Harnessing Genetic Diversity of Wild Gene Pools to Enhance Wheat Crop Production and Sustainability: Challenges and Opportunities

Abstract

Wild species are extremely rich resources of useful genes not available in the cultivated gene pool. For species providing staple food to mankind, such as the cultivated Triticum species, including hexaploid bread wheat (Triticum aestivum, 6x) and tetraploid durum wheat (T. durum, 4x), widening the genetic base is a priority and primary target to cope with the many challenges that the crop has to face. These include recent climate changes, as well as actual and projected demographic growth, contrasting with reduction of arable land and water reserves. All of these environmental and societal modifications pose major constraints to the required production increase in the wheat crop. A sustainable approach to address this task implies resorting to non-conventional breeding strategies, such as "chromosome engineering". This is based on cytogenetic methodologies, which ultimately allow for the incorporation into wheat chromosomes of targeted, and ideally small, chromosomal segments from the genome of wild relatives, containing the gene(s) of interest. Chromosome engineering has been successfully applied to introduce into wheat genes/QTL for resistance to biotic and abiotic stresses, quality attributes, and even yield-related traits. In recent years, a substantial upsurge in effective alien gene exploitation for wheat improvement has come from modern technologies, including use of molecular markers, molecular cytogenetic techniques, and sequencing, which have greatly expanded our knowledge and ability to finely manipulate wheat and alien genomes. Examples will be provided of various types of stable introgressions, including pyramiding of different alien genes/QTL, into the background of bread and durum wheat genotypes, representing valuable materials for both species to respond to the needed novelty in current and future breeding programs. Challenging contexts, such as that inherent to the 4x nature of durum wheat when compared to 6x bread wheat, or created by presence of alien genes affecting segregation of wheat-alien recombinant chromosomes, will also be illustrated.

Synergistic Effect of Sulfur and Nitrogen in the Organic and Mineral Fertilization of Durum Wheat: Grain Yield and Quality Traits in the Mediterranean Environment

“…Grain quality has become one of the most important goals for the breeders and growers [2,3], because it is essential in obtaining premium prices and meeting markets needs for high-quality end-products of durum wheat such as pasta, couscous and burghul [4].…”

Engineered Durum Wheat Germplasm with Multiple Alien Introgressions: Agronomic and Quality Performance

“…where MS is the mean square. The 2015 trial alone was partly described in [25] by a subset of yield-related traits, included also in the present multi-year assessment (SNM2, BM2, GYM2, GNM2, HI). Furthermore, traits such as TGW, GYS, GNS and GNSP were re-analysed here with respect to [25], on a bigger number of samples per plot (8 vs. 5), and in the case of HD, by adopting April 1st as more common starting date for day count instead of the sowing date.…”

“…Introduction of the Gli-D1/Glu-D3 genes into the tetraploid context resulted in improved SDS, gluten index and dough strength (W) values, as well as a good dough tenacity-to-elasticity (P/L) ratio, potentially suitable for both pasta and bread making [49,56]. Meiotic stability of the triple introgression line was shown not to be upset, and the simultaneous transmission of the three alien segments to be normal through both germlines [25,48]. Notwithstanding, the potential use in breeding and cultivation of any type of wheat-alien recombinant line depends upon its overall agronomic performance validated under field conditions.…”

Jerusalem Artichoke (Helianthus tuberosus L.): A Versatile and Sustainable Crop for Renewable Energy Production in Europe

“…The inter-specific hybridization of JA with other Helianthus species should be preferred instead [48,59]. Strategy of using related species to introgress useful gene variants is commonly used also in other polyploids e.g., wheat [60,61], canola [62] or cotton [63]. In the case of breeding for traits associated with biofuel production (e.g., top and tuber yield, carbohydrate content), both inter-and intra-specific breeding were used, resulting in various superior cultivars.…”