Soybean root and nodule nitrate reductase

Nitrate reductase (NR) activity was followed in root and nodule from Glycine max (L.) Merr. (Cv. Tracy) inoculated with Rhizobium japonicum . Initially, a plus NO^3- in vivo assay was used. When chlorate-resistant mutants were used as inoculum, nodule NR activity was reduced by about 90%. indicating that the bacteroid accounts for much of the normal nodule's NR. With plants 3 to 15 weeks of age nodule NR activity (g fresh weight)^-1 was highest in young plants and root activity highest in old plants. Root and nodule total NR activity increased with plant age and were often not greatly different. Root NR activity correlated with plant NO^3- supply and increased from 0.8 to 11.4 μmol plant^-1 h^-1 as NO^3- was increased from 0 to 3 m M . In contrast, nodule NR activity was high in plants grown without NO^3- and did not appear to increase as nitrate supply to the plant was increased. Nodule activity was 6 to 14 μmol NO^2- plant^-1 h^-1. Use of a minus NO^3- in vivo assay had little affect on root NR activity, but greatly reduced nodule activity. Root tissue was found to have 5 to 38 times more NO^3- than nodule tissue. It is concluded that low nitrate levels within the nodule limit NR activity and that it is improbable that the nodule is a major site of plant nitrate reduction.     

栽培因子对胡麻天亚9号产量的影响

为了探讨甘肃省胡麻高产栽培方案,以‘天亚9号’为试验材料,采用播种量（X₁）、底施氮肥（X₂）、底施磷肥（X₃）、底施钾肥（X₄）、叶面施钾肥（X₅）、叶面施硼肥（X₆）、生长调节剂（多效唑,X₇）、生育期灌水量（X₈）的8因素均匀设计,研究不同栽培因子对高产优质胡麻‘天亚9号’籽粒产量的影响,并对胡麻产量与各栽培因子进行相关性分析、通径分析及主成分分析.结果表明： 影响胡麻产量的因素为播量、底施氮肥、底施钾肥、生长调节剂、底施磷肥、叶面喷施钾肥;其相关性依次为播量>生长调节剂（多效唑）>底施氮肥>底施磷肥>叶面喷施钾肥>底施钾肥.进一步进行最高产量模拟寻优,采用频数分析法得到胡麻产量大于173.58 kg·hm^-2的优化栽培因子为：播量4.68～4.92 kg·hm^-2,底施氮肥11.59～14.75 kg·hm^-2,底施磷肥17.26～21.95 kg·hm^-2,底施钾肥7.00～12.50 kg·hm^-2,叶面肥（磷酸二氢钾）1.41～1.81 kg·hm^-2,生长调节剂（多效唑）751.74～954.04 g·hm^-2.     

日本血吸虫雄性成虫的细胞电活动特征的研究

应用玻璃微电极的电生理实验技术,研究日本血吸虫雄性成虫的细胞电活动。结果显示：日本血吸虫雄性成虫皮层细胞膜电位为－４７±５． ６ｍＶ（Ｘ±ＳＥ;ｎ＝１０３）;肌细胞膜电位为－３０．２±４．３ｍＶ（Ｘ±ＳＥ;ｎ＝１２６）．肌细胞可记录到自发放电活动,电位去极化幅值为９—２８ｍＶ。微电极记录的部分细胞（皮层细胞 ｎ＝２５;肌细胞 ｎ＝２２）用辣根过氧化酶（Ｈｏｒｅｒａｄｉｓｈ ｐｅｒｏｘｉｄａｓｅ,ＨＲＰ）标记,进行了细胞组织学鉴定．     

亚热带毛竹人工林土壤呼吸组分动态变化及其影响因素

利用Li-8100土壤碳通量测量系统,研究了2013年4月—2014年3月浙江临安市毛竹人工林土壤呼吸、异养呼吸和自养呼吸速率的动态变化规律.结果表明：毛竹人工林土壤总呼吸速率、异养呼吸速率和自养呼吸速率均呈现出明显的季节变化特征,最高值出现在7月,最低值出现在1月,年平均值分别为2.93、1.92和1.01 μmol CO₂·m^-2·s^-1.毛竹林土壤总呼吸、异养呼吸和自养呼吸年累积CO₂排放量分别为37.25、24.61和12.64 t CO₂·hm^-2·a^-1.土壤呼吸各组分均与土壤5 cm温度呈显著指数相关,土壤总呼吸、异养呼吸和自养呼吸的温度敏感系数Q₁₀值分别为2.05、1.95和2.34.土壤总呼吸速率、异养呼吸速率与土壤水溶性有机碳(WSOC)含量均呈显著相关,而自养呼吸与WSOC无显著相关性;土壤呼吸各组分与土壤含水〖JP2〗量以及微生物生物量碳均无显著相关性.土壤温度是影响毛竹人工林土壤呼吸及其组分季节变化的主要驱动因子,土壤WSOC含量是影响土壤总呼吸和异养呼吸的重要环境因子.     

Some kinetic properties of a purified glutamine synthetase from bacteroids of Glycine max

Abstract A purified glutamine synthetase was prepared from bacteroids of Rhizobium japonicum from nodules of Glycine max . For the biosynthetic assay the K _m values (mM) were l -glutamate 12.9, NH₄Cl 8.9 and ATP 14.3. When the enzyme was assayed by the γ-glutamyltransferase reaction the K _m values (mM) were l -glutamine 11.1 and hydroxylamine 3.3 compared with 7.7 and 1.2, respectively, for the purified enzyme from Rhizobium japonicum grown in culture. The enzyme prepared from bacteroids of Glycine max was 80% adenylylated.     

Isolation and characterization of polymorphic DNA microsatellite markers from Schistosoma japonicum

The ability of microsatellite loci to reveal genetic diversity within the trematode Schistosoma japonicum is demonstrated. Eleven novel microsatellite markers were isolated, assessing variability within 80 S. japonicum individuals from three Chinese and one Philippine population. Novel primers were also tested upon S. mansoni and S. haematobium. Eight primers showed polymorphic amplification from all S. japonicum groups, three amplified S. mansoni DNA, but none amplified S. haematobium DNA. Only six of 27 previously isolated S. mansoni‐specific primers amplified S. japonicum DNA. Allelic diversity and observed heterozygosity ranged from 4 to 21 and 0.05 to 0.82, respectively, suggesting high variability.     

大蓟紫外光谱鉴别特征的初步研究

为了研究大蓟(Cirsium japonicum)紫外光谱的显著鉴别特征，以快速、准确地鉴别正品大蓟，采用多溶剂紫外光谱法分析福建省不同地区的自采大蓟和市售18批不同厂家商品大蓟在无水乙醇、氯仿及石油醚溶剂中紫外特征差异，并采用主峰值(含肩峰值)及主谷值的均值加方差归纳比较特征。结果表明，自采大蓟在无水乙醇溶剂中表现为“谷—峰—谷—峰”，即在273±3 nm、326±2 nm处的峰值和250±2 nm、298±1 nm处的谷值具有显著鉴别意义；在氯仿溶剂中，表现为“峰—谷—峰”，即在245±3 nm、273±4 nm处的峰值和260±3 nm处的谷值具有显著鉴别意义；在石油醚溶剂中表现为“肩峰—谷—峰”，即在233±3 nm处的肩峰、265±5 nm处的峰值和257±5 nm处的谷值具有显著鉴别意义。紫外光谱的峰谷特征可用于大蓟鉴别。