【作者】 周娅；

【导师】 周兰英；

【作者基本信息】 四川农业大学 ， 林木遗传育种， 2012， 硕士

【摘要】 松属(Pinus)隶属于松科(Pinaceae)松亚科(Pinoideae),是一类颇具经济价值和生态价值的裸子植物。本文以9种松属植物种子为试材,其中火炬松(P. taeda)和黑松(P. thunbergii)为外来树种,高山松(P. densata)、思茅松(P. kesiya var. langbianensis)、云南松(P. yunnanensis)、华山松(P. armandii)、马尾松(P. massoniana)、赤松(P. densiflora)和油松(P. tabulaeformis)均为乡土树种。对常规压片法进行了改良,以种子萌发的根尖为材料,对9个树种体细胞染色体核型特征及其间的进化趋势进行了分析研究,采用聚类分析的方法对种间亲缘关系进行了初步探讨。主要结果如下：1.对染色体压片法中的预处理液和处理时间、解离液和解离时间等参数进行优化,建立的松属植物染色体制片技术体系为：种子于25℃人工气候箱中培养,待幼根长至0.5-1.Ocm时,于上午9-11时切取生长旺盛的根尖作实验材料；0.15%秋水仙素溶液25℃恒温下预处理5-6h；卡诺氏固定液4℃冰箱中固定20-24h；1mol/L HCL60℃水浴条件下解离10-16mmin；改良苯酚品红染液染色。2.9种松属植物均为二倍体,染色体数目稳定为24条；核型公式相同,为2n=2x=24=24m,即全部由中部着丝点染色体(m)组成；核型类型均属于1A型,是Stebbins核型分类标准中最对称核型。3.9个树种核型不对称系数变化范围52.37%-53.16%,平均臂比1.114-1.150,染色体长度比1.491-1.742,着丝点指数均值46.64%-47.42%。高山松、思茅松、云南松、马尾松、火炬松、赤松和油松的染色体相对长度组成相同,均为2n=24=14M2+8M1+2S；黑松为2n=24=16M2+6M1+2S；华山松为2n=24=14M2+10M1。4.通过种间核型特征的比较和核型不对称性程度散点图分析,单微管束松亚属种华山松的核型不对称程度最低；思茅松核型不对称程度最高,其次是高山松；云南松和油松相近,马尾松和黑松相近；赤松核型应较火炬松不对称,两者是8个双微管束松亚属种中核型不对称程度最低的。5.以染色体核型参数作聚类分析,可将9种松属植物分为三组：第一组包括黑松、马尾松、赤松和火炬松；第二组包括油松、云南松、高山松和思茅松；第三组仅有华山松。黑松和马尾松、油松和云南松的种间距离相对较小；被聚为一组的几个种的亲缘关系相对接近,华山松与其它种亲缘关系相对较远。更多还原

【Abstract】 The plants of Pinus in Pinoideae of Pinaceae are well-known gymnosperm which have great economic and ecological value. The seeds of nine species of Pinus were taken as the experimental materials in this paper, P. taeda and P. thunbergii are exotic tree species, P. densata、P. kesiya var. langbianensis、P. yunnanensis、P. armandii、P. massoniana、P. densiflora and P. tabulaeformis are indigenous tree species. In this study, the conventional squashed method was improved, the root tips germinated by seeds were taken as the experimental materials, analyses and research were carried out on the karyotypic features and the evolution trend of the somatic-cell-chromosomes of these nine plants, and with the method of cluster analysis, a preliminary study was taken on their interspecific genetic relationships. The main results were as follows:1. The parameters of chromosome squashing method for Pinus species had been optimized, for example the reagent and time for pretreatment and the reagent and time for dissociation, and a technique of chromosome preparation for Pinus species had been established:seeds were cultivated in the growth cabinet of25℃, and the root tips were taken as experimental materials at9-11clock in the morning when they growed to0.5-1.0cm; then they were pretreated in the solution of0.15%colchicin under25℃for5-6h; next fixed in Camoy’s liquid for20-24h at4℃; after fixation, the root tips were treated in lmol/L hydrochloric acid for10-16min at60℃; finally,the root tips were stained with the improved carbol fuchsin solution.2. The results showed that all the chromosomes of nine species of Pinus were diploid and the number is24; they all had the same karyotype formula what was2n=2x=24=24m, and all constitute of metacentric chromosomes (m); all of the karyotype of them belonged to1A type, which is the most symmetrical karyotype in the classification standard of karyotype by Stebbins.3. The results showed that the karyotype asymmetry index of these nine species ranged from52.37%to53.16%, mean arm ratio varied from1.114to1.150, ratio of the longest chromosome to the shortest varied from1.491to1.742, mean of centromere index ranged from46.64%to47.42%. P. densata、P. kesiya var. langbianensis、P. yunnanensis、 P. massoniana、P. taeda、P. densiflora and P. tabulaeformis had the same composition of relative length that was2n=24=14M2+8M1+2S; P. thunbergii was2n=24=16M2+6M1+2S; P. armandii was2n=24=14M2+10M1.4. According to the comparison of karyotypic features and the analysis of scatter diagram which based on the degree of karyotype asymmetry on nine species of Pinus, the degree of karyotype asymmety of P. armandii of Subgen Strobus was the the lowest, P. kesiya var. langbianensis was the most hightest, the second was P. densata; P. yunnanensis and P. tabulaeformis were similar, P. massoniana and P. thunbergii were also similar; then P. densiflora should be more asymmetical than P. taeda, they had least degree of karyotype asymmety in the eight species of Subgen Pinus.5. Nine species of Pinus were finally divided into3groups by cluster analysis with chromosome karyotype parameters, as follows:the first group include P. thunbergii、P. massoniana、P. densiflora and P. taeda; the second group include P. tabulaeformis、P. yunnanensis、P. densata and P. kesiya var. langbianensis; the third group include P. armandii only. The interspecific gap between P. thunbergii and P. Massoniana、P. tabulaeformis and P. Yunnanensis was relatively samll, the next was; the genetic relationships of species clustered in the same group was approach relatively, while the genetic relationships between P. armandii and other species was much further relatively.更多还原