Question

Section B (Plant Microbes) 1. Compare the ecology and spread of plant-pathogenic bacteria and fungi. (maximum two pages) 20 marks

Answer 1

1. Ecology deals with the relationship between organisms and the physical environment they live.Comparision of ecology and plant pathogenic organisms helps in the better management of Plant diseases ( disease management is based on fundamental understanding of ecology & biology of pathogens).

The crop production includes surveillance, host resistance, use of biocides and other biocontrol agents which are based on genetic diversity, host range, habitat and mechanism of virulence of plant pathogens in turn controlled by biotic and abiotic factors.

#In context of global change, knowledge of ecology of plant pathogens will play important role in anticipation and response to diseases. Here, the global change includes climate change, changes in biodiversity & geographical distribution of biomes and even social economic adaptations. Thus, numerous aspects of plant pathogens (Bacterial and Fungal) interaction with their environment will change by which diseases will arise with increasingly varied models. The varied models include-

1. Increase of activity of old pathogens in a new context in which climate is favourable,

2. Change in geographical zones of pathogens with increased movement of plants,

3. Expansion of host range of pathogens as a result of genetic modifications (or) increase in susceptible plant variety,

4. New genetic lines of pathogens and novel pathogens due to genetic exchanges (or) hybridisation.

# This varied models can spread easily and can be resistance to wide range of pathogen control agents due to genomic changes and change in interactions with environment.