Yensi Yanez

Fusarium circinatum (anamorph of Gibberella circinata) is the etiological agent of resinous canker in conifers, especially within the genus Pinus. This pathogen can impact all phases of tree development. Infections caused by F. circinatum in pine forests have been catastrophic in numerous countries globally, underscoring the necessity of understanding the geographical distribution of this fungus to enhance ecological comprehension and inform effective control measures. This study aims to report the existence of F. circinatum as a potential pathogen of pine trees in Honduras. Samples were obtained from mature trees and tree nurseries of Pinus oocarpa in three departments of Honduras, exhibiting symptoms such as chlorosis, needle wilting, and progressive mortality. Samples underwent microbiological and molecular identification. The isolates were identified using phenotypic approaches focused on micro and macro morphology, followed by the amplification and sequencing of three genes: ITS, EF-1α, and Beta-tubulin. Three isolates of the fungus were identified as F. circinatum. No genetic diversity was seen among the three isolates; nevertheless, some diversity was evident in comparison to sequences deposited in databases from different geographic regions. This is the first report and molecular characterization of F. circinatum isolated from Pinus oocarpa in Honduras.

Bark beetles are one of the major causes of tree mortality in coniferous forests worldwide. The large-scale disturbances by beetle outbreaks have strongly increased in Honduras and other countries, leading to significant ecological, economic, and social consequences. However, the taxonomy, local distribution, and environmental aspects of most bark beetles and their biological predators remain poorly studied. Here, we applied a morphological approach to identify Scolytinae individuals across different forest areas in Honduras. Moreover, the barcoding approach was used by amplifying and sequencing the mitochondrial COI gene. The intraspecific genetic diversity of Ips apache was also analyzed. 1,131 individuals were examined, and 27 genera were identified. Most of the specimens were identified as belonging to the genus Ips, accounting for 53.2% of the total. Xyleborus accounted for 16.5% and Temnoscheila accounted for 10%. Less than four individuals were found for fifteen genera. Ips, Temnoscheila, Xyleborus, Hypothenemus and Pityophthorus exhibited the most extensive geographic distribution among the sampled sites. At the genus level, Olancho, El Paraíso, and Copán displayed the highest diversity. This study is the first report of two genera (Xylomeira and Stephanopachys) in Honduran pine forests. Among individuals of I. apache, there was evidence of intraspecific genetic diversity, but no population structure was detected. While our findings update the list of bark beetles and biological predators associated with Honduran coniferous forests, more taxonomic inventories and ecological studies are required to understand the spread of bark beetles in pine forests.

Pine is one of the important coniferous genera in America. In Honduras, Pinus oocarpa is the most critical conifer species since it plays an essential role for the country's economy and represents a symbol of national identity. Endophytic fungi are defined as microorganisms that reside in the internal tissues of plants without causing any obvious immediate negative effects and are an integral part of their associated microbial communities. This study aimed to isolate and characterize the endophytic fungi present in the pines of Honduras through the amplification and sequencing of the ribosomal RNA gene's internal transcribed spacer (ITS). A total of 7 pines from the department of El Paraíso in eastern Honduras were analyzed. A total of 14 fungi grouped into 6 genera and 7 species were isolated: Fusarium lateritium, F. pseudocircinatum, Pestalotiopsis pini, P. microspora, Xylaria grammica, Trichoderma atroviride, y Nigrospora oryzae. To our knowledge, this is the first report of endophytic fungal species in pines in Honduras. Although some endophytic fungi may be mutualistic or saprophytic, the present study shows the presence of several genera of endophytic fungi that have been reported as pine pathogens. The presence of these fungi in the pines of Honduras represents a potential threat to the health of the forest. Further research is needed to increase knowledge about the importance of these fungi and the potential impact they could have on pine forests in Honduras. Keywords: Endophytic fungi, Pinus oocarpa, Honduras