水稻低淀粉粘滞突变体的理化特性和淀粉结构

以水稻低淀粉粘滞突变体RSV-1及其野生型品种II-32B为材料,研究了低淀粉粘滞突变的理化特性和淀粉结构。结果表明,低淀粉粘滞突变体的最高粘度、热浆粘度和冷胶粘度明显小于野生型,但表观直链淀粉含量、胶稠度、碱消值均大于野生型,达最高粘度时间接近,糊化过程中所需能量较低,糊化过程较长;淀粉晶体表现为C型结构,淀粉颗粒与野生型的正六面体颗粒完全不同,呈大小不等的无规则形,淀粉晶体及颗粒结构的改变可能是导致淀粉粘滞性下降及其他理化指标改变的重要原因。     

Overexpression of the LASAP2 gene for secretory acid phosphatase in white lupin improves the phosphorus uptake and growth of tobacco plants

Secretion of acid phosphatase (APase) from the roots to take up phosphorus (P) is a well-known strategy of plants under P-deficient conditions. White lupin, which shows vigorous growth in low-P soils, is noted for its ability to secrete APase under P-deficient conditions. The APase secreted by white lupin roots is stable in soil solution and shows low substrate specificity, suggesting that genetic modification of plants using the APase gene LASAP2 might improve their ability to use organic P. The objective of the present study was to evaluate the potential of LASAP2 transgenic plants to increase organic P utilization. Dry matter production and P accumulation were higher in LASAP2 transgenic tobacco plants grown in gel media containing soluble phytate as the sole P source than in wild-type tobacco plants. Phosphorus uptake by the transgenic plants also increased in soil culture conditions. LASAP2 was apparently more effective in the liberation of organic P, including phytate, in the soil than the native tobacco APase. Thus, the enzymatic stability of LASAP2 in the soil appears to be an important factor for P acquisition.     

运用多隔层根箱研究黑麦草根际微域中芘的降解

采用多隔层根箱,通过尼龙撩网插片的控制,实现根室土(S0)、离根室0～2 mm(S1)、2～4 mm(S2)、4～6 mm(S3)及>6 mm(S4)各室层土壤的分离采集,测定各室层土壤可提取态芘含量、土壤微生物生物量碳、土壤基础呼吸强度、微生物熵、代谢熵、脱氢酶和多酚氧化酶活性。结果表明:种植黑麦草处理的各室层内土壤可提取态芘含量存在显著的不同,可提取态芘含量在各室层的大小顺序为S4>S3>S0>S2>S1;各室层土壤微生物生物量碳、土壤基础呼吸强度、微生物熵、代谢熵、脱氢酶和多酚氧化酶活性表现出与可提取态芘含量变化相反的趋势。未种植黑麦草处理的各室层土壤可提取态芘含量、土壤微生物生物量碳、土壤基础呼吸强度、微生物熵、代谢熵、脱氢酶和多酚氧化酶活性没有差异。种植黑麦草处理各室层土壤可提取态芘含量与土壤微生物生物量碳、土壤基础呼吸强度、微生物熵、代谢熵、脱氢酶活性和多酚氧化酶活性之间均存在显著的负相关性(p<0.05)。主成分分析结果表明种植黑麦草处理土壤微生物活性在各室层间发生了明显的变化。     

平耳孔蜈蚣细胞色素b基因序列变异分析

[目的]对中国平耳孔蜈蚣种群的地理变异进行初步探讨。[方法]中国平耳孔蜈蚣标本经95%乙醇浸制后进行总基因组提取、PCR扩增和测序,最后进行序列分析。[结果]共定义26个单元型,单元型之间的平均遗传距离为0.13。种群的遗传多样性波动范围较大,系统发生树中各样地平耳孔蜈蚣的单元型呈现一种混杂的分布格局。[结论]根据节肢动物分子钟,推断现代平耳孔蜈蚣遗传分布格局均比较古老,早在第三纪中期就已经形成,可见更新世冰期对平耳孔蜈蚣种群没有影响。     

一点红不同生长期氨基酸含量分析

[目的]分析一点红营养生长期和花期的氨基酸含量。[方法]利用日立L-8800氨基酸自动分析仪测定氨基酸含量。[结果]营养生长期和花期的一点红分剐含16种氨基酸,氨基酸总量分剐达13．892％、13．746％;其中7种人体必需氨基酸占氨基酸总量分剐为43．968％、44．507％;人体必需氨基酸总质量分数与非必需氨基酸总质量分数比分别为0．785、0．802;它们分别舍有9种药效氨基酸,分别占氨基酸总量的60．834％、61．851％。[结论]一点红具有较高的营养价值和药用价值,值得大力开发和利用。     

野生水果冷饭团的研究现状及开发利用前景

冷饭团是一种具有较高药用价值、观赏价值和食用价值的野生植物,具有广阔的发展前景。论述了冷饭团的引种栽培、果实营养及药用成分,并对其发展现状及存在的问题提出研究展望,以期为冷饭团的开发利用提供一定的参考价值和科学依据。     

水分胁迫对4种绢蒿属植物生理特性的影响

在土培条件下,研究水分胁迫对沙漠绢蒿(Seriphidium santolinum)、伊犁绢蒿(S.transiliense)、针裂叶绢蒿(S.sublessingianum)和民勤绢蒿(S.minchnense)4种绢蒿属植物生理特性的影响,并对4种绢蒿属植物进行抗旱性综合评价。结果表明,在水分胁迫下,伊犁绢蒿和针裂叶绢蒿叶片相对含水量显著降低;丙二醛、脯氨酸和可溶性糖含量均随胁迫程度的加强呈上升趋势,丙二醛和脯氨酸含量增加幅度较大的为针裂叶绢蒿和伊犁绢蒿,增加幅度较小的为沙漠绢蒿和民勤绢蒿;沙漠绢蒿和伊犁绢蒿根系活力呈先升高后降低的趋势;沙漠绢蒿和民勤绢蒿根冠比显著升高。模糊数学隶属函数法综合评价结果表明,4种绢蒿属植物抗旱性由强到弱为:民勤绢蒿>沙漠绢蒿>伊犁绢蒿>针裂叶绢蒿。     

当归中阿魏酸的超临界CO_2萃取工艺条件及GC-MS分析

考察超临界CO_2萃取当归中阿魏酸的最佳工艺条件、有效物质定量方法及萃取物组成.采用正交试验法,使用乙醇为夹带剂,以收膏率和提取物中阿魏酸含量为目标函数,对药材粒度、夹带剂(乙醇)浓度、萃取压力、萃取温度等当归超临界萃取工艺条件进行研究,GC-MS分析和比较夹带剂对萃取效果的影响.结果优选出最佳超临界萃取条件是:药材粒度0.30～0.85 mm、夹带剂(乙醇)浓度80%、萃取压力35 Mpa、萃取温度60℃-50℃-45℃;纯CO_2超临界萃取物鉴定出 62个组分,使用夹带剂的超临界萃取物鉴定出83个组分,两者有54个相同组分;优选超临界萃取工艺所得的挥发油及阿魏酸提取量较高,使用夹带剂有利于阿魏酸等极性物质的萃取.     

鹧鸪茶种质资源ISSR分子标记中的引物筛选（摘要）

[目的]为快速和准确地对鹧鸪茶种质材料进行ISSR分析提供有效引物。[方法]基因组DNA的提取采用改良的CTAB法：先用0.8%琼脂糖凝胶电泳检测DNA完整性,EB染色,以Lambda DNA/HindⅢ＋Eco RIMarkers为参照,电泳结果用Gel Doc XR型凝胶成像分析系统下照相并记录。再用Biophotometer紫外分光光度计分别测定OD_（260）和OD_（280）,并计算出OD_（260）/OD_（280）值,每份样品的OD_（260）/OD_（280）比值均要求在1.8～2.0范围内。测定每份样品DNA浓度（ng/μl）,并将其稀释至20 ng/μl,分装后置-20℃保存。利用99个ISSR引物,对来自海南岛境内的10个居群中共20份鹧鸪茶种质材料进行PCR扩增,以筛选出适合于所有鹧鸪茶种质材料ISSR分析的有效引物。[结果]从99个供试引物中共筛选出15个多态性丰富、条带清晰且可重复性良好的有效引物。用筛选出的15个引物对66份鹧鸪茶种质材料进行ISSR-PCR扩增,均可获得带型丰富和清晰可辨的DNA指纹图谱;15个引物共扩增出286条DNA谱带,其中231条为多态性带,占总扩增带数的80.77%,平均每个引物扩增出19.1条谱带。[结论]所筛选的15条引物可以有效地应用于鹧鸪茶种质资源材料的ISSR分析。     

Ameliorative Effects of Brassinosteroid on Excess Manganese-Induced Oxidative Stress in Zea mays L. Leaves

Manganese （Mn） is becoming an important factor limiting crop growth and yields especially on acid soils. The present study was designed to explore the hypothesis that brassinosteroid application can enhance the tolerance of maize （Zea mays L.） to Mn stress and if so, whether or not the mechanism underlying involves regulation of antioxidative metabolism in leaves. The effects of 24-epibrassinosteroid （EBR） on the growth, photosynthesis, water status, lipid peroxidation, accumulation of reactive oxygen species, and activities or contents of antioxidant defense system in maize plants under Mn stress were investigated by a pot experiment. At supplemented Mn concentrations of 150-750 mg kg^-1 soil, the growth of plants was inhibited in a concentration-dependent manner. The semi-lethal concentration was 550 mg Mn kgq soil. Foliage application with 0.1 mg L^-1 EBR significantly reduced the decrease in dry mass, chlorophyll content, photosynthetic rate, leaf water content, and water potential of plants grown in the soil spiked with 550 mg kg^-1 Mn. The oxidative stress caused by excess Mn, as reflected by the increase in malondialdehyde （MDA） content and lipoxygenase （LOX, EC 1.13.11.12） activity, accumulation of superoxide radical and H2O2, was greatly decreased by EBR treatment. Further investigations revealed that EBR application enhanced the activities of superoxide dismutase （SOD, EC 1.15.1.1）, peroxidase （POD, EC 1.11.1.7）, catalase （EC 1.11.1.6）, ascorbate peroxidase （APX, EC 1.11. 1.11）, dehydroascorbate reductase （DHAR, EC 1.8.5.1）, and glutathione reductase （GR, EC 1.6.4.2）, and the contents of reduced ascorbate and glutathione, compared with the plants without EBR treatment. It is concluded that the ameliorative effects of EBR on Mn toxicity are due to the upregulation of antioxidative capacity in maize under Mn stress.