NODES - SPOKE 6 Project FORMIDABILÆ - D2.1 Environmental and climatic factors for plant adaptation, physiology and production

The present activity aims to identify genetic markers associated to specific environmental factors in 28 Italian maize landraces by a landscape genomics approach to support the development of resilient maize genotypes. Within the 12 ancestral population detected, well-defined populations as well as completely admixed groups were observed; this high degree of genetic fragmentation was reflected in the phylogenetic and PCA analysis, although clear differentiation of individual populations was exhibited. Partial redundancy analysis revealed that 30% of the genetic variance in our collection was explained together by climate (45%), geography (11%), and genetic structure (31%). Three significantly associated SNPs were identified and two of these localized in two distinct genes. Finally, we found a gene encoding the AP2-EREBP-transcription factor in the LD-window of one significant SNP. Results highlight significant intra-population variability within the examined germplasm and reveal unique populations tied to ancestral lineages. Most notably, we identified distinct genetic markers strongly correlated with environmental factors. The principal component analysis (PCA) of grain quality traits measured by near-infrared spectroscopy (NIRS) on 28 maize landraces revealed that the first two principal components accounted for a cumulative 85.4% of the total variance, with PC1 and PC2 explaining 66.9% and 18.5%, respectively. The PCA shows a clear separation of genotypes into three clusters based on their compositional profiles. The temporal growth dynamics of NDVI values across the 28 maize landraces, monitored at five time points from 42 to 86 days after sowing (DAS), revealed the presence of two distinct phenotypic clusters based on the progression of canopy development. Overall, the NDVI temporal profiles of these landraces are consistent with their phenological and phenotypical traits, supporting the reliability of vegetation indices in defining growth dynamics. This document is a deliverable of the project FORMIDABILÆ ("Forage system to make resilient Maize, Dairy and Biogas supply chains for a Lasting Agricultural Ecosystem"), which promotes approaches aimed at improving the smart, resilient, circular and diversified farm to ensure food security and social economic sustainability of dairy food chains with the aim of reducing greenhouse gas emissions in this sector. This document is part of the project NODES which has received funding from the MUR – Missione 4, Componente 2, Investimento 1.5 – Creazione e rafforzamento di “Ecosistemi dell’innovazione”, costruzione di “leader territoriali di R&S'' – del PNRR funded by the European Union - NextGenerationEU with grant agreement no. ECS00000036