Seed Health Management for Better Productivity - Govind Ballabh ...

(Seed Health Management for Better Productivity)Detection of Smut and Red Rot Pathogens in Sugarcane for Productionof Healthy SeedO.K. SinhaIndian Institute of Sugarcane Research, Lucknow- 226 002 (UP)Of economically important seed transmitted diseases of sugarcane, smut and red rot are ofgreater significance in sugarcane cultivation especially in seed production. The spread of the twodiseases takes place primarily through inadvertent movement of infected seed material, as theincipient infection cannot be distinguished. The only dependable method for detection of thepathogens is through planting the setts and wait for appearance of symptoms.Due to this constraint, the methods of in situ detection of the two pathogens have beendeveloped as detailed below:1. Detection of smut pathogen (Ustilago scitaminea Syd.) in nodal buds of sugarcane bystain techniqueNature of diseaseSmut of sugarcane is a systemic disease. The fungus colonizes the meristematic tissue ofnodal buds and apical meristem.During development of plant (mother shoot and tillers), the fungus is seated in nodal budspresent at each node and in apical growing point.Material required1. Naturally infected bud2. Forceps3. Scalpel/blade4. Distilled water5. Trypan blue stain (0.1%)6. 1-N Sodium hydroxide solution (6%)7. Ethanol (80%)8. Lactophenol9. Hot plate10. Micro-slide & cover-slip11. Light microscopeMethodology1. Scoop out nodal bud with the help of scalpel.2. Take thin cross sections of infected bud from basal side till circular rings of bud scales arevisible.3. Press the bud so that growing point is ejected. Pick it with forceps.4. Put growing point in Trypan blue + NaOH (1:1, v/v) solution for 3.5 hours.5. Remove and wash in distilled water. Put in ethanol for 2 min for dehydration.- 104 -