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Ten pure isolations of Aspergillus, obtained from previously-disinfected seeds of Leucaena leucocephala cv. Peru, were evaluated from the cultural and morphological point of view, in order to identify to which species they belonged. The fungi were planted from mycelial discs of 7 mm diameter, of cultures which were 10-15 days old, that were placed at the center of glass Petri dishes of 9 cm diameter and were incubated for10 days at 25 ºC, with alternance of 8 h of light by 6 h of darkness. The experimental design was completely randomized, and for each isolate three dishes were used as replications. The cultural aspects measured were: color of the colony on the obverse and reverse, diameter, texture, linear growth (cm/day), aerial growth and substratum pigmentation; and the morphological aspects: size, shape and color of the structures with taxonomic value for the determination of the Aspergillus species. Isolates No. 2, No. 3, No. 4 and No. 5 were in correspondence with the species Aspergillus flavus Link; No. 19, with Aspergillus wentii Wehmer; and treatments No. 7, No. 20 and No. 21, with Aspergillus niger van Tieghem. It is concluded that three Aspergillus species were associated with the stored leucaena seeds. It is recommended to continue the studies to achieve the identification of isolates No. 6 and No. 22 to the species level. [ABSTRACT FROM AUTHOR]

The objective of this work was to characterize cultural and morphologically ten Fusarium isolates, obtained from stored Leucaena leucocephala cv. Peru seeds, aiming at their taxonomic classification. Their pure cultures were preserved in Eppendorf tubes with Potato Dextrose Agar (PDA) medium, in cold chamber at 10ºC. Each isolate was planted in three sterilized Petri dishes, of 9 cm diameter; they contained, separately, the PDA and Potato Sucrose Agar (PSA) media, which constituted the replicates; at their center a mycelial disk was placed, of 7 mm diameter, from 10-15-day-old cultures, also planted in such media. Afterwards, the dishes were sealed with wax paper and incubated for ten days at 25ºC, alternating 8 h of light/16 h of darkness, or in constant darkness. The measured cultural variables were: colony color on the obverse and reverse, texture and lineal and aerial growth; and the morphological variables were: size, shape and color of the vegetative and reproductive structures which appeared in the cultures. A completely randomized design was used, and the data were statistically processed through a descriptive analysis. For the fungi identification different taxonomic keys were used. Isolates 10, 18 and 29 were in correspondence with the characteristics described in scientific literature for the species Fusarium oxysporum Schlecht; 17, 28 and 30, to Fusarium sambucinum Fuckel; 27, to Fusarium semitectum Berk & Rav.; 25 and 26, to Fusarium incarnatum (Rob) Sacc, and 31, to Fusarium chlamydosporum Wollenw & Reinking, which allowed the identification of five Fusarium species associated to the stored seeds. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify the fungal agents associated to seeds of Leucaena leucocephala cv. Peru stored under ambient conditions, from the cultural and morphological characterization of 12 pure isolations; they were obtained from planting the fungal structures (vegetative and/or reproductive), in Petri dishes (9 cm diameter) which contained Potato Dextrose Agar (PDA) and Malt Agar (MA). The dishes were incubated for 10 days at 25°C, alternating 8 h light/16 h darkness or at constant darkness, according to the requirements of each organism. Seven fungal agents associated to the seeds were identified, which were classified taking into consideration the cultural and morphological characteristics, and they were corroborated with the taxonomic keys. This allowed to group: Penicillium expansum Link, Rhizopus stolonifer Ehrenb. Ex Fr., Cladosporium sphaerospermum Penz., Chaetomium indicum Corda, Alternaria alternata (Fr) Keissl., Pestalotia sp. and Trichoderma sp. Such characteristics constitute an important tool for the identification of fungi to the species level, for which new studies with isolations #9 and #11 are recommended in order to complete the identification to species level in the case of genera Trichoderma and Pestalotia; as well as to identify the fungal species of the other isolations. [ABSTRACT FROM AUTHOR]

The quality of seeds from Leucaena leucocephala constitutes the guarantee for the future seeding of the Cuban livestock areas; on it depends, to a certain extent, the use of this important protein feed source for animals and its spreading throughout the country. The objective of this work was to determine the quality of the seeds from L. leucocephala cv. Peru, one of the most cultivated commercial varieties nowadays, through the tests recommended by ISTA. The seeds were from the storehouse of the "La Rioja" farm belonging to the Marti Livestock Firm. A completely randomized design with four replications was used. The purity (97,0 and 94,5%) as well as the moisture content (10,09 and 9,87%) were within the optimum range for the stored seeds of this forage plant (6 and 18 months, respectively) and the germination percentages corresponded to the physiological age of the seeds (71 and 26%). Nine fungal genera {Aspergillus, Penicillium, Rhizopus, Chaetomium, Fusarium, Alternaría, Cladosporium, Trichoderma and Pestalotia) and a bacterial one (Erwinia sp.) were detected. The viability values (93,5 and 67,7% for lot 1 and 2, respectively) are considered acceptable for the seeds from this forage plant when it is stored under ambient conditions; nevertheless, the lower value in the seeds of lot 2 may have been caused by the increase in the percentage of seeds rotten by fungi, which had a direct influence on deterioration. Hence, it is recommended to continue the studies for identifying the fungal species associated to them and determining the ones that are pathogenic of this tree legume widely distributed in the livestock systems of the country. [ABSTRACT FROM AUTHOR]

La calidad de las semillas de Leucaena leucocephala constituye la garantía de las futuras siembras de las áreas ganaderas de Cuba; de ella depende, en cierta medida, la utilización de esta importante fuente de alimentación proteica animal y su propagación por el país. El objetivo de este trabajo consistió en determinar la calidad de las simientes de L. leucocephala cv. Perú, una de las variedades comerciales más cultivadas en la actualidad, a través de las pruebas recomendadas por ISTA. Las semillas procedían del almacén de la finca "La Rioja" de la Empresa Pecuaria Martí. Se utilizó un diseño completamente aleatorizado con cuatro réplicas. Tanto la pureza (97,0 y 94,5%) como el contenido de humedad (10,09 y 9,87%) estuvieron en el rango óptimo para las semillas almacenadas de esta forrajera (6 y 18 meses, respectivamente) y los porcentajes de germinación se correspondieron con la edad fisiológica de las semillas (71 y 26%). Se detectaron nueve géneros fungosos (Aspergillus, Penicillium, Rhizopus, Chaetomium, Fusarium, Alternaría, Cladosporium, Trichoderma y Pestalotia) y uno bacteriano (Erwinia sp.). Los valores de viabilidad (93,5 y 67,7% para el lote 1 y 2, respectivamente) se consideran aceptables para las semillas de esta forrajera cuando es almacenada al ambiente; no obstante, el menor valor en las del lote 2 pudo estar dado por el incremento en el porcentaje de semillas podridas por los hongos, lo cual influyó directamente en el deterioro. De ahí que se recomiende continuar los estudios para identificar las especies fungosas asociadas a ellas y determinar las que resulten patógenas de esta leguminosa arbórea ampliamente distribuida en los sistemas ganaderos del país. [ABSTRACT FROM AUTHOR]

A mycological diagnosis was carried out on seeds from Leucaena leucocephala cv. Peru which had been stored for 18 months under environmental conditions, with the objective of identifying the main fungi associated to them, and to determine the ones that had not been previously recorded. For that, Blotter Test was used according to the recommendations of ISTA (1999) for the pathological analysis of the seeds from tropical trees. The isolations of the fungi obtained were characterized from the morphological, cultural and pathogenic point of view. The most important finding was the detection and identification, for the first time in Cuba, of the legume tree under study; characteristics which coincided with the description in the different taxonomic keys consulted. Besides, the pathogenic character of such fungal agent could be detected as it caused a 20% rot to seeds that had not been germinated. [ABSTRACT FROM AUTHOR]