Assessing the success of breeding maize inbred lines with contrasting diferulate concentrations.

Background: The crosslinking of maize cell wall components, particularly mediated by the formation of ferulic acid dimers or diferulates, has been associated with important crop valorization traits such as increased pest resistance, lower forage digestibility, or reduced bioethanol production. However, these relationships were based on studies performed using diverse unrelated inbred lines and/or populations, so genetic background could interfere on these associations.

Results: In the present research, the success of a pedigree selection program aimed to obtain inbred lines from a common antecessor with contrasting diferulate concentration was evaluated.

Validation of QTLs associated with corn borer resistance and grain yield: implications in maize breeding.

Introduction: Validations of previously detected quantitative trait loci (QTLs) to assess their reliability are crucial before implementing breeding programs. The objective of this study was to determine the reliability and practical usefulness of previously reported QTLs for resistance to stem tunneling by the Mediterranean stem borer (MSB) and yield. These authors used approximately 600 recombinant inbred lines (RILs) from a multiparent advanced generation intercross (MAGIC) population to map QTL using a genome-wide association study (GWAS) approach.

Cell Wall Composition Impacts Structural Characteristics of the Stems and Thereby the Biomass Yield.

Maize stalks support leaves and reproductive structures and functionally support water and nutrient transport; besides, their anatomical and biochemical characteristics have been described as a plant defense against stress, also impacting economically important applications. In this study, we evaluated agronomical and stem description traits in a subset of maize inbred lines that showed variability for cell wall composition in the internodes. Overall, a great proportion of lignin subunit G and a low concentration of -coumaric acid and lignin subunit S are beneficial for greater rind puncture resistance and taller plants, with a greater biomass yield.

Genetics of Germination and Seedling Traits under Drought Stress in a MAGIC Population of Maize.

Drought is one of the most detrimental abiotic stresses hampering seed germination, development, and productivity. Maize is more sensitive to drought than other cereals, especially at seedling stage. Our objective was to study genetic regulation of drought tolerance at germination and during seedling growth in maize.

Elucidating the multifunctional role of the cell wall components in the maize exploitation.

Background: Besides the use of maize grain as food and feed, maize stover can be a profitable by-product for cellulosic ethanol production, whereas the whole plant can be used for silage production. However, yield is reduced by pest damages, stem corn borers being one of the most important yield constraints. Overall, cell wall composition is key in determining the quality of maize biomass, as well as pest resistance.

Methods for Determining Cell Wall-Bound Phenolics in Maize Stem Tissues.

We compared two methods with different sample pretreatment, hydrolysis, and separation procedures to extract cell wall-bound phenolics. The samples were pith and rind tissues from six maize inbred lines reportedly containing different levels of cell wall-bound phenolics. In method 1, pretreated samples were extracted with a C solid-phase extraction cartridge, and it took 6 days to complete.

Chemical Changes during Maize Tissue Aging and Its Relationship with Mediterranean Corn Borer Resistance.

The Mediterranean corn borer (MCB), Sesamia nonagrioides Lef, is an important pest of maize in temperate areas, causing significant stalk lodging and yield losses. The main goals of this study were to determine possible changes in chemical traits (phenols, flavonoids, anthocyanins, sugars, fibers, and lignin) during plant development after the flowering stage and to assess how those traits may differ in diverse genotypes of maize, such as MCB resistant and susceptible. Higher values for some particular traits in more mature tissues seemed to increase their effectiveness against the MCB attack.

Defensive changes in maize leaves induced by feeding of Mediterranean corn borer larvae.

Background: Plants can respond to insect attack via defense mechanisms that reduce insect performance. In this study, we examined the effects of several treatments applied to two maize genotypes (one resistant, one susceptible) on the subsequent growth and survival of Sesamia nonagrioides Lef. (Mediterranean corn borer, MCB) larvae.