Analysis of strawberry genetic collection (Fragaria L.) for Rca2 and Rpfl genes with molecular markers

I V Luk’Yanchuk,A S Lyzhin,I I Kozlova

doi:10.18699/vj18.423

Abstract

Strawberry (Fragaria x ananassa Duch.) varieties are susceptible to many fungal diseases. Identification of forms, carrying resistance genes, is an important stage in breeding programs leading to resistant varieties. The use of molecular markers allows to determine with high reliability the presence of the necessary genes in the genome and to identify promising forms. Some of the common strawberry's diseases, causing significant damage to strawberry plantations, are anthracnose (Colletotrichum acutatum Simmonds) and red stele root rot (Phytophthora fragariae var. fragariae Hickman). Dominant Rca2 gene is involved in monogenic resistance to C. acutatum pathogenicity group 2. Rpf1, Rpf2, Rpf3 genes are determined in monogenic resistance to red stele root rot. The purpose of this study was molecular genetic testing genotypes of genus Fragaria L. to identify carriers of Rca2 allele anthracnose resistance and Rpf1 allele red stele root rot resistance. The objects of study were the wild species of the genus Fragaria L. and strawberry varieties (Fragaria x ananassa Duch.) of different ecological and geographic origin. To assess allelic state Rca2 anthracnose resistance gene the dominant SCAR marker STS-Rca2_240 was used, was linked to the resistance gene Rca2 with a genetic distance of 2.8 cM. Rpf1 gene red stele root rot resistance was identified with the dominant SCAR marker R1A, was linked to the resistance gene Rpf1 with a genetic distance of 3.0 cM. The resistant allele of the marker STS-Rca2_240 was identified in the Laetitia variety (Rca2Rca2 or Rca2rca2 genotype), which allows us to recommend it as a promising source in breeding for anthracnose resistance. The other studied forms have homozygous recessive state of the marker STS-Rca2_240 (putative genotype rca2rca2). The resistant allele of the marker SCAR-R1A in the varieties and wild species of strawberry under study is absent, which presumably indicates their homozygous recessive genotype of Rpf1 gene (rpf1rpf1).

Highlights

Сорта земляники садовой (Fragaria × ananassa Duch.) восприимчивы ко многим грибным заболеваниям
The objects of study were the wild species of the genus Fragaria L. and strawberry varieties (Fragaria × ananassa Duch.) of different ecological and geographic origin
For the last years the pathogens of anthracnose and red stele root rot being tested in strawberry plantings of Russia and besides Phytophthora fragariae var. fragariae is included in the list of Quarantine pests, weeds and plant diseases in Russia (Aleksandrov et al, 2007; Golovin, 2014; Dudchenko et al, 2015)

Summary

Introduction

Сорта земляники садовой (Fragaria × ananassa Duch.) восприимчивы ко многим грибным заболеваниям. Для оценки аллельного состояния гена Rca устойчивости к антракнозу использовали доминантный SCAR-маркер STS-Rca2_240, локализованный на расстоянии 2.8 cM от гена. Для выявления гена Rpf устойчивости к фитофторозной корневой гнили использовали доминантный SCAR-маркер R1A, находящийся на расстоянии 3.0 cM от гена. Доминантный аллель маркера STS-Rca2_240 идентифицирован у сорта Laetitia (генотип Rca2Rca или Rca2rca2), что позволяет рекомендовать его в качестве перспективного источника устойчивости к антракнозу для селекции. Anthracnose (Colletotrichum acutatum Simmonds) and red stele root rot The most of commercial strawberry varieties of foreign breeding are susceptible to anthracnose and red stele root rot (Van de Weg, 1997a; Denoyes-Rothan et al, 2005). For the last years the pathogens of anthracnose and red stele root rot being tested in strawberry plantings of Russia and besides Phytophthora fragariae var. The occurrence of pathogen can be observed mainly after using of infected planting material, and the oospores can persist in soil in the absence of host plant according to the different data from 3 to 17 years (Duncan, Cowan, 1980ж Szkuta, 2006)

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