DNRA was limited by sulfide and nrfA abundance in sediments of Xiamen Bay where heterotrophic sulfide-producing genus (Pelobacter) prevailed among DNRA bacteria

Journal of Soils and Sediments - Dissimilatory nitrate (NO3?) reduction to ammonium (DNRA) is a significant nitrogen (N) transformation process in estuarine ecosystem. The objectives...     

A global meta-analysis shows soil nitrogen pool increases after revegetation of riparian zones

Purpose

Sustainable management of riparian zone soils is required to ensure the health of natural ecosystems and maintenance of soil nitrogen (N) pools and soil N cycling. However, the effect of revegetation type and age on soil N pools remains poorly understood.

Materials and methods

This study compiled data from published articles to understand the effects of revegetation types and age on soil total N (TN) and soil inorganic N (NH₄⁺-N, and NO₃^?-N) using a meta-analysis. We extracted 645 observations from 52 published scientific articles.

Results and discussion

The revegetation of riparian zones led to a significant increase of soil TN (mean effect size: 11.5%; 95% CI: 3.1% and 20.6%). Woodland increased soil TN significantly by 14.0%, which was associated with the presence of N fixing species and high litter inputs. Soil NH₄⁺-N concentration significantly increased (mean effect size: 20.1%; 95% CI: 15.1% and 25.4%), whereas a significant decrease in soil NO₃^?-N (mean effect size: ? 21.5%; 95% CI: ? 15.0% and ? 27.5%) was observed. Of the revegetation types considered in this paper, NO₃^?-N concentration in soil followed the order: grassland < shrubland < woodland, suggesting that woodland might be more efficient in soil NO₃^?-N retention than grassland. The high plant N uptake and accelerated NO₃^?-N leaching in grassland could be related to the decreased soil NO₃^?-N in grassland compared with other revegetation types. Revegetation significantly decreased soil moisture by (mean effect size: ? 7.9%; 95% CI: ? 3.3% and ? 12.2%) compared with the control, which might be associated with the selection of exotic species as dominant vegetation in the riparian zone. Soil TN increased in revegetation ages between 10 and 40 years following revegetation and was related to increased soil organic carbon inputs within those ages following the establishment.

Conclusions

This study provides insight into influence of different vegetation types and age on soil N pools and soil moisture. This study also highlights the importance of revegetation in riparian zones to increase soil TN.

     

中国大鸨东方亚种群体间遗传关系分析

在中国境内松辽平原西北部的大鸨繁殖地、呼伦贝尔高原西南部的大鸨繁殖地及山东黄河三角洲地区,采集了大鸨东方亚种(Otis tarda dybowskii)18个个体,对线粒体DNA控制区Ⅱ的部分序列进行了测定和遗传关系分析.研究结果显示:18只大鸨mtDNA控制区301 bp序列的突变只有转换和颠换;核苷酸多态性为0.001 11±0.000 52;松辽种群与呼伦贝尔种群间有共享单倍型,两繁殖地存在遗传交流;山东种群与松辽种群、呼伦贝尔种群都有共享单倍型.根据研究结果,建议:应将松辽种群与呼伦贝尔种群作为一个保护单元进行保护;重视越冬地的保护;繁殖地与越冬地之间的迁徙通道和中途停留地,也应纳入大鸨的保护规划.     

阻燃稻秸人造板力学性能

对稻秸进行表面化学处理后,施加异氰酸酯和脲醛树脂胶,并在拌胶过程中添加阻燃剂,探索压制的稻秸人造板力学性能的主要影响因素.研究中采用正交试验方法确定胶黏剂和阻燃剂的最佳加入量,并按国家标准对板材进行物理力学性能测试,发现:稻秸人造板的内结合强度、弹性模量、静曲强度都超过了国家标准;2 h吸水厚度膨胀率略低,但也基本上达到国家标准;板材阻燃性能提高,但是阻燃剂的添加对稻秸人造板的力学性能影响较小.     

水稻品种松辽2号的选育与栽培技术

水稻新品种松辽2号从通粳288品种变异株经多世代田间选拔培育而成,具有熟期适宜,株型理想,受光率高,丰产性好,抗逆性强,适应性广,米质优良等综合性状优异的特点,通过省区域试验、生产试验,分别比对照品种增产6.2%和6.8%,稻米品质有5项指标达到部颁一级米标准,3项指标达到部颁二级米标准,松辽2号是我省乃至北方稻区中晚熟区较为理想的接替品种.     

70%噁霉灵可湿性粉剂防治甜菜立枯病药效评价

2007、2008年70%噁霉灵可湿性粉剂防治甜菜立枯病田间药效试验结果表明：70％噁霉灵可湿性粉剂有效成分4900 mg/kg甜菜种子,两年的防治效果分别为95.96%和92.17%,结合其他4个点次的试验结果,相比于对照药剂50%福美双可湿性粉剂,平均增加产糖量299.63 kg/hm2,折合人民币净增收1 115.49元,在此剂量下对甜菜安全,宜在黑龙江甜菜产区推广应用。     

云南普洱茶渥堆发酵过程关键控制因素分析

优质云南普洱茶是指以云南一定区域内种植的云南大叶种鲜叶制成的晒青毛茶及其压制茶在良好贮藏条件下长期贮存（10年以上）或云南大叶种晒青毛茶经人工渥堆发酵,使茶多酚、糖类等生化成分经氧化聚合水解等系列生化反应,最终形成具有条索肥壮紧实、色泽褐红（猪肝色）、陈香纯正、滋味醇厚回甘、汤色褐红透亮的品质特征,且质量卫生指标符合国家强制性标准要求的散状普洱茶产品或紧压茶产品。     

AFLP技术及其在干果遗传育种研究中的应用

AFLP(扩增片段长度多态性)是检测DNA多态性的一种高效的分子标记技术,该技术的运用不需要预知基因组的序列特征,可适用于任何来源和各种复杂度的DNA,兼具RFLP技术的可靠性和RAPD技术的方便性.近年来,AFLP技术已在干果遗传育种研究中得到广泛应用.该文对AFLP技术的基本原理和反应程序进行了介绍,综述了其在干果种质资源研究、遗传图谱构建、基因标记、分子辅助选择、基因表达等方面的应用,并对AFLP技术存在的问题及其在干果遗传育种研究上的应用前景进行了探讨.     

空间诱变柱花草品系比较试验

利用空间辐射技术选育柱花草新品种(系).空间辐射柱花草种子使其后代发生突变,经连续4a接种鉴定,选育出85个株系进行试验研究.结果表明,85个株系中30个株系的牧草产量、旱季干物质产量、抗病性、长势和植株存活率表现优良,其中2001-71,2001-2,2001-80,2001-84,2001-81,2001-24以及2001-73的综合测度值极显著高于其群体,有可能成为取代其亲本热研2号柱花草而在生产上推广利用的新品系.     

Association analysis reveals effects of wheat glutenin alleles and rye translocations on dough-mixing properties

The glutenin loci of wheat (Triticum aestivum L.) are important determinants of bread-making quality, although the effects of alleles at those loci are incompletely understood. We applied an association analysis method to assess the effects of glutenin alleles and 1RS wheat–rye (Secale cereale L.) translocations on dough-mixing properties in 96 wheat cultivars and advanced lines grown at three Colorado locations while accounting for population structure and relatedness of individuals in the population. The results indicated that (1) in the majority of cases, controlling relatedness of individuals reduced the significance of associations between glutenin loci and Mixograph traits; (2) the Glu-D1 and Glu-B3 loci and 1RS translocations had greater impacts on dough-mixing properties compared to other glutenin loci; (3) Glu-B1w, Glu-D1d, and Glu-B3b were consistently associated with greater (more favorable) Mixograph peak time (MPT) than other alleles at the respective loci, whereas Glu-B1e, Glu-D1a, and Glu-B3c were associated with reduced MPT; (4) the 1BL.1RS translocation was associated with a decrease in Mixograph properties. Our results indicate that taking multiple-level relatedness of individuals into account can improve the results of association analysis for wheat-quality traits.