MBTAE分光光度法测定微量锰

本文报道用2-(6-甲基-2-苯并噻唑偶氮)-5-二乙胺基酚(MBTAE)分光光度法测定微量锰。配合物的表观摩吸光系数为7.12×10~4L·mol~-1·cm~-1。MBTAE与Mn2 形成1∶2紫色配合物。配合物最大吸收波长为585nm。Mn2 浓度在0～8μg/25ml范围内符合比尔定律。方法用于人发中微量锰的测定,结果满意。     

牙鲆早期发育和变态期间Pitx2基因的表达(英文)

Pitx2基因被认为是脊椎动物中调节内脏器官左右不对称的关键转录因子。为进一步探讨牙鲆变态期间的左右不对称是否也受Pitx2的左特异活性调节,采用逆转录聚合酶链式反应(RT-PCR),拟在变态的牙鲆的头部组织中克隆编码Pitx2基因的部分cDNA序列,并通过以18s rRNA为内标的半定量RT-PCR研究其在牙鲆早期发育和变态期间的表达情况。克隆和测序的结果表明Pitx2在牙鲆早期发育和变态期间也存在基因表达;而半定量的结果表明它的左特异性功能很可能在变态的早期阶段发挥作用。但是,牙鲆变态期间的右眼移动是否受Pitx2的左特异活性调控,以及变态期间的左右不对称和内脏器官的左右不对称是否拥有相同的分子机制,仍需进一步研究。     

N-硝基-N-(2,4,6-三氯苯基)-N′-2-甲氧基苯基脲生物活性的研究

研究了N -硝基 -N - ( 2 ,4,6—三氯苯基 ) -N′ - 2 -甲氧基苯基脲对单子叶作物水稻的植物生长调节活性及对单子叶杂草稗的除草活性 ,结果表明 :在一定的浓度范围内 ,该化合物对水稻具有植物生长调节活性 ,对稗具除草活性。     

天山云杉林分树高测定的灰色动态模型

本文据根天山云杉林分树干解析资料,应用灰色系统理论建模方法,依树高和胸径的定期生长量随时间的增长而变化的数据序列,建立了测定树高的GM(1,2)灰色动态模型,求得模型计算值,进而以模型计算值作为蓄积量测定的要素之一,参予了林分蓄积量计算,并与实测值分别进行了对照检验,结果表明:所建模型拟合效果较好,其树高和蓄积量计算值,具有较高的精度。     

湖北光敏感核不育水稻育性转换机理初探

用乙烯生物合成抑制剂CoCl_2处理湖北光敏感核不育水稻(HPGMR),可在长日照不育条件下出现可育现象,而在育性转换临界光长下显著促进可育性表达。HPGMR幼穗中乙烯释放量,在长日照下所形成的幼穗比普通农垦58品种高2.5-5倍,而在育性转换临界光长下所形成的幼穗则降低至接近普通农垦58的低水平。表明HPGMR中可能存在受光周期调节的乙烯代谢系统,其育性转换受乙烯代谢水平的调控。     

杨树树皮挥发物的超临界萃取及对青杨脊虎天牛行为的影响

通过正交试验研究以收率为指标的CO2超临界萃取小叶杨树皮挥发物的最佳萃取工艺条件.结果表明:萃取压力25 MPa、温度50℃、时间60 min为小叶杨树皮挥发物的最佳萃取条件,收率为3.56%;依此条件分别萃取白城二号杨、小黑杨、俄罗斯杨、中东杨、小青杨、小青×黑杨、大青杨、斯大林杨、银中杨和小叶杨的树皮挥发物.采用气相色谱-质谱联用(GC-MS)技术对挥发物的化学组成及相对含量进行测定.结果表明:挥发性物质主要包括醛类、酯类、酸类、烃类等化合物,其中以酸类物质含量最高,其他物质含量均较低;萘、醌、奠、酮等大分子物质含量较少;中东杨和斯大林杨树皮中特异化合物种类较多.同时利用"Y"形嗅觉仪测定青杨脊虎天牛对10种杨树树皮100 μL挥发物的行为反应.结果表明,雄成虫对小青杨的选择率54.17%,为最高;雌成虫对小青x黑杨的最大选择率为58.33%,其次是对小青杨和中东杨的选择率54.17%.雄成虫对10种杨树树皮CO_2超临界萃取液的选择率差异不显著(P＞0.05),而雌成虫呈显著差异(P＜0.05).     

Atmospheric carbon dioxide enrichment reduces carbohydrate and nitrogen reserves in overwintering Picea mariana

Abstract

Elevated levels of atmospheric carbon dioxide (CO₂) can directly affect the cold hardening process in evergreens through their effect on the accumulation of carbon and nitrogen reserves. This study investigated the biochemical responses of black spruce [Picea mariana (Mill.) B.S.P.] seedlings to CO₂ enrichment during growth, cold hardening and dehardening. Seedlings were grown under 350 (ambient) or 710 (elevated) ppm of CO₂ for 12 months in eight mini-greenhouses. Photoperiod and temperature were gradually lowered in autumn to induce cold hardening, and the conditions were reversed in spring to promote dehardening. At regular intervals, cold tolerance was assessed and sugars, starch and amino acid concentrations were measured. The freezing tolerance differed between the two treatments only in early autumn, with seedlings growing under high CO₂ being more tolerant. The northern ecotype was more cold tolerant with concomitant higher concentrations of sucrose, fructose, pinitol, glucose and total soluble sugars. The concentration of soluble sugars increased in needles and roots of black spruce along with cold hardening, and the concentrations of the cryoprotective sugars sucrose and raffinose were lower under elevated CO₂. Amino acid concentrations were also lower under elevated than under ambient CO_2. The lower level of reserve did not translate into a lower level of freezing tolerance.     

超临界CO_2萃取结合高速逆流色谱分离八角茴香精油中的化学成分(英文)

建立了超临界CO2提取,高速逆流色谱分离纯化八角茴香中精油的分离方法。首先利用超临界CO2提取八角茴香中的精油,萃取压力为25 MPa,萃取温度为35℃。1.3 g粗提物经高速逆流色谱分离,两相溶剂体系为正己烷-乙酸乙酯-甲醇-水(体积比1∶0.2∶1∶0.1),一次分离出3种化合物,经EI-MS鉴定为茴香醛10.3 mg、异丁香酚甲醚7.1 mg和反式-茴香脑636.5 mg,纯度分别为98.9%、96.8%和99.7%。     

牡丹PsAP2基因的克隆及表达

以牡丹品种‘赵粉’为试材,采用RT-PCR和RACE方法从花瓣中获得1个牡丹APETALA2基因cDNA全长,命名为PsAP2,GenBank登录号为HM167511。序列分析结果表明:PsAP2全长2138bp,包含47bp的5'非编码区、557bp的3'非编码区和1个长度为1533bp编码510个氨基酸的开放阅读框。氨基酸序列分析显示该基因属于AP2家族。序列比对和系统进化分析表明,PsAP2与葡萄的亲缘关系最近,相似性达70%以上。相对荧光定量PCR分析表明,PsAP2在根、茎、叶和四轮花器官中均有表达。花瓣中的表达量最高,叶片中表达量最低。     

Cloning and sequence analysis of nine novel MYB genes in Taxodiaceae plants

Myeloblastosis(MYB) is one of the largest transcribed factor families in plants. To gain an overall picture of the evolution of MYB genes in relict plants, we cloned nine novel MYB genes in Taxodiaceae plants(Taxodium distichum, Taxodium ascendens, Cryptomeria japonica var. Sinensis, Cryptomeria japonica cv. Araucarioides, Cryptomer Japonica, Metasequoia glyptostroboides, Cunninghamia lanceolata, Taiwania cryptomerioides and Glyptostrobus pensilis). The deduced amino acid sequences for MYBs showed that the nine MYB proteins contained two DNA binding domains. The first domain is from amino acid position 29 to 78, wherein three tryptophanes at 33, 53 and 73 were separated by 19 amino acids, respectively. The second domain is from amino acid position 82 to 127, wherein three tryptophanes at 86, 105 and 124 were separated by 18 amino acids, respectively, whereas the first tryptophane at amino acid position 86 is replaced by a phenylalanine. The characterization of these conserved domains at nine MYBs indicated that they all belong to the R2R3-MYB group. The secondary structure analysis showed that α-helix and β-turn are the major motifs of the predicted secondary structure of MYBs. The three dimensional model of each MYB protein showed that the structure is like clip, making it more flexible and mobile. The similarities between the nine MYB proteins in Taxodiaceae were calculated. The highest identical value of 99% is between CjsMYB, CjMYB and CjaMYB, whereas the lowest value of 82% is between TaMYB and ClMYB. According to the phylogenetic tree, the distances between different genera were relatively large whereas those within genera were relatively small. As expected, accessions of the same genus formed a subgroup before being grouped with other genera.