Black dot root rot occurred severely in greenhouse tomatoes in Jangseong area of Korea in April, 1996. The causal fungus of the disease was identified as Colletotrichum coccodes based on the morphological and cultural characteristics. Pathogenicity tests revealed that isolates of the fungus were responsible for the disease, and two cultivars of cherry tomato were less susceptible to the disease than other cultivars of tomato and cherry tomato tested.

Cooking surimi paste from Pacific whiting results in a gel with poor texture due mainly to myosin degradation caused by a cysteine proteinase. Cysteine and serine proteinase inhibitors were isolated from injured and methyl jasmonate treated tomato leaves. Tomato cysteine proteinase inhibitor was stable at 60C but inactivated at 90C, making it suitable for use in surimi. Tomato proteinase inhibitors (TPI), having 7.9 papain inhibitor units, inhibited autolysis about 95% in 10 g of Pacific whiting surimi. Gel strength of Pacific whiting surimi was improved by adding only 0.027% of TPI to the surimi formulation. Addition of TPI did not affect the color of whiting surimi gel while egg white needed to prevent gel weakening caused the gels to have more yellow hue (P < 0.05). SDS-PAGE showed that myofibrillar protein degradation was prevented during cooking when 0.027% of TPI was included in the surimi. TPI extracted from tomato plants has potential for use as food grade additive in Pacific whiting surimi.

A typical mosaic and malformation symptom was found on heterozygrous resistant tomato "Momotarou" in Okayama prefecture. Electron microscopic examination, inoculation to a series of differential hosts and immunodiffution test revealed that the causal virus was tomato strain of tobacco mosaic virus (TMV). Two isolates were identified as Pelham's strain 0, and four isolates were identified as strain 1 on the basis of their reaction to the differential varieties of tomato. This is the first report of a strain 1 in Okayama prefecture. Both of isolates caused top necrosis on heterozygrous resistant varieties carrying Tm-2a gene. But these isolates caused no visible reaction on homozygous resistant varieties carrying Tm-2 or Tm-2a gene, and heterozygrous resistant varieties carrying both Tm and Tm-2 genes

Inheritance of resistance to tomato anthracnose caused by Colletotrichum coccodes (Wallr.) S.J. Hughes was evaluated in parental, F1, F2, and backcross populations developed from crosses between adapted resistant (88B147) and susceptible (90L24) tomato (Lycopersicon esculentum Mill.) breeding lines. Resistance was evaluated via measurement of lesion diameters in fruit collected from field-grown plants and puncture inoculated in a shaded greenhouse. Backcross and F2 populations exhibited continuous distributions suggesting multigenic control of anthracnose resistance. Anthracnose resistance was partially dominant to susceptibility. Using generation means analysis, gene action in these populations was best explained by an additive-dominance model with additive x additive epistatic effects. A broad-sense heritability (H) of 0.42 and narrow-sense heritability (h(2)) of 0.004 was estimated for resistance to C. coccodes. One gene or linkage group was estimated to control segregation for anthracnose resistance in the cross of 90L24 x 88B147.

Biocontrol of soilborne diseases of tomato caused by Rhizoctonia solani and Pythium ultimum alone or in combination with Sclerotium rolfsii and Fusarium oxysporum f. sp. lycopersici were studied in the greenhouse and field. Soilborne diseases of pepper caused by the first three pathogens were also studied alone or in combination with Phytophthora capsici. Tomato and pepper seeds were treated with biomass of Gliocladium virens (Gl-3) and Burkholderia cepacia (Bc-F), individually and in combination, and planted in pathogen-infested soilless mix. Seedling stands for tomato from treated seeds were comparable to that in non-infested soilless mix. Although seed treatments with individual biocontrol agents reduced damping-off in peppers, only the Gl-3 + Bc-F treatment resulted in stands similar to the non-infested control. When healthy seedlings of both crops were transplanted into pathogen-infested soil/soilless mix in the greenhouse, and supplementary root drenches of suspensions of Gl-3, Bc-F, and Gl-3 + Bc-F were applied, the plant fresh weight was significantly greater and the disease severity (DSI) significantly less than for infested controls. When transplants were set out into infested field plots, the combined Gl-3 + Bc-F application resulted in greater fresh weight and lower DSI for pepper, and greater fruit yield for tomato than those obtained with either Gl-3 or Bc-F alone.

Sixty Ecuadorian isolates of Phytophthora infestans from potato and 60 isolates from tomato were compared for dilocus allozyme genotype, mitochondrial DNA haplotype, mating type, and specific virulence on 11 potato R-gene differential plants and four tomato cultivars, two of which contained different Ph genes. Restriction fragment length polymorphism (RFLP) fingerprints of subsamples of isolates from each host were compared by using RG57 as the probe. All potato isolates had the allozyme genotype, haplotype, and mating type of the clonal lineage EC-1, which had been previously described in Ecuador. With the same markers, only one isolate from tomato was classified as EC-1; all others belonged to the globally distributed US-1 clonal lineage. RFLP fingerprints of isolate subsets corroborated this clonal lineage classification. Specific virulence on potato differentials was broadest among potato isolates, while specific virulence on tomato cultivars was broadest among tomato isolates. Some tomato isolates infected all tomato differentials but no potato differentials, indicating that specific virulence for the two hosts is probably controlled by different avirulence genes in P. infestans. In two separate experiments, the diameters of lesions caused by nine isolates from potato and 10 from tomato were compared on three tomato and three potato cultivars. All isolates produced larger lesions on the host from which they were isolated. No isolates were found that were highly aggressive on both tomato and potato. We conclude that there are two different populations of P. infestans in Ecuador and that they are separated by host.