The first step will be to identify the tomato varieties with the highest toleranceto water and nutrient stress, as well as the new alleles and genetic traits that give the plant greater efficiency in water and nutrient use. From a sample of more than ten thousand available copies, a screening will be carried out to select approximately two hundred that are resilient in different pedoclimatic conditions, while also maintaining the quality of the fruit and their tolerance to pests and diseases. The selection will be made taking into account the complex interactions between plants, soils and underground biodiversity. The goal is to identify between ten and twenty alleles that can be reproduced.
For this experiment, the tomato plants will be divided into three plots that will be given different doses of nutrients and water, using state-of-the-art technology to carry out a detailed monitoring of their physiological and agronomic condition, including remote measurements. These data will be compared with those of another parallel experiment carried out at the German University of Bonn, but in greenhouses. The most resistant varieties will be chosen based on the results obtained.
The UIB researchers will not only collaborate in the selection of germplasm and its screening, but also in the evaluation of the efficiency of water and nutrient use of the selected varieties in the different stages of the project. In this sense, the scientists will be focusing on "ramellet" tomatoes, flagship product of the Balearic Islands and one of the region's most representative crops.
Unlike others, this variety has two qualities that make it a very interesting tomato from an agronomic point of view. The first one has to do with the fruit ripening process, which makes it possible for it to be preserved naturally from year to year without the loss of its organoleptic properties. The second is its greater resistance to drought, which allows for rainfed cultivation; an aspect that seems to be closely linked to the product's long shelf life.
In an increasingly drier world, where the use of water has to be highly optimised, the characteristics of "ramellet" tomatoes are of great interest for the obtainment of new varieties with a greater resistance to water stress and lack of nutrients.
The preservation of local crop varieties is one of the policies that have shown to be indispensable to maintain a source of genetic resources that can provide material in future improvement plans, either to deal with environmental stress, pests or changes in market tastes.
The team of researchers from the PLANTMED group participating in the TOMRES project are Dr Jeroni Galmés (Head Researcher), Miquel Ribas-Carbó and Jaume Flexas, Professors of the Biology Department of the UIB; doctors Miquel Àngel Conesa, Cyril Douthe, Hanan Elaouad and Xurxo Gago (postdoctoral contractors); doctoral student Mateu Fullana; biologists Gerardo Costea and David Alonso; and the final grade students of Agro-food and Rural Engineering Jaume Canyelles, Joana Maria Fontclara and Xavier Coll.
Also involved are Mr Antoni Ribot, owner of the farm where the research is carried out, and Mr Carlos Oliveros and the company NorDron, responsible for the measurements made with unmanned aerial robots (drones).