Micropropagation of the potential blueberry rootstock—Vaccinium arboreum through axillary shoot proliferation

Abstract

Vaccinium arboreum is adapted to soils with low organic matter and high pH. It is considered as a potential blueberry rootstock. The objective of this research was to establish a rapid mass propagation protocol of V. arboreum through axillary shoots proliferation with minimum somaclonal variation. Nodal segments from cuttings were cultured on Driver and Kuniyaki walnut medium (DKW) with different cytokinins for initial culture establishment. DKW, woody plant medium (WPM), and Long and Preece medium (LP) were compared for best shoot proliferation. Zeatin (ZT) concentrations from 0 to 4.56 μM were evaluated for optimizing the concentration. Both in vitro and ex vitro rooting were evaluated. The pH tolerance of in vitro shoots was investigated by adjusting the media pH from 5 to 8.5. Best shoot proliferation was achieved by LP medium supplemented with 2.28 μM ZT and 0.05 μM indole-3-butyric acid (IBA). In vitro shoots proliferated best on medium pH 5, though the shoots could survive on pH 8. All the micropropagated shoots successfully rooted by ex vitro rooting after dipping with auxin. All rooted plantlets acclimatized and grew well in greenhouse. Micropropagation through axillary shoots proliferation is an efficient method to propagate true-to-type V. arboreum in large number for future use as rootstock.