Avaliações fisiológicas de híbrido de maracujazeiro amarelo enxertado em maracujazeiro silvestre submetido ao déficit hídrico

Abstract

The current water crisis is a major concern for most of the world's nations, transposing the geographical boundaries of the arid and semi-arid regions. In this case, the cultivation of yellow passion fruit in regions with low availability of water resources should prioritize the development of new genetic materials more tolerant to water stress, as well as the use of grafting among productive cultivars and wild species more resistant to the water deficit, to improve the efficiency of water use without compromising the production. Like this, objective was to evaluate the influence of the P. gibertii rootstock on the initial growth of yellow passion fruit hybrid BRS GA1 and also on the responses to water deficit. The study was conducted in the experimental area of the Federal Institute of Bahia, Guanambi Campus, In pots under nursery of seedlings, following a completely randomized design (DIC), with the use of a yellow passion fruit hybrid BRS GA1 (Passiflora edulis f. flavicarpa), a hybrid of passion fruit BRS GA1 grafted on wild passion fruit (Passiflora gibertii N. E. Brown) and wild passion fruit submitted to water suppression for 12 days, constituting in three treatments and ten repetitions. Were measured the gas exchanges and phytotechnical number of leaf nodes, number of leaves and length of main branches. The yellow passion fruit hybrid (BRS GA1) grafted on wild passion fruit P. gibertii, is less sensitive to water deficit compared to the yellow passion fruit hybrid (BRS GA1). The BRS GA1 X P. gibertii graft, compared to the giant yellow passion fruit (BRS GA1), presented greater instant efficiency of water use (A/E), of carboxylation (A/Ci), photochemistry (A/QLeaf) and greater assimilation of CO2 (A). The graft BRS GA1 X P. gibertii, compared to the giant yellow passion fruit (BRS GA1), presented better responses of the physiological characteristics of stomatal conductance (gs), photosynthesis (A), water use efficiencies (A/E), carboxylation (A/Ci) and photochemistry (A/QLeaf), in the occurrence of variations of air humidity and temperature. In relation to the yellow passion fruit hybrid without grafting, the grafted passion fruit (BRS GA1 X P. gibertii) has less photoinhibitory damage to FSII when submitted to severe water deficit