关键词: 可口革囊星虫, 可口革囊星虫, 总RNA提取, 改良Trizol法

Abstract: The soil fertility indicators on the township scale can embody the local basic soil fertility, and can also guide scientific fertilization effectively. The spatial distribution of soil fertility in 1504 agricultural towns of Shandong Province was studied by principal component analysis and spatial cluster analysis. The results showed that: (1) the content of organic matter, total nitrogen, available phosphorus and available potassium was (12.93±0.1) g/kg, (0.87±0.01) g/kg, (31.89±0.51) mg/kg and (128.64±1.48) mg/kg, respectively, based on the comprehensive score of soil quality, the soil fertility of each township in Shandong Province was divided into three categories: fertile, moderate and barren, accounting for 14.20% , 46.67% and 39.13% , respectively; conclusively, the quality of soil fertility in Shandong was at a lower level, and the proportion of middle and below was 85.8%; (2) the spatial distribution of soil fertility in Shandong increased first and then decreased from north to south, increased and then reduced from west to east; the region with relatively high soil fertility was centered on the central part, with divergence and ring-like distribution; via the central part of Weifang City, Zibo City, the northeast and southeast of Linyi City, the junction of the west of Zaozhuang City and Jining City, constituted a S-type; the southeastern Shandong peninsula had low soil coefficient, organic matter and available potassium were the main limiting factors, and the main reason for the lower soil fertility grade in the south- central, southwestern and southeastern regions were the low content of available phosphorus and available potassium; total nitrogen and available phosphorus were the main limiting factors of soil fertility in the northwest and northern regions. The results of this study have guiding significance for the targeted formulation of soil fertility improvement programs appropriate for different regions of Shandong Province.