Paper Details

Abstract

UCB-1 (Pistacia integerrima × P. atlantica) is a prominent, stress-tolerant hybrid rootstock widely used for pistachio cultivation worldwide due to its vigorous growth, high productivity, and superior adaptability to diverse soil conditions. The purpose of the current study is to develop and to optimize a rapid and efficient in vitro propagation protocol enabling its efficient large-scale production. This protocol was established through a sequential evaluation of the effects of basal media mineral composition (POM, MS, and WPM), the impact of cytokinin type (mT, TDZ, BAP, and ZT) and concentration (0.5, 1.0, 1.5, and 2.0 mg/L), the combined effect of two cytokinins (mT and BAP), and the effect of an ethylene inhibitor, namely AgNO₃, on UCB-1 in vitro proliferation and elongation. The highest multiplication rate (MR) of UCB-1 shootlets (2.55) was obtained with TDZ at 2 mg/L. However, the combination of mT and BAP at equal doses (0.75 mg/L each) produced the best overall proliferation response, achieving the highest MR (3.53) and fresh weight (5.04 g). The negative impact of ethylene was alleviated by adding 2 mg L⁻¹ silver nitrate (AgNO₃), which reduced shoot necrosis and improved growth, vigor, and quality. In vitro rooting on POM medium was influenced by auxin type and concentration. The highest rooting rate (55%) occurred with 0.5 mg/L IBA, whereas 1.5 mg/L IBA promoted the fastest root induction (14.33 days) and the longest roots (117.61 mm). Ex vitro rooting using peat alone was highly effective and cost-efficient, achieving a 69.23% rooting rate. During acclimatization, peat alone (S1) outperformed the mixture of 2/3 peat + 1/3 perlite (S2), with a survival rate of 53% after ten weeks. This protocol provides an efficient and scalable method for UCB-1 micropropagation, supporting its large-scale use in pistachio production.

To Cite This Article