Modeling °Brix and pH in Wine Grapes from Satellite Images in Colchagua Valley, Chile

To monitor the ripeness and composition of wine grape berries and establish an optimal harvest date, the determination of °Brix and pH is vital. This research studies two harvest seasons of Cabernet Sauvignon wine grapes: 2017 and 2018. Field data were periodically collected to follow the phenological state of the fruits. In parallel, eight bands and four spectral indices from Sentinel-2 image time series were used, which are directly related to the foliage properties and activity, and indirectly to the fruit evolution. They were related to the variables measured from field samples: °Brix and pH. The °Brix models obtained with the spectral indices presented an R2 of 69% and 73% in the 2017 and 2018 seasons, respectively. In pH modeling, the 2017 season had low R2 results, reaching 43%, improving considerably in the 2018 season, reaching 63.8%. Estimated Brix and pH maps were obtained, expressing the spatial variability in the evolution of the fruit, which is useful for zoning the plots and to improve the sampling task prior to harvest. They are therefore a valuable tool to monitor the maturation, to improve the efficiency of harvest and subsequently, the quality of the wine.

Structural diversity of fruits: conceptual reflexions and taxonomic implications / Diversidade estrutural de frutos: reflexões conceituais e implicações taxonômicas

Fruit either originates solely from the ovary or ovary and other floral parts and inflorescence. Besides the ovary itself, the pedicle, bracteoles, receptacle, hypanthium, sepals, petals and inflorescence axis are included in the fruit development. Analysis was made in embedded historesin/paraffin material and sectioned in microtome. In the fruit ontogeny the pericarp either may be non-multiplicative or multiplicative. In the first case, the ovary wall differentiates in pericarp without the installation of meristem. Adaxial, middle or abaxial meristems can be installed in the multiplicative pericarp fruits from the periclinal cell divisions that occur in both the epidermis and the ovary mesophyll. Separation tissue takes place in the carpel margins and midrib in dehiscent fruits or it can remain as residual tissue in indehiscent fruits. Fruit classification is complex, and it may show divergence in nomenclature among fruit specialists. Structural fruit ontogeny can be a useful tool for its classification. Fruit structure has been used as diagnostic character of species, genera and tribes of angiosperms. Hypothesis about fruit evolution indicates that apocarpic fruit with follicles can be a basic evolutionary condition, at least among the sensu lato dicots. The Araucaria angustifolia pine seed is considered here as a fruit with protocarps/spermatocarps.

Phylogeny of Paullinia L. (Paullinieae: Sapindaceae), a diverse genus of lianas with rapid fruit evolution

Paullinia L. is a genus of c. 220 mostly Neotropical forest-dwelling lianas that displays a wide diversity of fruit morphologies. Paullinia resembles other members of the Paullinieae in being a climber with stipulate compound leaves and paired inflorescence tendrils. However, it is distinct in having capsular fruits with woody, coriaceous, or crustaceous pericarps. While consistent in this basic plan, the pericarps of Paullinia fruits are otherwise highly variable—in some species they are winged, whereas in others they are without wings or covered with spines. With the exception of the water-dispersed indehiscent spiny fruits of some members of Paullinia sect. Castanella, all species are dehiscent, opening their capsules while they are still attached to the branch, to reveal arillate animal-dispersed seeds. Here we present a molecular phylogeny of Paullinia derived from 11 molecular markers, including nine novel single-copy nuclear markers amplified by microfluidics PCR. This is the first broadly sampled molecular phylogeny for the genus. Paullinia is supported as monophyletic and is sister to Cardiospermum L., which together are sister to Serjania Mill + Urvillea Kunth. We apply this novel phylogenetic hypothesis to test previous infrageneric classifications and to infer that unwinged fruits represent the ancestral condition, from which there were repeated evolutionary transitions and reversals. However, because the seeds of both winged and unwinged fruits are all dispersed by animals, we conclude that the repeated transitions in fruit morphology may relate to visual display strategies to attract animal dispersers, and do not represent transitions to wind dispersal.