选择红壤丘陵区典型柑橘园,设置清耕、自然生草和竹豆间种3种种植模式,研究不同种植模式下柑橘园土壤化学性质、微生物生物量、微生物碳源代谢特征变化,并探明主导碳源代谢特征变化的土壤环境因素。结果表明,相对于清耕和自然生草种植模...选择红壤丘陵区典型柑橘园,设置清耕、自然生草和竹豆间种3种种植模式,研究不同种植模式下柑橘园土壤化学性质、微生物生物量、微生物碳源代谢特征变化,并探明主导碳源代谢特征变化的土壤环境因素。结果表明,相对于清耕和自然生草种植模式,竹豆间种模式下柑橘园土壤pH提高了24.03%和21.65%,有机碳、碱解氮、有效磷、速效钾分别提高了19.40%和25.14%、14.02%和18.61%、2.69和3.12倍、63.40%和1.14倍。柑橘园土壤微生物生物量碳受种植模式影响不显著,但是竹豆间种显著提高了土壤微生物碳源利用能力(Average well color development,AWCD)和均匀度指数。竹豆间种模式下土壤微生物对于酰胺、氨基酸、酚类和多聚物等多个大类碳源的代谢强度显著高于其他处理,清耕模式下土壤微生物对于糖类尤其是赤藓糖醇、葡萄糖-1-磷酸、D-纤维二糖的代谢强度显著高于其他处理。逐步回归分析结果表明,微生物的碳源利用能力和土壤有机碳密切相关,而pH是影响微生物功能多样性及多个特异性碳源代谢强度的首要因素。冗余分析结果表明,柑橘园土壤微生物碳源利用模式受土壤环境因素影响的大小顺序为:pH>有效磷>碱解氮>有机碳>速效钾。因此,竹豆间种能够缓解柑橘园土壤酸化,提高土壤养分含量,改善微生物群落结构和功能多样性,有利于柑橘园土壤生态健康和可持续利用。展开更多
Green manure can be used as a substitute for chemical fertilizer without reducing rice yield.We studied the responses of soil fertility and rice yield to different combinations of Chinese milk vetch(CMV;Astragalus sin...Green manure can be used as a substitute for chemical fertilizer without reducing rice yield.We studied the responses of soil fertility and rice yield to different combinations of Chinese milk vetch(CMV;Astragalus sinicus L.)and chemical fertilizer in a subtropical double-rice cropping system.Our goal is to reduce chemical fertilizer use and decrease environmental contamination.Compared with the recommended rate of chemical fertilizer(CF),both early-and late-rice yields in the two treatments supplied with 15 and 22.5 Mg CMV ha^-1 plus 60%CF(represented as 60 A and 60 B,respectively)showed no significant differences while the two treatments supplied with 30 and 37.5 Mg CMV ha^-1 plus 60%CF(represented as 60 C and 60 D,respectively)showed significantly higher values.The sustainable yield index(SYI)values in the 60 C and 60 D treatments with double-rice croppong system were significantly higher than those in other treatments(P<0.05).Early-rice yield showed a significant positive relationship with the Chinese milk vetch incorporation rate.The coefficients increased annually from 2009 to 2013 and then decreased in 2014.Soil organic matter increased over time by the end of the experiment in all of the treatment groups.Soil organic matter in 60 A,60 B and 60 C showed no significant difference compared with that in CF,while soil organic matter in 60 D was significantly higher than that in CF.The slopes of soil organic matter and total nitrogen over six years were the highest in 60 C and 60 D.The soil total nitrogen content in 60 A,60 B,60 C and 60 D was higher than that in CF,but the differences were not significant(P>0.05).Therefore,a relatively high Chinese milk vetch incorporation rate(≥30 Mg ha^-1)was more effective in improving the productivity and sustainability of paddy soil.The decreased coefficients of early-rice yield and the Chinese milk vetch incorporation rate in 2014 implied that the benefits of soil fertility and rice yield created by Chinese milk vetch input may decline after five years under a continuously high rate of Chinese milk vetch incorporation.展开更多
Parent materials and the fertility levels of paddy soils are highly variable in subtropical China.Bacterial diversity and community composition play pivotal roles in soil ecosystem processes and functions.However,the ...Parent materials and the fertility levels of paddy soils are highly variable in subtropical China.Bacterial diversity and community composition play pivotal roles in soil ecosystem processes and functions.However,the effects of parent material and fertility on bacterial diversity and community composition in paddy soils are unclear.The key soil factors driving the changes in bacterial diversity,community composition,and the specific bacterial species in soils that are derived from different parent materials and have differing fertility levels are unknown.Soil samples were collected from paddy fields in two areas with different parent materials(quaternary red clay or tertiary sandstone)and two levels of fertility(high or low).The variations in bacterial diversity indices and communities were evaluated by 454 pyrosequencing which targeted the V4–V5 region of the 16S rRNA gene.The effects of parent material and fertility on bacterial diversity and community composition were clarified by a two-way ANOVA and a two-way PERMANOVA.A principal coordinate analysis(PCoA),a redundancy analysis(RDA),and multivariate regression trees(MRT)were used to assess changes in the studied variables and identify the factors affecting bacterial community composition.Co-occurrence network analysis was performed to find correlations between bacterial genera and specific soil properties,and a statistical analysis of metagenomic profiles(STAMP)was used to determine bacterial genus abundance differences between the soil samples.The contributions made by parent material and soil fertility to changes in the bacterial diversity indices were comparable,but soil fertility accounted for a larger part of the shift in bacterial community composition than the parent material.Soil properties,especially soil texture,were strongly associated with bacterial diversity.The RDA showed that soil organic carbon(SOC)was the primary factor influencing bacterial community composition.A key threshold for SOC(25.5 g kg^(–1))separated low fertility soils from high fertility soils.The network analysis implied that bacterial interactions tended towards cooperation and that copiotrophic bacteria became dominant when the soil environment improved.The STAMP revealed that copiotrophic bacteria,such as Massilia and Rhodanobacter,were more abundant in the high fertility soils,while oligotrophic bacteria,such as Anaerolinea,were dominant in low fertility soils.The results showed that soil texture played a role in bacterial diversity,but nutrients,especially SOC,shaped bacterial community composition in paddy soils with different parent materials and fertility levels.展开更多
目的探讨联合临床、CT和放射组学特征预测肺腺癌的表皮生长因子受体(EGFR)和间变性淋巴瘤激酶(ALK)基因突变状态的价值。方法回顾性收集深圳市人民医院2017年1月至12月143例经手术病理证实肺腺癌和明确了EGFR及ALK基因状态、且于术前3...目的探讨联合临床、CT和放射组学特征预测肺腺癌的表皮生长因子受体(EGFR)和间变性淋巴瘤激酶(ALK)基因突变状态的价值。方法回顾性收集深圳市人民医院2017年1月至12月143例经手术病理证实肺腺癌和明确了EGFR及ALK基因状态、且于术前3个月内行CT检查的患者的临床资料。采用单因素分析比较3个临床特征、16个CT特征和94个CT放射组学特征与肺腺癌的EGFR和ALK基因突变的相关性。将有统计学意义的变量引入多因素Logistic回归模型分析预测EGFR和ALK基因突变状态的独立相关因素,最后作ROC曲线确定其诊断效能。结果143例肺腺癌患者中,EGFR突变型共63例(44.1%),野生型共80例(55.9%);ALK突变型共20例(14.0%),野生型共123例(86.0%)。单因素分析显示吸烟状况(P=0.002)、磨玻璃成分(P=0.042)、肿瘤周围肺气肿(P=0.043)、纵隔淋巴结肿大(P=0.020)和放射组学特征中的Size Zone Non Uniformity Normalized(P=0.031)与EGFR突变相关。Logistic回归分析结果显示,吸烟状况(OR=2.775,P=0.014)、纵隔淋巴结肿大(OR=2.056,P=0.039)和Size Zone Non Uniformity Normalized(OR=1.906,P=0.045)是预测EGFR基因突变的独立危险因素。年龄(P=0.002)、瘤肺界面(P=0.002)、毛刺征(P=0.021)、肿瘤坏死(P=0.000)与ALK突变相关。年龄(OR=2.436,P=0.041)、瘤肺界面(OR=3.367,P=0.032)和肿瘤坏死(OR=7.582,P=0.002)是预测ALK基因突变的独立危险因素。联合临床、CT特征和放射组学特征预测EGFR基因突变的AUC值0.694(95%CI:0.608~0.780),临床和CT特征预测ALK基因突变的AUC值为0.763(95%CI:0.617~0.910)。结论联合临床、CT和放射组学特征可以预测肺腺癌的EGFR和ALK基因突变状态,为临床治疗方案的选择提供决策支持。展开更多
文摘选择红壤丘陵区典型柑橘园,设置清耕、自然生草和竹豆间种3种种植模式,研究不同种植模式下柑橘园土壤化学性质、微生物生物量、微生物碳源代谢特征变化,并探明主导碳源代谢特征变化的土壤环境因素。结果表明,相对于清耕和自然生草种植模式,竹豆间种模式下柑橘园土壤pH提高了24.03%和21.65%,有机碳、碱解氮、有效磷、速效钾分别提高了19.40%和25.14%、14.02%和18.61%、2.69和3.12倍、63.40%和1.14倍。柑橘园土壤微生物生物量碳受种植模式影响不显著,但是竹豆间种显著提高了土壤微生物碳源利用能力(Average well color development,AWCD)和均匀度指数。竹豆间种模式下土壤微生物对于酰胺、氨基酸、酚类和多聚物等多个大类碳源的代谢强度显著高于其他处理,清耕模式下土壤微生物对于糖类尤其是赤藓糖醇、葡萄糖-1-磷酸、D-纤维二糖的代谢强度显著高于其他处理。逐步回归分析结果表明,微生物的碳源利用能力和土壤有机碳密切相关,而pH是影响微生物功能多样性及多个特异性碳源代谢强度的首要因素。冗余分析结果表明,柑橘园土壤微生物碳源利用模式受土壤环境因素影响的大小顺序为:pH>有效磷>碱解氮>有机碳>速效钾。因此,竹豆间种能够缓解柑橘园土壤酸化,提高土壤养分含量,改善微生物群落结构和功能多样性,有利于柑橘园土壤生态健康和可持续利用。
基金funded by the National Key Research and Development Program of China(2016YFD0800500 and 2016YFD0200800)the National Natural Science Foundation of China(31860592)+2 种基金the earmarked fund for China Agriculture Research System(CARS-22-Z-06)the Special Scientific Research Fund of Agricultural Public Welfare Profession of China(201503123-07)the Innovation Fund of Jiangxi Academy of Agricultural Sciences,China(2015CBS007 and 20182CBS002)。
文摘Green manure can be used as a substitute for chemical fertilizer without reducing rice yield.We studied the responses of soil fertility and rice yield to different combinations of Chinese milk vetch(CMV;Astragalus sinicus L.)and chemical fertilizer in a subtropical double-rice cropping system.Our goal is to reduce chemical fertilizer use and decrease environmental contamination.Compared with the recommended rate of chemical fertilizer(CF),both early-and late-rice yields in the two treatments supplied with 15 and 22.5 Mg CMV ha^-1 plus 60%CF(represented as 60 A and 60 B,respectively)showed no significant differences while the two treatments supplied with 30 and 37.5 Mg CMV ha^-1 plus 60%CF(represented as 60 C and 60 D,respectively)showed significantly higher values.The sustainable yield index(SYI)values in the 60 C and 60 D treatments with double-rice croppong system were significantly higher than those in other treatments(P<0.05).Early-rice yield showed a significant positive relationship with the Chinese milk vetch incorporation rate.The coefficients increased annually from 2009 to 2013 and then decreased in 2014.Soil organic matter increased over time by the end of the experiment in all of the treatment groups.Soil organic matter in 60 A,60 B and 60 C showed no significant difference compared with that in CF,while soil organic matter in 60 D was significantly higher than that in CF.The slopes of soil organic matter and total nitrogen over six years were the highest in 60 C and 60 D.The soil total nitrogen content in 60 A,60 B,60 C and 60 D was higher than that in CF,but the differences were not significant(P>0.05).Therefore,a relatively high Chinese milk vetch incorporation rate(≥30 Mg ha^-1)was more effective in improving the productivity and sustainability of paddy soil.The decreased coefficients of early-rice yield and the Chinese milk vetch incorporation rate in 2014 implied that the benefits of soil fertility and rice yield created by Chinese milk vetch input may decline after five years under a continuously high rate of Chinese milk vetch incorporation.
基金This work was supported by the National Key Research and Development Program of China(2018YFD0301104-01)the National Natural Science Foundation of China(41201242 and 41907041)+1 种基金the Major Research and Development Program for Science and Technology of Jiangxi Province,China(20182ABC28006)the“135”Plan and the Field Frontier Project,China(ISSASIP1642).
文摘Parent materials and the fertility levels of paddy soils are highly variable in subtropical China.Bacterial diversity and community composition play pivotal roles in soil ecosystem processes and functions.However,the effects of parent material and fertility on bacterial diversity and community composition in paddy soils are unclear.The key soil factors driving the changes in bacterial diversity,community composition,and the specific bacterial species in soils that are derived from different parent materials and have differing fertility levels are unknown.Soil samples were collected from paddy fields in two areas with different parent materials(quaternary red clay or tertiary sandstone)and two levels of fertility(high or low).The variations in bacterial diversity indices and communities were evaluated by 454 pyrosequencing which targeted the V4–V5 region of the 16S rRNA gene.The effects of parent material and fertility on bacterial diversity and community composition were clarified by a two-way ANOVA and a two-way PERMANOVA.A principal coordinate analysis(PCoA),a redundancy analysis(RDA),and multivariate regression trees(MRT)were used to assess changes in the studied variables and identify the factors affecting bacterial community composition.Co-occurrence network analysis was performed to find correlations between bacterial genera and specific soil properties,and a statistical analysis of metagenomic profiles(STAMP)was used to determine bacterial genus abundance differences between the soil samples.The contributions made by parent material and soil fertility to changes in the bacterial diversity indices were comparable,but soil fertility accounted for a larger part of the shift in bacterial community composition than the parent material.Soil properties,especially soil texture,were strongly associated with bacterial diversity.The RDA showed that soil organic carbon(SOC)was the primary factor influencing bacterial community composition.A key threshold for SOC(25.5 g kg^(–1))separated low fertility soils from high fertility soils.The network analysis implied that bacterial interactions tended towards cooperation and that copiotrophic bacteria became dominant when the soil environment improved.The STAMP revealed that copiotrophic bacteria,such as Massilia and Rhodanobacter,were more abundant in the high fertility soils,while oligotrophic bacteria,such as Anaerolinea,were dominant in low fertility soils.The results showed that soil texture played a role in bacterial diversity,but nutrients,especially SOC,shaped bacterial community composition in paddy soils with different parent materials and fertility levels.
文摘目的探讨联合临床、CT和放射组学特征预测肺腺癌的表皮生长因子受体(EGFR)和间变性淋巴瘤激酶(ALK)基因突变状态的价值。方法回顾性收集深圳市人民医院2017年1月至12月143例经手术病理证实肺腺癌和明确了EGFR及ALK基因状态、且于术前3个月内行CT检查的患者的临床资料。采用单因素分析比较3个临床特征、16个CT特征和94个CT放射组学特征与肺腺癌的EGFR和ALK基因突变的相关性。将有统计学意义的变量引入多因素Logistic回归模型分析预测EGFR和ALK基因突变状态的独立相关因素,最后作ROC曲线确定其诊断效能。结果143例肺腺癌患者中,EGFR突变型共63例(44.1%),野生型共80例(55.9%);ALK突变型共20例(14.0%),野生型共123例(86.0%)。单因素分析显示吸烟状况(P=0.002)、磨玻璃成分(P=0.042)、肿瘤周围肺气肿(P=0.043)、纵隔淋巴结肿大(P=0.020)和放射组学特征中的Size Zone Non Uniformity Normalized(P=0.031)与EGFR突变相关。Logistic回归分析结果显示,吸烟状况(OR=2.775,P=0.014)、纵隔淋巴结肿大(OR=2.056,P=0.039)和Size Zone Non Uniformity Normalized(OR=1.906,P=0.045)是预测EGFR基因突变的独立危险因素。年龄(P=0.002)、瘤肺界面(P=0.002)、毛刺征(P=0.021)、肿瘤坏死(P=0.000)与ALK突变相关。年龄(OR=2.436,P=0.041)、瘤肺界面(OR=3.367,P=0.032)和肿瘤坏死(OR=7.582,P=0.002)是预测ALK基因突变的独立危险因素。联合临床、CT特征和放射组学特征预测EGFR基因突变的AUC值0.694(95%CI:0.608~0.780),临床和CT特征预测ALK基因突变的AUC值为0.763(95%CI:0.617~0.910)。结论联合临床、CT和放射组学特征可以预测肺腺癌的EGFR和ALK基因突变状态,为临床治疗方案的选择提供决策支持。
