Search bioRxiv⌕ Search

bioRxiv · 10.1101/2023.08.02.551668

Prevalence of mango postharvest Stem-end rot disease in Cote d'Ivoire and identification of fungal pathogens associated

Abstract

The Stem-end rot (SER) postharvest disease of mango (Mangifera indica L.) fruits is a significant economic threat to mango production. If suitable conditions are not maintained, it can lead to losses of up to 100 %. Despite its importance, very little information is known about this disease in Cote dIvoire. This research aimed determining the incidence and severity of SER in mango orchards, assess how preharvest climate parameters affect the disease and determine the pathogenic fungi associated with SER. Therefore, mango SER was evaluated on 1500 mango fruits collected from 15 orchards.in Boundiali, Ferkessedougou, Korhogo, Odienne, and Sinematiali departments. Mango SER incidence ranged from 10 % to 30 %, while severity ranged from 5 % to 20 %. No significant differences in these parameters were observed between the different departments (P>0.05). The study also revealed a low correlation between SER disease incidence and mean air temperature (r=0.36) and minimum air temperature (r=0.26) data, indicating that preharvest weather conditions may have a marginal impact on mango SER disease intensity in the postharvest phase. Pathogenic fungi associated with SER were isolated and identified using morphological characteristics and multilocus sequence analysis of the rDNA internal transcribed spacer (ITS) region and the translation elongation factor 1-alpha (tef1-). We identified various fungal species associated with mango SER disease, with Lasiodiplodia species (74%) being the most prevalent (including Lasiodiplodia theobromae, L. euphorbicola, and L. caatinguensis), followed by Colletotrichum gloeosporioides, Curvularia pseudobrachyspora, Diaporthe endophytica and Fusarium mangiferae. However, only Lasiodiplodia species and Diaporthe endophytica induced SER symptoms. This study was the first ever evaluation of mango SER disease and associated fungal pathogens identification in Cote dIvoire. This result will assist researchers in developing a control method for mango SER.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yeo, Y. S., KONE, Y., DEMBELE, D. D., Amari, G. E., Rey, J.-Y., Del Ponte, E. M., Fernandez, D., KONE, D.. 2023-08-05. Prevalence of mango postharvest Stem-end rot disease in Cote d'Ivoire and identification of fungal pathogens associated. https://doi.org/10.1101/2023.08.02.551668

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

In-cell structural analysis reveals a distinctive chloroplast ribosome in Chlamydomonas reinhardtii

Chloroplast ribosomes synthesize plastid-encoded components of photosynthetic machinery, yet their structure and organization remain poorly understood. We combined cryo-focused ion beam milling, cryo-electron tomography and subtomogram averaging to determine native chloroplast ribosomes in Chlamydomonas reinhardtii. The 4.4-4.9 [A] structure revealed a large arch-like extension on the small subunit (SSU). Comparisons with bacterial and plant chloroplast ribosomes, supported by proteomics, AlphaFold3 predictions and a recent atomic model, indicate that the arch is formed by insertions and extensions in SSU proteins. Classification resolved active, thylakoid-associated ribosomes with density adjacent to the nascent peptide exit and an arch-moved state enriched among thylakoid-associated particles, with coordinated displacement of the arch and beak. Phylogenetic analysis revealed an evolutionary mosaic: the uS3c insertion is broadly distributed across Chlorophyceae, whereas the uS2c insertion, uS5c and PSRP7 are concentrated in Chlamydomonadales, with PSRP7 also in Sphaeropleales. Nuclear-encoded components were recruited stepwise onto a plastid-encoded scaffold, with all four under comparable purifying selection. These findings link a lineage-specific SSU extension to ribosome dynamics, thylakoid association and evolution, highlighting the value of in-cell structural analysis.

plant biology↗

Implementation and calibration of the Vaganov-Shashkin model in the virtualRings R package

Process-based tree growth models provide a mechanistic framework for investigating how climate conditions regulate tree growth across daily to annual time scales. Yet, their broader application across species and environments is constrained by the limited accessibility in open-source environments and the difficulty of estimating physiological parameters that are rarely measured directly. Here, we present virtualRings, a new R package integrating the Vaganov-Shashkin model (VSM) and the RINGS3 models, and focus on the implementation and calibration of VSM. Using tree-ring width observations from seven Northern Hemisphere sites across various environmental conditions, we compared the traditional bootstrap-based calibration approach with the Covariance Matrix Adaptation Evolution Strategy (CMA-ES). CMA-ES improved agreement between simulated and observed radial tree growth and provided an efficient approach for model parameter estimation. We further evaluated practical CMA-ES settings to balance computational cost and performance and discussed its potential limitations. The virtualRings package provides an open and reproducible platform for tree growth simulation, facilitating the application of important process-based models across species and environments and the investigation of how temperature and moisture constraints regulate daily tree-ring formation across spatial and temporal scales.

plant biology↗

Timing of transient darkness shapes carbon-nitrogen metabolism and sugar signaling in sugarcane

Fluctuating light is common in field environments. Yet, the mechanisms by which C4 crops coordinate carbon and nitrogen metabolism during short-term carbon deprivation remain poorly understood. Here, we imposed transient darkness at different phases of the diel cycle to assess how the timing of light loss affects photosynthesis, carbohydrate turnover, amino acid dynamics, and sugar-sensing pathways in commercial sugarcane leaves. Early-day darkness significantly impaired photosynthetic induction and revealed a temporal disconnect between stomatal and metabolic limitations, whereas midday and late-day treatments caused temporary, time-specific disruptions in carbon assimilation. These shifts altered the balance between sucrose preservation and catabolic mobilization, leading to treatment-dependent changes in starch reserves and free amino acids. Core circadian components largely maintained their phase relationships, but their amplitudes varied across treatments, consistent with partial decoupling from carbon status. Darkness also reorganized energy signaling, with SnRK1 and DIN6 responses associated with greater declines in sucrose. Notably, trehalose-pathway transcripts showed marked changes in network connectivity, with ScTPSIIG consistently emerging as a highly connected candidate associated with photosynthetic performance, water-use traits, sugar sensing, and amino acid metabolism. Overall, these results indicate that the timing of carbon limitation and residual sucrose availability shape distinct metabolic responses, while trehalose metabolism provides a candidate regulatory layer coordinating carbon-nitrogen adjustment during the diel cycle, highlighting class II TPS proteins as targets for functional investigation of metabolic resilience in sugarcane.

plant biology↗