Italian maize germplasm is particularly rich in local materials and each region is characterized by the presence of peculiar local varieties deriving from centuries of adaptation, selection and cultivation. While the introduction of hybrids, during the 1950s, led to the disappearing of many of these varieties, some have been maintained in cultivation by farmers, frequently in marginal areas, as a kind of family heritage. Local varieties were identified throughout field surveys carried out in recent years. The discovery of a traditional popcorn variety over the most common flint and semi-flint materials used for production of polenta was interesting. Since these varieties have never been adequately described and reported in scientific literature, this study was aimed to solve this lack of knowledge on recently discovered local maize populations. Characterization represents the first step of a process focused on the preservation and possible exploitation of important genetic resources. Traditional materials are a useful reservoir of genes for adaptation to local conditions and climate changes. Adequate breeding programs can use such germplasm for developing new and more resilient varieties. These local materials have been characterized at the morphological level highlighting plant, ear and kernel differences. Genetic characterization, carried out on 455 individuals by the use of 10 SSR markers, revealed 62 different alleles ranging from four for markers phi127, phi076 and phi084 to nine for marker p-bnlg176. The landraces are well distinguishable at genetic level since 40% of genetic variability is present among accessions. Five landraces are characterized by the presence of private alleles and heterozygosity levels are generally good. These findings support the possibility to correctly preserve local materials through in situ conservation. Phylogenetic analysis evidenced the presence of varietal clusters, the clearest one formed by three red-pigmented accessions. STRUCTURE analysis revealed that five landraces have a well-defined genetic attribution while the remaining two (EMR04-Mais Rosso di Rasora and EMR10-Mais del Principe di Scavolino) are both constituted by two different backgrounds.

No abstract

Maize is mainly affected by two fungal pathogens, Fusarium verticillioides and Aspergillus flavus, causing Fusarium ear rot (FER) and Aspergillus ear rot (AER), respectively. Both fungi are of concern to stakeholders as they affect crop yield and quality, contaminating maize grains with the mycotoxins fumonisins and aflatoxins. The easiest strategy to prevent pre-harvest contamination by F. verticillioides and A. flavus is to develop maize hybrids resistant to FER and AER, as well as to their associated mycotoxins. The objective of this investigation was to test 46 F1 hybrids, originated from different Italian, US and Canadian breeding groups, for these important traits and their agronomic performances. All hybrids were planted and artificially inoculated with toxigenic strains of F. verticillioides and A. flavus at two locations in 2017, and the best performing 17 out of 46 were also tested in 2018. Ear rots were present in all hybrids in 2017 and 2018, with percentages ranging from 6.50 to 49.50%, and 5.50 to 45.53%, for FER and AER, respectively. Seven hybrids (PC8, PC15, PC9, PC11, PC14, PC34 and PC17) presented the lowest levels of both diseases considering the overall locations and growing seasons, and three of these (PC8, PC11 and PC14) were also amongst the least mycotoxin contaminated hybrids in 2017. The inbred lines used in hybrid production may provide additional sources of resistance suitable in breeding programs targeting multiple pathogens and their mycotoxins.

No abstract

Sorghum [Sorghum bicolor (L.) Moench] is a subsistence crop and the main food for populations in arid or semiarid regions and it is appreciated for the production of gluten-free products, forages, raw materials for industrial transformation and packaging. The end-use of different sorghum purposes having various plant or kernel characteristics require specific breeding programs to develop the desired ideotype. Sorghum grains can be classified according to kernel color, tannins and polyphenols content: white, yellow, red, brown, and black. White sorghum is characterized by a low level of total phenolic content and tannins. The advantage of using white sorghum is: increased protein digestibility, nutritional composition and consumer acceptance similar to other cereals. A collection of 117 white grain sorghums was characterized using 10 SSRs and preliminary agronomic observations were made for main traits. SSR analysis revealed from 10 to 33 alleles per locus.Observed heterozygosity was lower than expected according to the reproduction system of sorghum. Phylogenetic analysis revealed 6 main groups of genotypes. Only one group is constituted by genotypes with the same geographical origin (Egypt) while other groups are admixtures of different countries. The principal coordinate analysis revealed good correspondence between genetic profiles and groups evidenced by similar agronomic performances.