有机物料还田对土壤导水导气性的综合影响

【目的】 综合分析不同有机物料还田对土壤透水通气能力的影响,对改善作物根区土壤水分和空气环境,提高土壤生产力具有重要意义。【方法】本研究在陕西关中平原塿土上开展了2年（2014年6月至2016年6月）田间小区定位试验,以单施化肥为对照,分析不同有机物料（麦秆、麦壳、土粪和生物肥）配施化肥对0—30 cm土层土壤孔隙性、导水性和导气性的影响,并运用主成分分析综合评价土壤导水导气性。【结果】 有机物料还田可改善土壤孔隙性,促进土壤已有孔隙向较大孔隙发育,尤其在0—10 cm和20—30 cm土层,土壤大孔隙较对照显著（P<0.05）增加12.3%—136.4%;而在10—20 cm土层仅增施麦秆2 年后土壤大孔隙显著（P<0.05）增加。有机物料还田显著（P<0.05）提高了0—10 cm和10—20 cm土壤导水性,增加土壤初渗率、稳渗率、平均入渗率、90 min累积入渗量和饱和导水率,其中增施麦秆在0—10 cm土层增幅最大,较对照增加5.3—8.8倍,增施生物肥在10—20 cm土层增幅最大,较对照增加2.0—4.5倍;增施生物肥也显著改善了20—30 cm土层土壤导水性。在土壤导气性方面,增施麦秆和麦壳较对照显著（P<0.05）提高0—10 cm土层土壤孔隙连通性进而增加土壤导气率;而增施生物肥较对照显著（P<0.05）提高了10—20 cm和20—30 cm土层的土壤导气率。通过主成分分析综合评价0—30 cm土层土壤导水导气性,结果表明0—10 cm土层增施麦秆最优;10—20 cm和20—30 cm土层增施生物肥最优。【结论】 综合考虑,增施生物肥是关中平原相对较好的有机物料还田方式,对10—30 cm土层导水导气性的综合改善效果最优,可有效缓解塿土亚表层紧实化,改善根区土壤的透水通气效能。     

三峡水库成库初期氮、磷分布特征

三峡库区及其上游区是我国水土流失的重要地区。2003年6～12月三峡水库成库后，在三峡水库设置6个水平监测断面和2个垂直断面，每月对营养盐（NH3－N，NO2－N，NO3－N，TN，TP）进行浓度监测。结果表明，6个测点表层水NH3－N，NO2－N、NO3－N，TN，TP含量均值分别为0.11mg／L，0.019mg／L，1.28mg／L，1.62mg／L，0.13mg／L。沿水流方向TN浓度逐渐增高，TP浓度逐渐降低。在同一位置垂直方向按3个不同水深（表层、0.6倍水深和0.8倍水深）设置测点。连续7个月测试结果表明，营养盐在垂直方向上差异不明显。总磷浓度变化与流量变化有很大关系，总磷浓度最大值均出现在丰水期，最小值为枯水期。     

灰色系统理论在豫南稻区杂交稻品种抗病性综合评价中的应用

本文运用灰色系统理论综合评价了豫南稻区主要种植的七个杂交稻品种的综合抗病性。其结果表明:运用该法评价杂交稻品种的综合抗病性,比其它方法更简便易行,且全面、客观,可避免单独评价水稻品种对某一病害的抗性而引起的偏差。     

聊城市徒骇河风景区常绿植物对大气颗粒物削减作用

文章以聊城市徒骇河风景区10种常绿植物群落为研究对象,测定植物群落内的大气颗粒物浓度和叶面积指数、叶表特征等指标,结果表明,10种群落对3种粒径大气颗粒物的吸附作用存在较大差异。刚竹、圆柏对PM2.5和PM10的吸附作用较强,而白皮松、红叶石楠对PM2.5和PM10的吸附作用则较弱;圆柏、广玉兰对TSP吸附作用较强,大叶女贞、红叶石楠对TSP的吸附作用则较弱;叶面积指数和叶表特征对植物群落吸附不同粒径大气颗粒物具有一定的影响。通过观测冬季不同常绿植物群落对不同粒径大气颗粒物的削减作用,以及叶表面特征和群落冠层对其影响,为大气颗粒物污染的治理在植物选择上提供参考。     

猕猴桃细菌性溃疡病菌T3SS关键效应蛋白基因致病功能

[目的]由丁香假单胞菌猕猴桃致病变种(Pseudomonas syringae pv.actinidiae,Psa)引起的猕猴桃细菌性溃疡病是全球猕猴桃产业最具毁灭性的病害.病原细菌主要通过Ⅲ型分泌系统(typeⅢsecretion system,T3SS)将多种效应蛋白(T3SS effector,T3SE)注入寄主...     

用PCR鉴定大肠杆菌O157∶H7

根据大肠杆菌Ｏ１５７∶Ｈ７的编码ｅａｅ蛋白的ｅａｅＡ基因和大肠杆菌编码Ｈ７抗原的ｆｌｉＣ基因的核甘酸序列,合成了２对寡核苷酸引物,建立了一个检测大肠杆菌Ｏ１５７∶Ｈ７的ＰＣＲ方法。对１１株已知大肠杆菌Ｏ１５７∶Ｈ７（ＮＭ;无运动性）株和其他不同属的４２株已知肠道致病菌的检测结果表明,该方法只从大肠杆菌Ｏ１５７∶Ｈ７（ＮＭ）株的ＤＮＡ中产生预期的扩增产物,而从其他菌株的ＤＮＡ中未扩增出任何ＤＮＡ产物。该方法从基因水平直接确定大肠杆菌的血清型,特异性强,克服了以往血清学方法有非特异性反应的缺陷,为检测和鉴定大肠杆菌Ｏ１５７∶Ｈ７（ＮＭ）提供了一个新方法。     

让历史悠久的中国名犬走向世界

现时中国犬展的频率用“遍地开花、风起云涌”来形容不算为过,大有与国际接轨的趋势：但是,一味套用国际规则使得中国的名犬并未登上国际舞台,难为世界所认可,犬展犬赛上大多见到的是外国名犬甚至获奖的也大多是外国犬种。这也正是中国犬业繁华背后的隐忧——缺乏后劲,缺乏中华品牌的特色犬种品系。     

QTL Mapping of Hard Seededness in Wild Soybean Using BSA Method

【Objective】 Hard seededness of wild soybean is an important effector that limits the utilization of wild resources in soybean genetic improvement. Bulked segregant analysis (BSA) was employed to identify major quantitative trait loci (QTLs) related with hard seededness in soybean, which laid a foundation for effective utilization of wild soybean germplasm in cultivated soybean improvement. 【Method】 F₂ and F₇ segregation populations were constructed from a cross between cultivated soybean Zhonghuang39 and wild soybean NY27-38. Uniformly sized seeds were selected from each line, and 30 seeds were soaked in a petri dish with 30 mL distilled water for 4 hours at 25℃. The assay was replicated 3 times. The number of permeable and impermeable seeds were counted. In F₂ population, the first DNA pool was constructed from 22 individuals with permeable seeds (imbibition rate ＞90%), and second DNA pool was constructed from 16 individuals with impermeable seeds (imbibition rate ＜10%). In F₇ population, 20 lines with permeable seeds (100% imbibition) and 20 lines with impermeable seeds (no imbibition) were used to construct two DNA pools, respectively. To detect genomic regions associated with hard seededness, these DNA bulks were genotyped with 259 polymorphic SSR markers to identify markers linked to QTL. A linkage map was constructed with 192 SSR markers, QTLs related with hard seededness were identified by composite interval mapping in F₇ segregation population. 【Result】 Out of 259 SSR loci polymorphic between Zhonghuang39 and NY27-38, 10 and eight polymorphic SSR markers between the permeable and impermeable pools were detected in 16.3 Mb interval on chromosome 2 and 23.4 Mb interval on chromosome 6, respectively, in F₂ population. The QTL region (276.0 kb) located between Satt274 and Sat_198 on chromosome 2 contained previously cloned gene GmHs1-1, the QTL explained 17.2% of the total genetic variation. The other QTL was mapped on chromosome 6 flanked by BARCSOYSSR_06_0993 and BARCSOYSSR_06_1068, accounting for 17.8% of the total genetic variation. In F₇ population, eleven, nine and four SSR polymorphic markers between the permeable and impermeable pools were detected in 27.4 Mb interval on chromosome 2, 27.8 Mb interval on chromosome 6, 18.2 Mb interval on chromosome 3, respectively. A linkage map of 192 SSR markers and covering 2 390.2 cM was constructed through composite interval mapping in F₇ population. Three QTLs related with hard seededness were detected. The QTL on chromosome 2 located between Satt274 and Sat_198, explained 23.3% of the total genetic variation; the QTL on chromosome 6 flanked by Sat_402 and Satt557, explained 20.4% of the total genetic variation; the QTL on chromosome 3 flanked by Sat_266 and Sat_236 accounted for 4.9% of the total genetic variation. 【Conclusion】 In this study, three QTLs related to soybean hard seededness were identified by both BSA and traditional linkage mapping, indicating that BSA is an effective strategy for identifying QTLs in soybean.     

低温胁迫下8种柑橘的生理响应与抗寒性评价

本研究比较了8个柑橘品种的抗寒性并对其进行综合评价,以期了解这8种柑橘的抗寒能力差异并筛选评价柑橘抗寒能力差异的关键指标,这不仅为评价柑橘抗寒性提供了重要参考指标,也为柑橘的扩大引种和栽培提供了依据.以8种柑橘离体枝条为材料,分析0℃、-2℃和-4℃时柑橘的形态和生理生化指标的变化,通过隶属函数综合比较8种柑橘的抗寒能...     

高效靶向降解烟草花叶病毒核酸的dsRNA筛选与大量制备

[目的]筛选高效靶向降解烟草花叶病毒(tobacco mosaic virus,TMV)的dsRNA,实现其大量制备,并探究其作用机制.[方法]以TMV编码的CP、MP、RdRP功能基因为靶序列,体外转录合成相应的dsRNA,浸润本氏烟(Nicotiana benthamiana),24 h后接种TMV,于接毒后2、3...