Hybridisation of Malus sylvestris (L.) Mill. with Malus × domestica Borkh. and Implications for the Production of Forest Reproductive Material

Mateja Kišek,Robert Brus,Kristjan Jarni

doi:10.3390/f12030367

Abstract

This study focuses on the morphological and genetic characteristics of European crab apple (Malus sylvestris (L.) Mill.) and the occurrence of hybrids in its populations. We analyzed a total of 107 putative European crab apple trees in Slovenia: 92 from nine natural populations, five from a seed stand and 10 from a stand of unnatural origin. We also included 18 domesticated apple trees (Malus × domestica Borkh.) and two Japanese flowering crab apple trees (Malusfloribunda van Houtte) as outliers. The trees were classified into groups of European crab apples, hybrids and domesticated apples according to their morphological and genetic characteristics. Classification based on morphological traits produced different results (58.75% European crab apple, 37.11% hybrids and 4.14% domesticated apple) compared to those based on genetic analysis (70.10% European crab apple, 21.64% hybrids and 8.26% domesticated apple). When genetic and morphological characteristics were combined, only 40.20% of the trees were classified as European crab apple, and an additional group of feral cultivars of domesticated apples (6.18%) was identified. The analysis revealed that hybridization with domesticated apple is taking place in all studied natural European crab apple populations; however, hybrids and feral cultivars only occur to a limited extent. When introducing European crab apple into forests in the future, only genetically verified forest reproductive material obtained exclusively from suitable seed stands should be used.

Highlights

European crab apple (Malus sylvestris (L.) Mill.) is a tree species that occurs individually in forests and is the only indigenous species of the genus Malus Mill. in Europe
The analysis revealed that hybridization with domesticated apple is taking place in all studied natural European crab apple populations; hybrids and feral cultivars only occur to a limited extent
The first component is most influenced by the leaf width at 70% and 80% of the leaf surface length (W70% and W80%) and the second at 5% and 15% of the leaf surface length (A5% and A15%) (Table 3)

Summary

Introduction

European crab apple (Malus sylvestris (L.) Mill.) is a tree species that occurs individually in forests and is the only indigenous species of the genus Malus Mill. in Europe. European crab apple (Malus sylvestris (L.) Mill.) is a tree species that occurs individually in forests and is the only indigenous species of the genus Malus Mill. It is a light-demanding species and prefers to grow as an individual specimen, mostly on forest edges [1]. Because of its contribution to the rapid regeneration of forests, European crab apple has a large impact on the stability of the forest ecosystem in the event of a major disruption [2]. The resulting increase in forest clearings and forest edges will create good ecological conditions for the growth of European crab apple

Methods

Results

Discussion

Conclusion