Ocurrencia natural de hongos entomophthorales de áfidos plaga de Medicago sativa L. en Argentina / Natural occurrence of entomophthoroid fungi of aphid pests on Medicago sativa L. in Argentina

Se encontraron cuatro especies de hongos Entomophthorales, Pandora neoaphidis, Zoophthora radicans, Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) y Neozygites fresenii (Neozygitales: Neozygitaceae) infectando a Aphis craccivora, Therioaphis trifolii, Acyrthosiphon pisum y a especies no identificadas pertenecientes al género Acyrthosiphon en cultivos de alfalfa (Medicago sativa L.), en la Argentina. Los muestreos fueron realizados en cinco sitios (Ceres, Rafaela, Sarmiento, Monte Vera y Bernardo de Irigoyen) de la provincia de Santa Fe. Zoophthora radicans fue el patógeno más importante registrado principalmente en Acyrthosiphon sp. Zoophthora radicans fue exitosamente aislado y mantenido en cultivos puros. Este estudio documenta por primera vez en la Argentina la presencia de hongos Entomophthorales infectando áfidos en alfalfa

Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Zoophthora radicans (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae) were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen) in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L.) aphids in Argentina

Alfalfa dodder (Cuscuta campestris) toxicity in horses: clinical, haematological and serum biochemical findings.

The objective of this observational study is to describe clinical, haematological and serum biochemical findings of horses affected with alfalfa dodder (Cuscuta campestris) toxicity. Twenty horses naturally exposed to alfalfa dodder toxicity were examined and information was collected on history and clinical signs. Physical examination was done on horses in the premises (n=20), and venous blood samples of 12 horses were submitted for haematology and serum biochemical examination for each horse. Abnormal clinical signs started around 36 hours after horses were fed the contaminated alfalfa. Abnormal signs were seen in 11 horses and those included diarrhoea (n=8), decreased appetite (n=7), neurological signs (n=4) and abdominal pain (n=1). Some horses had multiple clinical signs of the above. The results of complete blood cell count revealed leukocytopenia, neutropenia and thrombocytopenia. Serum biochemical analysis revealed decreased ALP, AST and CPK levels and increased direct bilirubin level. The used alfalfa was stopped immediately and a different alfalfa from a new container that did not contain any weeds was fed. Horses on the premises were observed closely, and the abnormal clinical signs resolved within three days. No treatment was implemented. Knowledge about toxicity of horses by Cuscuta species is scarce in the English veterinary literature and very limited.

Toxicity of non-protein amino acids to humans and domestic animals.

Non-protein amino acids are common in plants and are present in widely consumed animal feeds and human foods such as alfalfa (Medicago sativa), which contains canavanine, and lentil (Lens culinaris), which contains homoarginine. Some occur in wild species that are inadvertently harvested with crop species. Some non-protein amino acids and metabolites can be toxic to humans, e.g. Lathyrus species contain a neurotoxic oxalyl-amino acid. Some potential toxins may be passed along a food chain via animal intermediates. The increased interest in herbal medicines in the Western countries will increase exposure to such compounds.

Alelopatia intra-específica de extratos aquosos de folhas e raízes de alfafa na germinação e no crescimento inicial de plântulas de dois materiais de alfafa: crioulo e melhorado / Intra-specific allelopathy of leaves and roots aqueous extracts on germination and early seedling growth of two alfalfa materials: crioulo and improved

A alfafa é uma das culturas conhecidas que apresentam um tipo específico de alelopatia denominado autotoxicidade. Dessa forma, o objetivo deste trabalho foi avaliar os efeitos da concentração de extratos aquosos de partes (folhas e raízes) da planta de alfafa (material Crioulo) na germinação e no crescimento inicial de plântulas de dois materiais de alfafa (Crioulo e P5454). Placas de Petri contendo 50 sementes de cada variedade foram umedecidas com 10ml dos extratos em duas concentrações: 50 por cento e 100 por cento (extrato puro). Água deionizada foi usada como controle. O delineamento experimental foi inteiramente casualizado, com cinco repetições para cada variedade. Após seis dias da germinação, procedeu-se à contagem do número de sementes germinadas, bem como à medição do comprimento do hipocótilo e da radícula de cada plântula. Os extratos aquosos das folhas inibiram a germinação e o comprimento da radícula e do hipocótilo das duas variedades. No entanto, para o material Crioulo, a inibição na germinação e no desenvolvimento inicial só ocorreu com o uso do extrato puro das folhas, enquanto que na P5454 o extrato diluído a 50 por cento já reduziu tanto a germinação quanto o comprimento das plântulas. Os extratos aquosos das raízes não causaram inibição na germinação nem no comprimento das plântulas. Os resultados sugerem variações intra-específicas na tolerância aos compostos aleloquímicos e uma produção preferencial dos mesmos na parte aérea da planta de alfafa, material Crioulo.

Alfalfa is one of the known crops that present a specific type of allelopathy called autotoxicity. Hence, this research was aimed at evaluating the concentration effects of aqueous extracts of plant parts (leaves and roots) of alfalfa (var. Crioula) on germination and early development of seedlings of two alfalfa (Crioula and P5454) varieties. Fifty seed of each variety were placed in Petri dishes with moistened filter paper. Aliquots (ten ml) from each part extracts at two concentrations, 50 or 100 percent (pure extract), were added to petri dishes, and distilled water was used as a control. Treatments placed in Petri dishes were randomly arranged in a completely randomized design with five replicates. Measurements included: germination, and radicle and hypocotyl lengths taken six days after germination. The aqueous extracts of leaves inhibited germination and radicle and hypocotyl length of the two alfalfa varieties. However, on the var. Crioula germination and early development was inhibited only when it was used pure extracts of leaves, while in var. P5454 leaves extracts diluted to 50 percent already had some reduction on germination and seedlings length. The aqueous extracts of the alfalfa roots did not cause inhibition on germination and seedlings lengths. The results suggest intra-specific variations on tolerance to the allelochemicals and a preferential production of them in the aerial part of the alfalfa plant, var. Crioula.

[A toxicological study of a phytopreparation made from an extract of alfalfa (Medicago sativa)]. / Toksikologicheskoe izuchenie fitopreparata iz ékstrakta liutserny posevnoi.

A phytopreparation from lucerne (Medicago sativa) was studied with respect to the acute and chronic toxicity and the action upon the cellular genetic mechanism. It was found that the preparation belongs to the group of practically nontoxic properties.

Liver disease in cattle induced by consumption of moldy hay.

Normally innocuous forages are sporadically associated with hepatogenous photosensitization outbreaks at certain times of the year or when grown and harvested during unusual environmental conditions, such as periods of excessive rainfall. Allegations of livestock illness following consumption of such moldy hays are associated with clinical syndromes uncharacteristic of known forage-related diseases, suggesting that unidentified toxin(s) may be responsible. This study was instigated by field observations of hepatogenous photosensitization in cattle fed alfalfa-grass forage. To document the toxic nature of the hay, large bales of hay (450 kg) were fed, ad libitum, to 3 groups of 2 calves each. Elevated serum liver enzymes provided evidence of hepatobiliary disease. Gamma glutamyl transferase activities in serums of the calves sustained at least a 10-fold increase above baseline during the feeding trials. Histologic examination of liver biopsies and postmortem sections revealed mild periportal fibrosis and biliary hyperplasia. Culture material from 12 fungal isolates from the hay failed to induce liver disease in calves.

Effect of chronic ingestion of tarbush (Flourensia cernua) on ewe lambs.

Efforts to increase livestock utilization of tarbush are being coupled with studies to examine tarbush toxicity. Thirty-eight (19/treatment) ewe lambs were assigned at birth to receive either tarbush or alfalfa (15%, dry matter basis) in a sorghum-based growing ration. Lambs were pen-fed this diet 60 d pre-weaning and 60 d post-weaning. No differences existed between treatments in feed consumption. In the tarbush group, 1 lamb died of unknown causes at 90 d of age, while 3 lambs died between 115 and 120 d of age. There were no deaths in the alfalfa group. Shortly before death, lambs fed tarbush appeared lethargic, disoriented and anorectic. At 122 d of age, 5 lambs were randomly selected from each group. Feces and jugular blood samples were obtained from each lamb before being euthanized and necropsied the following day. All fecal samples were negative for occult blood. Serum gamma glutamyl-transpeptidase (P < 0.001) and aspartate aminotransferase (P < 0.001) activities and platelet counts (P < 0.05) were elevated in lambs fed tarbush, while serum calcium concentrations tended (P < 0.10) to be greater. Histologic examination revealed diffuse liver apoptosis in lambs fed tarbush. These data indicate tarbush leaves cause liver damage when fed for extended periods of time.

Elimination of toxicity from diets containing alfalfa seeds.

Cynomolgus macaques were fed autoclaved alfalfa seeds for up to 1 yr. There were no humoral signs of a syndrome resembling systemic lupus erythematosus. The data are in contrast to those previously reported in monkeys fed raw alfalfa seeds, in which a systemic lupus erythematosus-like syndrome was induced in a shorter interval. The autoclaved seeds retained antihypercholesterolaemic effects.

Minimizing the saponin content of alfalfa sprouts and leaf protein concentrates.

Biologically active saponins were found to be concentrated in the white and green alfalfa leaf protein fractions at levels higher than in the original alfalfa. Coagulation and washing of the leaf protein at pH 8.5 resulted in a fourfold decrease in saponin compared to the protein coagulated at pH 6.0 and washed at pH 4.5. The press cakes from high and low saponin alfalfa retained 65 and 87% of the saponin. Protein fractions prepared from a low saponin alfalfa contained saponin levels less than 0.07%, compared to a saponin level of 1.33% in leaf protein prepared form a high saponin alfalfa. The saponin contents of three varieties of alfalfa sprouts ranged from 1.55 to 7.27% depending upon the maturity of the sprouts. The saponin content rapidly increased after sprouting and reached a maximum after eight days' growth. Both starch and total sugar decreased with the age of the sprouts while fiber increased from 8 to 18.7%.