杜仲叶片愈伤组织诱导的激素优化研究

以杜仲优树L33的幼叶为材料,在B5培养基上添加不同浓度的生长素与细胞分裂素进行愈伤组织诱导研究,结果表明：无激素的培养基上不能诱导出愈伤组织,单独加入2,4-D、NAA和IBA均可诱导出愈伤组织,以0.5 mg·L^-1 2,4-D、0.5～1.0 mg·L^-1 NAA、1.0 mg·L^-1 IBA出愈率最高,达100%,且愈伤组织生长较好;在适宜浓度的生长素的培养基上加入细胞分裂素时,KT的加入对愈伤组织的诱导及生长起抑制作用;1.0 mg·L^-1 NAA+0.3～0.5 mg·L^-1 BA与1.0 mg·L^-1 IBA+0.3～0.5 mg·L^-1 BA 的组合可明显促进愈伤组织的诱导和生长,适合进一步继代培养。     

Stimulation of plant growth and gutta content in Eucommia ulmoides Oliv. by 2-diethylaminoethyl-3,4-dichlorophenylether [DCPTA]

The application of 2000 ppm 2-diethylaminoethyl-3,4-dichlorophenylether [DCPTA] to greenhouse-grown Eucommia ulmoides Oliv. plants resulted in an 18% increase in the gutta content. Leaf area and plant height were also enhanced. Field studies employing 100 ppm of a proprietary regulator, FVCL2, produced a 20% increase in leaf gutta.Reference to a company or product name does not imply approval or recommendation of the product by the U.S. Department of Agriculture to the exclusion of others that may be suitable.     

中国特有金钱槭属植物物种分化研究

金钱槭属(Dipteronia Oliv.)隶属于槭树科(Aceraceae),是北温带植物区系中古老、残遗的木本属之一,为中国特有属,属下仅包括金钱槭(D.sinensis Oliv.)和云南金钱槭(D.dyerana Henry)2个物种。本实验从形态学、分子遗传学及基因序列分析等方面对金钱槭(D.sinensis Oliv.)和云南金钱槭(D.dyerana Henry)进行对比研究,探讨其物种间分化程度。结果表明:(1)形态学研究显示两物种形态性状存在显著差异,表明其在形态上发生了显著分化;(2)基因组DNA的AFLP标记分析表明,两物种间存在极显著遗传分化(ΦST=0.390 4),在物种水平及群体水平,两物种遗传多样性及遗传变异水平皆有明显差异(金钱槭云南金钱槭);(3)从GenBank数据库中选出2物种已知的叶绿体基因(psbM-trnD、trnD-trnT、trnL、trnL-trnF、rpl16)和核基因ITS(ITS1、5.8SRNA、ITS2)进行序列进化比对分析,t-test检验表明,2物种叶绿体基因序列间有极显著差异。研究结果表明:金钱槭和云南金钱槭两物种间产生了极显著的分化,推测可能由于长期的地理隔离所致。     

Efficiency of DNA barcodes for species delimitation: A case in Pterygiella Oliv.(Orobanchaceae)

DNA barcoding is becoming an increasingly popular means to identify species. The obscure discrimination in the genus Pterygiella calls into question the re-assessment of the criterion for species delimitation. We collected 20 individuals, representing all five described species of this genus in its distributional range. The aim was to use three proposed barcode DNA regions (rbcL, matK, and ITS) to diagnose Pterygiella species, and examine which barcode is more suitable for discerning the congeneric and related species. The results showed that the core barcodes matK and rbcL were comparatively less effective. However, the ITS region, especially ITS-1and ITS-2, successfully identified all species in the genus. Furthermore, the secondary structure of ITS-2 RNA, especially compensatory base changes, appears complementary to classical primary sequence analysis for DNA barcoding.     

金钱槭属植物的遗传多样性与保护策略

金钱槭属包括2个种:金钱槭(Dipteronia sinensis Oliv.)和云南金钱槭(Dipteronia dyeriana Henry),均为珍稀濒危植物,主要分布于中国的中部和南部。该研究应用18种随机扩增多态性DNA(RAPD)引物、8对扩增片段长度多态性(AFLP)引物和10种多态性叶绿体微卫星基因(cpSSR)引物,获得金钱槭和云南金钱槭的遗传多样性与种群结构的相关信息。结果表明,在物种水平上,由RAPD(金钱槭:H=0.386 4,Hsh=0.556 3;云南金钱槭:H=0.304 7,Hsh=0.445 0)和AFLP(金钱槭:H=0.331 9,Hsh=0.488 0;云南金钱槭:H=0.304 7,Hsh=0.4450)2个核标记的遗传多样性具有可比性,而cpSSR标记(金钱槭He=0.603 2,云南金钱槭He=0.671 1)的遗传多样性高于AFLP和RAPD标记的遗传多样性,遗传分化系数(GST)也显示出相似的结果,由此揭示2个种均拥有相对较高的遗传多样性和遗传分化。研究认为,人类活动破坏植物栖息地是造成2种物种处于濒危状态的主要原因;从长远来看,保护2种金钱槭属植物的主要策略是保护植物栖息地,同时应加强扩大种群规模以维持现有遗传变异水平。     

金钱槭属植物AFLP反应体系的建立与分析

本实验旨在建立金钱槭属植物的AFLP反应体系。并应用PstⅠ＋GAA／MseⅠ ＋CAC引物组合对金钱槭属植物进行了选择性扩增,获得了清晰稳定的扩增图谱,表明该反应体系对金钱槭属植物的AFLP分析是可行的。对影响金钱槭属植物基因组DNA的制备、酶切、连接以及扩增反应等因素进行了分析讨论。     

人工调水对额济纳胡杨荒漠河岸林繁殖的影响

研究了围封禁牧条件下人工调控黑河水文过程对额济纳胡杨荒漠河岸林繁殖的影响。结果表明:在分水实施的3a中,胡杨主要靠根蘖繁殖更新,种子繁殖几乎不存在。在没有放牧干扰的条件下,不同年份之间林窗内胡杨的根蘖繁殖差异明显,胡杨幼苗个体密度平均为(213.9±112.5)株/100m2,其中1龄为(27.5±18.8)株/100m2,2龄为(113.8±67.7)株/100m2,3龄为(71.0±73.9)株/100m2。胡杨幼苗的丛密度平均为(108.3±56.0)丛/100m2,其中1龄为(19.2±13.9)丛/100m2,2龄为(59.0±37.8)丛/100m2,3龄为(29.8±22.8)丛/100m2。这种差异与当年的生态水文条件有关。划分的整体、大林窗、小林窗3种类型中,大林窗内2龄胡杨幼苗的根蘖繁殖更新受到了距样方最近和最远母树距离的影响。在生态水文条件较好的年份(2龄苗对应于2002年),在距母树较远的地方根蘖繁殖最容易发生。在其它林窗中,胡杨根蘖繁殖主要受林窗生境如环样方母树株数(Tn)、距样方最近母树距离(Nd)、距样方最远母树距离(Fd)和林窗面积(Ga)等因子的综合影响,任何一个因子的单独影响都不显著。总之,本研究的初步结论是黑河分水工程实施对胡杨的繁殖更新无疑是有利的,但前提是消除放牧等干扰因素的影响。     

杜仲雄花中次生代谢物合成积累的动态变化

对杜仲(Eucommia ulmoides Oliv.)雄株不同花期雄花中次生代谢产物含量进行分析测定,并对杜仲雄花次生代谢的生理基础及不同花期次生代谢产物含量差异进行了探讨.研究结果表明,雄花在不同花期次生代谢产物含量均有差异.总黄酮含量在花蕾期最高(4.010%),始花期最低(2.422%),从盛花期到末花期逐渐上升;桃叶珊瑚苷和绿原酸含量均在花蕾期最高(分别为2.351%和1.075%),盛花期最低(分别为1.463%和0.503%),至末花期含量上升;京尼平苷酸含量在始花期最低(0.217%),从盛花期开始逐渐升高,至末花期高达1.403%;次生代谢产物总量也以花蕾期为最高(7.420%).杜仲雄花的花蕾期和盛花期是兼顾质量和产量的最佳采摘期.     

香果树茎段和叶片的组织培养

以香果树（Emmenopterys henryi Oliv．）实生苗带芽茎段和叶片为外植体进行组织培养。结果表明,香果树带芽茎段愈伤组织的最适诱导培养基为含有1．0mg·L^-1～6-BA和0．01mg·L^-1 NAA的MS培养基,愈伤组织诱导率达100％;愈伤组织分化的最适培养基为添加2．0mg·L^-1KT和0．01mg·L^-1 NAA的MS培养基;在含有1．0mg．L^-1～6-BA和0．1mg·L^-1 NAA的MS培养基上,叶片诱导不定芽的效果较好,诱导率可达80％;在含有2．0mg．L^-1 KT和0．1mg·L^-1 NAA的MS培养基上,不定芽的增殖系数可达3—4;以含有1．5mg·L^-1 IBA的1／2MS培养基为生根培养基,香果树试管苗生根率达72．73％。移栽至大田后,香果树试管苗的成活率达到30％。     

Stand structure and regeneration of <Emphasis Type="Italic">Populus euphratica</Emphasis> forest in the lower reaches of the Heihe River,NW China

Populus euphratica Oliv. is a main tree species that forms natural riparian forests in arid and semi-arid areas from Morocco to the Ordos Plateau. This study is designed to clarify the forest structure and dynamics of P. euphratica and to elucidate the ecological mechanisms sustaining riparian forests under unreliable environmental conditions. This study was conducted in a P. euphratica forest of the Ejina Oasis in Inner Mongolia, China, which is a hyperarid area. According to their tree size distribution, P. euphratica forests can be grouped into juvenile, mature, and overmatured stages. Almost all large P. euphratica showed dieback. The regeneration density on the forest floor shows a relation with the degree of height decrease due to dieback damage, as evaluated using the ratio of actual height to the maximum height estimated from the D–H relation. Therefore, after the mature stage, individual trees continue to grow while controlling their canopy size to adjust to changing environmental conditions in the overmatured stage. Our results suggest that P. euphratica growing under large fluctuations in groundwater levels exhibit a sophisticated regeneration system with canopy degradation.