| heal.abstract |
Studies on micropropagation of Malosorbus florentina revealed difficulties for in vitro rooting. Attempting to improve rooting percentages and reduce microshoot tip necrosis the use of IAA alone or in combination with IBA was tested, as well, as darkness during the first week of culture and addition of activated charcoal (AC) into the culture medium. One week-culture on solid media with low concentration of auxins (0.5 or 1 mg/L IBA and 4 or 8 mg/L IAA) before transferring to a hormonefree medium improved rooting (25-67%) as compared to one week culture on medium with plain IBA (0.5 or 1 mg/L) or IAA (2-20 mg/L). Dipping the base of microshoots in solutions with high concentration of auxins (500-1,000 mg/L IBA and 250-1,000 mg/L IAA) for 10 sec before culture on hormone-free 1/2MS presented lower rooting rates (0-19%) than dipping in 1,000 mg/L IBA solution (18-27%). Darkness during the first week of culture improved rooting percentages but led to increased callus formation simultaneously. AC completely inhibited rooting when added during the first week of culture in solid medium with low concentration of auxin, while it had no effect after the transfer to hormone-free medium supplemented with AC. Culturing microshoots on a hormone-free medium with AC after dipping their base in a dense solution of auxin (500-1,000 mg/L IBA and 250-1,000 mg/L IAA) led to reduced shoot tip necrosis. |
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