Protocol

Centre : Central Citrus Research Institute, Nagpur
Name of the Protocol
Development of conventional and Real-Time PCR assays for rapid and sensitive detection of P. nicotianae causing root rot and gummosis of citrus
Nature : Modification of existing protocol
Crop / Pathogen : Citrus / Phytophthora nicotianae

Inventors

  1. Das A.K.
  2. Nerkar S.G.
  3. Kumar A.
  4. Kadam R.
  5. Bawage, S. S.

Objectives

  1. To develop species-specific detection methodology of P. nicotianae infecting citrus through PCR- based techniques

Procedure / Summary

Conventional-PCR: A set of ITS region-based primer pair (PNIC1/PNIC2) specific to Phytophthora nicotianae was used. PCR amplifications were carried out on BIORAD T100TM Thermal Cycler in a 25µl volume consisting 1X PCR buffer, 2 mM MgCl2, 0.2 mM each dNTP, 0.5 µM of each primer (PNIC1/PNIC2), 1 U of Taq DNA polymerase (Bioline Inc, USA) and 1 µl of template DNA. The PCR conditions used were: initial denaturation at 94°C for 3 min, followed by 35 cycles of denaturation, annealing and elongation steps respectively at 94°C for 30 sec, 60°C for 30 sec and 72°C for 1 min and final extension step of 72ºC for 10 min. Real-Time-qPCR: ITS region primer pair (Ph.nicF/Ph.nicR) and probe (Pn.pro-FAM) specific to P. nicotianae were used. The Real-time PCR amplification reaction was performed using a ABI 7300 Real Time PCR system (Applied Biosystems, California) in a 25 µl reaction volume consisting of 200 nM (each) primer, 100 nM probe, 1X TaqMan® universal Master Mix (Applied Biosystems, CA) and 1 µl of template DNA. The standard amplification protocol was: The standard amplification protocol was 95°C for 15 min followed by 40 cycles at 94°C for 15 sec and 60°C for 1 min.

Applications

  1. The developed PCR-based assays proved to be robust and reliable technique to detect and quantify P. nicotianae in mycelial culture as well as in host tissues, soil and water.

Publications

  1. Das AK, Nerkar S, Kumar A, Kadam R (2013) Detection and quantification of Phytophthora nicotianae from root, water and soil samples using Real-Time PCR. National citrus Meet. August 12-13,2013, NRC for Citrus, Nagpur, India, pp.225.
  2. Das, A. K., Nerkar, S., Kumar, A. and Bawage, S. (2016). Detection, identification and characterization of Phytophthora spp. infecting citrus in India. Journal of Plant Pathology 98(1): 55-69.