西南桦优树选择的研究

通过对西南桦Betula alnoides 分布区的调查, 实测了25 个县261 株西南桦候选优树的数量性状、质量性状及环境因子, 对候选优树9 个性状进行相关分析后选择出材积和通直度作为西南桦选优的主要性状。采用数量化回归的方法来制定优树选择的指标, 建立了各立地因子、林分类型和树龄与材积的多元数量化模型, 其复相关系数达0.920 815 。西南桦材积实测值与理论值间差值的频率分布呈正态分布, 以其差值作为西南桦优树选择的选择指标Ii , 以I 0.5 作为分级依据, 结合通直度制定出西南桦优树选择的标准为①Ⅰ级优树:通直度为Ⅰ级, 同时Ii 0.381 257 。②Ⅱ级优树:通直度为Ⅰ级或Ⅱ级, -0.381 257 Ii 0.381 257 。③一般林木(Ⅲ级木):Ii -0.381 257 。用此标准筛选出西南桦I 级优树46 株,占候选优树的17.62 %, Ⅱ级优树145 株, 占候选优树的55.56 %。图2 表2 参11     

铁力木苗木分级研究

采用逐步聚类分析方法,对铁力木容器苗苗木的分级标准进行了探讨。提出了以苗高和地径作为该树种苗木分级的质量指标,并得出铁力木苗木的3级分级标准,即 Ⅰ级苗 树高≥19.4 cm,地径≥0.25 cm、Ⅱ级苗 19.4 cm>树高≥12.3 cm,0.25 cm>地径≥0.16 cm、Ⅲ级苗 树高<12.3 cm,地径<0.16 cm。西北林学院学报21卷第1期杨斌等铁力木苗木分级研究     

滇东南石漠化地区封山育林前后群落生态学特征比较

通过样地法比较了滇东南石漠化地区封山育林前后植被的群落学特征,从生活型谱、叶型谱、光照生态类型谱、水分生态类型谱和优势植物等群落特征看,封山育林后群落的水湿条件有所改善,群落正向地带性植被—半湿性亚热带常绿阔叶林演替;从物种多样性来看,封山育林后群落的物种丰富度、物种多样性指数、生态优势度和群落均匀度均有很大的提高,物种多样性增加,群落稳定性增强,且破坏后修复能力增强。结果说明封山育林措施是石漠化地区植被恢复的很好措施之一。西北林学院学报21卷第5期李品荣等滇东南石漠化地区封山育林前后群落生态学特征比较     

SSR Marker Analysis on indica-japonica Differentiation of Natural Population of Oryza rufipogon in Yuanjiang, Yunnan Province

It was generally recognized that the common wild rice (Oryza rufipogon Griff.) was the ancestor of cultivated rice (O. sativa L.) and there was indica-japonica differentiation in common wild rice before it evolved into cultivated rice [1-10]. The analysis…     

板栗花序与叶的cDNA-AFLP的差异表达分析

为给板栗的分子遗传育种工作提供重要的分子数据参考,作者通过cDNA-AFLP的方法,以同株板栗幼年花序和叶片为实验材料,在转录水平上进行差示分析。结果显示：64对引物组合共产生了2131条PCR产物,对其中的110条克隆测序,发现有28条基因与已知功能基因相关,其中包括参与植物转运﹑代谢﹑能量产生相关的蛋白,从而证明这些基因在板栗生长发育中的重要作用。     

3S技术在水土保持动态监测中的应用

近年来,随着社会和经济的发展,毁林开荒的现象比较普遍,林地面积锐减,植被大面积破坏,从而造成我国的水土流失现象日益严重,因此,对全国水土流失进行适时动态监测已势在必行。3S技术是集遥感、全球定位系统与地理信息系统于一体的高新技术手段,它可以快速、准确地获得地面各种信息。分别介绍了RS、GPS和GIS三种技术在水土保持动态监测中的应用,并对3S技术在水土保持动态监测方面的应用前景进行了展望。     

观赏石榴新品种‘火凤凰’

观赏石榴新品种‘火凤凰’是从微型石榴的播种实生苗中筛选而来。树形丛状,树冠开张,各枝分生能力较强;5年生树高50 ~ 85 cm,叶片长椭圆形（0.5 cm × 1.5 cm）,叶色艳绿,叶面光滑亮泽;花期150 ~ 220 d,花蕾橘红,花瓣朱红色,3 ~ 4片,每片1 cm × 2 cm;种球较匀称,直径3.5 ~ 5.0 cm,每株种球15 ~ 25个,果球呈大红、紫红和玫瑰红,花果同株达110 d,具有较高的观赏性。     

枣基因组大小研究

采用流式细胞技术,以4个酸枣类型、9个枣品种的新鲜幼嫩叶片为材料,以Otto为解离液,日本晴（Oryza sativa ssp.japonica cv.Nipponbare）为外标,测定其基因组大小（2C值）,比较枣和酸枣的2C值差异。结果表明,枣的基因组大小为(360.70±4.73)Mb,小于酸枣的基因组（388.20±8.32 Mb）;枣品种间基因组大小无显著差异,酸枣类型间差异显著,说明酸枣具有更高的基因组变异,且酸枣到枣的进化中可能伴随着基因组的缩减。     

Variation in morphophysiological characters of fruits of <Emphasis Type="Italic">Trigonobalanus doichangensis</Emphasis> (Fagaceae) according to individual trees,populations and years

Trigonobalanus doichangensis is recognized as a rare and endangered plant of China. The morphological and physiological traits of fruits were investigated in one population over 2 years (2006–2007) and in four populations during 2007 in order to facilitate ex-situ conservation and eventual reforestation through planting of propagules. The results indicated that morphological traits including fruit length, fruit width and 1,000-fruit weight showed significant variation among individual trees within populations (P < 0.01), however, not among populations. And each of them had significant positive correlation with each other (P < 0.01). Seed abortion occurred, and there was significant variation in percentage of fruit fill among populations and among individual trees within populations, whereas, percentage of fruit fill showed no correlation with the morphological traits. As for fruit germination, germination percentage, germination index and vigor index presented significant variation among populations and among individual trees within populations. The three germination-related indices had significant positive correlations with each other (r ≥ 0.9, P < 0.01) and with percentage of fruit fill (r > 0.86, P < 0.01), however, possessing weak correlations with morphological traits. It was also found that each of the traits mentioned above showed significant variation among individual trees within years, however, not between years. In addition, more than 48% of the variation occurred among individual trees both within populations and within years in all the fruit characters. We suggest that collecting fruits from various individuals at each of populations will be the preferred strategy to conserve the most genetic diversity of the species.