IN VITRO PR0PAGATION AND GRAFTING TECHNOLOGY PROMOTE ROOT INITIATION, SHOOT PROLIFERATION AND GRAFTING OPERATION OF VOLKAMER LEMON CITRUS ROOTSTOCK (Citrus volkameriana Ten. )

Abstract

The in vitro response of shoot tip and epicotyl explants from Volkamer lemon Citrus rootstock (Citrus volkameriana Ten) coupled with shoot tip micro-grafting were observed for the first time. Further analysis was performed to verify the in vitro shoots and roots proliferation in these explants under different treatments. It were observed there different patterns of morphogenic shoots and roots gradient between the two tested explants noticed. These different patterns were influenced by factors related to explants type and the composition of the culture medium either for shoots or roots proliferation. The epicotyls could be used as source of explants for micro-propagation of Volkamer lemon to improve the efficiency of shoots and roots production with higher qualities. Culturing medium to in vitro best shoot proliferation was MS (1962) basal medium at full strength supplemented with BAP at 1.5mg/L and Kin at 1.00 mg/L plus a fixed 0.50 mg NAA/L. The statistical analysis technique used to indicate the effect of each growth regulator applied either solely or in combinations confirmed the superiority of BAP during proliferation stage as the limited factor affecting proliferated shoot characteristics on both explants type. Medium to best in vitro rooting was that of the same basal medium containing IBA and NAA at 2.00mg/L each plus a fixed 0.50 mg Kin/L. Micro-grafting study of Washington navel and Valencia scions onto Volkamer lemon rootstock through the measurements of three parameters, are known to be good measures for evaluating the graft compatibility between the two partners, obviously cleared that Valencia scion onto this rootstock is more compatible than Washington navel scion onto the same rootstock.