Molecular Bases of Fruit Quality in Species: An Integrated Genomic, Transcriptomic, and Metabolic Review with a Breeding Perspective.

In plants, fruit ripening is a coordinated developmental process that requires the change in expression of hundreds to thousands of genes to modify many biochemical and physiological signal cascades such as carbohydrate and organic acid metabolism, cell wall restructuring, ethylene production, stress response, and organoleptic compound formation. In species (including peaches, apricots, plums, and cherries), fruit ripening leads to the breakdown of complex carbohydrates into sugars, fruit firmness reductions (softening by cell wall degradation and cuticle properties alteration), color changes (loss of green color by chlorophylls degradation and increase in non-photosynthetic pigments like anthocyanins and carotenoids), acidity decreases, and aroma increases (the production and release of organic volatile compounds). Actually, the level of information of molecular events at the transcriptional, biochemical, hormonal, and metabolite levels underlying ripening in fruits has increased considerably.

Genetic inhibition of flowering differs between juvenile and adult Citrus trees.

Background And Aims: In woody species, the juvenile period maintains the axillary meristems in a vegetative stage, unable to flower, for several years. However, in adult trees, some 1-year-old meristems flower whereas others remain vegetative to ensure a polycarpic growth habit. Both types of trees, therefore, have non-flowering meristems, and we hypothesize that the molecular mechanism regulating flower inhibition in juvenile trees is different from that in adult trees.

Physico-chemical and physiological changes during fruit development and on-tree ripening of two Spanish jujube cultivars (Ziziphus jujuba Mill.).

Background: Few studies have been performed on changes in organoleptic, nutritive, functional, and physiological properties during jujube fruit development and on-tree ripening. In this work, a comparative study on the evolution of physical, chemical, nutritive, and physiological parameters and bioactive compounds of two Spanish jujube cultivars was performed.

Results: Both cultivars showed a non-climacteric ripening pattern, although the JM cultivar was smaller, sweeter, softer, and more highly coloured than the JG, which was characterised by having larger and firmer fruits, although less sweet and coloured.