Chickpea

The narrow genetic base of cultivated chickpea warrants systematic collection, documentation and evaluation of chickpea germplasm and particularly wild Cicer species for effective and efficient use in chickpea breeding programmes. Limiting factors to crop production, possible solutions and ways to overcome them, importance of wild relatives and barriers to alien gene introgression and strategies to overcome them and traits for base broadening have been discussed. It has been clearly demonstrated that resistance to major biotic and abiotic stresses can be successfully introgressed from the primary gene pool comprising progenitor species. However, many desirable traits including high degree of resistance to multiple stresses that are present in the species belonging to secondary and tertiary gene pools can also be introgressed by using special techniques to overcome pre- and post-fertilization barriers. Besides resistance to various biotic and abiotic stresses, the yield QTLs have also been introgressed from wild Cicer species to cultivated varieties. Status and importance of molecular markers, genome mapping and genomic tools for chickpea improvement are elaborated. Because of major genes for various biotic and abiotic stresses, the transfer of agronomically important traits into elite cultivars has been made easy and practical through marker-assisted selection and marker-assisted backcross. The usefulness of molecular markers such as SSR and SNP for the construction of high-density genetic maps of chickpea and for the identification of genes/QTLs for stress resistance, quality and yield contributing traits has also been discussed

Genetics and genomics of carrot sugars and polyacetylenes

Carrot root carbohydrates, composed mainly of reducing and non-reducing free sugars, influence flavor, total dissolved solids and dry mater content, all quality traits for fresh-market and processing carrots. In the last decades, important advances have been made in biochemistry, physiology and genetics of carrot sugar metabolism. Several enzymes involved in sucrose metabolism and their corresponding genes have been isolated and functionally characterized, increasing our understanding of their individual roles and of their interactions in complex regulatory systems that influence major plant physiological processes, including partitioning of photoassimilates, plant growth and storage of different sugar types in the carrot tap root. Polyacetylenes represent a large group of non-volatile lipid compounds produced primarily by members of the Apiaceae family. The major carrot polyacetylenes have been extensively studied with regards to their analytical identification and elucidation of their chemical structures as well as their biological activities, which have revealed numerous health-promoting properties for these compounds. Very recently, with the publication of the carrot genome sequence and related genomic and transcriptomic sequence resources, key genes and enzymes involved in the biosynthesis of carrot polyacetylenes were discovered. In this chapter, advances in genetics and genomics of carrot sugars and polyacetylenes were reviewed and discussed.Fil: Cavagnaro, Pablo Federico. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción Agropecuaria. Cátedra de Horticultura y Floricultura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentin