Características vegeto produtivas e propriedades nutracêuticas em pêssego ‘brs-libra’ sob diferentes porta-enxertos

Abstract

The main form of production of commercial peach seedlings is through grafting, yet agronomic characteristics can be altered due to unknown genetic origin,.The objective of this work was to verify the vegeto-productive characteristics and nutraceutical properties of different clonal rootstocks grafted under scion cultivar BRS Libra and own-rooted cultivar BRS Libra. The experiment was carried out in an orchard located in the experimental area and in the fruit growing and post-harvest laboratory at UFFSChapecó. The orchard is composed of different cultivars of clonal rootstocks, and ownrooted BRS plants. The experimental design used was in randomized blocks, consisting of 22 treatments, being ‘Tsukuba-2’, ‘Clone 15’, ‘Nemared’, ‘Tsukuba-1’, ‘Barrier’, ‘Ishtara’ , ‘Cadaman’ , ‘Capdeboscq’ , ‘De Guia’, ‘Rosaflor’ , ‘G×N.9’, ‘Flordaguard’ , ‘Rigitano’ , ‘Tardio-01’, ‘P. mandshurica’ , ‘Tsukuba-3’, ‘Okinawa’, ‘Santa Rosa’, ‘México Fila-1’, ‘I-67-52-4’, ‘GF 677’, and own-rooted seedlings, with 4 replications each. The vegeto-productive variables analyzed were pulp firmness (FP), xylem water flow (FX), productivity (PD) dry mass of leaves (MS), fruit diameter (DF) and height (AF), trunk diameter(DT), and annual increment index(IA). The physicochemical and nutraceutical properties evaluated were soluble solids (SS), total sugars (AT), reducing sugars (AR), ascorbic acid (AA), and total phenolic compounds (CF). Higher values of FP ranged from 35.70 to 29.65 N. The average height of the fruit was greater than its diameter in all the rootstocks used. The ‘own-rooted BRS’, ‘De guia’, ‘Flordaguard’, ‘Gx N.9’, ‘Rosa Flor’’, Tsukuba-2’, and ‘Tsukuba-3’ rootstocks showed higher productivity, with an average of 35.95 t/ha. For the xylem (leaf) water potential of the scion under the rootstock, ‘Okinawa’ showed the lowest xylem water flow, while ‘Nemared’ and ‘Flordaguard’ induced higher xylem flow. Higher DT above grafting point and IA in the years 2020 and 2021 were observed for ‘Mexico Fila-1’, as well as greater trunk development below the grafting point. For leaf dry matter, there was no relationship between nutrient accumulation and productivity. Higher concentration of soluble solids were observed for the ‘GF 677’, ‘Clone 15’, ‘De guia’, ‘Okinawa’, and ‘Rigitano’ rootstocks, with an average of 12.11° Brix. Greater ascorbic acid accumulation was observed for ‘Okinawa’, ‘Capdebosq’,and ‘Tsukuba-1’ rootstocks, with values between 11.58 and 14.71 g/100 mL-1 . As for the total phenolic compounds, the rootstock ‘Santa Rosa’ had the highest content with 199.83 mg EqAG 100g-1 sample. For reducing sugars, fruits from the rootstock cultivar 'Santa Rosa', followed by ‘Rigitano’, ‘Nemared’ and ‘Clone 15’, showed the highest concentration with an average of 5.55%, and the lowest value was found for ‘own-rooted BRS’. For total sugars, higher values were found for ‘Okinawa’, ‘México Fila-1’, ‘Santa Rosa’, and ‘Ishtara’, with an average of 5.34%, and the lowest value was observed for ‘Nemared’. Clonal rootstocks alter the vegeto-productive performance and chemical composition of fruits under 'BRS-Libra'.Self-rooted plants are viable for planting in orchards and as rootstock cultivars 'Okinawa' and 'Santa Rosa' excelled in the nutraceutical variables.