摘要:
Amaranthus mangostanus is a green vegetable which is also used as sudorific, febrifuge, emollient, lactogogue and a specific treatment for colic. This study was aimed to determine antibacterial and antifungal activities of the methanol, dichloromethane, petroleum ether and ethyl acetate extracts from different parts of A. mangostanus against microbes that cause plant or human diseases and food contamination. At concentrations ranging from 40-100 mg/mL, ethyl acetate extracts from leaves and stems exhibited concentration-dependent inhibition against Pseudomonas solanacearum Smith, Acidovorax avenae subsp. A. Citrulli, Rhizoctonia solani, Colletotrichum capsici (syd.) Butl, Pseudomonas aeruginosa, Bacillus cereus and Escherichia coli, but not Magnaporthe grisea, Alternaria alternata Keissler, Phytophtora parasitica var. nicotianae Tucker and Fusarium graminearum Sehw., with MIC values of 519-713 and 463-697 mg/mL, respectively, whereas the ethyl acetate extract from roots only showed antibacterial activity against P. solanacearum Smith with an MIC of 815 mg/mL. Ethyl acetate extracts from leaves and stems also showed inhibitory effect on the fungus R. solani, with MICs of 686 and 734 mg/mL, respectively. Consequently the information on the antimicrobial functions of the extracts can shed light on the discovery of natural products for management of plant and human infectious diseases.
摘要:
Background Rice-duck cultivation is the essence of Chinese traditional agriculture. A scientific assessment of the mechanism and its capacity is of theoretical significance and practical value in improving modern agricultural technology. Results The duck's secretions, excreta and their treading, pecking and predation decrease the occurrence of plant diseases, pests and weeds, enrich species diversity and improve the field environment. The rice-duck intergrowth system effectively prevents rice planthoppers and rice leafhoppers. The control effects can be up to 98.47% and 100% respectively; it also has effects on the control of Chilo suppressalis, Tryporyza incertulas and the rice leafrollers. Notable control results are found on sheath blight, while the effects on other diseases are about 50%. Harm from weeds is placed under primary control; prevention of weeds is sequenced by broadleaf weeds>sedge weeds>Gramineae weeds. Contents of soil organic matter, N, P and K are improved by the system; nutrient utilization is accelerated, resulting in decreased fertilizer application. Greenhouse gas emissions are reduced by 1-2% and duck fodder is saved in this system. There is also an obvious economic benefit. Conclusion Compared to conventional rice cultivation, rice-duck cultivation shows great benefits to ecologic cost and economic income. (c) 2013 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry
作者机构:
College of Orient Science and Technology, Hunan Agricultural University, Changsha 410128, China;Natl. Res. Center of Eng. Technology for Utilization of Functional Ingredients from Botanicals, Changsha 410128, China;College of Horticulture and Gardening, Hunan Agricultural University, Changsha 410128, China;[黄璜] College of Agronomy, Hunan Agricultural University, Changsha 410128, China;[史云峰] College of Orient Science and Technology, Hunan Agricultural University, Changsha 410128, China, Natl. Res. Center of Eng. Technology for Utilization of Functional Ingredients from Botanicals, Changsha 410128, China
通讯机构:
[Yu, L.-J.] N;Natl. Res. Center of Eng. Technology for Utilization of Functional Ingredients from Botanicals, Changsha 410128, China
摘要:
Sheath blight, a disease caused by the fungus Rhizoctonia solani Kuhn (anamorph), has been the most economically significant disease of rice. It was frequently reported that the disease was well-controlled in integrated rice-duck system without the employment of fungicides. However, the effecting factors behind this phenomenon were rarely reported. In this research, experiment was carried out between two treatments, rice combined with ducks (RD) and conventional rice field without ducks rearing (CK) in early season rice paddy, to investigate the variations of sclerotia in floodwater and on rice plant, microclimate 10 cm above the waterline in rice paddy and activity of protective enzymes in rice plants. The results showed that the floating sclerotia in floodwater in RD was 86-91% lower than that in CK, and adhering sclerotia in rice plant in RD was 67-78% lower than that in CK. The relative humidity tested significantly lower and light intensity tested significantly higher in RD. The temperature in the early rice growth stages in RD was slightly lower than that in CK, but it was significantly higher (32.3-36.5°C) in the middle stage rice growth stages. The polyphenoloxidase (PPO) activity in RD were lower than that in CK, but the enhanced activity of phenylalanine ammonia-lyase (PAL), peroxidase (POD) and Chitinase was observed in different stages of rice growth in RD, especially the Chitinase which showed higher activity in all investigating days.