Disease resistance in tomato crops produced in Spain
Spain produces about 4 million tons of tomato for fresh market or industry. Andalusia, in the south of Spain, represents a major part of the tomato production, generating almost 200 million plants in 2014. Several diseases, caused by viruses, fungi, bacteria and nematodes, are limiting factors in tomato cultivation, and resistance traits are fundamental in management of these diseases. About 39 seed companies operate in Spain, offering 400 tomato cultivars to the market. Data on the features of these cultivars were obtained from the seed companies, either from publicly available source or through formal inquiries. Commercial data containing the numbers of plant seedlings produced and sold during the year 2014 were from the Andalusian Society of Horticulture Nurseries. A detailed analysis of the numbers of cultivars and plants, marketed and commercialized, revealed that tomatoes resistant to infectious diseases are highly preferred by farmers: 88% of all tomato cultivars available on the market have one or more resistances, and 187 million plants, that is, about 97% of all tomato seedlings produced, are resistant to one or more viruses (80%), fungi (93%), nematodes (61%) and/or bacteria (5%). Most of the fungi-resistant tomatoes are resistant against Fusarium wilt (Fusarium oxysporum f. sp. lycopersici) (95%) and Verticillium wilt (Verticillium dahliae/Verticillium albo-atrum) (81%). Farmers also prefer tomato plants with resistances to Tomato mosaic virus (ToMV), Tomato yellow leaf curl virus (TYLCV) and Tomato spotted wilt virus (TSWV), which make up 99, 68, and 32%, respectively, of all virus-resistant plants. Both open-field and greenhouse-grown crops are challenged by an increasing number of established and emerging pathogens, which require disease management strategies, but, according to the data from seed companies and those from nurseries, farmers consider it hard to produce tomato without disease resistances, especially regarding Fusarium wilt and ToMV.
Janssen, D., García, C., Ruiz, L., de Cara-García, M., Simon, A. and Martinez, A. (2018). Disease resistance in tomato crops produced in Spain. Acta Hortic. 1207, 63-68
Fusarium, nematodes, nursery, seeds, Verticillium, virus, wilt