贵州杜鹃属的5种新记录

本文报道了贵州杜鹃属Rhododendron L新记录的植物，它们是云上杜鹃 R. pachypodum Balf.f. et W. W. Smith朱砂杜鹃 R. cinnabarinum Hook. f. Rhodod 西昌杜鹃 R. sichangense I.J. Zhao,涧上杜鹃 R. subflumieum Tam 和白花杜鹃R. mucronatum （Blume） G. Don。     

叶片表皮指纹在杜鹃花属分类中的意义

本实验于2004年在东北林业大学进行。用指甲油印记法在光学显微镜下观察了杜鹃花属6个种(牛皮杜鹃 Rh.aureaum,兴安杜鹃Rh. dauricum, 照白杜鹃Rh. micranthum,迎红杜鹃Rh. mucronulatum,苞叶杜鹃 Rh. Redowskianum 和大字杜鹃Rh. schlippenbachii)的表皮指纹特征。对叶片的形态特征包括叶片下表皮气孔类型、保卫细胞和副卫细胞的特征、叶片两面的普通细胞(形状和垂周壁特征)和表皮毛进行了较详细的描述。所研究的6种杜鹃花中,有3种气孔类型,其中兴安杜鹃、照白杜鹃、和迎红杜鹃为单细胞型气孔(Pericytic 型),苞叶杜鹃为不规则型气孔(Anomocytic 型),牛皮杜鹃和大字杜鹃是平轴式气孔(Diacytic 式)。不同种间,单细胞型和平轴式气孔的副卫细胞类型在形状和表面特征上有所不同。普通表皮细胞的表面观为从四边形、六边形, 多边形或不规则型, 垂周壁呈平直或弯曲状。兴安杜鹃、照白杜鹃和迎红杜鹃3种的叶片两面均有腺鳞。所有这些叶片特点表明上述6种杜鹃花的表皮指纹具有种的特性。图4表2参29。     

Inheritance of Corolla Size, Number of Stamens and Percentage of Plants with Petaloid Stamens in Evergreen Azaleas (Rhododendron Subsect. obtusa)

Research has been carried out on the inheritance of corolla size, number of stamens and percentage of plants with petaloid stamens (double flower) in evergreen azaleas (Rhododendron Subsect. obtusa). For this purpose two incomplete diallel crosses were used. The first one included seven species and one cultivar and the second diallel 13 cultivars. In both diallels for all three characters the GCA mean squares were high. Also, the positive correlation between the parental values and the GCA estimates for flower size and number of stamens indicates that the expression of these characters is mainly determined by additive gene action. A negative correlation was found between GCA estimates for die n number of stamens and the percentage of plants with petaloid stamens. When breeding azaleas with large double flowers, parents can be directly selected on the basis of these characters since additive genetic variance dominates. As no genetic correlations were found between corolla size and number of stamens (percentage of plants with petaloid stamens) the breeding will not be hampered by unfavourable linkage of genes for these characters.     

照山白杜鹃组织培养研究

以照山白杜鹃(Rhododendron micranthum)试管苗的茎段为外植体,研究不同激素组合对其外植体诱导、丛生芽增殖及试管苗生根的影响.结果表明:最适丛生芽诱导培养基为Read+ ZT 4.0 mg/L+ NAA 0.05 mg/L+蔗糖(3％),诱导率达92.41％;最适丛生芽增殖培养基为Read+ ZT 3.0 mg/L+ NAA 0.1 mg/L+蔗糖(3％),增殖系数达7.56;生根培养基为Read+ IAA 0.5mg/L+蔗糖(2％),生根率达92.5％;NAA不适宜照山白杜鹃生根诱导;将试管苗移栽到松毛土∶泥炭土∶河沙=1∶2∶1的基质中,成活率达89％.     

西洋杜鹃花期调控试验

选用有特色花、叶且市场潜力大的3种西洋杜鹃与比利时杜鹃进行花期调控比较,探索不同温度、光强度、药物处理对它们花期的影响,结果表明,塑料薄膜保温防霜有利促花,与不保温处理花期有明显差异,可提高1个月;遮光可推迟开花时间;用质量分数1 000×10-6"九二○"+0.1%叶面宝促花效果明显,花径可增加15%～20%。     

大白杜鹃与露珠杜鹃杂交亲和性及其杂交果实发育动态研究

以大白杜鹃为母本,露珠杜鹃为父本进行杂交试验,通过测算露珠杜鹃与大白杜鹃的花柱长度比进行杂交可行性分析,利用荧光显微镜观察授粉后露珠杜鹃花粉管的生长状况确定杂交亲和性,并对温室和露天两种条件下的杂交果实的纵横径动态变化情况进行观测。研究结果显示,露珠杜鹃与大白杜鹃的花柱长度比为0.98,推测两种杜鹃杂交容易成功。露珠杜鹃花粉管在授粉后9 d进入大白杜鹃胚珠并完成受精,证实两种杜鹃杂交亲和。温室和露天条件下的杂交果实形态成熟时间均约180 d,其中,授粉后0~9 d为第1次缓慢生长期,授粉后9~105 d为第1次迅速生长期,授粉后105~135 d为第2次缓慢生长期,授粉后135~180 d为第2次迅速生长期;果实纵径和横径的生长动态变化过程相似,但横径的生长动态曲线较纵径平缓。温室条件下的杂交果实纵横径大小明显高于露天条件下的杂交果实。研究认为,大白杜鹃与露珠杜鹃杂交亲和,杂交果实生长动态曲线为"双S"型,其形态成熟时的纵横径大小与其栽培条件直接相关。     

Identification of endophytic <Emphasis Type="Italic">Streptomyces</Emphasis> sp. R-5 and analysis of its antimicrobial metabolites

In a previous study, endophytic Streptomyces sp. R-5 isolated from a field-grown rhododendron was able to confer disease resistance on tissue-cultured seedlings of rhododendron when applied to medium surfaces in flasks. Here, the isolate was identified as Streptomyces galbus Frommer based on various physiological characteristics and analysis of the 16S rDNA sequence. Its major antimicro-bial metabolites were identified as actinomycin X₂ and fungichromin by analyses using liquid chromatography/mass spectometry and nuclear magnetic resonance.     

东祁连山杜鹃属植物形态特征及其生态适应性

对东祁连山杜鹃灌丛草地杜鹃属植物的形态特征及其生态适应性研究表明:百里香杜鹃和头花杜鹃个体相对低矮,叶片近革质、密被鳞片、有芳香但不强烈;烈香杜鹃个体较前者略高,叶片软革质、上无鳞片但背面有稀疏鳞片、有强烈芳香;陇蜀杜鹃个体最高,叶片坚革质、无鳞片、无芳香。花的数目陇蜀杜鹃和烈香杜鹃较多,为12～17朵;头花杜鹃3～8朵;而百里香杜鹃则为单一、偶成双。其叶片显示出不同的生态适应特点,即百里香杜鹃为小叶密鳞半落叶、头花杜鹃为小叶密鳞强反卷、烈香杜鹃为中叶疏鳞角质反卷、陇蜀杜鹃为大叶厚角质反卷。     

千里香杜鹃挥发性成分的分析研究

 采用水蒸汽蒸馏法和毛细管气相色谱—质谱联用法对野生杜鹃挥发性化学成分进行了分析,分离出83 个峰, 确认了其中的77 种化合物, 其含量共占全油的98. 63 % , 其主要化学成分为5 - 羟基- 2- 甲基苯甲醛; 2 - 氟苯基异氰酸盐; 5 - 乙基- 5 - 甲基- 环己酮; 1 - 乙基- 1 - 甲基- 环己烷; 4α- 甲基- 十氢萘; β- 榄香酮; 1 , 2 , 3 , 5 , 6 , 7 , 8 , 8α- 八氢萘等。     

黄杜鹃花粗提物及闹羊花素-III 对斜纹夜蛾幼虫杀虫活性的研究

研究了闹羊花素-III防治斜纹夜蛾幼虫的盆栽试验和黄杜鹃花甲醇提取物田间小区的防治试验。盆栽试验结果表明,以浓度500"g/ml的闹羊花素-III处理,第1,3,7天,斜纹夜蛾的虫口减退率分别为53.18%,64.14%和79.73%,处理后5天和10天的叶片保护率分别为63.64%和68.18%,效果优于川楝素(250"g/ml)。田间小区试验结果表明,以2%黄杜鹃花甲醇提取物处理后第1,3,7,10天的防治效果分别为62.03%,81.87%,92.92%和97.88%,优于2.5%功夫乳油的1000倍液的防治效果。