Apricot micropropagation

Apricot (Prunus armeniaca L.) is the second most important species of the stone fruits, although far behind peach and very much geographically located by its peculiar ecological needs. During the last years the world production of apricot fruit has oscillated around 2.5 million tons, and more than half of world production concentrated in the Mediterranean basin countries.

Micropropagation has been applied to the commercial production of fruit and nut crops since the late 1970s. Initially, it was used for small (soft) fruit crops such as strawberry and raspberry and for the rootstocks of several tree fruit species, especially peach (Zimmerman & Debergh, 1991). Apricot is well suited for in vitro propagation because cuttings are difficult to root and scions are currently budded onto apricot seedlings (Reighard et al., 1990). Therefore, growing apricots on their own roots appears to be a logical undertaking. Very little, however, has been reported on the tissue culture of this species and most of it is relatively recent. Most commercial production of micropropagated fruit trees has been focused on the production of rootstocks. Although grafting of scions onto seedling rootstocks is a common practice, the production of scions on their own roots has been limited. To our knowledge, apricot cultivars have never been commercially micropropagated, and also apricot rootstocks. Only one small Spanish company has been producing small quantities of selected apricot cultivars on their own roots, for the last 2 years. Here we describe a protocol containing different steps necessary to micropropagate apricot cultivars. It has proven useful for most cultivars tested although often some parameters have to be optimized for each single cultivar. When parameters depended on the genotype, it is indicated in the text and a range is provided.