EARLY DETECTION OF COMPATIBILITY OF GRAFTS OF GUAVA (Psidium guajava L.) THROUGH BIOCHEMICAL ANALYSIS

Abstract

Objective: To evaluate the compatibility of different guava selections grafted on Cass and Nayarit through the concentration of total soluble sugars (TSS) and total phenolic compounds (TPC).
Design/methodology/approach: Three guava genotypes were used and grafted onto two rootstocks: Nayarit and Cass. Two types of grafts were evaluated: approach and inverted thorn. After six months of grafting, samples were taken from different sections of the stem above and below, and at the graft union. TSS concentration was carried out spectrophotometrically using Anthrone method; glucose, fructose and sucrose were determined enzymatically by the sequential addition of hexokinase, phosphoglucose isomerase and invertase. TPC determination was made by the redox
reaction of Folin-Ciocalteu.
Results: The highest concentration of TSS was observed in the combination of Roja Exterior Redonda (RER)/Nayarit and the lowest concentration in the RER/Cass combination, sucrose was the sugar found in highest concentration. The concentration of TPC was higher in Enana Roja Cubana/Nayarit, while in the combinations grafted on Cass were lower. The inverted thorn graft showed the highest concentration of TSS, but in the approach grafting, it had a higher concentration of TPC.
Limitations of the study/implications: A more detailed study is required on the type and content of phenolic compounds that may affect the graft in the future.
Findings/conclusions: These analyzes allow establishing the affinity of grafted plants at an early age.