Protocol

Centre : Central Tuber Crops Research Institute(CTCRI),TVM
Name of the Protocol
A rapid and efficient method for in vitro screening of taro for leaf blight disease caused by Phytophthora colocasiae
Nature : Novel
Crop / Pathogen : Taro/Phytophthora colocasiae

Inventors

1. Nath V. S.
2. Shyni,B
3. Hegde V. M.
4. Misra R. S.
5. Veena S. S.
6. Raj M.
7. Jeeva M. L.

Objectives

1. To screen taro germplasm lines for taro blight caused by Phytophthora colocasiae in vitro

Procedure / Summary

Taro leaves were detached from 2- to 3-month-old plants and surface sterilized using 0.8% sodium hypochlorite for 1 min followed by rinsing three times in sterile distilled water. Five taro leaf discs (5x5 cm) floating on sterile distilled water in 200 mm petri plates were inoculated with 50 µl of zoospore suspension (5x105 zoospore/ml) of P. colocasiae isolate and incubated at 25°C in the dark for 4 days. Control experiments consisted of leaf discs inoculated with sterile water. The leaf discs were visually examined daily, and lesion development was recorded. Accessions were classified into four categories (0 to 4) based on lesion diameter. 0–1 cm: highly resistant; 1–2 cm: moderately resistant; 2–3 cm: moderately susceptible; and 3–4 cm: highly susceptible.

Applications

1. The method is rapid, inducing disease symptom as early as 24 h.p.i offering high-throughput application in screening large sample sizes,
2. Highly useful when there is a limited amount of sample available, as the size of the leaf disc used is small (5 x 5 cm) which allows for sufficient replications even with the limited sample size,
3. Highly reproducible and shows consistency with the field disease incidence scores.

Publications

1. Nath V. S., Shyni, Hegde V. M., Misra R. S., Veena S. S., Raj M., Jeeva M. L. (2016). A rapid and efficient method for in vitro screening of taro for leaf blight disease. Journal of Phytopathology. doi: 10.1111/jph.12477.