Production and dispersal of Colletotrichum gloeosporioides spores on Stylosanthes scabra under elevated CO2

Effects on Net Photosynthesis in Field-Grown Hot Peppers Responding to the Increased CO2and Temperature

“…Excess carbon due to global warming may increase plant size resulting in increased canopy humidity, which may increase disease susceptibility or be used to produce non-structural carbohydrates, which may reduce the incidence of pest attacks. More Colletotrichum gloeosporioides spores were collected in a Stylosanthes canopy under elevated [CO2] 23) . Instantaneous water use efficiency (IWUE), the relative ratio of Pnet to gs in a cuvette where the boundary layer is reduced, overestimates gs 24) .…”

Climate change and plant diseases

“…According to these authors, pathogens tend to follow the host plant in its geographical distribution, but the rate at which pathogens become established in the new environment is a function of the mechanism of pathogen dispersal, suitability of the environment for dispersal, survival between seasons, and physiological and ecological changes in the host plant. According to Chakraborty et al (2000a), more aggressive strains of pathogen with broad host range, such as Rhizoctonia, Sclerotinia, Sclerotium and other necrotrophic pathogens can migrate from agroecosystems to natural vegetation, and less aggressive pathogens from natural plant communities can start causing damage in monocultures of nearby regions. Regarding unspecialized necrotrophs, the range of hosts can be extended due to crop migration.…”

“…Hibberd et al (1996a,b) conducted detailed studies of these effects on the powdery mildew (Erysiphe graminis) cycle for barley. Chakraborty et al (2000b), studying the effects of elevated CO 2 concentration on the epidemiological components of anthracnose caused by Colletotrichum gloeosporioides in Stylosanthes scabra demonstrated that the gas influences both the pathogen and the host, with differences in the expression of the disease resistance under these conditions, however varying with the cultivar. In a controlled environment, the increase in CO 2 concentration promoted higher plant growth, but did not compensate for reduced growth due to anthracnose in the most resistant cultivar.…”

“…Many changes in plant physiology can alter the resistance mechanisms of cultivars obtained by both traditional and genetic engineering methods. Several studies provide evidences of these alterations, such as significant increases in photosynthetic rates, papillae production, silicon accumulation in appressorial penetration sites, higher carbohydrate accumulation in leaves, more wax, additional epidermal cell layers, increased fiber content, reduction in nutrient concentration and alteration in the production of resistance-related enzymes (Hibberd et al, 1996b;Chakraborty et al, 2000a;Osswald et al, 2006). Paoletti & Lonardo (2001) conducted one of the few studies to verify the effects of increased CO 2 concentration on disease control by using resistant cultivars.…”

“…Some studies revealed that in spite of a delay in the initial development and a reduction in host penetration, the established colonies develop faster. The increased fecundity of the pathogen, associated to a favorable microclimate within enlarged canopies favors the occurrence of epidemics (Hibberd et al, 1996b;Chakraborty et al, 2000a).…”