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This article aims i) to review the state of the art in the knowledge of phytosanitary problems reported in the initial stages of cacao cultivation in Ecuador, and ii) to describe the presence of such problems in Milagro vivariums. The sources of information were mixed, and these varied according to geographic scale. Information at the country level came from books or articles; in contrast, primary data to identify fungi and information provided by local farmers interviewed to describe local particularities, were used. At the same time, secondary data from undergraduate theses, institutional technical reports and press articles were used. Secondary information, with low visibility but available in digital repositories, contains valuable information for local knowledge. The damages caused by fungi and by arthropods (sensulatupests) were grouped by symptom and causal agent. Symptoms of abiotic origin are also included. The management of insect damage is considered of little importance by nurserymen, unlike those caused by fungi and chromists that constitute the fundamental challenge.

One of the main problems in the production of cacao in Ecuador is the disease caused by the fungus Moniliophthora roreri (frosty pod rot) which affects the pods. Here, we evaluate the genetic diversity of this fungus in Ecuador, and its sensitivity to the fungicide azoxystrobin. We evaluated 76 monosporic cultures from the Amazon and the Pacific coast regions. In vitro sensitivity assays tested several doses of the fungicide azoxystrobin to determine the percent of growth inhibition and the IC50. Concentrations of 1 to 0.1 µg mL−1 inhibited the growth of at least 91% of the isolates. Three isolates were the less sensitive (IC50 = 0.0220–0.0364 µg mL−1), two from Guayas (Pacific coast) and one from Sucumbíos (Amazon) provinces. However, M. roreri is highly sensitive, and it could be used in integrated management of the disease. Genetic analyses were carried out by amplifying microsatellite markers (SSR). All the genetic diversity statistics show a higher diversity in the Amazon compared to samples of the coast region; however, the molecular variance was low (FST = 0.11). Discriminant analysis clearly distinguishes three clusters concurrent with the provinces (Sucumbíos, Orellana and El Oro) and a group with the rest of the provinces. Minimum spanning networks shows, unexpectedly, that M. roreri from the coast were derived from at least three independent introductions from the Amazon. Findings are discussed in light of previous Pan-American genetic studies and available historical reports. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agronómica is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Biológica Colombiana is the property of Universidad Nacional de Colombia, Facultad de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phytophthora spp. comprises four species responsible for canker of the trunk and black pod of cacao (Theobroma cacao L.) in Venezuela. Pytophthora palmivora (E.J. Butler) E.J. Butler is the most widely distributed species, followed by Pytophthora megasperma Drechsler, Pytophthora capsici Leonian, and Pytophthora citrophthora (R.E. Sm. & E.H. Sm.) Leonian. In order to understand the genetic basis of the population of Phytophthora spp. on cacao, its diversity was analyzed by ISSR molecular markers. Samples from the three main cocoa growing areas of Venezuela were collected. Forty nine isolates were morphologically identified at the genus level, from which genetic profiles were generated with three out of six, ISSR primers (880, 888 and 890). A matrix 49x55 was analyzed by Principal Coordinates Analysis (ACoP), Cluster Analysis and External Logistics Biplot (BLE). The ISSR primers allowed the construction of the genetic fingerprinting of the isolates; it showed no association with the site of origin. The ACoP distinguished three main groups, which could be predictive of at least three species, which in turn would be the most frequently affecting cocoa plantations in the country. At the same time, BLE enabled us to identify that, of the total of 55 amplified fragments, only three bands of the primer 888 (1.400pb, 3.200pb, and 4.600pb) were directly involved in the separation of the groups. Thus, BLE showed not only the relationship among isolates, but at the same time the relationship between isolate-allele and allele-allele. [ABSTRACT FROM AUTHOR]