Characterization, pathogenicity, and fungicide sensitivity of Alternaria isolates associated with preharvest fruit drop in California citrus was written by Camiletti, Boris X.;Lichtemberg, Paulo S. F.;Paredes, Juan A.;Carraro, Thiago A.;Velascos, Jhordan;Michailides, Themis J.. And the article was included in Fungal Biology in 2022.Electric Literature of CuH2O2 This article mentions the following:
Alternaria rot has been recently described as an emerging fungal disease of citrus causing significant damage in California groves. A survey was conducted to determine latent infections on fruits, twigs, and leaves and investigate their seasonal patterns during 2019 and 2020. On fruits, latent infections were more associated with the stem end than with the stylar end, except during spring when a significantly high percentage of flowers (86%) had latent infections. Latent infections on twigs varied markedly between years (28% in 2019 and 9.5% in 2020), while Alternaria spp. were also recovered from citrus leaves. Alternaria isolates collected during the survey were identified based on multigene sequence anal., confirming that Alternaria alternata and Alternaria arborescens are the two species associated with infections of citrus fruits. Of the 23 isolates, 19 were identified as A. alternata and demonstrated the dominance of this species over A. arborescens. Isolates representing populations of these two species were selected as representative isolates for physiol. and morphol. studies. A. alternata and A. arborescens showed similar conidial dimensions but differed in the number of conidia produced. Growth rates demonstrated that A. alternata grows faster than A. arborescens at all the temperatures evaluated, except at 25 and 35°C. The growth patterns were similar for both species. The sporulation rate of the Alternaria isolates was influenced differently by temperature This parameter also influenced conidial germination and appressorium formation, and no significant differences were observed between Alternaria species. Pathogenicity and aggressiveness tests on detached fruit demonstrated the ability of A. alternata and A. arborescens to cause internal lesions and produce fruit drop in the orchards with no quant. differences between them (disease severity indexes of 58 and 68%, resp.). The fungicide sensitivity tests showed that DMI fungicides are the most effective fungicides in reducing mycelial growth. The SDHI fungicides had intermediate activity against the mycelial growth but also suppressed spore germination. The spore germination assay suggested that some of the isolates included in this study might have some level of resistance to QoI and SDHI fungicides. The findings of this study provide new information about the pathogens associated with the excessive fruit drop recently observed in some California citrus groves. In the experiment, the researchers used many compounds, for example, Cuprichydroxide (cas: 20427-59-2Electric Literature of CuH2O2).
Cuprichydroxide (cas: 20427-59-2) belongs to copper catalysts. Copper has continued to be one of the most utilized and important transition metal catalysts in synthetic organic chemistry. Copper of different valence states can be used to catalyze the coupling reaction, especially the Ullmann coupling reaction. Electric Literature of CuH2O2
Referemce:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”