大连地区岛屿与大陆玉竹种群遗传多样性的ISSR分析

选取大连地区大陆与海岛共有植物玉竹为研究对象,采用ISSR分子标记技术对来自5个海岛和4个大陆种群的262个玉竹个体进行遗传多样性的比较和分析。从10个筛选出的ISSR引物扩增得到120个位点信息,其中多态性条带百分率为91.67%,Nei's基因多样性指数（h）为0.346 0,Shannon信息指数（I）为0.510 8。其遗传分化系数（G_st）为0.117 4,基因流（N_m）为3.758 5。研究结果表明玉竹天然种群的遗传多样性较为丰富,种群间基因交流较为频繁,遗传距离与地理距离具有一定的相关性。通过海岛与大陆种群遗传多样性的比对发现,海岛种群的遗传多样性略高于大陆种群,表明在孤立的生境和更为复杂的选择压力下,海岛玉竹种群可能会积累更多的遗传变异从而形成较高的遗传多样性水平。本文研究结果将为进一步探讨隔离生境中天然植物种群遗传进化规律提供证据。     

Karyotype Analysis of Eight Species of Polygonatum Mill.

Meiosis and mitosis of eight species of Polygonatum from Sichuan, China, were investigated. Ten bivalents (n=10) at meiosis of pollen mother cells were observed ih P. odoratum (Mill.) Druce. Meiotic observation on pollen mother cells in P. punctatum Royle ex Kunth shows 16 bivalents (n=16) at diakinesis, P. kingianum Coll. et Hemsl. 13 bivalents (n=13) at diakinesis. P. zanlanscianense Pamp. 15 bivalents (n=15) in MI, P. cirrhifolium (Wall.) Royle 28 bivalents at diakinesis. Somatic chromosomes were observed in root tip cells. The karyotype formulae are as follows: P. odoratum (Mill.) Druce K(2n)=20=4st+6sm+10m; P. cyrtonema Hua K(2n)=20=6sm+14m; P. punctatum Royle ex Kunth K(2n)=32=2t+8st+ 2sm+20m; P. kingianum Coll. et Hemsl. K(2n)=26=8st(2SAT)+14sm+4m; P. alternicirrhosum Hand.-Mzt. K(2n)=32=6st+8sm+18m(2SAT); P. zanlanscianense Pamp. K(2n)=30= 2t+6st+6sm+16m(2SAT); P. sibiricum Delar. ex Redouté K(2n)=24=2t+14st(2SAT)+6sm +2m; P. cirrhifolium (Wall.) Royle K(2n)=56=18st+10sm+28m. The karyotypes of P. punctatum, P. kingianum, P. alternicirrhosum and P. cirrhifolium are reported for the first time. Both the chromosome number and structure in our materials are certainly different from thoses in previous reports. Of numerical variation polyploidy and aneuploidy have been recorded, and aneuploidy is frequent. According to degree of asymmetry of the karyotype, the 8 species are divided into three types: 2B, 3B, 2C. The increasing asymmetry is correlated with the increasing of the chromosome number. There are no obvious differences in chromosome number and karyotype between Alternifolia Baker and Verticillate Baker. They are not two natural groups. This opinion is different from that of Therman and Suomalainen.     

Taxonomic Study on Polygonatum odoratum Complex

This paper deals with the morphological and cytological variation in various forms of P. odoratum complex. A quantitative analysis on the correlation between some diagnostic characteristics was also made with pictorialized scatter diagram and histogram. The results show that the presence or absence of angles on stems is closely correlated with smooth or verrucate lower surface of leaves and the position of stamens (above or below the middle). With chromosome numbers, they heve 2n=18 and 2n=20 respectively. It is suggested to treat them as two distinct species and restore P. simizui Kitag as species status.     

湖北黄精大小孢子发生及雌雄配子体发育

【目的】研究湖北黄精花部形态结构特征和大小孢子发生及雌雄配子体发育过程,以丰富黄精属植物的生殖生物学理论,为进一步开展湖北黄精的品种选育提供依据。【方法】以不同发育时期的湖北黄精花芽为试验材料,用显微观察法观察花部形态结构特征,石蜡切片技术对单花雌雄蕊进行切片观察。【结果】湖北黄精的花被为白色或淡黄绿色,花被筒近喉部稍缢缩;具6枚雄蕊,花丝下端与花被合生,花药开裂方式为纵裂;雌蕊子房上位,3心皮,花柱与子房等长。湖北黄精花药壁由4层细胞组成,成熟的绒毡层具多核,绒毡层发育类型为分泌型;小孢子母细胞减数分裂为连续型,四分体呈左右对称型排列,成熟花粉粒为2-细胞型;存在小孢子发育不同步的现象。雌蕊胚珠具双珠被、厚珠心;四分体呈直线型排列,胚囊发育类型为蓼型;存在双胚囊胚珠现象。在雄蕊的花药壁和雌蕊的子房壁都观察到有束状草酸钙针晶。【结论】湖北黄精雌雄蕊具有较原始的发育特征,虽然在发育过程中都存在异常现象,但雄蕊最终能形成正常的雄配子体,雌蕊低频率的双胚囊现象对总体受精结果影响很小。湖北黄精杂交育种可以选择花药开裂前一时期的花粉,花药壁和子房壁观察到的束状草酸钙针晶无法作为湖北黄精物种鉴定的...     

滇黄精叶绿体全基因组序列及其密码子使用偏性分析

为探究滇黄精(Polygonatum kingianum)叶绿体全基因组特征和密码子使用偏性,利用第二代测序技术对滇黄精嫩叶进行测序,再经组装与注释后得到其叶绿体基因组全序列,通过MISA、EMBOSS和CodonW等软件对滇黄精叶绿体全基因组的SSR位点、系统发育及密码子偏好性进行分析。结果表明,滇黄精完整叶绿体基因组长度为155 852 bp,基因组平均GC含量为37.7%,其大、小单拷贝区(LSC)长度分别为84 633和185 25 bp,反向重复区长度为26 347 bp,注释了132个基因,包括86个蛋白编码基因、38个tRNA基因和8个核糖rRNA基因。叶绿体基因组中共有69个SSR位点,绝大多数属于单碱基重复的A/T类型。系统发育分析表明滇黄精与格脉黄精(P. tessellatum)亲缘关系近,可能与分布地域有关。密码子偏好性分析表明,滇黄精叶绿体基因组密码子使用模式受到自然选择影响大于突变因素,最终确定9个最优密码子。因此, 滇黄精叶绿体基因组遗传结构和系统发育位置及其密码子偏倚的分析,为叶绿体基因工程研究提供理论依据。     

小玉竹的胚胎学研究

小玉竹Polygonatum humile Fisch．ex Maxim．的花药四室．绒毡层腺质型,发育后期出现双核至多核。小孢子四分体左右对称型,偶见四面体型,胞质分裂连续型。成熟花粉具2细胞。子房3室,中轴胎座。胚珠倒生,双珠被,厚珠心,珠孔由内珠被形成。胚囊发育为葱型。受精后,子房壁和外珠被细胞中含有草酸钙针晶。胚发育类似于紫菀型,基细胞有时纵裂形成两个子细胞。胚乳核型。根据实验结果,并结合前人的资料,本文提出了黄精属的胚胎学特征,并在此基础上对黄精族的概念以及属间系统关系进行了探讨。     

Root CEC determinations to establish root biomasses of two plant species grown in mixtures

Summary The use of measurements on the cation exchange capacity (CEC) of roots in competition experiments with two plant species is suggested. If the root-CEC differences between the two species are not too small, measurement of this parameter offers a very simple way to determine the separate contributions of the two plant species in the total root biomass of the mixture. This root-CEC method can be applied to total root yields as well as to detailed root-zone studies.Grassland Species Research Group, Publication no. 48     

广西隆安屏山石灰岩山地飞机草群落特征分析

对隆安屏山石灰岩山地有害的入侵杂草飞机草(Eupatorium odoratum)群落的区系组成、地理成分、生活型、结构及物种多样性进行统计分析,结果表明:该群落内常见的维管植物约有62种,隶属38科58属。植物地理分布以泛热带类型最多,有15属,占总属数的34.88%;其次是热带亚洲分布类型,有8属,占18.6%。按Raunkiaer生活型统计,高位芽植物占48.39%,一年生植物占17.74%,地面芽植物占12.90%,地上芽植物占11.29%。群落内植物叶的性质以草质、单叶、小型叶和全缘为主。群落垂直结构简单,分层不明显,只分为灌木层和草本层,并有少量的层间植物。灌木层种间相遇机率指数和Shannon-Wiener指数较高,表明该群落目前仍相对稳定,该地区外来飞机草目前处于种群建立时期。     

飞机草中木犀草素和槲皮素分析样品制备工艺

研究了飞机草中木犀草素和槲皮素分析样品的制备工艺,确定了超声提取法制备分析样品的最佳工艺条件为：溶剂85%乙醇,液固比10：1,提取时间1h,飞机草中木犀草素和槲皮素的提取率为0.031 8%和0.019 2%,平均加样回收率为99.601 7%和99.032 6%,表明此分析样品制备工艺准确度高,可靠性强。     

玉竹的不同溶剂提取物中化学成分的GC-MS对比分析

建立了采用气相色谱-质谱技术分析压竹的不同溶剂提取物中化学成分的方法.分别用石油醚、正己烷和乙酸乙酯浸泡萃取玉竹,然后将萃取液于25℃、0.015 MPa下减压蒸馏浓缩,并对石油醚和正己烷的浓缩提取物进行了GC-MS对比分析.实验结果表明,石油醚提取物中含有11种芳香族化合物和13种其它组分,它们占总出峰面积的81.33%,其中,甲苯和1,2-二甲苯为主要成分,含量分别达到了9.38%和13.38%.正己烷提取物中含有37.03%的柠檬油精(D-limonene),而石油醚提取物中未发现此柠檬油精(D-limonene),在正己烷提取物中确认了19种化合物,它们占总出峰面积的95.99%.乙酸乙酯不适合直接做浸泡萃取玉竹精油的提取溶剂.