Effects of monochromatic red and blue light-emitting diodes and phenyl acetic acid on in vitro mass production of Pyrus communis ‘Arbi’

Abstract

Purpose: In Tunisia, Pyrus communis ‘Arbi’ is broadly imperiled by Erwinia amylovora. The breeding of resistant rootstocks is an effectual control strategy for disease management. Therefore, a sound protocol for micropropagation and for the extensive production of high-quality plantlets was developed. Research method: Three groups of LED treatments were carried out: (1) 100% blue (B) LED, (2) 100% red (R) LED and (3) 50% B + 50% R (=BR) LED. Stock plants were micropropagtaed on modified Murashige and Skoog (MS) medium with half concentration of NH4NO3 and KNO3. Findings: Throughout the propagation stage, red LED displayed important advantages: it produced optimal shoot height and leaf surface. The least leaf area was obtained with fluorescent light. The blue / red combination yielded considerable amelioration. Shoot weight/callus weight was maximal, along with shoot number and shoot length. The root formation of in vitro grown pear plantlets was greatly influenced by the various light types and by the incorporation of a new root-promoting substance, phenyl acetic acid (PAA). When combining red light and PAA, 89 % of rooting was observed in pear plantlets. The acclimatized pear vitroplants achieved rapid growth without morphological anomalies. Research limitations: In order to improve the survival rates of the acclimatized vitroplants, the acclimatization stage needs to be further studied. Originality/Value: The study compared the impact of different combinations of monochromatic blue and red LED lights and phenyl acetic acid against that of fluorescent light during the micropropagation, rooting and acclimation of a resistant pear (Pyrus communis L., cv. Arbi).

Keywords

• acclimation
• led
• pyrus
• rooting
• shoot multiplication