Efeito da interação entre copa e porta-enxerto na minienxertia de citros

Abstract

Mini-grafting is a technique that, in addition to enabling the regeneration of plants obtained and improved in vitro, also allows the acquisition of disease-free seedlings in a short period, constituting a useful tool for genetic improvement and propagation in citrus, the rootstock being a fundamental factor. The present study aimed to analyze the the union of plant tissues and development of mini-grafted canopy varieties on different citrus rootstocks, aiming to establish an efficient protocol of the mini-grafting technique, in addition to evaluating the biometric and emergence characteristics of the rootstock varieties. The experiments comprised the tangerine canopy varieties 'Ponkan' and 'Mexiraca' and the tangerine rootstocks 'Sunki Tropical', HTR - 051 and citrandarin 'Índio - 256'. For mini-grafted plants, the graft diameter (mm) at 1 cm above the grafting region, crown height (cm), number of green and senescent leaves, percentage of mini-graft survival and growth of crown height and diameter were analyzed . The rootstocks were evaluated by the variables number of seedlings emerged per tube, percentage of emergence, height of shoot (cm), stem diameter (mm), number of green leaves and number of senescent leaves. The rootstock evaluations took place 120 days after sowing, and the mini-grafts two and six months after the mini-xetia. For the rootstocks, the highest seedling emergence rate was from the 'Sunki Tropical' Tangerine tree, which also showed good results for the variables number of green and senescent leaves. With the mini-grafted plants it can be concluded that for the 'Ponkan' mandarin canopy the best combination was with the 'Sunki Tropical' mandarin, and for the 'Mexerica' mandarin canopy, the Citrandarin 'Índio' stood out, therefore, high graft setting after six months.