Apples are cultivated globally, valued not only for their taste but also for their beneficial compounds. In addition to primary components like sugars, fibers, and organic acids, apples contain secondary metabolites, including polyphenols, known for their health-promoting properties, such as anti-inflammatory and antimicrobial effects. The project 'CLEARGENES' aims to explore the genetic basis responsible for the formation of these secondary metabolites in apples.
Walter Guerra, head of the Institute for Fruit and Wine Research at the Laimburg Research Centre and project leader, stated, 'With 'CLEARGENES', we aim to determine which apple varieties offer the greatest benefits for human health. At the same time, we rely on bioinformatics and innovative breeding strategies to promote the cultivation of high-quality and environmentally friendly apples, which is particularly important to adapt the variety spectrum to the challenges of climate change.'
'CLEARGENES' (CLimatE chAnge Resilience GENES in Italian fruits and vegetables) is funded by the PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR). Other institutions involved are focusing on grapevines, tomatoes, and other vegetable species. The apple segment of 'CLEARGENES' is a collaborative effort among three partners: Laimburg Research Centre, the University of Trento, and LandLab.
The researchers are examining apples from a reference collection named 'RefPOP', which includes 600 different apple varieties representing the genetic diversity of apples. Established in 2016 across six macroclimatic locations in Europe, 'RefPOP' aims to investigate the interactions between genetics and environment. A focus is placed on how climatic influences affect the quality traits of apples. To this end, part of the apple collection is irrigated, while another part is grown without irrigation.
As part of 'CLEARGENES', samples of various apple varieties are collected from the experimental fields to analyze secondary metabolites and nutritional properties. Specifically, the project seeks to identify which gene segments regulate the formation and content of polyphenols. Additionally, the metabolome of the apples, encompassing all plant substances, including primary and secondary components, will be analyzed. The effects of different cultivation conditions (irrigated vs. non-irrigated) on the metabolome will also be studied. Francesco Panzeri, a member of the 'Pomology' group at the Laimburg Research Centre, remarked, 'This analysis allows us to better understand the impacts of environmental factors on the health-promoting properties of apples and to identify varieties with high health value.'
Another project, 'AppleBIOME', also focuses on the 'RefPOP' collection, expanding investigations from agronomic traits such as yield, fruit quality, and disease susceptibility to the microbiological diversity of apple varieties. The project examines the microbiome—the totality of microorganisms inhabiting a plant. These microorganisms, found on leaves and fruits, play a crucial role in plant health and resilience. For the first time, 'AppleBIOME' analyzes the microbiome of the leaves from 600 different apple varieties, aiming to understand the interplay between the genetics of apple trees and their microbiome, and how microorganisms affect plant adaptability and resilience. This project creates a valuable resource for developing future-oriented breeding strategies and sustainable apple varieties. 'AppleBIOME' is funded by the MASAF - Joint FACCE-JPI SusCrop program.