Structure and functions of Pinus sylvestris var. Sylvestriformis plantation ecosystem

IntroductionChangbaipli1e(Pbllissylvestrisvar.sJIvesII.doIwlis)whicl1isararetreespeciesisendel11icil1Cl1al1gbaiMouIltaiI].TheareaofitSnaturaldistributiollisveryllinited,olllyabout2o()hm2onnortl1erl1sl()pcofCha11gbaiMoulltaill.However,Changbaipli1easal1il1lportanttrcesPecieshasmanyexcellentllatures,sllcl1asfastgrowing,straigl1ttrunk,goodwoodandsool1.Itiscalled"BeautyPli1e".Since196o's,lnanyCl1angbaipinepla11tatio11sllavebee1]planted.WeconductedstudicsOIlstructurealltIfl111ctiol1sofore…     

红菜薹自交不亲和性快速测定初报

红菜薹的自交不亲和性表现为柱头抑制。授粉后24h的柱头,在电镜和荧光镜下观察,即可对其不亲和性进行测定。有些单株老龄花亲和性比幼龄花亲和性稍高。亲本亲和指数同后代条和指数的平均值呈正相关,因此在选择时,最好选择那些亲和指数低,不亲和性强的单株。     

Pathogenic, Genetic and Molecular Characterisation of Fusarium oxysporum f.sp. lilii

Isolates of Fusarium oxysporum from lily were screened for pathogenicity, vegetative compatibility and DNA restriction fragment length polymorphisms, and compared to reference isolates of F. oxysporum f.sp. gladioli and F. oxysporum f.sp. tulipae to justify the distinction of F. oxysporum f.sp. lilii. Twenty-four isolates from different locations in The Netherlands (18 isolates), Italy (4 isolates), Poland and the United States (1 isolate each) shared unique RFLP patterns with probes D4 and pFOM7, while hybridization did not occur with a third probe (F9). Except for a self-incompatible isolate, these 24 isolates all belonged to a single vegetative compatibility group (VCG 0190). Isolates belonging to VCG 0190 were highly pathogenic to lily, but not to gladiolus or tulip, except for a single nonpathogenic isolate. Six saprophytic isolates of F. oxysporum from lily were nonpathogenic or only slightly aggressive to lily, gladiolus and tulip, belonged to unique VCGs and had distinct RFLP patterns. Three pathogenic isolates previously considered to belong to F. oxysporum f.sp. lilii were identified as F. proliferatum var. minus; all three belonged to the same VCG and shared unique RFLP patterns. These three isolates were moderately pathogenic to lily and nonpathogenic to gladiolus and tulip. The reference isolates of F. oxysporum f.sp. tulipae were pathogenic to tulip, but not to lily and gladiolus; they shared a distinct RFLP pattern, different from those encountered among pathogenic and saprophytic isolates from lily, and formed a separate new VCG (VCG 0230). Reference isolates of F. oxysporum f.sp. gladioli belonging to VCG 0340 proved pathogenic to both gladiolus and lily, but not to tulip. These isolates, as well as isolates belonging to VCGs 0341, 0342 and 0343 of F. oxysporum f.sp. gladioli, had RFLP patterns different from those encountered among the isolates from lily or tulip. These findings identify F. oxysporum f.sp. lilii as a single clonal lineage, distinct from F. oxysporum f.sp. gladioli and f.sp. tulipae.     

樟子松人工林鼠害防治的探讨

根据樟子松人工鼠害发生特点和以往防治实践,提出了“以营林为基本措施”,生物,化学防治,人工和机械防除为辅助措施,综合防治樟子松鼠害”的方针,并着重阐述了营林防治措施及营造防鼠混交林的可行性和方法。     

高温强光下耐热性不同的两个甘蓝品种幼苗光合作用差异的研究

 以耐热性不同的两个甘蓝(Brassica oleracea L. var. capitata) 品种为材料, 对短期高温强光胁迫下光合作用的差异做了初步探讨, 结果表明: 在叶温40℃, 1 200μmol·m^{- 2} ·s^{- 1}的光强下, ‘大牛心’净光合速率比‘无粉8号’高出约30% , 与28℃叶温下光合速率结果相比较, 两品种分别降低7%和24% , 高温下, 大牛心的光合速率显示较强的耐热性。40℃预处理后随着光强的升高, 光系统II ( PSII)的电子传递效率(ΦPSII) 和PSII的激发能捕获效率( Fv'/Fm') 持续下降, 而非光化学猝灭(NPQ) 持续增加, 慢组分( qI) 一直维持在NPQ的10%左右, NPQ的增加主要是快组分( qf) 的迅速增加。可见高温强光胁迫下依赖于叶黄素循环的高能态猝灭是甘蓝幼苗叶片耗散过剩激发能的主要方式。然而两品种之间ΦPSII、Fv'/Fm'、NPQ及其qf和qI均无显著性差异, 且最大光化学效率( Fv/Fm) , 细胞间隙CO₂ 浓度(Ci) , 光呼吸速率( Pr) 也无显著性差异。因此在短期高温强光胁迫下两品种净光合速率差异主要取决于与光反应无关的非气孔限制。     

Incidence of Verticillium wilt of artichoke in eastern Spain and role of inoculum sources on crop infection

Surveys of 94 artichoke fields throughout the artichoke production areas of Comunidad Valenciana (eastern Spain) were conducted from 1999 to 2002 to determine the incidence and distribution of Verticillium wilt.Verticillium dahliae was isolated from 80.9% of the sampled fields, and detected in all artichoke-growing areas, with a mean disease incidence of 53.8% infected plants. The disease was found to cause severe damage to cv. ‘Blanca de Tudela’, which is the most important artichoke cultivar grown in Spain, and was also observed on the seed-propagated cv. ‘Imperial Star’. In field trials to study the role of infected planting material and soil inoculum on infection of artichoke plants during the cropping season,V. dahliae was transmitted from infected stumps to the plants, confirming that the use of infected stumps could have greatly contributed to the dissemination of the pathogen. Inoculum density ofV. dahliae in soil had an effect on crop infection, in that a higher number of microsclerotia per gram of soil resulted in a higher percentage of infected plants. In addition, yield of cv. Blanca de Tudela was significantly affected byV. dahliae infection, showing that a higher percentage of infection corresponded with lower yield. http://www.phytoparasitica.org posting July 21, 2005.     

纹孔塞位置回弹对改善长白鱼鳞云杉木材渗透性作用初探

本文通过对难浸注的长白鱼鳞云杉气干5年心材进行水浸泡处理,探讨了纹孔塞位置可否回弹以提高木材渗透性的可能性。试验结果表明,气干5年长白鱼鳞云杉心材经水浸泡11周并用有机溶剂置换干燥后,平均气体渗透性增加了110%,但经成对比较试验t检验,以可靠性95%计差异不显著。表明气干5年后心材通过水浸泡处理,平均气体渗透性虽有增加,但偏移的纹孔塞可能并未重新回弹到中央位置使其渗透性获得真正的提高。     

浑善达克沙地榆遗传多样性的研究

浑善达克沙地榆 ( Ulmuspumila var. sabulosa)是白榆的一个变种 ,天然分布于浑善达克沙地 ,在维护草原生态系统的稳定方面起着重要作用。本文应用 RAPD技术对浑善达克沙地榆的遗传多样性和系统地位进行了研究。在浑善达克沙地榆六个居群和对照白榆两个居群中 ,1 6个有效引物共获得了 1 1 5个位点 ,其中居群水平多态性位点为 49个 ,占 42 .6 ,高于 H amrick等的统计得出的平均多态位点比率 ( 3 4 ) ,表明在长期的进化过程中 ,居群内发生了较高的遗传变异 ,个体水平多态性位点为 89个 ,占 77.4。根据遗传距离进行聚类得出 :居群水平上以 0 .1为阈值 ,浑善达克沙地榆和对照白榆聚为明显的两支 ,本实验结果支持浑善达克沙地榆作为白榆一个变种的结论 ;遗传多样性指数分析表明 ,个体水平上浑善达克沙地榆各居群之间遗传距离有一定的差异 ,并与地理分布范围相关。浑善达克沙地榆由于各居群都存在相对较大的遗传变异 ,反映了在居群内具有较大的变异潜力。本实验结果也表明 ,RAPD可应用于浑善达克沙地榆遗传多样性及系统学的研究。文中还对浑善达克沙地榆的遗传变异与繁育系统的关系进行了讨论。     

不同营养液浓度对莴苣生长特性的影响

 以长叶莴苣( Lactuca sativa var．1ongifolia Lam．)为试材，研究了NFT栽培条件下莴苣水分与养分吸收特性，以及NFT对其生长发育的影响。试验结果表明，莴苣蒸腾效率前期>中期>后期；整个生育过程中，P、K、Mg的吸收成分组成浓度(养分与水分吸收比，n/w)均低于原始营养液浓度，而Ca则相反；NO3^--N因处理浓度不同而异。叶片中各无机成分含量随生育过程而提高，同一生育期随营养液浓度提高而增加；综合莴苣产量因子与商品性状，以3/4倍园试均衡液最佳。     

菜薹茎尖培养中的激素与热激调控

 BA和NAA不同浓度组合对菜薹茎尖培养会产生不同的影响，BA 0.8 mg·L^-1 以上浓度能获得较好的增殖效果，NAA浓度不宜超过0.5 mg·L^-1。KT和ZT混用不及单一使用效果好。外植体放置方式会影响茎尖的增殖效率。45 ℃ 2 h以内热激处理可促进菜薹茎尖的增殖。