Infection and Colonization of Several Bermudagrasses by Ophiosphaerella korrae.

Bermudagrass (Cynodon spp.) is the most commonly used turfgrass in the southern United States where it is severely affected by spring dead spot (SDS) caused by Ophiosphaerella herpotricha, O. korrae, and O. narmari. In this study, infection of bermudagrass roots and stolons by O. korrae was characterized using a transformant that expressed the red fluorescent protein tdTomato. Roots of interspecific hybrid cultivars Midlawn and Tifway 419, C. transvaalensis accessions Uganda and 3200, and C. dactylon cultivar U3 were inoculated and observed from 2 to 14 days postinoculation (DPI) while stolons were observed from 2 to 22 DPI. For all five cultivars tested, a similar level of root colonization was observed; however, differences were observed in the rate of necrosis development. Necrosis of Tifway 419 and Midlawn tissues was evident at 2 DPI, in Uganda and 3200 at 8 DPI, and in U3 necrosis was often absent as late as 14 DPI. The fungus rapidly penetrated the root epidermis and colonized the cortex of all cultivars by 4 DPI. Colonization of stele tissues by O. korrae was rare in hybrid cultivars but common in C. transvaalensis and C. dactylon accessions. On intact stolons, the fungus did not penetrate the epidermis 22 DPI though epidermal necrosis was evident on the surface of only the hybrid bermudagrasses. Wounded stolons became necrotic in all cultivars. Infection and colonization of various bermudagrasses by O. korrae was found to be similar to that by O. herpotricha, suggesting that host genetic resistance may be used for effective management of SDS caused by both species.

[1]  T. Mitchell,et al.  Reactive oxygen species production in response toOphiosphaerellaspp. colonization of bermudagrass roots , 2016 .

[2]  T. Mitchell,et al.  Infection and colonization of turf-type bermudagrass by Ophiosphaerella herpotricha expressing green or red fluorescent proteins. , 2010, Phytopathology.

[3]  L. Tredway,et al.  First Report of Spring Dead Spot of Zoysiagrass Caused by Ophiosphaerella korrae in the United States. , 2007, Plant disease.

[4]  N. Tisserat,et al.  Effect of Cold Acclimation and Freezing on Spring Dead Spot Severity in Bermudagrass , 2005 .

[5]  D. Skinner,et al.  Geographic Distribution and Genetic Diversity of Three Ophiosphaerella Species that Cause Spring Dead Spot of Bermudagrass. , 1999, Plant disease.

[6]  C. Alabouvette,et al.  Process of tomato root colonization by a pathogenic strain of Fusarium oxysporum f. sp. lycopersici in comparison with a non‐pathogenic strain , 1999 .

[7]  N. Tisserat,et al.  Spring Dead Spot of Buffalograss Caused by Ophiosphaerella herpotricha in Kansas and Oklahoma. , 1999, Plant disease.

[8]  M. Payton,et al.  Bermudagrass Resistance to Spring Dead Spot Caused by Ophiosphaerella herpotricha. , 1998, Plant disease.

[9]  T. Hsiang,et al.  Low level of DNA polymorphisms in isolates of Leptosphaeria korrae pathogenic on Poa pratensis , 1998 .

[10]  C. Taliaferro,et al.  Evaluating Freeze Tolerance of Bermudagrass in a Controlled Environment , 1993 .

[11]  C. J. Nelson,et al.  Characterization of Thatch, Rhizomes, Carbohydrates, and Spring Deadspot in Twenty Cultivars of Bermudagrass1 , 1980, Journal of the American Society for Horticultural Science.

[12]  J. Walker,et al.  Leptosphaeria narmari and L. korrae spp.nov., two long-spored pathogens of grasses in Australia , 1972 .

[13]  N. Walker,et al.  Spring dead spot of bermudagrass: a challenge for researchers and turfgrass managers. , 2009 .

[14]  A. Ram,et al.  Novel aspects of tomato root colonization and infection by Fusarium oxysporum f. sp. radicis-lycopersici revealed by confocal laser scanning microscopic analysis using the green fluorescent protein as a marker. , 2002, Molecular plant-microbe interactions : MPMI.

[15]  P. H. Demoeden.  First Report of Necrotic Ring Spot (Leptosphaeria korrae) in Creeping Red Fescue in Maryland. , 1995 .

[16]  N. Tisserat,et al.  Pathogenicity of Rhizoctonia solani AG-2-2 and Ophiosphaerella herpotricha on zoysiagrass , 1993 .

[17]  N. Tisserat,et al.  Ophiosphaerella herpotricha, a Cause of Spring Dead Spot of Bermudagrass in Kansas , 1989 .

[18]  N. O'neill,et al.  Growth and pathogenicity of Leptosphaeria korrae in bermudagrass , 1988 .

[19]  R. M. Endo,et al.  Leptosphaeria korrae,a Cause of the Spring Dead Spot Disease of Bermudagrass in California , 1985 .

[20]  H. C. Young,et al.  Spring dead spot of Bermudagrass. , 1960 .