空间诱变辣椒AFLP反应体系的优化

为了建立适合空间诱变辣椒的AFLP反应体系,以3～4叶期的辣椒叶片为试材,对体系中的DNA用量、酶切与连接、预扩增及产物的稀释倍数等关键因素进行了优化,确立了适合空间诱变辣椒的AFLP反应体系.结果表明:采用该体系对空间诱变辣椒进行AFLP分析,能够得到清晰稳定的分子标记图谱.     

瞿麦组织培养和快速繁殖

以瞿麦种子获得的无菌苗和无菌苗的茎段作为外植体,以MS为基本培养基,添加不同浓度的激素,研究瞿麦组织培养的最佳条件.结果表明:最适宜无菌苗丛生芽诱导的培养基为MS+6-BA 1.0mg/L+NAA 0.4 mg/L;无菌苗茎段丛生芽诱导中,在MS+6-BA 0.2 mg/L+KT0.4 mg/L+NAA 0.1 mg/L有利于瞿麦的快速繁殖;最适宜的生根培养基为1/2MS+NAA0.1 mg/L.为提高试管苗增殖率及避免玻璃化现象的发生,最佳继代周期28 d,最适宜光照3 000 lx.     

红脂大小蠹对4种针叶树树皮的行为趋向研究

通过GC-MS顶空进样的方法测定油松、落叶松、马尾松和黄山松树皮的挥发性物质,显示α-蒎烯和β-蒎烯是树皮的挥发性物质中的主要成份;单一树皮饲喂证实红脂大小蠹对4种树皮均能钻蛀取食;嗅觉行为实验和取食趋向实验比较红脂大小蠹对4种针叶树树皮的行为趋向,结果表明4种树皮间存在差异性:对油松的选择趋向性最为明显;其次是落叶松;对马尾松和黄山松的趋向性较弱。4种松树树皮的挥发性成份的分析结果与红脂大小蠹对其的选择趋向性间相关性不明显。     

苯并噻二唑甲酸三氟乙酯诱导仙客来抗枯萎病的研究

为了明确新型化合物苯并噻二唑甲酸三氟乙酯对土传病害的诱导抗病作用,本文研究了该化合物诱导仙客来对枯萎病的抗病效果。通过叶面喷施苯并噻二唑甲酸三氟乙酯可诱导仙客来对枯萎病的抗病效果,在仙客来移栽缓苗后7d叶面喷施该化合物,不同浓度对枯萎病的抗病效果不同,其中100mg.L-1的处理,在诱导后25、30和35d的抗病效果分别为82.90%、58.59%和64.17%;在仙客来成株枯萎病发病初期用该化合物诱导,抗病效果仍可达63.91%,显著高于噁霉灵处理（47.63%）。该研究将为寻求通过叶面喷雾施药防治园艺作物土传病害的新途径起到参考作用。     

防御酶系对山茶灰斑病诱导抗性的响应

为揭示水杨酸(SA)诱导山茶产生抗病性反应机制,采用琼脂平板法测定了SA对山茶灰斑病菌Pestalotiopsis guepinii ( Desm.) Stey的影响.结果表明,浓度为0～5 mmol/L的SA对该菌的生长没有抑制作用.用SA喷雾涂布叶片诱导山茶抗性,其植株内过氧化物酶(POD)、多酚氧化酶(PPO )、过氧化氮酶(CAT)、苯丙氛酸解氨酶(PAL)等防御酶时山茶灰斑病菌诱导信号有不同响应.诱导并挑战接种处理的植株体内上述酶活性比只诱导不接种处理上升速度快,不同浓度的SA诱导及诱导后挑战接种植株体内的POD,PPO,CAT,PAL活性与SA浓度呈正相关.各防御酶活性与感病指数的相关性分析表明,CAT活性与感病指数显著负相关(r = - 0.9730),除PPO与感病指数的相关系数很低外,其它酶均较高,尽管未达到显著水平,但仍说明POD,PAL在诱导山茶抗病性中具有重要作用.     

Low pesticide rates may hasten the evolution of resistance by increasing mutation frequencies

At very low pesticide rates, a certain low proportion of pests may receive a sublethal dose, are highly stressed by the pesticide and yet survive. Stress is a general enhancer of mutation rates. Thus, the survivors are likely to have more than normal mutations, which might include mutations leading to pesticide resistance, both for multifactorial (polygenic, gene amplification, sequential allelic mutations) and for major gene resistance. Management strategies should consider how to eliminate the subpopulation of pests with the high mutation rates, but the best strategy is probably to avoid too low application rates of pesticides from the outset.     

Wood-ash fertilization and fire treatments in a Scots pine forest stand: Effects on the organic layer,microbial biomass,and microbial activity

We studied the reactions of humus layer (F/H) microbial respiratory activity, microbial biomass C, and the fungal biomass, measured as the soil ergosterol content, to the application of three levels of wood ash (1000, 2500, and 5000 kg ha^-1) and to fire treatment in a Scots pine (Pinus sylvestris L.) stand. Physicochemical measurements (pH, organic matter content, extractable and total C content, NH ₄ ⁺ and total N content, cation-exchange capacity, base saturation) showed similarity between the fire-treated plots and those treated with the lowest dose of wood ash (1000 kg ha^-1). The ash application did not change the level of microbial biomass C or fungal ergosterol when compared to the control, being around 7500 and 350 g g^-1 organic matter for the biomass C and ergosterol, respectively. The fire treatment lowered the values of both biomass measurements to about half that of the control values. The fire treatment caused a sevenfold fall in the respiration rate of fieldmoist soil to 1.8 l h^-1 g^-1 organic matter compared to the values of the control or ash treatments. However, in the same soils adjusted to a water-holding capacity of 60%, the differences between the fire treatment and the control were diminished, and the ash-fertilized plots were characterized by a higher respiration rate compared to the control plots. The glucose-induced respiration reacted in the same way as the water-adjusted soil respiration. The metabolic quotient, qCO₂, gradually increased from the control level with increasing applications of ash, reaching a maximum in the fire treatment. Nitrification was not observed in the treatment plots.     

辐射诱变培育玉米自交系辐746及其应用

内容用60Coγ射线105Gy剂量照射杂交组合铁13×C103 F1干种子,用系谱法选育出配合力高、抗病性强、早熟质佳的玉米自交系辐746。用辐746作亲本育成龙辐玉1号、龙辐玉2号、龙高1号、龙单16等玉米杂交种,辐746玉米自交系在黑龙江省玉米育种中具有一定的应用价值。     

零磁空间诱发优质籼稻雄性不育系的选育

水稻新型不育系玉-08A是经零磁场空间处理后,经多年人工及试管离体授粉回交转育选育而成。生产试验结果表明,该不育系不育性稳定,不实率达100%,比珍汕97A产量增产58.1%;制种产量增产62.6%。杂交组合玉优一号比对照汕优63增产5%~8%,杂交稻米质经农业部稻米及制品质量监督检验测试中心检验的12项指标中,蛋白质、垩白度、透明度等9项指标达优质米一级标准,综合评价为优质二级米标准。     

葡聚六糖诱导后黄瓜叶片几种酶的活性变化动态

该文以葡聚六糖为试材，研究了葡聚六糖叶面喷施诱导后黄瓜幼苗叶片5种酶的活性变化状态，研究结果表明：葡聚六糖诱导的黄瓜幼苗叶片中几丁质酶、β-1,3-葡聚糖酶、苯丙氨酸解氨酶和多酚氧化酶活性明显增加，而抗坏血酸氧化物酶活性呈下降趋势，这些酶活性的变化可能与葡聚六糖诱导黄瓜幼苗的抗病机制相关。