. serriola, L. saligna, L. aculeata, L. squarrosa) and one L. serriola×L. sativa hybrid were screened for field resistance to Bremia lactucae. In the L. serriola group, significant differences in the level of field resistance were distinguished. The accessions PI 281876 and PI 253467 were free of infection. Moreover, all L. saligna accessions tested were totally free from disease during three-year-investigation. 相似文献
4.
Effect of different organic amendments on lettuce fusarium wilt and on selected soilborne microorganisms
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This study evaluated the effect of different organic amendments on lettuce fusarium wilt caused by Fusarium oxysporum f. sp. lactucae in pots under controlled conditions. Their effects on the density of the pathogen, on the total fungi and on fluorescent Pseudomonas spp. were also evaluated after two subsequent lettuce crops. A significant reduction in the severity of the symptoms of F. oxysporum f. sp. lactucae was found after the use of Brassica carinata pellets (52–79% reduction) and compost (49–67% reduction), while Brassica green manure and cattle and chicken manure only provided partial control of fusarium wilt. However, variations in effectiveness were observed for the same treatment in repeated trials. In general, an increase was observed in Pseudomonas and a decrease in fungal populations in the growing medium, which was obtained by mixing a blonde sphagnum peat and a sandy loam soil with B. carinata pellets and compost after two consecutive cropping cycles. Prolonging the Brassica and compost treatments from 30 to 60 days did not significantly affect disease severity, plant growth or the microbial population of the total fungi or Pseudomonas. The largest lettuce biomass was obtained in the non‐inoculated growing medium amended with brassica flour, chicken manure, B. carinata pellets and compost, as a consequence of fertilization. The treatment with B. juncea green manure, B. carinata (pellets and flour) and compost applied 30 days before planting led to promising results and merits further investigation for use under field conditions. 相似文献
5.
A. Lebeda 《Plant Breeding》1992,108(2):126-131
Forty-one lettuce cultivars (butterhead type), carrying race-specific resistance gene Dm11 in combination with some others, were studied for field resistance to Bremia lactucae. Significant differences in the level of field resistance were revealed. Most of the cultivars under study were highly susceptible under field conditions. There are evident relationships between combinations of race-specific Dm genes and field resistance. The cultivars with gene combinations Dm2, Dm3 and Dm11 are susceptible. A very high level of field resistance was detected in the cultivars with combination of genes Dm5/8, Dm6 and Dm16 (cvs. ‘Celia’, ‘Katanga’ and ‘Musette’). This is in close link with their Lactuca serriola origin and a high level of field resistance in progenitors. 相似文献
6.
This study used the pathosystem of lettuce ( Lactuca spp.) and downy mildew ( Bremia lactucae ) as a model to investigate the inheritance of nonhost resistance, and focused on the contribution of quantitative trait loci (QTLs) to nonhost resistance at various developmental stages in the lettuce life cycle. A set of 28 backcross inbred lines (BILs) of L. saligna CGN05271 (nonhost) introgressions in a L. sativa cv. Olof (host) background identified 16 introgressions that contributed to resistance at various plant developmental stages: seedlings, young plants, adult plants in the greenhouse and adult plants in the field. This paper provisionally considered these introgressions to be 16 QTLs. Of these 16 QTLs, seven were identified previously and nine were new. For 15 QTLs ( Rbq1, Rbq2, rbq3–7 and Rbq8–15 ), the resistance alleles were derived from the nonhost L. saligna ; the resistance allele of the other QTL ( Rbq16 ) was from the susceptible L. sativa cv. Olof. Of the 15 QTLs in L. saligna , only two, rbq5 and rbq7 , were found to be effective at every plant developmental stage; the other 13 QTLs were only effective at certain developmental stages. Experiments with seven B. lactucae races did not provide evidence that any QTL was race-specific. The data suggest that nonhost resistance in L. saligna is the result of cumulative effects of many resistance QTLs operating at various developmental stages. 相似文献
7.
Norihito YAMAUCHI Seizo HORIUCHI Mamoru SATOU 《Journal of General Plant Pathology》2001,67(4):288-290
Isolates of Fusarium oxysporum f. sp. lactucae obtained from six localities in Japan were divided into three patho-genicity groups. Group 1 was highly pathogenic to lettuce
cultivars of crisphead and red leaf types and was less pathogenic to butterhead and green leaf type cultivars. Group 2 was
highly pathogenic to butterhead type and less pathogenic to crisphead and leaf types. Group 3 was less pathogenic to all lettuce
types than groups 1 and 2. These results indicated pathogenic differentiation in F. oxysporum f. sp. lactucae, roughly relating to horticultural types of host lettuce cultivars.
Received 21 February 2001/ Accepted in revised form 28 May 2001 相似文献
8.
本试验旨在筛选出防治茼蒿霜霉病的最佳药剂。病原菌试验采用组织分离纯化的方法,鉴定出病原菌为莴苣盘梗菌(Bremia lactucae. Regel)。防效试验采用含毒培养基生长速率的方法,测定七种杀菌剂对莴苣盘梗菌的防治效果,结果表明:药后72h,克菌灵EC50值为1.46mg/L,毒力指数最大,对莴苣盘梗菌防治效果最显著;安克和大生EC50值分别为4.31和5.63mg/L,防治效果较显著;甲霜灵的EC50值为9.19mg/L,防治效果较好;普力克和杀毒矾的EC50值分别为26.31mg/L和101.32mg/L,防治效果一般;优氯特EC50值最大,防治效果最差。药后96h各药剂对莴苣盘梗菌的防治效果与药后72h防治效果相似。在七种杀菌剂中克菌灵对莴苣盘梗菌防效最高,防治效果最好。 相似文献
9.
Masashi Fujinaga Hideki Ogiso Nobuaki Tuchiya Hideki Saito Shigeru Yamanaka Masayuki Nozue Mineo Kojima 《Journal of General Plant Pathology》2003,69(1):23-28
Pathogenic variation among 26 Japanese isolates of Fusarium oxysporum f. sp. lactucae (FOL) was tested using 21 lettuce cultivars to select commercial lettuce cultivars as race differential indicators. Cultivar
Costa Rica No. 4 was resistant to race 1 but susceptible to race 2, consistent with the conventional standard differential
line VP1010. Cultivar Banchu Red Fire was susceptible to race 1 but resistant to race 2, which showed an opposite type of
reaction as another differential line VP1013. Cultivar Patriot was susceptible to both races. The resistance reactions of
the three cultivars under field conditions were identical with that observed in the seedlings. Thus cv. Costa Rica No. 4 and
cv. Banchu Red Fire can be used as differential hosts to identify pathogenic races of FOL. This differential system showed
that all FOL isolates obtained from diseased butterhead lettuce in Fukuoka, Japan were new races (i.e., pathogenic to three
cultivars). We propose that the new race be designated race 3. Isolates of FOL, the pathogen of Fusarium wilt in lettuce,
obtained from California showed the same reaction as that of race 1. Furthermore, the Japanese isolate SB1-1 (race 1) and
California isolate HL-2 belonged to the same vegetative compatibility group. Our results suggest that both of the fungi are
the same forma specialis.
Received: March 25, 2002 / Accepted: August 26, 2002 相似文献
10.
A. Lebeda 《Plant Breeding》1989,102(4):311-316
Seven Bremia lactucae isolates from Lactuca serriola were tested for pathogenicity on 41 Lactuca sativa cultivars carrying a race specific resistance gene Dm11 which originated from L. serriola. Some of these cultivars also carried other Dm genes. Sporulation was observed in 34 % of the 287 cultivar/isolate combinations, but it was limited in most cases. A compatible response was recorded in 7.3% of cultivar/isolate. Cultivars with Dm 11 alone, or in combination with Dm 2, exhibited a higher decree of susceptibility then those also carrying Dm 3. There were differences in specific virulence among the isolates under study. Nearly all the isolates studied were virulent on newly described resistance genes Dm 15, Dm 16, and Dm 7 +? which originate from L. serriola. 相似文献
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