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Background: Protein percentage and kernel weight affect the endosperm hardness of maize grains. However, changes in starch composition could also modify kernel hardness, which is often predicted through milling ratio. The objective of this work was to evaluate the relationship between changes in starch composition and endosperm hardness, and to assess the effects of protein content and kernel weight on that relationship. For this, we used information obtained from three temperate hybrids in multi-environmental experiments, as well as experiments conducted under controlled conditions designed to modify starch composition. Milling ratio was determined as maize kernel hardness predictor in both experiments and it was correlated with grain weight and grain composition., Results: In both experiments, milling ratio presented a significant Spearman correlation coefficient with amylose/starch ratio. Milling ratio was significantly related to the amylose/starch ratio using a simple fit with datasets from different experiments and hybrids. Increases in amylose/starch ratio were associated with increases in milling ratio., Conclusion: Starch composition was related to milling ratio variations among hybrids of different aptitude for dry milling through different environments, regardless of protein content. Thus, increases in the amylose/starch ratio were related to increases in the milling ratio. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

Several preclinical studies have suggested that the regular consumption of flavonoid-rich foods is associated to a reduced risk of chronic diseases. For this reason, in the last years a renewed interest for the ancient landraces rich in flavonoids or other bioactive molecules is growing. Preservation and valorisation of these ancient landraces is very important, not only for economic considerations regarding the farmers within the small rural communities, where the particular maize germplasm has been developed, but also from a scientific point of view. In this work we characterized the ancient cultivar named 'Nero Spinoso' from the Camonica valley, the biggest valley in the north-west region of Lombardy (Italy). The peculiarity of this landrace is the colour and the pointed shape of the kernels. We showed after spectrophotometric and TLC analysis that this variety accumulates high amounts of phlobaphenes (320 A/100 g flour). Genetic data demonstrate that phlobaphene pigmentation is under the control of a monogenic dominant gene. Further mapping and sequencing data showed that the pigmentation is driven by the presence of a strong allele of Pericarp 1 ( P1) gene, a transcription factor belonging to the myb transcription factor gene family. The 'Nero Spinoso' variety represents an ancient landrace that could be considered a real functional food and a useful tool in future breeding programmes. [ABSTRACT FROM AUTHOR]

Abstract: Today''s modern Dent×Flint maize (Zea mays L. ssp. mays) hybrids have a high yield potential but often lack satisfying early vigour under typical low spring temperatures of temperate latitudes. Maize was introduced into Europe already in the 16th century and until the 1950s, landraces evolved and adapted well to various geographically restricted and climatically marginal regions in Europe. Therefore, the objective of this study was to assess representatives of the large pool of Swiss Flint maize landraces for their early vigour under cool conditions in the field. A set of 17 landrace accessions were tested for 2 years at sites on the Swiss plateau (450 and 550m a.s.l.) and in the foothills of the Swiss Alps (830 and 870m a.s.l.). Plant emergence (PE), emergence index (EI), the efficiency of the photosystem II (F v/F m), leaf greenness (SPAD) and plant dry weight at the three- and six-leaf stages (DW3P, DW6P) were measured. Compared to a modern European Dent×Flint reference hybrid of good early vigour (Magister), superior early growth was found for several accessions that originated in northern alpine valleys. Three of these landraces (176RV, 151RV and 055LV) combined their good early growth with good early establishment (PE) and seemed to break the usually observed negative association between PE and DW3P or DW6P, a prerequisite for high-yielding plant stands. Plant emergence and establishment were often markedly better for landrace accessions from the Southern Alps, mainly from Tessin region, but their growth performance was significantly lower at the three- and the six-leaf stages. We conclude that northern Swiss landrace accessions in particular show good potential for improving early vigour of maize in cool field environments and we propose that the fast, non-destructive early vigour scoring is an efficient tool for assessing differences in growth in the field during these early plant stages. [Copyright &y& Elsevier]