普通小麦K型三系花药过氧化物酶同工酶的初步观察

通过对普通小麦K型细胞质雄性不育系和保持系(两对)以及一个恢复系的花药过氧化物酶同工酶的观察,发现在单核期和双核期,K型三系的过氧化物酶同工酶酶谱无差异。在三核期,K型三系的酶谱出现差异并呈现出一定的规律性。     

玉米花粉超低温长期保存后遗传稳定性的研究

玉米自交系黄早四和郑１１４２的花粉在超低温（－１９６℃）保存１－２年后，冷冻花粉的过氧化物酶同工酶谱类型没有发生变化。冷冻保存的郑１１４２花粉授粉后所结的种子的过氧化物酶同工酶和醇溶蛋白电泳图谱同对照相比也没有变化，保持原自交系特征。冷花粉后代种子产生的植株，花粉母细胞染色体数目和结构正常。田间农艺性状正常，保持原自交系特征。     

Testing the Efficiency of Pollination Bag Materials

Crossing bags manufactured from three grades of polyester and three types of paper bags were tested for their permeability to grass pollen. Bags were placed on L. perenne plants of known PGI isozyme genotype. Any pollen passing through the crossing bag and pollinating the plant was detected by assaying its progeny for PGI isozymes. The results obtained allowed differentiation of the various materials for their suitability for pollen proofing.     

重金属Zn对菊芋幼叶生理生化指标的影响

利用不同浓度Zn处理菊芋幼苗,研究Zn在菊芋幼苗生长期间,对其幼叶中过氧化物酶(POD)同工酶、株高、叶绿素含量及细胞膜通透性的影响。结果表明:低浓度的Zn(0～5 mg/L)对菊芋幼苗的生长具有促进作用;随着Zn浓度的不断增加,菊芋幼叶中诱导型POD活性增强,增加了2种同工酶的表达;菊芋叶片中叶绿素含量呈下降趋势,细胞膜透性则持续上升。     

不同氮营养水平对水葫芦根系活力的影响

[目的]研究水葫芦(Eichhornia crassipes)根系活力与水体中氮浓度的关系。[方法]以不同氮营养水平培养水葫芦,研究水体中氮浓度对水葫芦根系活力的影响。[结果]氮浓度对水葫芦根系有较大的影响,在适宜的氮浓度水环境中水葫芦生长良好,并且根系活力和根系过氧化物酶活性都比较高。其中3.5 mg/L氮水平处理的水葫芦根系活力和根系过氧化物酶活性达到最高,过高的氮水平不但抑制水葫芦的根系活力,同时也抑制水葫芦根系的过氧化物酶活性。[结论]不同氮营养水平不仅影响水葫芦的根系活力,而且对根系过氧化物酶的活性也有明显影响。     

Genetic structure of populations of beech (Fagus sylvatica L.) in Denmark

The genetic structure in Danish indigenous and introduced provenances of beech (Fagus sylvatica L.) is described. Ten stands are analysed based on variation revealed by seven enzyme systems. The present study reveals significant allele frequency differences between populations with a small absolute amount of genetic differentiation, with no pattern related to geographic distance. The genetic differentiation between indigenous populations measured by Wright's F _ST‐statistic does not deviate significantly from zero, and only 2.9% of the total genetic variation in the foreign populations was due to interpopulation differences, The allele frequencies in relatively small and isolated populations do not differ from the frequencies found in larger areas with beech forest. The low genetic differentiation of isozyme level between indigenous and foreign populations was opposed by significant differences in foliation performance measured on three pairs of neighbouring stands. Foliation performance in adjacent stands of indigenous and introduced beech indicates that quantitative characteristics must be considered separately from neutral variation at single loci.     

Success rate of supplemental mass pollination in a seed orchard of Pinus sylvestris L.

Two experiments (Expt 1, Expt 2) with supplemental mass pollination (SMP) were carried out in a seed orchard of Pinus sylvestris L. in order to assess the biological and operational prospects for SMP. The success of the SMP was studied by means of allozyme markers. In Expt 1 the pollen mix was applied very close to each female strobilus. The estimated success rates for treatments varied between 66% and 84%. When supplemental pollination was done at peak receptivity, one single pollination was enough to obtain high success rates. In Expt 2 the pollen mix was dusted over clusters of receptive strobili on whole‐trees. The estimated success rates for treatments varied between 10% and 23%. The success rates improved when the trees were pollinated on more than one occasion per day during the receptive period. The overall conclusion is that SMP is practical for P. sylvestris seed orchards.     

Field performance of Salix clones propagated via shoot cultures in vitro

Survival, growth, plant structure and insect damage of in vitro‐derived cuttings from two Salix clones (5. schwerinii and 5. viminalis) were compared in a field trial with performance of conventional cuttings of the same clones. No obvious morphological abnormalities were induced by in vitro treatment. The survival rate of in vitro‐derived cuttings of the S. schwerinii clone was much higher than that of conventional cuttings. In the 5. viminalis clone, height growth was slightly but significantly reduced for in vitro‐derived cuttings compared with conventional cuttings although stem basal area and estimated plant dry weight were unaffected. The number of stems per cutting, the number of side shoots per stem and gall midge damage did not appear to be affected by the type of cutting. Electrophoretic analysis of 12 enzyme systems revealed identical isozyme patterns for m vitro‐derived and conventionally propagated plants.     

3个黄杨品种中过氧化物酶与吲哚乙酸氧化酶活性与其耐寒性的关系

本文以黄杨科黄杨属的小叶黄杨、锦熟黄杨、朝鲜黄杨3品种的成熟叶片为研究材料,测定其过氧化物酶(POD)和吲哚乙酸氧化酶(IAAO)的活性,通过其活性与其耐寒性之间的相关关系,来分析确定3个黄杨品种的耐寒性的大小排序.结果表明:3品种过氧化物酶与吲哚乙酸氧化酶活性从高到低依次均为:朝鲜黄杨＞锦熟黄杨＞小叶黄杨,因而得出3品种的抗寒性排序由高到低依次为:朝鲜黄杨＞锦熟黄杨＞小叶黄杨.     

荔枝果肉过氧化物酶酶学性质研究

本文从荔枝果肉中提取了过氧化物酶(POD),对其酶学性质进行了研究.结果表明,该酶最适反应温度为45℃,对热较敏感,当温度为70℃以上时,短时处理即可使酶活降至50％以下.最适pH 5,但在pH6.0～8.0范围内活力比较稳定.该酶在25℃和0.1 mol/L磷酸缓冲液(pH7.0)条件下对愈创木酚和没食子酸的Km值分别是4.64× 10-3和0.063 mol/L.谷胱甘肽和亚硫酸盐能完全抑制POD活性,但谷胱甘肽抑制浓度远低于亚硫酸盐,抗坏血酸只能在廷迟时间内抑制POD活性,对POD抑制具有暂时性,各抑制机制不同;CuSO4 、ZnSO4 、CaCl2 、MgCl2、EDTA对荔枝果肉POD活性有一定激活作用;FeSO4和MnSO4对POD活性有较强的抑制作用.