ENDOPHYTIC Botrytis cinerea ESTABLISHES INTERNAL INFECTION IN LETTUCE PLANT (Lactuca sativa L.)

Yahaya, S.M.

Department of Biology,

Kano State University of Science and Technology, Wudil, Kano State, Nigeria

E-mail: sanimyahya@yahoo.com

ABSTRACT

Understanding the epidemiology of the wide spread of necrotrophic pathogen Botrytis cinerea is of considerable horticultural interest, as the design of control strategies is of great economic importance. Here it was showed that seed is the source of systemic Botrytis cinerea in lettuce plants. This was determined by the detection of seed infection from plants which were grown in controlled conditions from infected seed collected from flower inoculated plants. Fragment analysis found that 62.5% of seed isolates detected from plants which were grown from non fungicide treated seeds was identical to the inoculated isolate. In contrast, all seed isolates detected from plants which were grown from fungicide treated seed have different genotypes to the inoculating isolate. The results show that with time as the plant grew infection from the seed spread to stems and leaves systemically without exhibiting symptoms. This confirmed the systemic spread of the seed isolate, but showed that other B. cinerea isolates were present and that single plants can host multiple isolates. The results of these experiments show that the age of the plant affects the spread of seed infection to other parts of the plant. This shows that the endophytic phase is an important component of the population dynamics of B. cinerea.