高效液相色谱法测定金荞麦超微粉原花青素B2含量

试验为测定金荞麦超微粉中有效成分原花青素B₂的含量,将四川金荞麦饮片粉碎至0.75 nm以下的超微粉,50%乙醇提取,并利用高效液相色谱测定原花青素B₂的含量。结果显示,在0.0352~1.4080 μg/mL范围内原花青素B₂与峰面积线性关系良好,回归方程为Y=59797X+592.3,r=0.996,金荞麦超微粉中原花青素B₂含量在1.305~1.541 mg/g之间。本试验结果表明该方法能快速、稳定、精确的检测原花青素B₂含量,为金荞麦制剂质量控制提供了科学依据。     

外源ALA对加工型番茄新番35号幼苗光合特性的影响

以加工型番茄新番35号为试材,研究了喷施外源ALA对其幼苗光合作用的影响。试验结果表明,与对照相比,新番35号番茄幼苗叶片的净光合速率(Pn),气孔导度(Gs),蒸腾速率(Tr)、胞间CO2浓度(Ci)显著提高,水分利用率也有小幅度提高,说明喷施ALA能提高番茄植株的光合能力。     

超干处理和贮藏对番茄和辣椒种子生活力和活力的影响

试验采用氧化钙为干燥剂对番茄和辣椒种子进行超平处理和贮藏，以研究其对种子生活力和活力的影响。结果表明，番茄种子水分降至3．77％、辣椒种子水分降至3．86％，未发现对种子生活力和活力有明显的影响；对不同含水量的番茄和辣椒种子室温密闭贮今6个月后的调查结果发现，超低水分种子生活力和活力较高，细胞膜能保持较好的完整性，脱氢酶活性和呼吸强度较高。由此可见超干贮藏有利于保持番茄和辣椒种子的生活力和活力。     

Effect of calcium concentration in nutrient solution before and after inoculation with Ralstonia solanacearum on resistance of tomato seedlings to bacterial wilt

We previously reported that calcium (Ca) nutrition in tomato (Lycopersicon esculentum Mill.) significantly affected the resistance to bacterial wilt caused by Ralstonia solanacearum Smith. To elucidate the mechanisms underlying the Ca-dependent resistance, the effect of the Ca concentration in the nutrient solution applied before and after inoculation with the pathogen on the resistance of tomato seedlings to bacterial wilt was studied. One week before inoculation, seedlings were transferred to nutrient solutions containing Ca at concentrations of 0.4, 4.4, or 20.4 mM. Soon after inoculation, the seedlings that were treated with each concentration of Ca before inoculation were transferred to solutions containing the same three concentrations of Ca. Although the disease development was not affected by the concentration of Ca in the solution before inoculation, a higher concentration of Ca after inoculation reduced the disease severity. This result suggests that the concentration of Ca in the host, especially in the cell walls, before infection may not be directly involved in the Ca-dependent resistance of tomato seedlings to bacterial wilt.     

渝东地区药用保护植物金荞麦群落数量分类和排序研究

在群落调查的基础上,采用双向指示种分析法（TWINSPAN）和除趋势对应分析（DCA）对重庆东部地区药用保护植物金荞麦群落进行数量分类和排序.TWINSPAN等级分类将金荞麦群落的116个样方分为14组,根据植被分类原则划分为14个群系,并论述了各群系的特征.分类结果反映了植物群落类型与环境梯度之间的关系,并在DCA二维排序图上得到了较好的验证.物种的DCA排序结果反映了光照、海拔等环境因子的梯度变化,表明光照和海拔是决定群落组成和空间分布的主要限制性影响因子.     

Biocontrol of the pathogen Phytophthora parasitica by arbuscular mycorrhizal fungi is a consequence of effects on infection loci

The impact of colonization by the arbuscular mycorrhizal fungus (AMF) Glomus mosseae on tomato root necrosis caused by the soil-borne pathogen Phytophthora parasitica was investigated. Studies in situ permitted infection loci to be identified and the effects of the AMF on numbers to be elucidated. Effects were significant and, 7 and 16 days after inoculation with zoospores of the pathogen, roots of plants colonized by the AMF had 39% and 30%, respectively, fewer infection loci than those that were not. Concurrent studies of the rate of spread of necrosis within roots showed no changes caused by the AMF. At harvest, 26 days following inoculation with the pathogen, 61% of roots of noncolonized plants were necrotic compared with only 31% in AMF-colonized plants. It is concluded that effects on numbers of infection loci are one mechanism via which AMF achieve biocontrol of this pathogen in tomato. Measures of the effects of the AMF on root system architecture suggest that no significant changes occur and are thus not the reasons for the reduction in infection loci. The implications of these data for agricultural practice and biocontrol research are discussed.     

烯效唑浸种对不同水分条件下苦荞生长的影响

以"黑丰一号"苦荞[Fagopyrum tataricum(L.)Gaertn]为试验材料,采用不同浓度(0、40、80和120mg/kg)烯效唑浸种,探讨不同水分条件(正常供水、中度干旱和重度干旱)下烯效唑浸种对苦荞生长的抗旱效应。结果表明,烯效唑浸种降低了苗高,提高了苦荞的茎粗、叶面积、最大根长和根冠比;同时还提高了叶片相对含水量、脯氨酸含量、可溶性糖含量、可溶性蛋白质含量和根系活力。烯效唑处理降低了丙二醛(MDA)含量,从而降低了膜脂过氧化程度,提高了保护酶活性。采用80 mg/kg烯效唑浸种,在正常供水、中度干旱胁迫及重度干旱胁迫条件下,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性较对照均有不同程度的提高;苦荞株穗数、株粒数、百粒重较对照均有不同程度的提高。由此可见,80 mg/kg的烯效唑浸种可以提高苦荞的抗旱能力。     

番茄茎叶提取物对菜粉蝶的生物活性研究

以乙醇、乙醚、苯、石油醚和丙酮为溶剂对番茄(Lycopersicon esculentum Mill.)茎叶进行浸提,测试各溶剂提取物对菜粉蝶5龄幼虫的触杀、拒食和胃毒活性。结果表明,各溶剂提取物对菜粉蝶(Pieris rapae L.)主要表现为拒食活性和胃毒活性,其中乙醇提取物的拒食和胃毒活性最强。     

Growth and yield of self-compatible and hybrid common buckwheat lines pollinated with and without flies

Common buckwheat is a self-incompatible, insect-pollinated allogamous plant. This study examined growth and yield of the common buckwheat self-compatible and hybrid lines pollinated with and without flies. Self-compatible ‘IH3’, hybrid ‘IP2/IH3’, and standard self-incompatible ‘Kitawasesoba’ were used in field and pot experiments. Self-compatibility of ‘IH3’ was shown to be of high purity. Approximately 10% segregation of pin plants from ‘IP2/IH3’ was observed. The harvest index of ‘Kitawasesoba’ pollinated without flies was considerably lower than that pollinated with flies in both field and pot experiments. The harvest index values of ‘IH3’ and ‘IP2/IH3’ were hardly affected by the presence or absence of flies. The morphological traits of ‘IH3’ were significantly lower than those of the other two genotypes. Large differences in these traits between ‘IP2/IH3’ and ‘Kitawasesoba’ were not observed in either the field or pot experiments. The seed yield of ‘Kitawasesoba’ pollinated without flies tended to be lower than that pollinated with flies. The seed yield of ‘IP2/IH3’ tended to be higher than that of ‘IH3’. The hybrid line ‘IP2/IH3’ showed a high fertilization rate, which was nearly as high as that of ‘IH3’. Rate of fertilization and percentage of ripe seeds were higher in ‘IH3’ and ‘IP2/IH3’, wherein they were hardly affected by the presence or absence of flies, than in ‘Kitawasesoba’. The ‘IP2/IH3’ hybrid line will be useful for understanding the stable high-yielding ability of self-compatibility common buckwheat.     

微生物菌剂对番茄生长发育及产量的影响

为了研究微生物菌剂对番茄(Lycopersicon esculentum Mill.)生长发育和产量的影响,采用田间试验的方法,研究了不同浓度微生物菌剂对番茄幼苗的生长发育、营养生长、病虫害、产量及品质的影响。结果表明,稀释200倍的微生物菌剂处理对番茄生长发育、产量和品质的促进效果最好,幼苗的出苗率、主根长度、鲜重分别比对照提高了42.81%、20.20%、26.23%,株高、果实横径、果实纵径、叶片相对叶绿素含量分别比对照提高了46.84%、49.76%、53.37%、44.03%,显著降低了病虫害的发生率,产量比对照增加16.16%,果实品质明显高于对照。实际应用可采用稀释200倍的微生物菌剂处理。