基于全基因组填充重测序关联分析鉴别影响苏山猪初生体尺与乳头数性状的遗传位点

旨在鉴别影响苏山猪初生体尺和乳头数性状的遗传位点,开发可用于辅助育种的分子标记,为苏山猪生长和繁殖性能的持续选育提供理论基础。本试验对269头苏山猪初生仔猪(出生后24 h内)的体尺和乳头数表型进行测定,并采集耳组织样品。基于全基因组重测序及基因型填充策略,利用全基因组关联分析(genome-wide association study, GWAS)和群体分化指数(fixation index,Fst)的方法挖掘与目的性状强关联位点,并对位置功能候选基因开展GO和KEGG分析,确定最有可能的主效基因。本研究共鉴别到4个候选位点,分布在13、14和X染色体上,其中与初生体尺性状显著关联的位点有2个,与乳头数性状显著关联的位点有2个。本研究筛选出1个与体长性状相关的候选基因ACTA2;1个与胸围性状相关的候选基因COL4A6;3个与乳头数性状相关的候选基因ACTA2、CRTAP和SEPTIN6,为苏山猪初生体尺性状和乳头数性状的遗传改良提供了重要的分子标记。     

Test Analysis of Ecosystem on Functional Groups of Microorganism in Spiral Up- flow Reactor System

The test of functional groups of microorganisms in Spiral Up-flow Reactor System and the correlation between microorganisms in the water and the main environmental factors are studied.The results show that the diversity of microorganisms population in the SUFR system is complex and the bio-community formed in the SUFR system is stable.The close relations between abundance of bacteria and nutrients are found.The correlation between heterotrophic bacteria and COD is 0.949.The correlation between organic phosphate bacteria and TP is 0.815. The correlation between nitrosobacteria and NH_3-N is 0.909. The correlation between disnitrifier bacteria and TN is 0.653.     

巢湖沿岸圩区稻季营养盐的输出特征研究

巢湖流域沿岸分布着很多圩区,人们在圩内进行各种农业活动,圩区营养盐的输出是造成巢湖流域非点源污染的重要因素。为了解圩区农业非点源营养盐的输出特征,笔者通过在巢湖流域河网地区选择比较典型的圩区,于2014年水稻生长期进行了较系统的野外调查观测、取样和室内水质分析,探讨在自然降雨-径流的条件下圩区各类营养盐的浓度变化及输出特征。2014年稻季共进行了9次排水,排水量总计73.09 mm,径流系数为0.37,9次排水事件总氮(TN)和总磷(TP)的平均浓度分别是3.42、0.22 mg/L,圩区水体处于富营养化水平。降雨-径流强度是影响营养盐浓度变化的重要因素,稻季生长期内TN和TP的输出量是0.28、0.017 kg/hm2,占稻季施肥总量的1.7%和0.16%。径流量是影响营养盐输出总量的关键因素,同时施肥量和施肥至排水事件的间隔天数也是是影响营养盐输出的重要因素。     

桃芽休眠诱导过程中IAA、ABA含量及PpPINs基因表达的变化

为认识桃芽休眠诱导过程中生理与相关基因表达的变化,分别用HPLC检测‘中农红久保’、‘中农3号’、03-30-035 3个桃品种(系)休眠诱导时期叶片和叶芽IAA和ABA含量,用RT-q PCR检测叶片和叶芽生长素极性运输载体基因Pp PIN1、Pp PIN3、Pp PIN5和Pp PIN8共4个基因的相对表达量。结果表明,在桃芽休眠诱导过程中,叶片IAA含量未见显著变化,ABA含量自10月6日开始升高,至10月16日含量达到高峰;叶芽中10月上中旬IAA含量骤增,而ABA含量逐渐降低。本研究中桃基因组的4个Pp PINs基因家族成员中,叶片中活跃表达为Pp PIN5,其次为Pp PIN3,在10月上中旬Pp PIN5出现强烈表达;而在10月26日,叶芽中活跃表达的Pp PIN1和Pp PIN3表达量骤降。桃休眠诱导过程中叶片和叶芽内内源激素和Pp PINs基因表达量变化明显不同。     

Effect of Timing and Nitrogen Fertilizer Application on Winter Oilseed Rape (Brassica napus L.). I. Growth Dynamics and Seed Yield

The field experiments conducted on the grey‐brown podzolic soil in the four growing seasons (1998–2001) at Krzeslice Farm, central‐western Poland comprised seven fertilization variants: 80_NF + 80_CAN; 80_CAN + 80_CAN; 80_AN + 80_AN; 80_NF + 50_CAN + 30_CN; 80_CAN + 50_CAN +30_CN; 80_AN + 50_AN + 30_CN (where NF – nitrofos NPK; CAN – calcium‐ammonium nitrate; AN – ammonium nitrate; CN – calcium nitrate) and control (without N) applied in split rates at the beginning of spring regrowth (80 kg N ha^?1), stem elongation (80 or 50) and flower buds visible stages (30). The yielding effect of tested fertilization variants was significant in comparison with the control (2.24 t ha^?1). The highest mean seed yield (3.64 t ha^?1) was collected from 80_AN + 80_AN and 80_CAN + 80_CAN variants. Mean values of 4 years indicate that the second N rate division (80 + 50 + 30) decreased yield, although not significantly in comparison with these two N treatments. Plants grown on these treatments have developed different patterns of growth to yield the seeds. These patterns were characterized by very high crop growth rate during flowering (above 21 g m^?2 day^?1) and negative at maturation (down to ?2.5 g m^?2 day^?1). Plants fertilized with ammonium nitrate (80_AN + 80_AN) reached maximum growth rate earlier (65 days), which lasted longer (20 days) than plants fertilized with calcium‐ammonium nitrate (71 days lasting 17.5 days). Plants grown on the control treatment reached the highest crop growth rate within 79 days (14.8 g m^?2 day^?1), which lasted 15 days.     

氮素营养水平对小麦后移栽棉氮代谢的影响

对不同氮素营养水平下的小麦后移栽棉叶片硝酸还原酶活性、棉株含氮量及叶片氨基酸含量等进行了测定。结果表明，除８月１９日外，叶片硝酸还原酶活性与施氮量呈极显著正相关（ｒ＝０．９６９３～０．９８８１）；地上部各器官的含氮率和绝对含氮量均随施氮量的增加而提高，且不同器官间呈同步增减的趋势，因而氮素分配比例的变化不大；提高氮素营养水平可显著增加小麦后移栽棉的叶片氨基酸总量和游离氨的含量（ｒ＝０．５３１６和０．５６０５），在１７种氨基酸中，谷氨酸、脯氨酸等７种氨基酸的含量与施氮量呈显著的正相关（ｒ＝０．５２５６～０．６０７４）。虽然施氮量越高，棉株的氮素代谢越旺盛，但小麦后移栽棉的适宜施氮量约为２０５ｋｇ／ｈｍ２。     

旱区覆膜滴灌棉田N 2 O排放对化肥减量有机替代的响应

覆膜滴灌条件下,采用静态箱-气相色谱法研究了不同施肥策略:CK(不施肥)、CF(N 300 kg/hm~2;P2O590 kg/hm~2;K2O 60 kg/hm~2)、60%CF+OF(普通有机肥6 000 kg/hm~2)、60%CF+BF(生物有机肥6 000 kg/hm~2)对棉田土壤N_2O排放的影响,旨在明确滴灌棉田连续不同施肥策略下土壤N_2O的排放特征。结果表明,棉花生育期N_2O排放通量表现为施肥处理大于不施肥处理,滴灌施肥后第3/4天N_2O排放通量顺序为CF60%CF+OF60%CF+BFCK,而滴灌后第7/8天N_2O排放通量则表现为有机肥处理高于化肥处理,滴灌施肥结束后表现与之相同;生育期的N_2O排放总量以100%化肥处理(CF)最高,与其相比,60%CF+OF和60%CF+BF处理分别降低3.75%和8.37%,N_2O排放系数则分别降低1.39%和73.8%;相关及通径分析均表明,与土壤NH+4-N相比,NO-3-N与N_2O排放的关系更密切。     

Simulation of drainage water quality with DRAINMOD

The design and management of drainage systems should consider impacts on drainage water quality and receiving streams, as well as on agricultural productivity. Two simulation models that are being developed to predict these impacts are briefly described. DRAINMOD-N uses hydrologic predictions by DRAINMOD, including daily soil water fluxes, in numerical solutions to the advective-dispersive-reactive (ADR) equation to describe movement and fate of NO₃-N in shallow water table soils. DRAINMOD- CREAMS links DRAINMOD hydrology with submodels in CREAMS to predict effects of drainage treatment and controlled drainage losses of sediment and agricultural chemicals via surface runoff. The models were applied to analyze effects of drainage intensity on a Portsmouth sandy loam in eastern North Carolina. Depending on surface depressional storage, agricultural production objectives could be satisfied with drain spacings of 40 m or less. Predicted effects of drainage design and management on NO₃-N losses were substantial. Increasing drain spacing from 20 m to 40 m reduced predicted NO₃-N losses by over 45% for both good and poor surface drainage. Controlled drainage further decreases NO₃-N losses. For example, predicted average annual NO₃-N losses for a 30 m spacing were reduced 50% by controlled drainage. Splitting the application of nitrogen fertilizer, so that 100 kg/ha is applied at planting and 50 kg/ha is applied 37 days later, reduced average predicted NO₃-N losses but by only 5 to 6%. This practice was more effective in years when heavy rainfall occurred directly after planting. In contrast to effects on NO₃-N losses, reducing drainage intensity by increasing drain spacing or use of controlled drainage increased predicted losses of sediment and phosphorus (P). These losses were small for relatively flat conditions (0.2% slope), but may be large for even moderate slopes. For example, predicted sediment losses for a 2% slope exceeded 8000 kg/ha for a poorly drained condition (drain spacing of 100 m), but were reduced to 2100 kg/ha for a 20 m spacing. Agricultural production and water quality goals are sometimes in conflict. Our results indicate that simulation modeling can be used to examine the benefits of alternative designs and management strategies, from both production and environmental points-of-view. The utility of this methodology places additional emphasis on the need for field experiments to test the validity of the models over a range of soil, site and climatological conditions.     

农田生态系统中氮循环模型研究进展

农田生态系统中的氮循环是影响农业生产力的主要因素之一,同时也会对环境产生影响。在农田生态系统氮循环的研究中模型已成为重要的工具而受到人们关注。在介绍国际上发表的模型基础上,阐述了目前一些比较成功的模型的研究进展,并指出了今后模型发展的趋势。     

陕西省几种黄土性土壤钾吸附固定动力学研究

采用平衡法研究了陕西省 4种黄土性土壤钾吸附固定的动力学性质。结果表明 :1黄土性土壤不同土类钾吸附固定量、吸附固定速度及平衡时间差异很大。土娄 土粘化层和黑垆土埋藏腐殖质层的钾吸附固定量约为耕层的 2倍 ,陕南黄褐土的钾吸附固定量仅次于 土娄 土粘化层 ,黄绵土的钾吸附固定量最小 ;2供试土壤不同时段的钾吸附固定速度随时间的衰减变化符合 Vt=A Blnt模型 ,衰减速率因土类而异 ;3供试土壤钾吸附固定过程符合 Elovich方程和一级扩散方程 ;4供试土壤钾吸附固定过程分为快、中、慢三个阶段或快、慢两个阶段 ,快反应约在 4 0 h完成 ,吸附固定钾量达总量的 64 %～ 93 % ,所用时间仅占总时间的 1 2 %～ 4 3 %。