Resumen :
Las mandarinas son uno de los cítricos más importantes en cuanto a producción y exportaciones a nivel mundial. Existen una amplia variedad de mandarinas comerciales, pero de las más destacadas son las recolectadas en la época invernal, las variedades tardías. Estas tienen un alto valor económico, p... Ver más
Mandarins are among the most significant citrus fruits in terms of production and exports worldwide. There is a diverse range of commercial mandarins, but the most notable are those harvested during the winter season, the late varieties. These have a high economic value due to their high fruit yields, their harvesting at a time when there are few commercial varieties, and their subjection to strict cultivation limitations by breeders. Consequently, the detailed analysis of late commercial varieties, the effect of rootstock on final fruit quality, and the adaptation of trees to increasingly extreme biotic and abiotic conditions due to climate change are of great interest to agriculture. The objective of this PhD Thesis is to characterize morphologically, biochemically, and agronomically three late varieties of mandarin (Citrus reticulata Blanco) under homogeneous growing conditions. Specifically, the fruits of the late varieties 'Afourer', 'Orri' and 'Tango' were characterized and compared, the influence of the rootstock on the fruits of late mandarin varieties was analyzed, and the metabolites present in the leaves of the late varieties 'Afourer', 'Orri' and 'Tango' were analyzed and their influence on the agronomic characteristics was determined. The results of the characterization of three late varieties revealed that the 'Afourer' variety exhibited the greatest size and weight, with an average of 20% greater than the other varieties. The 'Orri' variety exhibited a higher juice quantity and brightness, as well as an 18% higher sugar concentration, and a higher malic acid to citric acid ratio. The 'Tango' mandarins grafted on Forner Alcaide nº5 exhibited greater weight and size, as well as a more orange hue and a higher amount of total phenols. Metabolomic analysis revealed that all mandarin samples analyzed contained predominantly non-essential amino acids. The rootstocks Cleopatra mandarin and Carrizo citrange exhibited the most notable morphological, biochemical, and sensory characteristics. These rootstocks were associated with the production of larger fruits, higher juice yield, and superior organoleptic quality. The analysis of metabolites in the leaves revealed that the 'Afourer' variety exhibited greater vegetative growth, from an agronomic perspective, in comparison to the other varieties. In contrast, the 'Tango' variety demonstrated enhanced resilience to abiotic stress. Nevertheless, the variety 'Orri' exhibited the most notable resistance to both abiotic and biotic stresses, as well as the highest quality fruit, despite displaying the lowest vegetative growth
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