Screening Almond Rootstocks for Sources of Resistance to Armillaria Root Disease

. Prunus dulcis (almond) is one of the most susceptible horticultural crops to Armillaria root disease. Resistance to Armillaria mellea and Armillaria tabescens , the geographically isolated causal fungi that attack almond and closely related Prunus persica (peach), has been evaluated in studies of almond, peach, and other Prunus rootstocks, but not in one comprehensive study. We evaluated the relative resistance to A. mellea and A.tabescens ofsix clonally propagated almondandpeachrootstocks (Bright’s5, Empyrean 1, Hansen 536, Krymsk 1, Krymsk 86, and Lovell) in comparison with that of clonally propagated Marianna 2624 rootstock (resistant control) and clonally propagated Nemaguard rootstock (susceptible control). Replicate clones used in the growth chamber assay were micropropagated and rooted in vitro before inoculating the culture medium with Armillaria spp. At 2 months, the most resistant and susceptible rootstocks were Krymsk 86 and Hansen 536, respectively, with 27% vs. 89% mortality. This finding was consistent among two isolates of A. mellea and one isolate of A. tabescens in three replicate experiments. Our finding of low mortality among Krymsk 86, Krymsk 1, and cerasifera parentage, of resistance in field conflicts reports of susceptibility to A. tabescens Resistance to A. tabescens of genotypes with Myrobalan parentage in our assay tissue field biotic abiotic growth assay for and screen progeny of

[1]  Leon Bieber,et al.  Sas System For Mixed Models , 2016 .

[2]  Mee-Sook Kim,et al.  Incidence and phylogenetic analyses of Armillaria spp. associated with root disease in peach orchards in the State of Mexico, Mexico , 2013 .

[3]  K. Baumgartner,et al.  Evaluating Paradox Walnut Rootstocks for Resistance to Armillaria Root Disease , 2013 .

[4]  G. Schnabel,et al.  Aboveground Root Collar Excavation of Peach Trees for Armillaria Root Rot Management. , 2012, Plant disease.

[5]  W. Sherman,et al.  'MP-29', a Clonal Interspecific Hybrid Rootstock for Peach , 2012 .

[6]  M. Wingfield,et al.  Paleogene Radiation of a Plant Pathogenic Mushroom , 2011, PloS one.

[7]  M. Coetzee,et al.  Secrets of the subterranean pathosystem of Armillaria. , 2011, Molecular plant pathology.

[8]  K. Baumgartner,et al.  A rapid infection assay for Armillaria and real-time PCR quantitation of the fungal biomass in planta. , 2010, Fungal biology.

[9]  W. Sherman,et al.  ‘Sharpe’, a Clonal Plum Rootstock for Peach , 2008 .

[10]  K. Korhonen,et al.  A study on intersterility groups of Armillaria in China , 2007, Mycologia.

[11]  G. Schnabel,et al.  Identification and characterization of Armillaria tabescens from the southeastern United States. , 2005, Mycological research.

[12]  K. Baumgartner.  Root Collar Excavation for Postinfection Control of Armillaria Root Disease of Grapevine. , 2004, Plant disease.

[13]  T. Michailides,et al.  Compendium of nut crop diseases in temperate zones , 2002 .

[14]  D. Rizzo,et al.  Spread of Armillaria Root Disease in a California Vineyard , 2002, American Journal of Enology and Viticulture.

[15]  J. Mansilla,et al.  A fast method for production of Armillaria inoculum , 2001 .

[16]  P. L. Pusey,et al.  Field Testing Peach Rootstocks for Resistance to Armillaria Root Rot , 2001 .

[17]  Eric R. Ziegel,et al.  Multiple Comparisons and Multiple Tests , 2000 .

[18]  J. Connell,et al.  Efficacy of Sodium Tetrathiocarbonate and Propiconazole in Managing Armillaria Root Rot of Almond on Peach Rootstock. , 1999, Plant disease.

[19]  D. Rizzo,et al.  Spatial Distribution of Armillaria mellea in Pear Orchards. , 1998, Plant disease.

[20]  W. Okie,et al.  Relative Susceptibility of Peach and Plum Germplasm to Armillaria Root Rot , 1998 .

[21]  J. Ogawa,et al.  Compendium of stone fruit diseases. , 1995 .

[22]  R. Carlson,et al.  Rootstocks for fruit crops. , 1987 .

[23]  Pritam Singh.  Armillaria root rot: Artificial inoculation and development of the disease in greenhouse , 1980 .

[24]  J. S. Hunter,et al.  Statistics for experimenters : an introduction to design, data analysis, and model building , 1979 .

[25]  P. Lepoivre,et al.  IMPROVED MEDIA FOR IN VITRO CULTURE OF PRUNUS SP. , 1977 .

[26]  P. F. Kable.  Spread of Armillariella sp. in a peach orchard , 1974 .

[27]  F. Skoog,et al.  A revised medium for rapid growth and bio assays with tobacco tissue cultures , 1962 .

[28]  A. Amstutz,et al.  Rootstock susceptibility to Armillaria mellea. , 1948 .