2009年8—9月在福建南平芒荡山(Ⅰ)、贵州从江瑶人山(Ⅱ)、广西金秀大瑶山(Ⅲ)、云南屏边大围山(Ⅳ)和西双版纳南糯山(Ⅴ)等5个不同类型的分布区内设置样地,对越南安息香群落进行实地调查,研究了群落结构特征与物种多样性。结果表明:5个分布区的越南安息香群落均含有相对较少的物种数,越南安息香在各群落多与壳斗科、松科、杉科、桦木科、金缕梅科和山茶科等物种共优组成乔木层,或是壳斗科、杉科和漆树科的伴生物种;灌木层和草本层物种数量也较少,灌木层和草本层间还有一定数量的层间植物;群落丰富度指数(Dma)为乔木层>灌木层>草本层,优势度指数(D)和多样性指数(H)较小,变化趋势为Ⅴ>Ⅱ>Ⅳ>Ⅰ>Ⅲ。分布区气候类型的不同导致群落间共有物种数目少,相似性系数维持在较低水平。

利用来自乳源木莲主要分布区的12个种源在福建建瓯和浙江淳安两个试验点开展苗期遗传测定,系统研究苗木生长、苗高生长参数、叶片形态、根系特征和干物质积累等性状的种源遗传差异。研究结果表明:乳源木莲苗的生长、叶片形态、干物质积累量、主根长和根幅等性状存在显著的种源效应。由于乳源木莲侧根相对不发达,一级侧根数和最长侧根长的种源差异未达到统计学上的显著水平,但其绝对值间却相差2. 8倍。乳源木莲苗生长和形态等主要性状的种源变异受产地经度和纬度的双重控制,与北部和东部种源相比,来自于南部和内陆的种源其苗高径生长量和苗高生长参数较大,分枝数较多,叶片数多且较宽长。根据苗期种源测定结果,初选出江西全南、龙南和福建连城、沙县、将乐等优良种源,其苗高生长量比对照增加了8. 99%～56. 28%。

The provenance d ifference for pho tosynthet ic characters ofTaxus ch inensis var. mairer seedlingw as stud iedby use of provenance tria l under d ifferent shading cond ition located at Chun’ an of Zhe jiang. The resu lt ind icatedthat there w ere obv ious provenance d ifferences for height grow th, dry matter accumu lation, ch lo rophy ll a, b and thetota l conten,t photosynthesis rate w ith d ifferent geograph ica l genetic variation pa ttern. Seedling he ightw as found tobe positively and sign ificantly re lated to the altitude and long itude of its seed source. Con trast ing to seedling he igh,tdry matter appeared to be certainly and negatively re lated to the a ltitude and long itude of its seed source. Therew ereno obv ious geograph ica l variat ion pattern for ch lo rophy ll content and photosynthesis rate. The provenancesw ithmorech lorophy ll had h igher pho tosynthesis rate and greater dry matter accumulation. Ana lysis demonstrated that there existed great effect o f light env ironm ent on photosynthetic character o f seedling. A t September, the chlorophyll a, band to tal content o f the seed lings under light transm ittance 10% w ere 12. 0%, 16. 1% and 13. 7% more than theones under light transm ittance 25% respect ively. A t O ctober, the chlorophyll a, b and tota l conten t o f the mostprovenances w ere declined under light transm ittance 10% , and average pho tosynthesis rate of the provenances testedw as 13. 7% less than the one under light transm ittance 25%. The change o f ch lorophy ll con tent o f provenance seedling at various grow th stages varied w ith light condition. Under light transm ittance 25% , the content of chlorophy llw as low er atAugus,t h ighest at September, and decreased o r increased slightly at October. Under light transm ittance 10%, the content o f chlorophyll at Octoberw as descended above 20% than one at September.

Genetic diversity and genetic differentiation of 11 Manglietia yuyuanensis provenances from main distribution area were analyzed using ISSR molecular markers.A total of 108 amplified loci were detected by 9 primers,of which the proportion of polymorphic loci was 86.11%.A high degree of genetic diversity in M.yuyuanensis was detected,and the genetic diversity index in species level was 0.282 7,which was markedly higher than that of M.decidua and M.patungensis,the rare and endangered species belonging to the same genus with M.yuyuanensis.The result showed that there was significant difference in genetic diversity among provenances.Provenances from north and north-west Fujian province and the nearby area,including Shaxian,Jian'ou,Wuyishan of Fujian and Longquan of Zhejiang,had higher genetic diversity,which were the dominant regions to be protected and utilized. Small population effect brought by habitat fragmentation and distance isolation effect resulted in high genetic differentiation among provenances,which contributed to 25.89% of total genetic variation,and the differentiation within provenances contributed to 74.11% of total genetic variation.Results also showed that the genetic distance amog provenances was not significantly related to the geographical distance amog provenances.Based on the Nei's unbiased genetic distance,11 provenances might be obviously divided into 3 clusters.Shaxian and Jian'ou of Fujian with high genetic diversity and large nature population was clustered into one group.The genetic distance among Huangshan of Anhui,Longquan and Kaihua of Zhejiang,Wuyishan,Shaowu and Liancheng of Fujian,and Lichuan and Longnan of Jiangxi was small,then the above provenances were clustered.Quannan of Jiangxi,located at the south of distribution area,was an individual provenance.Based on the characteristic of its wider leaves,it was conferred that Quannan provenance was mistaken for M.fordiana Oliv.in the course of seed collection.

以位于浙江清凉峰国家级自然保护区1 hm2永久样地为研究材料,逐一测量并记录了样地中所有胸径≥1 cm树木的胸围,并对其挂牌标记、鉴定种名和确定坐标位置,分析了样地内木荷种群结构与空间格局。研究结果表明,DBH≤17.5 cm的木荷个体数量占80.5%,DBH>27.5 cm的仅占8.4%,种群能够实现自我更新,属稳定型种群。基于种群径级结构分析,木荷种群密度随个体胸径的变化趋势类似于偏正态分布形曲线。木荷在整个样地中的分布表现出明显的空间异质性,多数聚集于坡面和山脊的生境中。种群空间关联性分析表明,木荷大径级(DBH≥16.1 cm)和小径级(1 cm≤DBH＜16.1 cm)间在0-8 m的尺度上负相关,8-25 m的尺度上无关联。另外,25个小样地的木荷重要值为0-34.35%,平均重要值为8.24%,小样地间的这种巨大差异归因于木荷种群空间分布的聚集性。

调查了9个群体的14个表型性状,采用巢式方差分析、变异系数、相关分析和聚类分析等方法,分析了群体间和群体内表型多样性。结果表明:白花树表型性状在群体间和群体内都存在丰富的变异,群体间表型分化系数为59.08%,大于群体内变异;侧枝、叶片、果实和种子4类表型性状的平均变异系数分别为31.02%、16.85%、8.2%和6.6%,表明种子的稳定性较高,侧枝稳定性最低;种子千粒质量多与侧枝、叶片、果实和种子的单个性状间呈显著或极显著正相关,而与叶片、果实和种子的形状指数呈极显著负相关;14个表型性状中仅有叶长、叶面积和种子长、种子长宽比呈现纬度和经度的单向变异模式;通过表型性状的聚类分析将白花树9个天然群体划分为3类。

利用群落生态学方法对恩施桢楠林群落组成与结构进行调查分析。结果表明:恩施桢楠林群落物种丰富,共有维管束植物97科229属332种,含有单种植物的属较多,优势科主要有蔷薇科、禾本科、豆科、百合科。乔木层(DBH≥2.5 cm)优势树种明显,从个体数、平均胸径、胸高断面积和重要值分析来看,桢楠(Phoebe zhennan)在群落中占绝对优势地位。群落区系类型以热带成分较多,93属是热带分布,90属是温带分布。群落成层现象明显,可划分为乔木层、灌木层和草本层。样地内所有木本植物的径级分布呈峰型,表明群落正常生长;从主要树种的径级结构来看,桢楠、枫香(Liquidambar formosana)和杉木(Cunninghamia lanceolata)种群均为增长型或稳定型种群,群落更新良好,正渐趋稳定。灌木层植物种类最丰富,草本层次之,物种多样性大小顺序依次为灌木层>草本层>乔木层。

以江西吉水种源的白花树花粉为研究材料，进行了扫描电子显微镜下的花粉形态结构观察以及采用离体培养基法、I2-KI和TTC染色等花粉生活力测定方法的比较研究，探讨了不同贮藏条件对花粉萌发的影响。研究结果表明：白花树花粉粒为长球型，具3孔沟，外壁面具细网状纹饰；花粉平均极轴长52.33±0.577 μm，平均赤道轴长26.89±0.502 μm；3种花粉生活力测定方法中以离体培养基法最有效，花粉萌发的最佳组合为：10%蔗糖+0.05 g·L-1硼酸+100 mg·L-1 GA3+3 h；花粉最佳贮藏条件为-80 ℃密封保存，贮藏180 d后花粉的萌发率仍可达40.97%。