TY - JOUR

T1 - Elucidating the genetic mechanisms underlying tolerance to apple replant disease (ARD)

AU - Reim, S.

AU - Cestaro, A.

AU - Winkelmann, T.

AU - Flachowsky, H.

N1 - Funding Information: The authors gratefully acknowledge funding of the project BonaRes-ORDIAmur by the German Federal Ministry of Research and Education within the frame of the program BonaRes (grant no. 031B0025A and 031B0025B). The authors are grateful to Uta Hille, Eric Fritzsche, Julia Metzler, Melanie Platta, Arvid Lauber, Ines Polster and Ewa Schneider for their technical assistance. Francis Ofere Emeriewen is acknowledged for proofreading of the manuscript as a native speaker.

PY - 2021/12

Y1 - 2021/12

N2 - Apple replant disease (ARD) is a soil-borne disease, which is increasingly problematic for tree nurseries and orchards worldwide. Although, ARD is known for centuries, the ultimate causes remain unknown. The phenomenon occurs after repeated replanting of the same plant species on the same soil, leading to the soil losing its capacity to support the growth of the species. As a result, the replanted plants are characterized by a poor vegetative development, and reduced yield in terms of quantity and quality. The use of ARD-tolerant rootstocks is a sustainable approach to control this phenomenon, however, only a few Malus ARD-tolerant genotypes have been described. Moreover, less is known about the genetic mechanisms underlying these tolerances. Identifying ARD-tolerant genotypes and understanding the molecular basis for tolerance are prerequisites for future rootstock breeding. Six Malus accessions of the genebank at JKI in Dresden were previously identified as ARD-tolerant in a greenhouse bio-test. Since the previous classification was based on only one soil origin, these accessions were tested in a greenhouse bio-test using three different soil types in this study - thus confirming their ARD-tolerant status. To identify potential candidate genes related to ARD-tolerance, a comparative transcriptome study was performed. For this, the gene expression between the susceptible rootstock M.9 and the tolerant wild apple accession M. × robusta 5 were compared by RNA sequencing after cultivation on ARD-soil and disinfected (γ) ARD-soil. As a result, 81 candidate genes with a significant response in expression were selected for further validation.

AB - Apple replant disease (ARD) is a soil-borne disease, which is increasingly problematic for tree nurseries and orchards worldwide. Although, ARD is known for centuries, the ultimate causes remain unknown. The phenomenon occurs after repeated replanting of the same plant species on the same soil, leading to the soil losing its capacity to support the growth of the species. As a result, the replanted plants are characterized by a poor vegetative development, and reduced yield in terms of quantity and quality. The use of ARD-tolerant rootstocks is a sustainable approach to control this phenomenon, however, only a few Malus ARD-tolerant genotypes have been described. Moreover, less is known about the genetic mechanisms underlying these tolerances. Identifying ARD-tolerant genotypes and understanding the molecular basis for tolerance are prerequisites for future rootstock breeding. Six Malus accessions of the genebank at JKI in Dresden were previously identified as ARD-tolerant in a greenhouse bio-test. Since the previous classification was based on only one soil origin, these accessions were tested in a greenhouse bio-test using three different soil types in this study - thus confirming their ARD-tolerant status. To identify potential candidate genes related to ARD-tolerance, a comparative transcriptome study was performed. For this, the gene expression between the susceptible rootstock M.9 and the tolerant wild apple accession M. × robusta 5 were compared by RNA sequencing after cultivation on ARD-soil and disinfected (γ) ARD-soil. As a result, 81 candidate genes with a significant response in expression were selected for further validation.

KW - Genetic resources

KW - Greenhouse bio-test

KW - Malus germplasm

KW - RNA-sequencing

KW - Rootstock

KW - Transcriptome

UR - http://www.scopus.com/inward/record.url?scp=85120675292&partnerID=8YFLogxK

U2 - 10.17660/ActaHortic.2021.1327.6

DO - 10.17660/ActaHortic.2021.1327.6

M3 - Article

AN - SCOPUS:85120675292

VL - 1327

SP - 49

EP - 56

JO - Acta Horticulturae

JF - Acta Horticulturae

SN - 0567-7572

ER -