The objeticve of this research was to determine a more efficient way of micrografting in vitro Araucaria angustifolia plants. Autografting was performed onto 2, 6- and 12- month- old in vitro germinated plants. Two different graft types (saddle with or without slit) were perfomed on two different plant parts (stem or hypocotyl). Higher percentage of open slit micrografts was observed when micrografting was performed onto hypocotyls. Higher percentage of surviving micrografts was obtained when micrografting was perfomed on stem; the saddle without slit technique was the most efficient. Callus formation resulted from the combination of the three tested factors. However, more visible calluses were present in micrograftings perfomed on hypocotyls. Growth of the micrograftings was an indication of vascular connection recovering. Better growth was observed whem micrograftings were slit saddled onto 6-month-old stems. The methodology tested herein allowed us to conclude that the micrografting process is effective and efficient and may be used for production of Araucaria angustifolia micrografted plants.
parana-pine; biotechnology; micropropagation; tissue culture
