More than 70 percent of the planet's fresh water is used for agriculture, and the IPCC (Intergovernmental Panel on Climate Change) warns of a greater risk of droughts, which in certain regions may limit the local production of certain foods. The problem of water scarcity coincides with the pollution of water resources; fertilizers and pesticides are affecting its quality and the environmental cost to pay is very high. How can we meet this challenge?
The slogan "more food per drop of water" is the challenge, but this goes beyond optimising irrigation systems; it requires an interdisciplinary approach. Obtaining drought-resistant plants is not easy; it entails a thorough understanding of their molecular and physiological processes, as well as the development of agronomic and crop precision techniques.
The European project TOMRES (a new and integrated approach to improve multiple and combined stress tolerance using tomato plants as a model), funded by the European Union through the Horizon 2020 program, seeks to improve the resistance of tomato plants to water and nutrient stress, optimising the efficiency in the use of water and nutrients in the context of climate change.
For three years, universities and research institutions across Europe, as well as agricultural enterprises and agricultural technology services, will select varieties of drought-resistant tomatoes, study their physiological and molecular processes and develop new agronomic techniques. The research group on the Biology of Plants in Mediterranean Conditions (PLANTMED) of the UIB and the company Agroilla are two of the 24 entities that participate in this project.
Tomatoes are one of the most consumed fruit and vegetable products in the world and its demand continues to grow. Its cultivation takes place in most of Europe with many different systems, from open ground to greenhouses and hydroponics. Furthermore, because of its taxonomic characteristics, it is a species related to other crops, such as peppers, potatoes or aubergines, so it can be considered a model for the study of improvements in agricultural production systems.
However, in recent years, its cultivation has been facing a triple problem: firstly, the availability of water is gradually reduced, given the lower rainfall due to climate change; secondly, the availability of fertilizers is also reduced because of the rising costs of these products and the stricter restrictions on their use due to their impact on water quality and the environment; and thirdly, the genetic diversity of tomatoes for cultivation is limited. All of this has led to a situation in which the environmental and economic sustainability of tomato growing strategies is at risk.
The first step will be to identify the tomato varieties with the highest tolerance to 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.
The first step will be to identify the tomato varieties with the highest tolerance to 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.
In the framework of this project, 5,000 tomato plants of some 260 varieties have been planted on an experimental farm in Ariany, including local varieties from all over Europe, commercial varieties, hybrids and wild species.
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.
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).
Source: elmundo.es