TRANSCRIPTIONAL ANALYSIS OF EIGHT MAGIC MAIZE PARENTAL LINES INFECTED WITH FUSARIUM VERTICILLIOIDES

Maize (Zea mays L.) is among the most important crops worldwide for food, feed, biofuels, and industrial applications. Its cultivation faces significant constraints due to Fusarium species that affect the quality and quantity of maize products. Among these, Fusarium verticillioides is responsible for severe diseases including seedling blights, stalk rot, and ear rot. The impact of the fungus is worsened by the fact that chemical and agronomic measures used to control Fusarium infection are often inefficient. Hence, genetic resistance is considered the most reliable resource to reduce damages caused by F. verticillioides. This study aims to elucidate the genetic basis of resistance to this fungus in maize. Young seedlings of eight divergent maize lines, founder of the MAGIC population, were artificially inoculated with a F. verticillioides strain using the rolled towel assay method. Total RNA was extracted from both control and treated samples after 72 hours of artificial inoculation and underwent paired-end sequenced with Illumina technology. Here we report the use this large transcriptomic dataset to identify the early transcriptional changes and the differentially expressed genes (DEGs) involved in fungal infection. The analysis identified several hundred DEGs, whose functions were explored through Gene Ontology enrichment analysis. A co-expression network analysis further refined the set of genes with potential implications in disease response. The results identify a limited set of genes that might play an important roles in maize resistance to F. verticillioides providing new insights into the molecular resistance mechanisms against the pathogen

CHARACTERIZING HETEROSIS IN A SET OF RECOMBINANT INTERCROSSES (RIXS) DEVELOPED FROM A MULTIPARENTAL MAIZE POPULATION

The exploitation of heterosis is key in modern maize breeding to capture the superior performance of heterozygous genotypes. Here, we developed a recombinant intercross (RIX) population in maize by crossing pairs of multiparental MAGIC recombinant inbred lines (RILs) to evaluate the heterosis across mosaics of eight maize haplotypes. Field phenotyping was performed on 400 RIX genotypes considering 11 agronomic traits as well as the resistance to Fusarium Ear Rot (FER), caused by Fusarium verticillioides (Sacc.) Nirenberg, in 2018 and 2019 in Piacenza, northern Italy. Phenotypic data showed a broad range of diversity in production and phenology traits thanks to the high level of allelic diversity available in parental genomes. The heterotic response of agronomic traits was computed based on RIL values as mid parent heterosis (MPH) and best parent heterosis (BPH). Both heterosis measures showed different magnitudes for different traits, with higher level of heterosis in yield and lower in flowering time, suggesting effects from partial dominance to over-dominance. No correlation was observed between phenotypic performance and heterozygosity level of RIXs for most of the agronomic traits. A preliminary quantitative trait locus (QTL) mapping detected a number of significant associations with agronomic traits across all chromosomes. The RIX collection showed a moderate heritability of FER resistance, and QTL were associated to this trait as well. The allelic effect estimates by our mapping model indicated the presence of minor effect QTL with relatively small additive effects on disease resistance in both years. Our findings confirm the usefulness of the RIX population to decipher heterotic loci in maize and support utilizing this resource in future to accelerate crop improvement

Spazi per conoscere crescere confrontarsi: progetto per un nuovo polo scolastico a Reggio Emilia

Sono sperimentate le potenzialità progettuali della strategia pedagogica formulata da Reggio Children. Alla invenzione di spazi flessibili, adatti modalità di organizzazione delle attività didattiche strutturate e libere molto diversificate, si affianca l’applicazione di materiali ecologicamente sostenibili