CO2加富及亏缺灌溉对菜豆中期与后期生长的影响

为了探明菜豆中期与后期生长对CO₂加富与亏缺灌溉的生理响应,试验设两个CO₂水平:正常大气浓度和倍增CO₂浓度,两个灌溉水平:自然灌溉12次和亏缺灌溉6次,研究CO₂加富及亏缺灌溉对菜豆生长的影响。结果表明,CO₂加富显著提高菜豆生长中期株高与干质量,净光合速率(Pn)与胞间CO₂浓度(Ci)分别显著降低15.48%、37.67%,气孔导度(Gs)显著提高95.83%,菜豆生长后期的叶绿素a/b(Chla/b)显著提高12.29%,水分利用效率(WUE)显著提高46.51%,Ci显著降低12.87%。CO₂加富显著提高亏缺灌溉下生长中期菜豆的株高与干质量,但显著降低根冠比,显著提高叶绿素含量以及Gs;CO₂加富下生长后期的核酮糖-1,5-二磷酸羧化酶(Rubisco)及果糖-1,6-二磷酸酶(FBPase)活性分别显著提高78.05%与88.69%,CO₂加富使亏缺灌溉下碳酸酐酶(CA)与FBPase活性分别显著提高83.73%与64.84%。综上所述,CO₂加富提高菜豆生长中期对亏缺灌溉的适应性,对生长后期影响作用减小。     

The Exploitation of Nematode-Responsive Plant Genes in Novel Nematode Control Methods

The molecular interactions between plants and sedentary nematodes are undergoing intense study, not only for reasons of fundamental research but also for the potential benefits to agriculture. The present technology allows the transformation of an increasing number of crop plants, providing new ways to introduce resistance against plant-parasitic nematodes. The ability of sedentary nematodes to induce specialized feeding sites in plant roots is one of the most fascinating aspects of this host–parasite interaction. Molecular approaches have been initiated to identify and characterize plant genes altered in expression after infection by sedentary nematodes. The results obtained indicate that many genes indeed become up-regulated upon nematode infection. Surprisingly, several so-called constitutive promoters that are normally used to achieve high expression in plant cells are completely ‘silenced’ in the feeding sites within days after nematode infection. Generally, there are two options available for the genetic engineering of nematode resistance: the synthesis of anti-nematode proteins or the localized production of a cytotoxic protein that interferes with the development of feeding cells. Nematode-induced promoters are very useful for the production by plants of sufficiently high levels of anti-nematode proteins at feeding sites. Alternatively, interfering with feeding-cell development is somewhat similar to the hypersensitive response evoked by nematodes in a naturally resistant plant. Here, destruction of specific plant cells can be achieved by the localized expression of a cytotoxin such as barnase, a potent ribonuclease. This approach, however, calls for a highly specific ‘non-leaky’ promoter, which is active only in the feeding cells. Another possibility is to use a two-component system, where the leakiness of the promoter in other tissues is counterbalanced by the constitutive expression of a neutralizing gene.     

Synthesis and Anthelmintic Activity of 7-Hydroxy- 5-oxo-5H-thieno[3,2-b]pyran-6-carboxanilides and -6-thiocarboxanilides

7-Hydroxy-5-oxo-5H-thieno[3,2-b]pyran-6-carboxanilides and -6-thio-carboxanilides represent a novel series of anthelmintic compounds, with broad-spectrum activity against important parasitic nematodes in sheep and dogs. In particular, an improved efficacy against Trichostrongylus colubriformis in sheep over the related 3-carbamoyl-4-hydroxycoumarins has been noted. New synthetic routes to the key intermediate, 7-hydroxythieno[3,2-b]pyran-5-one, have been developed.     

基于IPV6协议重构校园网的研究

为适应我国对第二代教育与科研网的建设,对互联网的IPV6协议进行了深入探讨,并在分析校园网的实际需求基础上提出了相应的解决方案,为校园网的重构提出了指导性的方法。     

贵州优良草种苇状羊茅规范化栽培施肥试验

2003~2004年采用二次通用旋转组合设计研究了氮、磷、钾不同施用水平对苇状羊茅鲜草产量的影响,获得优化回归模型为y=3426．86 623．07x1 220．75x3;主效应分析表明,增施氮、钾肥的增产效果十分明显,而增施磷肥的作用很小。经模拟寻优,获得年产鲜草4 864kg／667m2的施肥方案为每667m2施纯N 50kg、纯K2O 55kg。     

典型旱作农田土壤氧化亚氮排放的氨氧化微生物相对贡献

氨氧化过程对氧化亚氮（N2O）排放具有重要贡献。在不同土壤类型和农田管理下,氨氧化微生物类群对N2O排放的相对贡献组成规律还缺乏系统的研究。本研究选取典型农田耕层土壤（潮土、黑土、砖红壤）,以及有机肥改良的砖红壤剖面土壤,采用选择性抑制法（乙炔和辛炔）研究氨氧化细菌（AOB）、氨氧化古菌和全程硝化菌（AOA+comammox）以及异养硝化菌对土壤硝化潜势、净硝化速率及N2O排放的相对贡献。结果表明,在耕层土壤中,潮土、黑土和砖红壤的pH分别是8.0、6.7和5.7,硝化潜势分别是N 32.5、6.6和4.8 mg?kg-1?d-1,净硝化速率分别是N 7.1、3.0和0.5 mg?kg-1?d-1,7天N2O累积排放量分别是N 38.0、35.4和8.7 μg?kg-1。AOB主导耕层土壤的硝化潜势,对硝化潜势的贡献分别是82%、58%和100%。对于净硝化速率,在潮土和砖红壤中,AOB和AOA+comammox贡献相当（均在30%~40%）,而黑土中由AOB主导（72%）。AOB主导耕层土壤的N2O排放,对N2O排放的贡献分别是72%、92%和58%。在改良的砖红壤剖面土壤中,在0~20 cm、20~40 cm和40~60 cm,pH分别是7.0、5.5和4.9,硝化潜势分别是N 6.6、2.0和1.1 mg?kg-1?d-1,净硝化速率分别是N 4.1、0.9和0.2 mg?kg-1?d-1,N2O排放分别是N 16.3、6.5和2.8 mg?kg-1?d-1。随土壤由深层至表层,硝化潜势、净硝化速率及N2O排放显著提高。AOA+comammox主导表层硝化潜势及净硝化速率的提高（分别贡献63%和54%）,AOB主导N2O排放的增加（贡献54%）。本研究为制定与土壤氨氧化特性及土壤性质相匹配的N2O减排措施提供了新的科学依据。     

GM1 gangliosidosis in a Japanese domestic cat: a new variant identified in Hokkaido,Japan

A male Japanese domestic cat with retarded growth in Hokkaido, Japan, showed progressive motor dysfunction, such as ataxia starting at 3 months of age and tremors, visual disorder and seizure after 4 months of age. Finally, the cat died of neurological deterioration at 9 months of age. Approximately half of the peripheral blood lymphocytes had multiple abnormal vacuoles. Magnetic resonance imaging showed bisymmetrical hyperintensity in the white matter of the parietal and occipital lobes in the forebrain on T2-weighted and fluid-attenuated inversion recovery images, and mild encephalatrophy of the olfactory bulbs and temporal lobes. The activity of lysosomal acid β-galactosidase in leukocytes was negligible, resulting in the biochemical diagnosis of GM1 gangliosidosis. Histologically, swollen neurons characterized by accumulation of pale, slightly granular cytoplasmic materials were observed throughout the central nervous system. Dysmyelination or demyelination and gemistocytic astrocytosis were observed in the white matter. Ultrastructually, membranous cytoplasmic bodies were detected in the lysosomes of neurons. However, genetic analysis did not identify the c.1448G>C mutation, which is the single known mutation of feline GM1 gangliosidosis, suggesting that the cat was affected with a new variant of the feline disease.     

ABA， H2O2与NO对木枣果实成熟生理的影响

在木枣白熟期分别用ABA、H2O2与NO供体硝普纳（SNP）喷洒果实,对其调控木枣果实成熟的生理基础进行了研究。结果显示用不同浓度的ABA,H2O2与SNP处理,枣果实中丙二醛（MDA）的含量明显升高,其中100 mg?L-1浓度时MDA含量为最高;Ca、Vc和β-胡萝卜素含量呈现先降低后升高再下降的趋势,其中75 mg?L-1浓度时Vc和β-胡萝卜素含量最高,50 mg?L-1时Ca含量最高;CAT和APX活性的变化呈现先升高后降低的趋势,75 mg?L-1时CAT和APX活性均最大;DNA含量的变化呈现先缓慢降低后升高再下降的趋势,ABA比H2O2、SNP处理对DNA含量影响更明显,100 mg?L-1时DNA含量最高。结论：ABA、H2O2与SNP对木枣果实发育成熟的影响效果较为明显,其生理效果在多方面表现基本一致,有加快木枣果实成熟衰老的作用。     

花桥板栗2号与邵阳它栗的比较研究

摘 要：本文以湖南省的花桥板栗2号和邵阳它栗为研究对象,从品种原产地的自然条件、品种特征特性等方面进行对比研究,认为花桥板栗2号和邵阳它栗具有一定的相似性但特性且各有优劣,宜扬长避短,实现板栗产业化生产。