Can the Caper (Capparis spinosa L.) Still Be Considered a Difficult-to-Propagate Crop?

Francesco Sottile,Chiara Caltagirone,Maria Beatrice Del Signore,Ettore Barone,Cristiana Peano

doi:10.3390/horticulturae7090316

Francesco Sottile, Chiara Caltagirone + Show 3 more

Open Access

https://doi.org/10.3390/horticulturae7090316

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Journal: Horticulturae	Publication Date: Sep 16, 2021
Citations: 15	License type: CC BY 4.0

Affiliation: University of Palermo, University of Turin

Abstract

As a perennial xerophytic shrub, characterized by plesiomorphic features, the caper (Capparis spinosa L.) is naturally spread throughout the Mediterranean basin and occupies an important ecological role, as well as an economic one, in traditional and specialized systems for commercial production. This species, in spite of its wide diffusion, is currently considered at risk of genetic erosion, mainly due to overgrazing and overharvesting for domestic uses and for trade. This situation is made more serious because of the lack of efficient propagation techniques, determining the caper as a “difficult-to-propagate species”. In this review, we report the main available sexual and vegetative propagation techniques with the aim of assessing whether, and to what extent, this criticality is still true for caper as a horticultural crop. In terms of seed propagation, germination rates have generally been considered quite low or unsatisfactory, and are also affected by hybridization phenomena that are likely to occur among both the wild and cultivated forms. The seeds show a physiological dormancy that can be lowered by adopting hormonal treatments, but in situ germination remains a critical phase. Vegetative propagation appears quite effective, mostly as related to in vitro techniques that allow caper cultivation that is no longer affected by propagation for an economic dissemination of the species in more intensive orchards. The research needs for Caper spinosa L. as a horticultural crop, especially in the field of genetic improvement and breeding, are also underlined.

Highlights

The caper (Capparis spinosa L.) is one of about 250 species of the genus of xerotropical origin belonging to the family Capparaceae, widely distributed from the Mediterranean eastwards to Central and Southeast Asia, Australia and Oceania [1]
7 ofand are exclusively rooted in the nursery where the use of bottom-heated systems and intermittent mist propagation techniques are recommended [37]
The best rooting results (100% of rooted explants) were obtained when explants were dipped for 10 min in 50 μM IBA solution and successively maintained in plant growth regulators (PGRs)-free medium

Summary

Introduction

The caper (Capparis spinosa L.) is one of about 250 species of the genus of xerotropical origin belonging to the family Capparaceae, widely distributed from the Mediterranean eastwards to Central and Southeast Asia, Australia and Oceania [1]. We describe the main available propagation techniques and the main factors influencing the results by reviewing the most relevant literature regarding both sexual and vegetative hazard [27], by enhancing landscape sustainability, water conservation [28], rehabilitation of rangelands and desert lands and dune stabilization [29,30] and by preventing fires from spreading [31]. These features make this species of potential strategic interest as an adaptive crop in a climate change context [32]. The underlying hypothesis is that the caper industry is, from an agronomic point of view, still in its infancy and that, some of the “traditional” propagation systems still widely utilized may be no longer valid for modern and specialized caper cultivation

Seed Propagation

Vegetative Propagation

In Vitro Propagation

Findings

Conclusions