[Effects of Long-term Straw Returning on Fungal Community, Enzyme Activity and Wheat Yield in Fluvo-aquic Soil].

To illustrate the effects of long-term straw returning on the fungal community, soil enzyme activity, and crop yield in a fluvo-aquic soil area typical of the Huang-Huai-Hai Plain, a 10-year field experiment (established in 2010) located in Dezhou City, Shandong province, was performed, including three fertilization regimes (NF, no fertilization control; NPK, fertilization with chemical N, P, and K fertilizers; NPKS, straw returning combined with chemical N, P, and K fertilizers). This study aimed to explore the regulation mechanisms of fungal communities on soil fertility, enzyme activities, and crop yield by employing co-occurrence network and structural equation model analyses. Our results showed that long-term straw returning significantly improved soil nutrients, enzyme activity, and wheat yield. Compared with the NPK and NF treatments, soil organic matter (SOM) increased by 9.20% and 34.75%, alkali-hydrolyzed nitrogen (AN) increased by 12.03% and 39.17%, dehydrogenase (DHA) increased by 37.21% and 50.91%, ß-glucosidase (ß-GC) increased by 17.29% and 73.48%, and wheat production increased by 16.22% and 125.53%, respectively. Different long-term fertilization regimes did not significantly change soil fungal α-diversity but resulted in significant differences in ß-diversity. Available phosphorus (AP), SOM, and AN were the main driving factors of fungal community differentiation based on redundancy analysis and hierarchical partitioning analysis. Different abundance analyses revealed significantly different fungal community compositions among fertilization regimes. The long-term NF treatment resulted in a significant enrichment of phosphate/potassium-solubilizing species (i.e., Mortierella, Aspergillus, Ceriporia, and Acremonium) and symbiotic species (i.e., Leohumicola and Hyalodendriella). The relative abundance of pathogenic fungi, namely Sarocladium, Fusarium, and Fusicolla, increased significantly in the NPK treatment. Long-term straw returning in the NPKS treatment significantly stimulated the growth of plant growth-promoting species (i.e., Pseudogymnoascus and Schizothecium) and straw-degrading species (i.e., Trichocladium and Lobulomyces). Co-occurrence network analysis showed that the fungal network was composed of four main modules; the cumulative relative abundance of module 2 was significantly increased under the NPKS treatment and showed a positive linear correlation with DHA and ß-GC. The structural equation model further indicated that the wheat yield was mainly regulated by SOM, whereas species of module 2 could indirectly affect SOM and wheat yield by positively regulating DHA and ß-GC. Taken together, long-term straw returning to the fluvo-aquic soil area of the Huang-Huai-Hai Plain could regulate fungal interspecific interactions, stimulate the growth of specific species groups, inhibit the activity of pathogens, increase the activity of soil enzymes, promote the accumulation of SOM, and achieve high crop yield.

Transumbilical single-port access laparoscopic surgery for colorectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the surgical outcomes after transumbilical single-port access laparoscopic surgery for colorectal cancer.</p><p><b>METHODS</b>Patients undergoing transumbilical single-port access laparoscopic radical resection for colorectal cancer at the Zhongshan Hospital of Xiamen University were included.</p><p><b>RESULTS</b>Three patients underwent transumbilical single-port access laparoscopic radical resection for sigmoid colon cancer and 1 for rectal cancer between August 2010 and September 2010. There were no intraoperative or postoperative complications. No conversion was required. The mean operative time was 206 min and the mean estimated blood loss was 75 ml. The mean number of harvested lymph nodes was 21. Patients were ambulatory in the same day of surgery or postoperative day 1. Length of hospital stay ranged from 7 to 10 days.</p><p><b>CONCLUSIONS</b>Transumbilical single-port access laparoscopic surgery is safe for colorectal cancer. Long-term outcomes warrant further investigation.</p>