DETECTION OF LATENT INFECTION OF PHYTOPHTHORA INFESTANS IN POTATO SEED TUBERS

Infected seed tubers are an important means of transmission of P. infestans in between potato crops. P. infestans is often brought to the field by latent infected seed tubers. The potato industry currently relies on postharvest, or preplanting, visual disease inspections to detect and sort out the infected tubers to minimise such losses. Disease inspection, however, reveals only established infections and contribution of latent infection to tuber loss is unknown. A diagnostic test that improves on visual inspection to give a rapid and accurate method for specific detection of P. infestans in seed tubers would be of benefit. A PCR based protocol was validated for detection of latent infection in commercial seed tuber stocks. The rapid NaOH tissue assay procedure and specific primer set were used to detect P. infestans from artificially and naturally infected tubers. The percentage of latently infected tubers ranged from 0 to 6.67%. P. infestans was detected by PCR from artificially infected tubers at 4 days post-inoculation with a sensitivity limit of 10 fg of DNA before any visible symptoms appeared on the inoculated tubers. The pathogen could be detected up to 25 mm away from the diseased lesions.

[1]  S. Sharma,et al.  OPTIMIZATION OF DUPLEX RT-PCR FOR SIMULTANEOUS DETECTION OF POTATO VIRUS Y AND S , 2013 .

[2]  G. Scott,et al.  THE RISE OF ASIA AS THE CENTRE OF GLOBAL POTATO PRODUCTION AND SOME IMPLICATIONS FOR INDUSTRY , 2012 .

[3]  D. Kelaniyangoda.  EXOTIC STRAINS OF Phytophthora infestans IN SRI LANKA , 2011 .

[4]  G. Scott,et al.  GROWTH RATES FOR POTATO IN INDIA AND THEIR IMPLICATIONS FOR INDUSTRY , 2011 .

[5]  T. Cummings,et al.  Latent Infection of Potato Seed Tubers by Phytophthora infestans During Long-Term Cold Storage. , 2009, Plant disease.

[6]  P. Kromann,et al.  Preemergence Infection of Potato Sprouts by Phytophthora infestans in the Highland Tropics of Ecuador. , 2008, Plant disease.

[7]  J. Duncan,et al.  Development of a species-specific and sensitive detection assay for Phytophthora infestans and its application for monitoring of inoculum in tubers and soil , 2005 .

[8]  L. C. Davidse,et al.  Nine years of practical experience with phenylamide resistance in Phytophthora infestans in the Netherlands , 2005, Netherlands Journal of Plant Pathology.

[9]  T. Cummings,et al.  Effect of Chemical Defoliation, Irrigation Water, and Distance From the Pivot on Late Blight Tuber Rot in Center-Pivot Irrigated Potatoes in the Columbia Basin. , 2003, Plant disease.

[10]  T. Cummings,et al.  Influence of Timing of Harvest in Relation to Haulm Killing and Planting Date on Potato Tuber Rot Caused by Phytophthora infestans. , 2002, Plant disease.

[11]  P. Ann,et al.  Rapid detection of Phytophthora infestans by PCR , 2002 .

[12]  Appel,et al.  A Method for the Artificial Inoculation of Potato Tubers with Phytophthora infestans and Polymerase Chain Reaction Assay of Latently Infected Sprouts and Stems , 2001 .

[13]  H. Judelson,et al.  Enhanced Polymerase Chain Reaction Methods for Detecting and Quantifying Phytophthora infestans in Plants. , 2000, Phytopathology.

[14]  F. Govers,et al.  Development of potato late blight epidemics: disease foci, disease gradients, and infection sources. , 1998, Phytopathology.

[15]  P. Tooley,et al.  Development of PCR primers from internal transcribed spacer region 2 for detection of Phytophthora species infecting potatoes , 1997, Applied and environmental microbiology.

[16]  Hong Wang,et al.  A simple method of preparing plant samples for PCR. , 1993, Nucleic acids research.

[17]  J. Lacey.  Susceptibility of potato tubers to infection by Phytophthora infestans , 1967 .