Evaluación de híbridos experimentales de tomate resistentes a hongos foliares

Tomato is the second most important vegetable in terms of production both worldwide and in Uruguay. There are several pathogens damaging tomato crops, including foliar fungi. To reduce this problem in many systems, chemical control is used with synthetic phytosanitary products, with negative effects both for the environment and for the operators who handle these substances, as well as product safety problems. For this reason, the use of tomato cultivars with genetic resistance is an interesting tool that allows to reduce these impacts, in addition to facilitate crop management, reducing production costs and allowing the implementation of biological control strategies. Today, few cultivars have resistance to the three main foliar fungi of tomato crop in Uruguay (Stephylium sp., Oidium neolycopersici and Passalora fulva). One of them is the experimental hybrid of INIA, HT117. This material has productive and quality limitations. The present work consists of evaluate from the productive, sanitary and fruit quality point of view, different experimental hybrids with resistance to foliar fungi (HT347, HT501, HT545, HT551, HT560),analyzing their behavior respect HT117 and two commercial cultivars as reference: ELPIDA and INIA FRONTERA. For this, a randomized block experimental design with three replications was carried out. The experimental plots were ten individual plants. Variables related to plant characteristics, production, fruit quality and disease resistance, were evaluated. Regarding plant characteristics, differences in plant vigor were observed, with hybrids with high vigor, even greater than ELPIDA (a commercial variety characterized by its high vigor), as is the case of HT501. On the other hand, same other hybrids showed low vigor, such as HT560 and HT545. The yield did not vary between materials, but there were differences in fruits number as well as in fruit size. Some hybrids were characterized by their high number and low size, such as HT347 and HT501, while others by their low number and larger size, such as HT560, HT551 and HT545. For this last group, tsize fruit uniformity must be improved. In terms of fruit quality, there is a lot of variation between experimental hybrids, standing out for color HT501and for firmness HT347 and HT545. Respect disease resistance, all the materials responded according to their previous characterization, there was only segregation for ash by HT545, HT551 and HT560, while HT501 was found segregating for cladosporiosis. All the materials have same positive particular, but none combines all the necessary ones to be a competitive commercial variety. For example, HT501 is a very complete material, but it has serious limitations in terms of fruit size and loss of firmness. For HT545, HT551 and HT560, although they have a very good size, have limitations in terms of commercial quality and low plant vigor. HT347 has very good firmness, but has no resistance to Passalora fulva and has medium resistance to Stemphylium sp. In addition, it has small fruit size. It is confirmed that the three pathogens affect tomato crop under the same environment, which is why they bring together the 3 resistance genes, which is very positive at the productive level. New materials must continue to be investigated in order to achieve a hybrid with resistances and competitive productive characteristics.