Fusarium solani f. sp. eumartii, historically considered solely a pathogen of potato (Solanum tuberosum), was associated with tomato plants (Lycopersicon esculentum) exhibiting foot rot symptoms in California. The pathogenicity of California isolates of F. solani f. sp. eumartii from potato plants with Eumartii wilt symptoms and tomato plants with foot rot symptoms was determined on potato, tomato, pepper (Capsicum anuum), and eggplant (S. melongena). Isolates from both potato and tomato caused dry rot symptoms on potato tubers and root or collar rot on all four host species in the greenhouse. In field trials, isolates from both tomato and potato were pathogenic on tomato, potato, and pepper, confirming that the host range of F. solani f. sp. eumartii is not limited to potato. The phylogeny of isolates from potato and tomato was determined based on sequences of two DNA fragments: rDNA internal transcribed spacer regions and partial sequences of elongation factor 1-α. All of the California isolates of F. solani f. sp eumartii from tomato and potato formed a single monophyletic clade distinct from other formae speciales and mating populations of F. solani. The results of this study demonstrate that Eumartii wilt and tomato foot rot in California both are caused by F. solani f. sp. eumartii.

A study was carried out at Food Technology Section, Agricultural Research Institute Tarnab, Peshawar during the year 2004-05 to know the effect of different stabilizers viz. guar gum, sodium alginate, pectin, CMC (carboxy methyl cellulose), xanthan gum and gum acacia on color, taste, consistency (texture), serum loss, flow value and overall acceptability of tomato ketchup during storage was studied. All stabilizers increased consistency of tomato ketchup; however, guar gum and xanthan gum caused maximum increase followed by CMC, sodium alginate, gum acacia and pectin. The consistency of tomato ketchup decreased with the increase in storage duration. Both serum loss and flow value decreased with the addition of all the stabilizers and increased with the increase in storage duration. Xanthan gum and guar gum caused maximum decrease in serum loss and flow value whereas pectin caused the least.

The effects of Pasteuria penetrans encumbered juveniles of Meloidogyne incognita, M graminicola and M. javanica with two levels of attachment (5-10 and greater than 11 spores/ J2) were studied on the invasion of roots of tomato, barn yard grass, sorghum and egg plant. Invasion by spore encumbered juveniles was significantly less as compared to juveniles without spores. There was no statistically significant difference in root invasions between the two attachment levels in case of tomato, barn yard grass and sorghum. However, a statistically significant difference was observed between the two attachments levels in case of M. javanica invading roots of egg plant. The encumbered juveniles (5-10 spores/ J2) of M. incognita, M. graminicola and M. javanica caused 41.76% reduction in invasion of tomato roots, 24.58 and 33.13% reductions of barn yard grass and sorghum roots and 11.20 and 19.55% reductions of tomato and egg plant roots, respectively. The reductions in invasions caused by the juveniles encumbered with greater than 11 spores/ J2 were: 46.47% in tomato by M. incognita; 25.54 and 38.40% in barn yard grass and sorghum by M. graminicola and 23.87 and 43.73% in tomato and egg plant by M. javanica, respectively.

The effect of indole-acetic acid (IAA) on the development of symptoms caused by Pythium ultimum on tomato plants was investigated using different bioassays. Application of IAA (5 μg ml-¹) on tomato seedlings inoculated with P. ultimum did not affect their emergence suggesting that IAA did not affect the severity of Pythium damping-off. However, IAA was shown to influence the development of P. ultimum symptoms on tomato plantlets. Low concentrations of IAA (0-0.1 μg ml-¹) within the rhizosphere of plantlets increased the severity of the symptoms caused by P. ultimum, while higher concentrations (10 μg ml-¹), applied either by drenching to the growing medium or by spraying on the shoot, reduced the symptoms caused by this pathogen. In addition, the study demonstrated that P. ultimum produces IAA in liquid culture amended with L-tryptophan, tryptamine or tryptophol (200 μg ml-¹) and in unamended culture.

Economically important diseases on tomatoes in Bulgaria are bacterial speck and bacterial spot caused by Pseudomonas syringae pv. tomato (Okabe)Young et al. and Xanthomonas vesicatoria (ex. Doidge) Vauterin et al., respectively. The efforts of the breeding scientists are oriented toward searching for resistance in tomato wild species and creating new resistant tomato cultivars. Thirteen accessions of wild tomato species belonging to subgenuses Eulycopersicon and Eriopersicon of genus Lycopersicon were examined. Investigated from us accessions are characterised for different degree of resistance to P. syringae pv. tomato (0, 1) and X. vesicatoria ('1, '3). Resistant to race '1 and '3 of X. vesicatoria are L. pimpinellifolium LA 121 and L. chilense CGN15531. Sources of resistance to P. syringae pv. tomato race 0 and 1 are not found.

The protective, curative and eradicant activity of the strobilurin fungicide trifloxystrobin against Cladosporium fulvum on tomatoes was determined under growth chamber and greenhouse conditions. In growth chamber experiments chlorothalonil applied at 100 μg ml-1 was used as standard fungicide treatment. Seven-week-old tomato plants, hybrid Alma F1, were inoculated by conidial suspension. Protective treatments were carried out by spraying plants 24, 48 and 96 h before inoculation at the doses of 5, 10 and 20 μg a.i. ml-1. Curative treatments were carried out with the same doses, at the same time intervals after inoculation. Additionally, spray treatments were applied after the appearance of the symptoms to evaluate the anti-sporulant activity of the fungicides tested. Protective treatments of trifloxystrobin applied 24 and 48 h before inoculation provided disease control higher than 88% at all the application doses tested, while only the dose of 20 μg a.i. ml-1 was highly effective when applied 96 h before the inoculation of the plants (IOP). The curative treatments were less effective than the protective treatments. Post-inoculation treatments of trifloxystrobin at 10 or 20 μg ml-1 were efficacious only when applied 24 or 48 h after IOP, with limited activity when applied 96 h after inoculation. Eradicant treatments of trifloxystrobin provided satisfactory anti-sporulant activity when applied at the dose rate of 20 μg ml-1. Applications of trifloxystrobin at the rates of 5 or 7.5 g a.i. 100 l-1 of spray solution carried out during a 2-year period (2004-2005), in the greenhouse, demonstrated the validity of the above findings, providing control efficacy values higher >90%. Moreover, during both years of the study, applications of trifloxystrobin either at 5 or 7.5 g a.i. 100 l-1, reduced spore production significantly on diseased tomato leaves. The results of the study showed that trifloxystrobin may play a crucial role as part of an integrated chemical control programme for tomato leaf mould caused by C. fulvum.

Tomato yellow leaf curl disease is widely recognized as a serious constraint to tomato production in North Vietnam. The disease is caused by at least two viruses belonging to the genus Begomovirus with ss DNA, Tomato leaf curl Vietnam virus(ToLCVV,AF264063)and tomato yellow leaf curl Vietnam virus(TYLCVNV) and they are found in tomato leaf samples with yellow leaf curl symptom by PCR using specific primers for ToLCVV (ToLCVV-sp F2 and ToLCVV-sp-R2)and TYLCNV (TYLCVNV-sp-F1andTYLCVNV-sp-R1).Management of the disease by vector control using traps, a bio product 'Somec 25L (0.15%)' and a pesticide' Actara 25WG (0.01%) showed effective to decrease the population of the virus vector Bemissia Fabaci and the occurrence of the disease in the fields.

Expression of a foreign gene to enhance plant disease resistance to bacterial pathogens is a favorable strategy. It has been demonstrated that expressing sweet pepper ferredoxin-I protein (PFLP) in transgenic plants can enhance disease resistance to bacterial pathogens that infect leaf tissue. In this study, PFLP was applied to protect tomato (Lycopersicon esculentum cv. cherry Cln1558a) from the root-infecting pathogen, Ralstonia solanacearum. Independent R. solanacearum resistant T1 lines were selected and bred to produce homozygous T2 generations. Selected T2 transgenic lines 24-18-7 and 26-2-1a, which showed high expression levels of PFLP in root tissue, were resistant to disease caused by R. solanacearum. In contrast, the transgenic line 23-17-1b and nontransgenic tomato, which showed low expression levels of PFLP in root tissue, were not resistant to R. solanacearum infection. The expansion of R. solanacearum populations in stem tissue of transgenic tomato line 24-18-7 was limited compared with the nontransgenic tomato Cln1558a. Using a detached leaf assay, transgenic line 24-18-7 was also resistant to maceration caused by E. carotovora subsp. carotovora; however, resistance to E. carotovora subsp. carotovora was less apparent in transgenic lines 26-2-1a and 23-17-1b. These results demonstrate that PFLP is able to enhance disease resistance at different levels to bacterial pathogens in individual tissue of transgenic tomato.

To study the function of LeERF1 in ethylene triple response on etiolated seedling, plant development and fruit ripening and softening, LeERF1 gene was introduced into tomato (Lycopersicon esculentum cv. No. 4 Zhongshu) through Agrobacterium-mediated transformation. The sense LeERF1 and anti-sense LeERF1 transgenic tomato were obtained. Overexpression of LeERF1 in tomato caused the typical ethylene triple response on etiolated seedling. In the adult stage, 35S::LeERF1 resulted in morphological changes in the leaves of the LeERF1-sn lines. Anti-sense LeERF1 fruits had longer shelf life compared with wild-type tomato. The results of this manuscript indicated that LeERF1 positively mediated the ethylene signals, while the function of LeERF1 was verified for the first time to be positively related with ethylene triple response on etiolated seedling, plant development and fruit ripening and softening using LeERF1-sn, wt and LeERF1-as tomato.

The present study aims (i) to find out the occurrence and parasitism of Tomato Leaf miner, (ii) to determine relationships between the seasonal variations in emergence and the degree of damage in tomato from summer to autumn, and (iii) to examine the chemical tolerance of Tomato Leaf miner to different chemical pesticides. Tomato Leaf miner was firstly identified at Atou city and Mutsumi village in 1999. The prevalence of the pest throughout the Yamaguchi prefecture occurred by 2002. In total 10 species parasitic plants in 4 familys were identified for the pest. Prevalence of the disease caused by Tomato Leaf miner starts from August and reaches in peak in autumn with sharp decline in winter. It is assumed that Tomato Leaf miners come to the infested area from another region in August. The degree of disease prevalence was measured through the counting of Tomato Leaf miner in a specific area by using yellow and sanagi trap. Therefore, pest control should be started from August for production of tomato in summer to autumn. The result indicated that Tomato Leaf miner had resistance of different degrees to different pesticides, so it is recommended to select most effective pesticides to control the pest.