Formas de fósforo no tecido de videiras: acúmulo, redistribuição e relação com parâmetros produtivos e composição da uva

Abstract

In grapevine production, requirement and phosphorus (P) doses are established on the basis total P content in leaves collected, change in color of fruit and productivity. Phosphorus absorbed, can be accumulated in plant organs in organic forms as metabolically active organic P in the cytoplasm (PSO), phospholipids (PLIP), P associated with RNA and DNA (PRNA and PDNA), phosphoprotein (PRES) and inorganic P (PSI). However, in adult grapevine, production is not known satisfactorily that increase in available P content in soil can enhance P in leaves and other annual and perennial parts of plant collected at different growth stages. The study was aimed to quantify the accumulation and redistribution of P forms in grapevine throughout its production cycle and evaluate the forms of P in leaves related to production parameters and grape composition. Two experiments were performed in vineyard 1 (V1) and vineyard 2 (V2) containing 11,8 and 34,6 mg P kg-1 of soil respectively with two cultivars of grapevine Tannat and Cabernet Franc. The plants were uprooted and separated into roots, stems, branches, groins, shoots, and leaves and flowering (F), early maturation (EM), harvest (H) and dormant (D) and each plant part was analyzed for P fractions (PSI, PSO, PLIP, PRNA, PDNA and PRES). Study 2 consisting of two experiments was conducted vineyard 1 (V1) and vineyard (V2) with 16,0 and 37,0 mg P kg-1 of soil to evaluate whether P forms in leaves collected in the F and EM are related to productive and enological parameters in vines grown on soils with values of available P in both cultivars Tannat and Cabernet Franc. At harvest, production parameters, number of fruits (FN) and 100 fruits weight (FW) were measured. Part of the grapes were crushed by hand and must was analyzed the total soluble solids (TSS), pH, titratable acidity (TA), total polyphenols (PF) and anthocyanins (AC). Results from study 1 show that grapevines P is preferentially accumulated in the form PSI in the leaves and bunches at F, EM and H and roots in PSO way in D. Part PSI roots is redistributed on the FL to the leaves and grapes vines grown in soil with low P availability, but on the other hand, grapevines grown in soil with high availability of P tend to redistribute least PSI from roots to leaves and bunches after F. In study 2, we found that grapevines grown in soil with high P content available soil have higher PT Tannat grapevines and higher levels of total polyphenols and anthocyanins. The total P content in leaves and their biochemical forms in leaves collected in the F and M have no relation to production parameters. But total P content in leaves at flowering and early maturation has relationship with the AC content in the Tannat grapevines.