Use of X-ray Mutagenesis to Increase Genetic Diversity of Zantedeschia aethiopica for Early Flowering, Improved Tolerance to Bacterial Soft Rot, and Higher Yield

Noam Reznik,Michal Sharon-Cohen,Gavriel Friesem,Iris Yedidia,Nir Carmi,Shoshana Weizman,Bijaya Sharma Subedi

doi:10.3390/agronomy11122537

Abstract

The development of new cultivars is important for the profitability of the floriculture industry. There is a limited number of cultivars of Zantedeschia aethiopica, an iconic ornamental cut flower, garden plant, and potted plant, because of the incompatibility of interspecific crossings within the genus. Most present-day varieties are the result of spontaneous mutations or classical breeding within the species, followed by a long selection process. Here, Z. aethiopica mutants were generated by treating seeds with 100 Gy of X-ray radiation. The resulting putative mutants were selected based on particular flowering parameters and compared to nonirradiated, control plants. Over two growing seasons, characteristics such as early flowering, flower size and shape, yield, and response to soft-rot disease were monitored, and considerable variation was observed among the mutated lines. Out of 319 mutants, 20 lines were selected based on their phenotypes and then propagated and further analyzed. Within this group, only two phenotypes displayed at least five improved flowering properties under natural Mediterranean conditions. The rest displayed two to four desired combinations of flowering traits, some with great commercial potential.

Highlights

Zantedeschia aethiopica (L.) Spreng., known as arum lily or calla lily, is an iconic ornamental, herbaceous perennial with high yields that grows well in a variety of soils [1].The genus Zantedeschia belongs to the family Aracea and is native to southern Africa
One of the major threats to Z. aethiopica crops around the world is the soft-rot disease caused by Pectobacterium spp., Z. aethiopica is more resilient than the colorful Zantedeschia hybrid (Aestivae) group [6,7,8]
Pcb1692 was cultivated in lysogenic broth (LB; Difco Laboratories, Detroit, MI, USA) at 28 ◦ C and inoculated in minimal medium (MM) as described [18]

Summary

Introduction

Zantedeschia aethiopica (L.) Spreng., known as arum lily or calla lily, is an iconic ornamental, herbaceous perennial with high yields that grows well in a variety of soils [1].The genus Zantedeschia belongs to the family Aracea and is native to southern Africa. Zantedeschia aethiopica (L.) Spreng., known as arum lily or calla lily, is an iconic ornamental, herbaceous perennial with high yields that grows well in a variety of soils [1]. Letty [4,5] grouped the species into two informal sections: Zantedeschia, containing two species of the evergreen Z. aethiopica and the summer dormant Z. odorata, both with white spathes and rhizomatous storage organs; and Aestivae, containing six winter-dormant species with colored spathes and tuberous storage organs [4,5]. One of the major threats to Z. aethiopica crops around the world is the soft-rot disease caused by Pectobacterium spp., Z. aethiopica is more resilient than the colorful Zantedeschia hybrid (Aestivae) group [6,7,8]. A major factor enabling commercial development of high-value cultivars is the species’ breeding potential, but unlike members of the Aestivae group, which can

Objectives

Methods

Results

Conclusion