Phytopathology (2015) 105, 26-34

Maria Bianney Bermúdez-Cardona, João Américo Wordell Filho and Fabrício Ávila Rodrigues (2015)
Leaf gas exchange and chlorophyll a fluorescence in maize leaves infected with Stenocarpella macrospora
Phytopathology 105 (1), 26-34
Abstract: This study investigated the effect of macrospora leaf spot (MLS), caused by Stenocarpella macrospora, on photosynthetic gas exchange parameters and chlorophyll a fluorescence parameters determined in leaves of plants from two maize cultivars ('ECVSCS155' and 'HIB 32R48H') susceptible and highly susceptible, respectively, to S. macrospora. MLS severity was significantly lower in the leaves of plants from ECVSCS155 relative to the leaves of plants from HIB 32R48H. In both cultivars, net CO₂ assimilation rate, stomatal conductance, and transpiration rate significantly decreased, while the internal to ambient CO₂ concentration ratio increased in inoculated plants relative to noninoculated plants. The initial fluorescence and nonphotochemical quenching significantly increased in inoculated plants of ECVSCS155 and HIB 32R48H, respectively, relative to noninoculated plants. The maximum fluorescence, maximum PSII quantum efficiency, coefficient for photochemical quenching, and electron transport rate significantly decreased in inoculated plants relative to noninoculated plants. For both cultivars, concentrations of total chlorophyll (Chl) (a + b) and carotenoids and the Chl a/b ratio significantly decreased in inoculated plants relative to noninoculated plants. In conclusion, the results from the present study demonstrate, for the first time, that photosynthesis in the leaves of maize plants is dramatically affected during the infection process of S. macrospora, and impacts are primarily associated with limitations of a diffusive and biochemical nature.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Fabrício A. Rodrigues

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Stenocarpella macrospora