Ethylene and expansin biosynthesis related genes polymorphism in local apple (Malus domestica Borkh.) cultivars from VIR Collection of plant genetic resources

I. N. Shamshin,A. A. Trifonova,A. M. Kudryavtsev,K. V. Boris,A. V. Shlyavas

doi:10.18699/vj18.408

Abstract

At Pushkin and Pavlovsk Laboratories of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) a diverse collec tion of local apple cultivars is maintained. Some of the cultivars are widely used in breeding programs for their ecological plasticity, increased adaptation to abiotic stress and disease resistance, still there have been no large-scale studies of these local cultivars for fruit storage ability. Fruit softening during storage is an important problem for apple production. Retention of desirable firmness after prolonged storage is one of the key requirements for new apple cultivars. Expansin and ethy lene biosynthesis related genes are known to be involved in control of fruit softening in apple, and gene specific molecular markers have been reported. In this study the polymorphism and allelic configuration of ethylene and expansin biosynthesis related genes Md-ACS1, Md-ACO1 and Md-Exp7 involved in control of fruit softening in 87 local apple cultivars from VIR Collection of Plant Genetic Resources were analyzed. PCR markers Md-ACS1, Md-ACO1 and SSR-marker Md-Exp7 were used in the study. The allele frequencies in the collection generally coincided with the data from previous studies. Md-ACS1 allele 2 associated with reduced ethylene production was found only in three local cultivars, while all the studied local cultivars were heterozygous for the Md-ACO1 locus, as well as most modern Russian apple cultivars. Half of the studied local cultivars were heterozygous for Md-Exp7 (198 : 202). Thirteen local cultivars with rare Md-Exp7 alleles (206, 210 and 212) were detected. No association was found between the Md-Exp7 genotype and the cultivars’ maturation time. The obtained results can be used for additional evaluation of the cultivars’ potential for breeding.

Highlights

Полиморфизм генов биосинтеза этилена и экспансина у местных и стародавних сортов яблони (Malus domestica Borkh.) из коллекции генетических ресурсов растений ВИР
The aim of this work was to study genetic diversity and allelic configuration of the ethylene and expansin biosynthesis genes (Md-ACS1, Md-ACO1 and Md-Exp7) involved in control of fruit softening in local apple cultivars from the ex situ collection of Pushkin and Pavlovsk Laboratories of VIR
For all the studied accessions, stable, clearly reproducible results were obtained from the three markers, and reference cultivars with known Md-ACS1, Md-ACO1 and Md-Exp7

Summary

Introduction

Полиморфизм генов биосинтеза этилена и экспансина у местных и стародавних сортов яблони (Malus domestica Borkh.) из коллекции генетических ресурсов растений ВИР. В настоящем исследовании проведен анализ аллельного разнообразия генов биосинтеза этилена и экспансина Md-ACS1, Md-ACO1 и Md-Exp, вовлеченных в контроль лежкости плодов у 87 местных и стародавних сортов яблони из коллекции генетических ресурсов растений ВИР. In studies of fruit softening in Russian and international apple germplasm collections, ethylene and expansin biosynthesis related genes markers are widely used (Nybom et al, 2013; Suprun, Tokmakov, 2013; Savel’ev et al, 2014a, b; Shamshin, Savelieva, 2014). The allelic composition of studied apple cultivars for the SSR marker was associated with differences in fruit softening: 198 bp (best firmness retention), 202 bp (intermediate) and 214 bp (worst) (Costa et al, 2008). Later screening of apple cultivars and species collections revealed some rare Md-Exp alleles with unknown effect on fruit softening (Nybom et al, 2012, 2013; Savel’ev et al, 2014b)

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