Changes in the Aggressiveness and Fecundity of Hot Pepper Anthracnose Pathogen (Colletotricum acutatum) under Elevated CO2 and Temperature over 100 Infection Cycles

Koo, Tae-Hoon;Hong, Sung-Jun;Yun, Sung-Chul

  • Received : 2015.09.03
  • Accepted : 2016.01.15
  • Published : 2016.06.01


We observed the changes in aggressiveness and fecundity of the anthracnose pathogen Colletotrichum acutatum on hot pepper, under the ambient and the twice-ambient treatments. Artificial infection was repeated over 100 cycles for ambient ($25^{\circ}C/400ppm$ $CO_2$) and twice-ambient ($30^{\circ}C/700ppm$ $CO_2$) growth chamber conditions, over 3 years. During repeated infection cycles (ICs) on green-pepper fruits, the aggressiveness (incidence [% of diseased fruits among 20 inoculated fruits] and severity [lesion length in mm] of infection) and fecundity (the average number of spores per five lesions) of the pathogen were measured in each cycle and compared between the ambient and twice-ambient treatments, and also between the early (ICs 31-50) and late (ICs 81-100) generations. In summary, the pathogen's aggressiveness and fecundity were significantly lower in the late generation. It is likely that aggressiveness and fecundity of C. acutatum may be reduced as global $CO_2$ and temperatures increase.


ambient $CO_2$;climate change;pathogenicity;reproductive fitness;twice-ambient $CO_2$


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