Comparison of in vitro plantlet regeneration aptitude of three Citrus species from cultured nodal segments via organogenic mode

摘要

Nodal segments excised from in vitro germinated seedlings of three citrus species viz: Citrus aurantiafolia, Citrus reticulata and Citrus sinensis were cultured on different fortifications of basal MS medium for multiple shoot proliferation. In vitromorphogenesis leading to plantlet regeneration varied considerably among species and with medium composition. In the present study, plantlets were regenerated directly via auxiliary bud proliferation as well as from callus culture. Induction medium MS5N.5B/MS5N.Kn (MS + 5.0 mgL'1 NAA + 0.5 mgL]BA/Kn) induced callusing in higher frequencies. Culture medium MS.lTd.5N/MS.5B.5N (MS + 0.1 mgL1 TDZ/0.5 BA + 0.5 mgl"1 NAA) enhanced shoot proliferating efficiency. Shoot (s) per explant in higher number (s) of higher length were documented on medium MS.lTd or MS.2Td (MS + 0.1/0.2 mg L"1 TDZ). Higher root proliferating efficiency was recorded on rooting medium MS.5IB (MS + 0.5 mg L"1 IBA). Roots in higher frequency were observed on culture medium MS2IB.5Kn (MS +2.0 mg L"1 IBA + 0.5 mg L"1 Kn), while culture media MS.5IB.5B (MS + 0.5 mg L1 IBA + 0. 5 mg L'1 BAP) enhanced mean root length. In terms of interspecific in vitro response, in general, Acid lime followed by Mandarin and Sweet orange responded decisively for the most of the culture phases. The in vitro raised plantlets were successfully acclimatized and transferred to the field.