Differential leaf gas exchange performance of mango cultivars infected by different isolates of Ceratocystis fimbriata

Abstract

Caused by the vascular fungus Ceratocystis fimbriata, mango wilt is considered to be one of the most serious threats in mango-producing regions worldwide. However, changes in leaf gas exchange level and the mechanisms underlying host responses to this fungal infection remain poorly described. This study aimed to evaluate potential changes in the leaf gas exchange of different mango cultivars (Ubá, Espada, Haden and Tommy Atkins) in response to two Brazilian isolates of C. fimbriata (CEBS15 and MSAK16) to non-invasively assess cultivar variability in relation to the basal level of resistance to mango wilt. Both isolates, regardless of the cultivar, caused reductions in stomatal conductance and, thus, a reduction in CO 2 assimilation via diffusive limitations. Taking into account the full length of the internal lesion and the radial colonization of the stem tissues, both isolates showed equivalent aggressiveness when inoculated into the Haden and Tommy Atkins cultivars. Conversely, when compared to the CEBS15 isolate of C. fimbriata, the MSAK16 isolate was more aggressive in cv. Espada and less aggressive in cv. Ubá.

Changes in leaf gas exchange, chlorophyll a fluorescence, and antioxidantsin maize leaves infected by Exserohilum turcicum

“…Stomatal limitations may be contributed to lower A since it was accompanied by a decreases in both gs and ci indicating a discrete influx of CO2 into the infected leaf tissue, which may have contributed to impairment photosynthesis. Similar results were reported for mango-Ceratocystis fimbriata interaction where a less CO2 influx in leaves is observed due to fungal infection on stem, which is accompanied by reductions in ci/ca ratio (Bispo et al 2016). Stomatal closure of infected maize leaves results in a lower E and corroborates with the findings from maize Stenocarpella macrospora interaction (Bermúdez-Cardona et al 2015b).…”

“…Chlorophyll a fluorescence imaging: The images and fluorescence parameters of Chl a, maximum quantum yield of photosystem (PS) II (Fv/Fm), effective quantum yield of PS II (Fv'/Fm'), quantum yield of regulated energy dissipation (NPQ), and quantum yield of nonregulated energy dissipation Y(NO) were obtained at 5, 10, 15, and 20 dai using an IMAGING-PAM fluorometer (a Maxi version) and the Imaging Win software (Heinz Walz, Effeltrich, Germany). In order to obtain images at a resolution of 640 × 480 pixels, the fourth leaf was used to obtain the images of Chl a fluorescence following the procedures previously described (Debona et al 2014, Silveira et al 2015, Bermúdez-Cardona et al 2015b, Tatagiba et al 2015, Bispo et al 2016, Rios et al 2017, Rios et al 2018.…”

Spatial distribution of beetle attack and its association with mango sudden decline: an investigation using geostatistical tools

“…Thus, the initial pathogen infection may be not observed; however, the presence of galleries may indicate existence of the disease in a seemingly healthy plant in orchards having a history of MSD. Studies show that it is appropriate to evaluate internal symptoms to determine disease progression prior to the onset of visible symptoms . A cut may induce significant damage for some time.…”

Susceptible and resistant olive cultivars show differential physiological response to Xylella fastidiosa infections

“…The stomatal conductance (g s ) was used to discriminate resistant and susceptible cultivars of mango ( Mangifera sp.) to the fungal vascular phytopathogen Ceratocystis fimbriata (Bispo et al, 2016 ). In this work measurements of g s showed a positive correlation with the cultivars responses based on the disease indices and plant colonization.…”