Impacts of passion fruit woodiness disease (Cowpea Aphid-Borne Mosaic Virus) on single-leaf gas exchange of Passiflora edulis.

Passion fruit woodiness disease (PWD) is primarily caused by potyviruses (Cowpea Aphid-Borne Mosaic Virus) and is considered the most economically important and a limiting factor for passion fruit production in Brazil. Understanding the effects of the infectious process on the host is one of the goals of parasitism physiology. The experiment was conducted at the commercial panting in Rio de Janeiro state, Brazil, with 10 healthy plants of yellow passion fruit (Passiflora edulis) [control (CTL) leaf], cv. FB200 with 7 months of age (beginning of fruit production), and 10 plants with PWD were selected. Leaves of field-grown passion fruit plants infected with PWD were selected to determine its influence on single-leaf gas exchange. Leaf stomatal conductance, transpiration and net CO2 assimilation rate were reduced by PWD infection. Negative effects on single-leaf gas exchange in the yellow passion fruit supported our initial hypothesis that PWD cause impacts on stomatal conductance, transpiration, and net CO2 assimilation rate. These results suggest that reduced growth, yield, and fruit quality in PWD-infected passion fruit plants is caused, at least partially, by reduced single-leaf gas exchange.