Toxicidade de óleos essenciais de alho e casca de canela contra fungos do grupo Aspergillus flavus Evaluation of essential oils from Allium sativum and Cinnamomum zeilanicum and their toxicity against fungi of the Aspergillus flavus group

Diante da propriedade inibitória de óleos essenciais vegetais sobre o desenvolvimento micelial de fungos e da importância das espécies do grupo Aspergillus flavus, que apresentam potencial para síntese de aflatoxina, este trabalho teve como objetivo avaliar in vitro a toxicidade de óleos essenciais vegetais contra fungos do grupo A. flavus, isolados a partir da cultura do amendoim. Inicialmente, foi avaliada a toxicidade de oito óleos essenciais vegetais no desenvolvimento micelial de dois isolados do grupo A. flavus, em comparação ao fungicida sintético benomyl. Em seguida, foi avaliada a toxicidade dos óleos de casca de canela (Cinnamomum zeilanicum Breym.) e de bulbilho de alho (Allium sativum L.) contra 37 isolados do grupo A. flavus, durante 12 meses. A maior inibição do desenvolvimento micelial de A. flavus foi obtida com o emprego dos óleos essenciais de casca de canela e de bulbilho de alho, e o efeito inibitório variou com o isolado testado.<br>Considering the inhibitory property of essential plant oils on the mycelial development of fungi, and the importance of Aspergillus flavus-like fungi which may produce aflatoxins, this research was designed to evaluate the toxicity of essential oils against fungi belonging to the group A. flavus isolated from peanut crops. The toxicity of eight essential oils against two isolates of A. Flavuslike fungi was evaluated in comparison to the synthetic fungicide benomyl. The toxicity of Cinnamomum zeilanicum Breym. and Allium sativum L. essential oils was also evaluated against 37 fungal isolates for a period of 12 months. The highest inhibition of the mycelial development of A. flavus was obtained with cinnamon and garlic essential oils. The inhibitory effect on growth was variable according to the fungal isolate

Biotechnology approaches to overcome biotic and abiotic stress constraints in legumes

Biotic and abiotic stresses cause significant yield losses in legumes and can significantly affect their productivity. Biotechnology tools such as marker-assisted breeding, tissue culture, in vitro mutagenesis and genetic transformation can contribute to solve or reduce some of these constraints. However, only limited success has been achieved so far. The emergence of “omic” technologies and the establishment of model legume plants such as Medicago truncatula and Lotus japonicus are promising strategies for understanding the molecular genetic basis of stress resistance, which is an important bottleneck for molecular breeding. Understanding the mechanisms that regulate the expression of stress-related genes is a fundamental issue in plant biology and will be necessary for the genetic improvement of legumes. In this review, we describe the current status of biotechnology approaches in relation to biotic and abiotic stresses in legumes and how these useful tools could be used to improve resistance to important constraints affecting legume crops.E. Prats is funded by an European Marie Curie Reintegration Grant, N. Rispail by (FP5) Eufaba project. Our work in this area is supported by Spanish CICYT project AGL-2002-03248 and European Union project FP6-2002-FOOD-1-506223. K. Singh’s work in this area is supported in part by the Grains Research and Development Corporation (GRDC) and the Department of Education, Science and Training (DEST) in Australia.Peer reviewe