渍水对油菜苗期生长及生理特性的影响

通过盆栽试验研究了模拟渍水条件对苗期油菜（Brassica napus L.）中双11号生长及生理特性的影响。结果表明,渍水超过3 d就会显著抑制苗期油菜的生长,这与渍水降低油菜叶片叶绿体和光合色素含量、降低氮素吸收利用和引起过氧化胁迫有关。渍水后苗期油菜的生理恢复,无论是叶绿体和光合色素含量,还是硝酸还原酶及抗氧化酶活性的恢复均表现出一定的滞后性,而且渍水时间越长滞后期越长。此外,在苗期油菜叶片光合色素中,渍水对类胡萝卜素的影响要大于对叶绿素的影响。     

贮藏时间对银杏花粉保护酶活性和萌发率的影响

研究了室温贮藏对银杏花粉萌发率及超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化物酶(Peroxi-dase,POD)、过氧化氢酶(Catalase,CAT)活性的影响。结果表明,随着贮藏时间的延长,花粉萌发率由88．89％降到15．76％;贮藏15d之后超氧化物歧化酶活性降低了80％;过氧化物酶活性减少到原来的10％;过氧化氢酶活性也减少了70％。在室温贮藏条件下萌发率随保护酶活性的下降而降低。POD酶对花粉萌发率的影响比SOD、CAT酶显著。     

泰山虫草对黄粉虫的侵染特性研究

报道了用泰山虫草分生孢子悬浮液接种活体黄粉虫,提取被侵染的黄粉虫体液,并测定不同侵染时间虫体液中酶活性的动态变化。结果表明:泰山虫草分生孢子能成功的侵染黄粉虫并长出子座;接种第2~4 d后即可导致黄粉虫体内活性发生不同程度的变化,说明黄粉虫具有独特的防御病原微生物的侵染机制。     

大蒜体细胞胚胎发生过程中抗氧化酶活性变化及某些生理特征

以大蒜的发芽叶基(鳞茎)为外植体诱导体细胞胚胎发生,研究大蒜体胚发生过程中SOD、POD和CAT 3种抗氧化酶的活性以及可溶性糖和可溶性蛋白质含量变化.结果表明:在大蒜体胚发生过程中,SOD、POD和CAT活性变化与胚性愈伤组织的诱导及体胚的发育密切相关,POD对体胚的诱导起主导作用,而SOD和CAT在体胚的发育和成熟中起主导作用.可溶性糖和可溶性蛋白质累积与大蒜体细胞胚胎发生密切相关.     

9个辣椒雄性不育材料花蕾生理生化特性研究

以9个辣椒雄性不育材料及其相应的保持系为试材,对有关花器的植物学性状进行了系统观察和研究,测定了花蕾中过氧化物酶、过氧化氢酶、多酚氧化酶的活性和游离脯氨酸的含量。结果表明:供试9个雄性不育材料和保持系的主要花器性状有一定差异;雄性不育材料的过氧化物酶活性和多酚氧化酶活性均高于相应的保持系, 而过氧化氢酶活性低于保持系;保持系游离脯氨酸含量离于不育材料;所测的3种酶活性和脯氨酸含量在雄性不育材料与保持系间差异显著。     

孑遗植物水杉种子萌发的生理生态特性研究

从种子活力和抗氧化酶活性两个方面研究了温度和光照对孑遗植物水杉 (Metasequoiaglyptostroboides)种子萌发的生理生态特性的影响。实验结果表明 ,萌发温度对水杉种子的活力和抗氧化酶活性有较大影响 ,在 19-2 8℃范围内 ,种子的发芽率、发芽速率、活力指数、脱氢酶及超氧化物歧化酶 (SOD)、过氧化物酶 (POD)和过氧化氢酶 (CAT)等抗氧化酶活性均较高 ,其中在 2 4℃条件下最高 ;当温度低于 15℃或者高于 32℃时 ,种子活力很低 ;10℃条件下种子几乎不萌发。可以认为 ,水杉种子萌发的适宜温度范围为 19- 2 8℃ ,最适温度为 2 4℃。光照萌发试验表明 ,6 5 μmol·m-2 ·s-1(12h/d)光照对水杉种子的萌发有较大的抑制作用 ,黑暗条件更适于水杉种子的萌发。自然状态下水杉种子质量很差 ,空瘪率超过 90 % ,加之产地春季温度不适于水杉种子的萌发 ,这两者可能是限制水杉种群更新的重要因素。这也许是水杉种群中缺乏幼苗和幼树的原因之一。     

水分胁迫及复水过程中小麦抗氧化酶的变化

对两个抗旱性不同的小麦品种进行水分胁迫和复水处理,研究其抗氧化酶活性的响应。在水分胁迫下,陇春-20的相对含水量高于优鉴-24,复水24h后,优鉴-24的相对含水量恢复较快且高于陇春-20。水分胁迫下,优鉴-24中H2O2含量增加迅速,而且各阶段含量均高于陇春-20,复水后两个品种的H2O2含量都下降,这表明优鉴-24在水分胁迫时受到更严重的氧化胁迫。采用温和胶电泳结合抑制剂实验发现小麦有3条Mn—SOD,一条Fe—SOD和Cu／Zn-SOD同工酶带,CAT同工酶有3条谱带。在水分胁迫和复水期间,优鉴-24的SOD和CAT活性高于陇春-20,随着水分胁迫程度的增加,两个品种的SOD和CAT活性都增强,复水后,优鉴-24的SOD活性继续增强,而陇春-20的Mn—SOD—3活性略微降低,Fe—SOD和Cu／Zn—SOD活性略微升高,陇春-20的CAT活性降低。水分胁迫诱导了Mn—SOD—1在优鉴-24及Mn—SOD-2和Fe—SOD在陇春-20中的表达。     

PAGE活性染色法分析D.radiodurans过氧化氢酶和超氧化物歧化酶

用PAGE活性染色法分析了D．rndiodurans过氧化氢酶（Cat）和超氧化物歧化酶(SOD)._2种同种异型D．radiodurans（RI和Sark）的Cat在电泳带型上存在差异,两者Kat均可分为A、B和C3条带,但各带所占比例明显不同。SOD的分析结果表明,D.radioduransSOD以Fe2 和Mn2 离子的嵌合体形式存在,其中Fe－SOD成分占90％以上。PAGE活性染色法可检出Cat和SOD的最低菌体总蛋白量分别为1.2和2.0μg。     

榛子种质资源、育种及栽培技术研究进展

榛子是一种重要的经济植物资源,其果实营养及经济价值高,是世界四大干果之一,市场需求量大,国内供不应求。本文综述了国内外榛子种质资源分布现状、引种、品种选育及栽培技术等方面的研究进展,简要评述了中国榛子种质资源利用与规模化种植中存在的问题,展望了相关研究的发展方向,以期为我国榛树良种选育、规范栽培技术及开发研究等提供参考。     

Identification of hazelnut (Corylus avellana) cultivars by RAPD analysis

The random amplified polymorphic DNA (RAPD) technique offers a useful tool to detect DNA polymorphisms. It can also be used to distinguish different clones and cultivars. We have developed a comprehensive RAPD-based procedure for the routine molecular typing of various plants. Here we report the application of this technique for the correct identification of six hazelnut cultivars (Corylus avellana) widespread in the Campania region (south Italy). The analysed hazelnut cultivars were successfully distinguished by their RAPD fingerprints using the DNA primers U2, U3, U4, U11 and U14. However, in each cultivar we observed very low genetic heterogeneity among the clonal variants. Since this technique is among the simplest and easiest methods used to fingerprint DNA, it could be easily transferred to less sophisticated laboratory infrastructures (e.g. outstations of crop regulatory agencies). Received: 20 December 1997 / Revision received: 6 August 1998 / Accepted: 13 November 1998     

Incompatibility alleles in Corylus avellana L. cultivars

Summary Pollen-stigma compatibility relationships are reported for 55 filbert cultivars (cvs) (Corylus avellana L.). A total of 11 S-alleles have been identified amongst 36 cvs for which one or both S-alleles have been established. For the 20 cvs with only one known allele and the 17 for which neither allele have been identified further information is provided as to which alleles can be excluded as possibilities.Oregon Agricultural Experiment Station Technical Paper No. 4985. Corvallis, Oregon 97331     

Ethylene and in vitro rooting of hazelnut (Corylus avellana) cotyledons

Ethylene may be one of the many factors that play a role in rooting. However, in some studies ethylene promoted rooting, while in others it was inhibitory or had no effect. Using cotyledons of hazelnut ( Corylus avellana L. cv. Casina) observations were made of the effect of ethylene precursors on adventitious root formation. l-methionine (Met) or 1-aminocyclopropane-1-carboxylic acid (ACC) added to a standard indole-3-butyric acid (IBA)-kinetin-containing medium did not enhance rooting, while 2-chloroethylphosphonic acid (CEPA) did. The ethylene inhibitor, aminoethoxyvinylglycine (AVG), inhibited root formation, but its effect was reversed by ACC when cotyledonary segments were transferred to rhizogenic medium plus ACC at day 10. Ethylene production by cotyledons cultured on rhizogenic medium or rhizogenic medium plus CEPA was high at the beginning of rooting. Thus, the wound-induced ethylene is a key stimulatory factor in the formation of root primordia. The data support the hypothesis that ethylene plays a positive role in root formation.     

Chloroplast DNA variation,postglacial recolonization and hybridization in hazel,Corylus avellana

To unravel the postglacial migration history of hazel, Corylus avellana, the genetic variation at two types of chloroplast DNA markers, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and microsatellites, was assessed in 26 natural hazel populations distributed across the range of C. avellana. In addition a sequence of 2468 base pairs, which contains the matK gene, was analysed in seven individuals. Very little variation was detected overall [hT:PCR-RFLP= 0.091, hT:microsatellite= 0.423, pi (nucleotide diversity) = 0.00093] but the microsatellite markers, which have the highest levels of variation, show a clear geographical structure that divides Europe into two areas: (i) Italy and the Balkans, on one hand and (ii) the rest of Europe, on the other hand. These data exclude Italy and the Balkans as possible origins of the postglacial recolonization but cannot unambiguously show which other area is the origin, since the genetic data does not indicate the direction of spread. If we take the pollen record into account, the most likely scenario would be an expansion from southwestern France into most of Europe except Italy and the Balkans, and then a local expansion in the latter area. The two main haplotypes identified with both PCR-RFLP and sequencing, A and B, were found not only in C. avellana but also in other European Corylus species and cultivars. Haplotype A, which is dominating all investigated natural populations of C. avellana, is also found in the European tree hazel (C. colurna) and haplotype B, which is rare in C. avellana, has been identified in the filbert (C. maxima) and C. avellana cultivars. This pattern seems to indicate a history of past hybridization among the European Corylus species and cultivars.     

Revised dominance hierarchy for S-alleles in Corylus avellana L.

Pollen-stigma compatibility was studied in cultivars and more than 1800 seedlings of the European hazelnut (Corylus avellana L). Four new S-alleles were identified, bringing the total to 25 unique alleles within C. avellana. The new alleles are the recessive alleles in ‘Tonda di Giffoni’ and ‘Segorbe’ (S₂₃), in ‘Neue Riesennuss’ (S₂₅), in ‘Gasaway’ (S₂₆), and a dominant allele in a seedling of Turkish origin (S₂₄). Dominance relationships in 233 of the possible 300 pairs of alleles were determined in both pistil and pollen. All alleles exhibited independent action in the pistil, whereas in the pollen either dominance or codominance was exhibited. The dominance hierarchy of alleles in the pollen was revised in light of the new information obtained. All 25 alleles have been assigned to a level in the hierarchy that is linear and now has eight levels. S₆ and S₉ were reassigned to lower levels in the hierarchy. Thirteen of the alleles are on the level of S₁, while S₄, S₆, S₁₁, and S₂₃ occupy unique positions in the hierarchy. Improved pollen tester clones were identified for several S-alleles. The alleles in 55 cultivars were determined. The alleles identified in ‘DuChilly’ (S₁₀ S₁₄) did not agree with previous reports. Four cultivars have the same alleles as ‘Römische Nuss’ (S₁₀ S₁₈) and are morphologically indistinguishable from it: ‘Frutto-grosso’, ‘Istarski Okrogloplodna’, ‘Payrone’, and ‘Romai’. ‘Belle di Giubilino’ and ‘Tonda di Biglini’ are both S₁ S₁₀ and appear to be synonyms for the same cultivar.     

外来入侵植物三叶鬼针草种子萌发与贮藏特性研究

研究了光照和温度对外来入侵植物三叶鬼针草(Bidens pilosa L．)种子萌发的影响及种子在不同温度下贮藏后的发芽力变化。结果表明,光照和变温不是三叶鬼针草种子萌发的必要条件,在15～30℃恒温条件下萌发率均达到80％以上,35℃恒温显著抑制其萌发且发芽的种子不能正常发育;零下低温(-10℃)和零上低温(4℃)贮藏6个月的三叶鬼针草种子萌发率(分别为95％和94．7％)与贮藏前的萌发率(97．7％)相比无显著差异,而在室温下贮藏6个月的种子,随着贮藏时间的增加萌发率逐渐下降,6个月后不仅萌发率急剧下降到16％、萌发时间延长至10d,而且发芽的种子亦不能正常发育。     

Pentose phosphate metabolism during dormancy breakage in Corylus avellana L.

Commercially obtained fruits of Corylus avellana exhibit the characteristic loss of dormancy of this seed following chilling under moist conditions. The activities of cytosolic and organellar enzymes of pentose phosphate pathway in cotyledonary tissue were assayed throughout stratification and over a similar period in damp vermiculite at 20° C. Glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconic acid dehydrogenase (6PGDH) were both found in cytosolic extracts in all treatments; only 6PGDH was present in the organellar fraction.The enzyme activities monitored in seeds at 20° C remained relatively constant over the course of the investigation except in the case of cytosolic 6PGDH where it is suggested an inhibitor of the enzyme accumulated. This inhibitor was removed by the partial purification procedure. Increases in the activities of the enzymes occurred during stratification, the major increase coinciding exactly with dormancy breakage but prior to the initiation of germination. The marked increase in G6PDH and 6PGDH concurrent with the change in germination potential of the chilled seed may have considerable biochemical significance in breaking down the dormant state.Abbreviations G6P glucose-6-phosphate - G6PDH glucose-6 phosphate dehydrogenase - NADP nicotinamide adenine dinucleotide phosphate - 6 PGDH 6-phosphogluconic acid dehydrogenase - PPP pentose phosphate pathway     

Detection and Molecular Characterization of ‘Candidatus Phytoplasma asteris’ in European Hazel (Corylus avellana) in Poland

Stunted European hazel (Corylus avellana L.) plants showing leaf yellowing were observed in south‐eastern Poland. Phytoplasma‐specific primers P1/P7 and R16F2n/R16R2, as well as primers specific for aster yellows (16SrI), X‐disease (16SrIII) and apple proliferation (16SrX) groups were singly used in nested polymerase chain reaction (PCR) to amplify the 16S rDNA from 22 symptomatic and asymptomatic hazel plants. Restriction fragment length polymorphism with MseI, HhaI, RsaI and BfaI enzymes of the 16S rRNA gene fragments amplified with the primers R16F2n/R16R2 from three symptomatic hazel plants of cvs Katalonski, Webba and Halle revealed patterns identical to those from the AY1 strain related to ‘Candidatus Phytoplasma asteris’. The nucleotide sequence analysis confirmed this result. This is the first report of the natural occurrence of ‘Ca. P. asteris’ in European hazel in Poland.