In vitro tissue culture of apple and other Malus species: recent advances and applications

Abstract

Main conclusion Studies on the tissue culture of apple have allowed for molecular, biotechnological and applied breeding research to advance. In the past 8 years, over 100 papers advancing basic biology, genetic transformation and cryobiology have emerged. Apple (Malus × domestica Borkh.; Rosaceae) is an important fruit crop grown mainly in temperate regions of the world. In vitro tissue culture is a biotechnological technique that has been used to genetically improve cultivars (scions) and rootstocks. This updated review presents a synthesis of findings related to the tissue culture of apple and other Malus spp. between 2010 and 2018. Increasingly complex molecular studies that are examining the apple genome, for example, in a bid to identify the cause of epigenetic mutations and the role of transposable elements in this process would benefit from genetically stable source material, which can be produced in vitro. Several notable or curious in vitro culture methods have been reported to improve shoot regeneration and induce the production of tetraploids in apple cultivars and rootstocks. Existing studies have revealed the molecular mechanism underlying the inhibition of adventitious roots by cytokinin. The use of the plant growth correction factor allows hypothetical shoot production from leaf-derived thin cell layers relative to conventional leaf explants to be determined. This updated review will allow novices and established researchers to advance apple and Malus biotechnology and breeding programs.

An efficient in vitro regeneration system from different wild apple (Malus sieversii) explants

“…Additionally, these methods can be used for the propagation of stress-tolerant somaclonal lines. Several in vitro micropropagation protocols have been established for apple by several research groups [12][13][14][15][16]. There has been research on micropropagation or tissue culture methods for M. sieversii.…”

Auxin and Its Interaction With Ethylene Control Adventitious Root Formation and Development in Apple Rootstock

“…M9-T337, an excellent rootstock widely used in commercial orchards, could lead to dwarf tree architecture, early fruiting, and high fruit yield and quality (Zhang et al, 2016). Since the apple genome is highly heterozygous, vegetative propagation is widely used for experimental and commercial propagation in apple rootstock (Teixeira et al, 2019). The induction of adventitious roots (ARs) is a prerequisite for vegetative propagation.…”

Phloroglucinol Improves Direct Rooting of In Vitro Cultured Apple Rootstocks M9 and M26

“…; Rosaceae) is an important fruit crop grown mainly in temperate regions of the world. In vitro tissue culture is a biotechnological technique that has been used to genetically improve cultivars (scions) and rootstocks [2]. An updated review presents a range of findings related to tissue culture of apple and other Malus spp.…”

“…An updated review presents a range of findings related to tissue culture of apple and other Malus spp. As in other plant species, micropropagation of apple generally includes four stages: establishment of in vitro cultures from ex vitro plants, shoot multiplication, rooting of microshoots, and acclimatization [2]. Obtaining high proportions of rooted and established plantlets from Malus cultivars is challenging, and micropropagation research has thus focused on rooting and physiology [1].…”

“…Phloroglucinol, a phenolic compound, is a growth regulator produced via degradation of phloridzin and is a precursor in the biosynthetic pathway of lignin. It promotes plant growth [2,13,14]. Phloroglucinol stimulates root development, root elongation, and induction of new roots in papaya [13] and banana [14].…”