All Are in a Drought, but Some Stand Out: Multivariate Analysis in the Selection of Agronomic Efficient Popcorn Genotypes.

The search for productive germplasm adapted to adverse conditions is an important action to mitigate the harmful effects of climate change. The aim was to identify the yield potential of 50 popcorn inbred lines grown in field conditions, in two crop seasons (CS), and under contrasting water conditions (WC). Morphoagronomic, physiological, and root system traits were evaluated. Joint and individual analyses of variance were performed, in addition to the multivariate GT bip-lot analysis. Expressive reductions between WC were observed in 100-grain weight (100 GW), popping expansion (PE), grain yield (GY), expanded popcorn volume per ha (EPV), row number per ear (RNE), plant height (PH), relative chlorophyll content (SPAD), and nitrogen balance index (NBI). It was found that the SPAD, 100 GW, GY, PE, and grain number per ear (GNE) traits had the most significant impact on the selection of genotypes. Regardless of WC and CS, the ideal lines were L294 and L688 for PE; L691 and L480 for GY; and L291 and L292 for both traits. SPAD, 100 GW, and GNE can contribute to the indirect selection. Our work contributes to understanding the damage caused by drought and the integration of traits for the indirect selection of drought-tolerant popcorn genotypes.

Divergence and conservation of defensins and lipid transfer proteins (LTPs) from sugarcane wild species and modern cultivar genomes.

Plant defensins and lipid transfer proteins (LTPs) constitute a large and evolutionarily diverse family of antimicrobial peptides. Defensins and LTPs are two pathogenesis-related proteins (PR proteins) whose characterization may help to uncover aspects about the sugarcane response to pathogens attack. LTPs have also been investigated for their participation in the response to different types of stress. Despite the important roles of defensins and LTPs in biotic and abiotic stresses, scarce knowledge is found about these proteins in sugarcane. By using bioinformatics approaches, we characterized defensins and LTPs in the sugarcane wild species and modern cultivar genomes. The identification of defensins and LTPs showed that all five defensins groups and eight of the nine LTPs have their respective genes loci, although some was only identified in the cultivar genome. Phylogenetic analysis showed that defensins appear to be more conserved among groups of plants than LTPs. Some defensins and LTPs showed opposite expression during pathogenic and benefic bacterial interactions. Interestingly, the expression of defensins and LTPs in shoots and roots was completely different in plants submitted to benefic bacteria or water depletion. Finally, the modeling and comparison of isoforms of LTPs and defensins in wild species and cultivars revealed a high conservation of tertiary structures, with variation of amino acids in different regions of proteins, which could impact their antimicrobial activity. Our data contributed to the characterization of defensins and LTPs in sugarcane and provided new elements for understanding the involvement of these proteins in sugarcane response to different types of stress.

Driving Sustainable Popcorn Breeding for Drought Tolerance in Brazil.

Drought currently affects several regions worldwide and tends to be more frequent due to climate change. It might compromise food security and the economic structure related to agribusiness. Popcorn has a crucial role in the Brazilian economy, but the cultivars that adapt to water stress, the most prejudicial abiotic stress for crop productivity, are unknown to date. This deficit of popcorn varieties adapted to heat and drought stresses will become more limiting with climate change. Given this scenario, knowing the genetic basis of agronomic traits under stress conditions is essential in promoting crop productivity and plant adaptation to abiotic stresses. Under two contrasting water conditions (WC) and different crop seasons (CS), we aimed to generate information about the combining ability of 10 popcorn progenitors and 15 hybrids through a partial diallel-mating design. The water stress was initiated at the male pre-anthesis stage. Significant genotype*crop seasons (G*CS), genotype*water condition (G*WC), and genotype*crop seasons*water condition (G*CS*WC) interactions were present. Regardless of CS and WC, non-additive effects controlled grain yield (GY), grain number per row (GN), ear length and diameter (ED), and 100-grain weight, while additive effects were present for popping expansion (PE). For each CS, regardless of WC, the cause-effect of GN (2018) and ED (2020) on GY seems to be an opportunity for indirect selection. Utilizing genetically broad-based hybrids is also a good opportunity for obtaining superior genotypes for GY and PE as it is possible to select inbred lines for both of these traits. We recommend the L76 × L61 hybrid for the Brazilian agribusiness context due to its greater productivity and dominance deviations.