Localized graft incompatibility in pear/quince (Pyrus communis/Cydonia oblonga) combinations: multivariate analysis of histological data from 5-month-old grafts

Abstract

To characterize the structural events associated with incompatibility of graft development, we conducted a histological study of compatible and incompatible pear/pear and pear/quince grafts that had been grown for five months in a greenhouse. Multivariate analysis of histological data describing the structure of the graft union allowed us to discriminate between compatible and incompatible combinations before either macroscopic examination or qualitative microscopic examination differences between graft combinations became evident. The histological variables responsible for the discrimination between incompatible and compatible unions were related to three typical symptoms of graft incompatibility: bark discontinuity, which was the main feature; cambial dysfunction; and accumulation of starch in the scion. Little cell necrosis was observed at the interface of incompatible grafts at the 5-month stage of graft development. Multivariate analysis of histological data provides a new tool for studying early structural events resulting from the graft incompatibility response and for diagnosing early graft incompatibility.

Incompatibilidade de enxertia em Prunus

“…Está associada a uma má formação estrutural do ponto de união, podendo resultar em ruptura do enxerto (PINA & ERREA, 2009;PEREIRA, 2012), devido à necrose do tecido cambial ou da ausência de diferenciação do tecido vascular na linha de união do enxerto. Plantas com esse tipo de incompatibilidade apresentam desenvolvimento lento, proporcional ao grau de descontinuidade da união (ERMEL et al, 1999;HARTMANN, et al, 2010). Os sintomas externos são pouco evidentes, podendo tardar vários anos para que sejam identifi cados (PINA & ERREA, 2008).…”

Graft Compatibility Between European Pear Cultivars and East Malling “C” Rootstock

“…Graft unions may lead to incompatibility problems among the grafted parts of plants, there by resulting in more plant death. Many common pear cultivars exhibit graft incompatibility when grafted onto quince (ERMEL et al, 1999). The graft interface exhibits a vascular discontinuity that is associated with the presence of necrotic cells in the wood and bark, the inclusion of unlignified cells in the wood, and invaginations or breaks in the cambium.…”

Production of quince nursery trees by different grafting methods

“…However, the cleft grafting favors higher graft survival rate and faster shoot development (BARBOSA et al, 1996;1998). Other studies have reported the production of pear trees grafted onto quince by budding in the winter (ERMEL et al, 1999). On the other hand, in this research, budding accomplished in the summer led to higher sprout length, in spite of the smaller bud sprout percentage.…”