Caracterización de la respuesta morfológica de variedades susceptibles y resistentes de yuca (Manihot esculenta Crantz) a la bacteriosis vascular causada por Xanthomonas axonopodis pv. manihotis

Abstract

Xanthomonas axonopodis pv. manihotis is one of the major limitations for cassava cultivation. In the present study, optical microscopy was used to perform a comparative analysis of the morphological and histochemical changes in the stem of a susceptible (TMS60444) and a resistant (CM6438-14) cassava variety at 7 and 14 days after inoculation with the pathogenic strain CIO151. The resistant variety was detected to generate callose barriers on the cell walls Sandino, T.; López-Kleine, L.; López, C.; Marquínez, X. Characterization of the morphological response of susceptible and resistant varieties of cassava (Manihot esculenta Crantz) to vascular bacterial blight caused by Xanthomonas axonopodis pv manihotis. Summa Phytopathologica, v.41, n.2, p.94-100, 2015.Additional keywords: Callose deposits, tylosis, phenolic compounds, epifluorescence. ABSTRACTof the cortical parenchyma and phloem, maintaining the functionality of this tissue. On the other hand, for the vascular tissues of the susceptible variety there is collapse in the phloem due to total obstruction by deposits of callose and phenolic compounds and in the xylem due to tylosis formation and/or phenolic compound accumulation, without stopping the progression of the systemic disease. Palavras-chave:Depósitos do calose, tilose, compostos fenólicos, epifluorescência.

Interfamily transfer of Bs2 from pepper to cassava (Manihot esculenta Crantz)

“…Histological studies on inoculated cassava plants have shown that the difference between resistant and susceptible cultivars is expressed as a variation in colonization rates and penetration into the vascular tissue. In addition, both resistant and susceptible plants have shown similar defense responses in vascular tissues, nevertheless these responses are more intense and faster in the resistant cultivar (Kpemoua et al 1996;Sandino et al 2015). This data support the hypothesis that cassava resistance to CBB is quantitative and polygenic (Kpemoua et al 1996;Jorge et al 2000).…”

Major Novel QTL for Resistance to Cassava Bacterial Blight Identified through a Multi-Environmental Analysis

“…These mechanisms have been extensively studied in model plants, but knowledge generated in cassava is relatively scarce. Histology and cytochemistry studies of the resistance mechanisms in cassava during Xam infection showed callose deposition that act as a barrier in cortical parenchyma cells and phloem to block bacterial multiplication and dispersion (Kpémoua et al, 1996; Sandino et al, 2015). Other mechanisms of defense response including cell wall fortification, lignification and suberization associated with callose deposition and production of flavonoids and polysaccharides were also observed and they are faster and stronger in resistant cultivars compared to susceptible ones (Kpémoua et al, 1996).…”