Promotion by Jasmonic acid of bulb formation in shoot cultures of Narcissus triandrus L.

Abstract

The in vitro bulb formation by shoot clumpcultures of N. triandrus on media with jasmonicacid (JA) alone or in association with both2-isopentenyladenine (2-iP) or naphthalene acetic acid(NAA) and on medium with only NAA was studied. Themedia with JA plus 2-iP or JA plus NAA caused a highmultiplication of leaves, significantly higher on thatwith 2-iP. Leaf proliferation was low on medium withJA alone. The media containing JA promoted theformation of a bulb at the base of the leaves and thebulbs attained different sizes. On the medium with JAplus NAA, the number of bulbs that reached up to 5 mmin diameter was higher than that on the medium with JAplus 2-iP, but the highest number was formed on themedium with JA alone. The medium with NAA alone led tothe formation of few small bulbs that were elongatedinstead of roundish as those formed on media with JA.Further culture of the bulbs on a growth mediumsuitable to their enlargement increased their size butthe dimensions attained were dependent upon the mediuminitially used for bulb formation. Bulbs derived frommedium with JA alone attained the largest diameter.Almost all the bulbs grown on the growth medium wererooted. Data described here show that JA promotes in vitro bulb formation in shoot cultures of N.triandrus and suggests that JA might play animportant role in the formation and enlargement ofbulbs in Narcissus plants.