Wheat and low-input agriculture: agronomic, nutritional and nutraceutical implications

Recently, the increasing interest in organic food products and environmental friendly practices has emphasized the importance of selecting crop varieties suitable for the low-input systems. Additionally, in recent years the relationship between diet and human health has gained much attention among consumers, favoring the investigations on food nutraceutical properties. Among cereals, wheat plays an important role in human nutrition around the world and contributes to the daily intake of essential nutrients such as starch and protein. Moreover, whole grain contains several bioactive compounds that confer to wheat-derived products unique nutraceutical properties (dietary fibre, antioxidants). The present research provided interesting insights for the selection of wheat genotypes suitable for low-input systems and the development of specific breeding programs dedicated to organic farming. The investigation involved 5 old not dwarf genotypes (Andriolo, Frassineto, Gentil rosso, Inallettabile, Verna) and 1 modern dwarf variety (Palesio), grown under biodynamic management, over two consecutive growing seasons (2009/2010, 2010/2011). Results evidenced that under low-input farming some investigated old wheat genotypes (Frassineto, Inallettabile) were comparable to the modern cultivar in terms of whole agronomic performance. As regards the nutritional and nutraceutical properties, some old genotypes (Andriolo, Gentil rosso, Verna) emerged for their relevant content of several investigated phytochemicals (such as insoluble dietary fibre, polyphenols, flavonoids, in vitro antioxidant activity) and nutrients (protein, lipid, minerals). Despite of the low technological features, the six wheat varieties grown under low-input management may efficiently provide raw material for the preparation of traditionally processed bread with valuable sensory and nutritional properties. Results highlighted that old wheat varieties have peculiar phytochemical composition and may be a valuable source of nutraceutical compounds. Some of the genetic material involved in the present study may be used in breeding programs aimed at selecting varieties suitable for low-input farming and rich in health-promoting compounds.

Wheat adaptation to climate change in the Mediterranean Basin: retracing the past to predict the future

Wheat productivity is alarmingly threatened by climate change in the Mediterranean Basin, where it is mainly cultivated as a rainfed crop and where the latest climatic projections foresee a rise in temperatures and a reduction in precipitation, with important yield losses expected, being drought the main abiotic stress hampering wheat productivity. Assessing and quantifying the alterations in wheat life cycle caused by climate change is thus a key goal, as well as understating the underlying mechanisms of drought resistance. The first part of this thesis is focused on these main topics. A precise quantification of climate change effects on wheat in this area was performed through a case study, coupling phenological, meteorological and grain quality data before and after climate change. Then, accurate and detailed literature search was performed, reviewing the main controversies regarding the reliability of various functional traits to be used as breeding tools for improving wheat drought stress resistance. The second part of this thesis is focused in identifying interesting genetic material to improve wheat drought stress resistance in the Mediterranean Basin, analyzing drought response on a panel of tetraploid wheat accessions in vitro and in vivo as well as in open field trials, chosen in the attempt to represent as much as possible the biodiversity of tetraploid wheat. The third part of this thesis highlights differences in technological, nutritional and nutraceutical quality between modern cultivars and landraces, focusing on lipids, primary metabolites and bioactive compounds. In fact, wheat adaptation to climate change does not only mean to guarantee satisfactory yields in adverse conditions. It also means to provide millions of consumers with a diet-base food crop, with an improved nutraceutical and nutritional quality. Therefore, investigation and selection process for abiotic stress resistance and for improved quality has to go hand in hand.

The genetic prehistory of Northern Calabria. Archeogenomic investigation of the human remains from Grotta di Pietra Sant’Angelo and Grotta della Monaca.

Given its strategic position at the center of the Mediterranean Basin, and its unique history of contacts and migrations, Calabria is an ideal region to decipher the genetic traces of at least some of the numerous demographic prehistoric events in Southern Italy. This thesis focuses on the genetic and social changes of ancient inhabitants of Calabria, covering a timeline of approximately 7000 to 3300 years ago, ranging from the Middle Neolithic to the Middle Bronze Age. We generated the first genome-wide data from Calabria, by focusing on the single inhumation of “Grotta di Pietra Sant’Angelo” (San Lorenzo Bellizzi, Cosenza) and on the vast community found buried in “Grotta della Monaca” (Sant’Agata di Esaro, Cosenza). Supported by archaeological evidence, the primary objective of this research was to employ paleogenomic evidence to decipher funerary customs, social organization, family ties, and demographic shifts in Southern Italy over a period extending beyond three millennia. The possibility of gender-related burial practices and kinship ties among the deceased was also explored. Subsequently, the biogeographical origin and ancestry of prehistoric people of Calabria was contextualized within the broad landscape of existing data on Mediterranean populations. By generating the first genomic evidence from prehistoric Calabria, unresolved questions were addressed, related to the appearance and persistence of distinct genomic components, such as the Iran-related and the Steppe-related ancestry, whose impact on ancient Southern Italian genomes remains uncharted.