RESUMO
Response of rhizosphere microbial community structure and co-occurrence patterns to liquid organic fertilizer in sunflower cropland was investigated. Moderate and severe saline-alkaline soils were treated with liquid organic fertilizer containing mainly small molecular organic compounds (450 g L-1) at a rate of 4500 L ha-1 year-1 over 2 years. Compared with the untreated soils, organic fertilizer treatment increased soil nutrient concentrations by 13.8-137.1% while reducing soil pH and salinity by 5.6% and 54.7%, respectively. Organic fertilizer treatment also improved sunflower yield, plant number, and plant height by 28.6-67.3%. Following organic fertilizer treatment, fungal α-diversity was increased, and the effects of salinity-alkalinity stress on rhizosphere microbial communities were alleviated. The relative abundances of some halotolerant microbes and phytopathogenic fungi were reduced in organic fertilizer-treated soils, in contrast to increases in the relative abundances of plant growth-promoting microbes and organic matter decomposers, such as Nocardioides, Rhizophagus, and Stachybotrys. Network analysis revealed that severe salinity-alkalinity stress stimulated cooperation among bacteria, while organic fertilizer treatment tended to stimulate the ecosystem functions of fungi with higher proportions of fungi-bacteria and fungi-fungi links. More keystone taxa (e.g., Amycolatopsis, Variovorax, and Gemmatimonas) were positively correlated with soil nutrient concentrations and crop yield-related traits in organic fertilizer-treated soils. Overall, liquid organic fertilizer amendment could attenuate the adverse effects of salinity-alkalinity stress on sunflower yield by improving soil quality and optimizing rhizosphere microbial community structure and co-occurrence patterns.
Assuntos
Helianthus , Microbiota , Bactérias , Fertilizantes , Rizosfera , Salinidade , Solo/química , Microbiologia do SoloRESUMO
Primary tumors of the heart are rarely seen. Cardiac angiosarcomas are malignant tumors that almost always have a poor prognosis. Atrium rupture and coronary artery fistula are very rare complications of primary cardiac angiosarcoma. We describe a 57-year-old man suffering from primary cardiac angiosarcoma with spontaneous ruptures of the right atrium and right coronary artery (RCA). Theoretically, either of these ruptures invariably results in pericardial effusion and tamponade that is rare but potentially life threatening. In this instance, however, the patient might have developed fibrous adhesions resulted from previous bloody pericardial effusion. A massive pericardial effusion was localized, which consequently prevented cardiac tamponade and hemodynamic collapse. Echocardiography revealed the tumor progression leading to detectable infiltration of solid mass into the right atrial (RA) wall, which is close to RCA. And color Doppler displayed the flow into the pericardial cavity through a disrupted RA wall and perforated RCA. Echocardiography remains the primary method of choice for evaluation of cardiac masses.