北萱草与大苞萱草区分为不同物种的核型证据

在文献中,小萱草Hemerocallis dumortierii Morr、北萱草H．esculenta Koidz．和大苞萱草H．mid- dendorfii Trautv et Mey被认为属于同一生物学复合体,并被处理为同一物种的不同变种。本文比较分 析了北萱草及大苞萱草的核型。北萱草和大苞萱草的核型分别为:2n=2x=22=12m+8sm+2T和2n =2x=22=10m+6sm+4st+2T。两个类群的核型差异水平已超出种内变异水。另外,大苞萱草以其 具有宽大苞片包裹的类头状花序,并且产黑龙江和吉林东部,南达辽宁干山地区,但绝不分布到大陆40° N以南地区而显著不同于分布华中、华北的北萱草。根据核型、外部形态及地理分布资料的综合分析,北萱草与大苞萱草应区分为不同物种,而不是同一物种的不同变种;同时,在系统发育上大苞萱草比北萱草进化。     

中国西北地区萱草属花粉形态研究

本文借助光学显微镜和扫描电镜,对我国西北地区萱草属6种1变种的花粉形态进行了比较研究,不同的种类,其花粉形态或多或少有所不同,说明花粉形态在种间具有分类意义,而且6种、1变种可自然地分为两大类群,第一类群包括小黄花菜、北萱草、黄花菜,第二类群包括北黄花菜、折叶萱草、萱草、重瓣萱草。#br#北黄花菜、小黄花菜的花粉形态差别较大,证明把小黄花菜做为北黄花菜的变种是不妥当的。     

中国萱草属数量分类研究

用聚类分析和主成分分析研究了国产萱草属11个类群的分类。结果发现这些类群形成4簇。第一簇：北黄花菜、黄花菜、小黄花菜和多花萱草。第二簇：小萱草和大苞萱草。第三簇：折叶萱草,西南萱草和矮萱草。第四簇：萱草及其三倍体类型。各簇都有其区别特征。讨论了簇内各类群之间的亲缘关系及属下分组问题。     

甘肃萱草属植物的核型研究

本文研究了甘肃萱草属6种、1变种的染色体核型;黄花菜K(2n)=22=12m+10sm(2SAT);小黄花菜K(2n)=22=10m+12sm;北萱草K(2n)=22=8m+14sm;北黄花菜K(2n)=22=14m+6sm+2st;萱草K(2n)=22=12m+8sm+2st;重瓣萱草K(2n)=33=18m+12sm+3st:折叶萱草K(2n)=22=10m+10sm+2st。以上核型可自然地分成两大类群,第一类群包括小黄花菜、北萱草、黄花菜;第二类群包括折叶萱草、萱草、重瓣萱草、北黄花菜。     

神农架世界自然遗产地种子植物科属的古老性

为了研究神农架世界自然遗产地的种子植物区系特征,基于Phylomatic建立时间树并综合多学科证据,探讨了该区系种子植物科属起源的时间特征。结果发现,神农架世界自然遗产地裸子植物占中国华中山地分布中心属和种的67%和74%,是中国裸子植物分布中心之一;被子植物科的基部类群科占中国的85%;种子植物单型科（仅含1属1种）占中国的42%;拥有中国特有属56属,占中国特有属总数的23%,很多为古老特有属;神农架世界自然遗产地还分布有中国超过50%的东亚-北美间断分布属。这些事实表明神农架世界自然遗产地种子植物区系起源古老,且有连续的传代线,是神农架世界自然遗产地突出普遍价值的重要体现。     

神农架种子植物中国特有属的分析

神农架种子植物区系分布中国特有属５１属,其中裸子植物３属,被子植物４８属。从生活习性看,木本习性２６属,草本习性２５属。本文着重分析了神农架种子植物特有属的地理分布及特点。结果显示,其特点主要表现为显著的温带性质、众多的古特有属和丰富的珍稀物种,在地理分布上与西南地区联系密切。     

萱草属有毒植物的研究

萱草属中某些种的根含神经性毒物,家畜采食或饲喂实验动物能引起中毒病的发生。在鉴于此对北萱草,黄花菜,北黄花菜,小黄花菜进行了植物调查鉴定及有毒成分—萱草根素的提取分离与毒性和结构再鉴定的研究,确认除黄花菜根外其它３种均含有萱草根素。讨论了黄花菜种鉴定中存在的问题。     

神农架世界自然遗产地落叶木本植物多样性及其代表性

神农架世界自然遗产地在生物多样性、栖息地和生态学过程上具有全球意义,属于北方温带落叶林生物群区。北方温带落叶林是世界落叶木本植物种类最为丰富的生物群区。本文选取该群区最具代表性的82个仅有落叶成分的属,对比分析了相关种、属在世界、中国、欧洲、北美、美国大烟山(Great Smoky Mountains)、日本Ogawa森林保护区(Ogawa Forest Reserve)和神农架世界自然遗产地的分布情况,重点分析了神农架世界自然遗产地落叶树种的多样性和代表性,为神农架世界自然遗产地突出普遍价值的认定提供重要证据,并为其科学管理提供理论依据。结果表明:神农架有62个落叶属,分别占中国和世界仅有落叶成分属的86%和76%;落叶种225个,分别占中国和世界的21%和7%。美国大烟山和日本Ogawa森林保护区亦属于典型的北方温带落叶林,然而,二者的落叶木本植物种、属多样性均低于神农架世界自然遗产地。这说明神农架世界自然遗产地是世界落叶木本植物集中分布地,其多样性和代表性具有全球意义。青藏高原的隆起导致中国中东部气候温暖湿润,地形复杂多变,而且该区域与亚热带热带植物区系落叶成分联系紧密,这可能是导致神农架植物区系具有丰富的落叶木本成分的生物地理成因。     

中国羊蹄甲属植物新分布三种

本文报道了三种羊蹄甲属植物在中国的新分布记录,即产自广西的中越羊蹄甲、耐看羊蹄甲和产自云南的圆叶羊蹄甲．     

中国萱草属药用植物资源学研究

对中国萱草属药用植物进行了本草学分类、分布、显微组织、化学成分、含量测定等方面的研究,为正确分类鉴定及安全有效地用药提供了依据。     

Numerical Cytotaxonomic Studies of Hemerocallis (Liliaceae) from China

Comparative studies of karyotypes in Hemerocallis from China have been carried out using numerical techniques. Taxa studied are as follows: Hemerocallis citrina, H. dumortieri , H. esculenta , H. forrestii , di- and triploid H. fulva , H. lilioasphodelus , H. middendorffii, H. minor, H. multiflora and H. plicata. The results show that variation in speciation has taken place at chromosomal level, and that karyotype variations have largely paralleled the morphological ones. Taxonomic proposals are given to treat H. citrina and H. minor as subspecies of H. lilioasphodelus, and H. esculenta as a variety of H. dumortieri. The results are not in favour of considering H. middendorffii as a variety ofH. dumortieri, and H. multiflora closely related to H. plicata.     

Karyotype Evidence for Distinguishing Between Hemerocallis esculenta and H. middendorfii

Hemerocallis dumortierii, H. esculenta and H. middendorfii were considered to belong to a biological complex, and were treated as different varieties of the same species, H. dumortierii. The present authors observed and compared the karyotypes of H. esculenta and H. middendorfii. Two plant samples for each of the species were studied. One sample of H. esculenta was from Wuán County, Hebei Province, at an altitute of 1000 m, the other from Shennongjia, Hubei Province, altitute 2100 m. The two samples of H. middendorfii were respectively from Antu County, at an altitute of 700 m, and Tonghua, altitute 500 m, in Jilin Province. The karyotypes are 2n＝2x=22=12m+8sm+2T for H. esculenta, while 2n＝2x＝22=10m+6sm+4st+2T for H. middendorfii. The karyotypical difference between the two taxa was obviously not intraspecific but interspecific. Based on the karyotype data as well as the morphological and phytogeographical data available, it is considered that H. esculenta and H. middendorfii should be recognized as different species, instead of different varieties of the same species as in literature, and that H. mid-dendorfii is more advanced than H. esculenta.     

Relative role of flower color and scent on pollinator attraction: experimental tests using F1 and F2 hybrids of daylily and nightlily

The daylily (Hemerocallis fulva) and nightlily (H. citrina) are typical examples of a butterfly-pollination system and a hawkmoth-pollination system, respectively. H. fulva has diurnal, reddish or orange-colored flowers and is mainly pollinated by diurnal swallowtail butterflies. H. citrina has nocturnal, yellowish flowers with a sweet fragrance and is pollinated by nocturnal hawkmoths. We evaluated the relative roles of flower color and scent on the evolutionary shift from a diurnally flowering ancestor to H. citrina. We conducted a series of experiments that mimic situations in which mutants differing in either flower color, floral scent or both appeared in a diurnally flowering population. An experimental array of 6 × 6 potted plants, mixed with 24 plants of H. fulva and 12 plants of either F1 or F2 hybrids, were placed in the field, and visitations of swallowtail butterflies and nocturnal hawkmoths were recorded with camcorders. Swallowtail butterflies preferentially visited reddish or orange-colored flowers and hawkmoths preferentially visited yellowish flowers. Neither swallowtail butterflies nor nocturnal hawkmoths showed significant preferences for overall scent emission. Our results suggest that mutations in flower color would be more relevant to the adaptive shift from a diurnally flowering ancestor to H. citrina than that in floral scent.     

神农架川金丝猴栖息地优势树种生态位及食源植物

该文采用定量分析法, 研究了湖北神农架千家坪地区川金丝猴 (Rhinopithecus roxellana) 现生栖息地优势树种的生态位宽度、生态位重叠和生态位相似比例, 分析了优势树种生态位对神农架川金丝猴生存的影响。结果如下:1) 在64000m2的样方中, 木本植物255种, 隶属于44科105属, 其中乔木23科51属129种, 灌木22科49属113种, 木质藤本7科9属13种。优势科主要有蔷薇科、樟科、槭树科、忍冬科、壳斗科和四照花科等。2) 生态位宽度在栖息地森林群落乔木层中最高的为红桦 (Betula albo-sinensis) (5.261), 华山松 (Pinus armandii) (4.545) 、巴山冷杉 (Abiesfargesii) (4.289) 和糙皮桦 (Betula utilis) (3.256) 次之;灌木层中最高的为红晕杜鹃 (Rhododendron erubescens) (2.245), 多枝柳 (Salixpolyclona) (2.064) 、华中山楂 (Crataegus wilsonii) (1.508) 和陇东海棠 (Malus kansuensis) (1.453) 次之。3) 主要树种生态位宽度大于1的有30种, 占总数的11.67%, 其中21种是川金丝猴食源植物, 占神农架川金丝猴食源植物总数的10.40%;重要值排名前25位的树种中, 18种为食源植物, 占重要值总和的74.50%。4) 优势种的生态位重叠值在0.4以上的有7对种群;大部分种群的生态位相似性比值在0~0.3之间, 占全部种对的83.82%。结果表明, 神农架川金丝猴栖息地植物组成复杂, 优势种多为食源植物;优势种的生境高度相似、生态位多有重叠、种间竞争较为激烈, 将导致现有栖息地森林群落结构及植物组成发生变化, 食源植物短缺, 甚至栖息地面积缩减等现象, 这些都会影响川金丝猴的生存。因此, 加强保护神农架千家坪川金丝猴现生栖息地森林为川金丝猴创造适宜生存空间迫在眉睫。     

神农架维管植物区系初步研究

本文为神农架维管植物区系的初步研究结果,扼要报道了本区系现知的2638种(包括种下等级),分隶193科850属;粗略分析了850属的分布区类型,表明本区系以温带分布特别是北温带分布为主要成份的性质;介绍了本区系一些主要的古老属种,世界单种属47属,在中国为单种属的有33属,分布于该地区的中国特有属43属及中国列入珍稀保护植物49种。通过对木本植物的统计(有99科290属1103种,其中乔木属128属),显示出该地区是中国北温带木本植物,特别是乔木属种最丰富的地区之一。     

对苞萱草的核型研究

本文报道用光学显微镜观察对苞萱草Ｈｅｍｅｒｏｃａｌｉｓｆｕｌｖａ（Ｌ．）Ｌ．ｖａｒ．ｏｐ ｐｏｓｉｔｉｂｒａｃｔｅａｔａＨ．ＫｏｎｇｅｔＣ．Ｊ．Ｗａｎｇ,ｖａｒ．ｎｏｖ．的染色体,按全国第一次植物染色体学术讨论会建议的标准进行核型分析。研究结果表明,对苞萱草体细胞染色体数目２ｎ＝２２,核型公式ｋ（２ｎ）＝２２＝１２ｍ＋６ｓｍ＋４ｓｔ,属于Ｓｔｅｂｂｉｎｓ核型的２Ｂ型。甘肃萱草属植物的核型可分为两大类群,对苞萱草的核型属于第二类群。对苞萱草与萱草Ｈ．ｆｕｌｖａ（Ｌ．）Ｌ．的核型较接近,为新变种的确立提供了细胞学方面的依据。     

Detecting adaptive trait introgression between Iris fulva and I. brevicaulis in highly selective field conditions

The idea that natural hybridization has served as an important force in evolutionary and adaptive diversification has gained considerable momentum in recent years. By combining genome analyses with a highly selective field experiment, we provide evidence for adaptive trait introgression between two naturally hybridizing Louisiana Iris species, flood-tolerant Iris fulva and dry-adapted I. brevicaulis. We planted reciprocal backcross (BC1) hybrids along with pure-species plants into natural settings that, due to a flooding event, favored I. fulva. As expected, I. fulva plants survived at much higher rates than I. brevicaulis plants. Backcross hybrids toward I. fulva (BCIF) also survived at significantly higher rates than the reciprocal backcross toward I. brevicaulis (BCIB). Survivorship of BCIB hybrids was strongly influenced by the presence of a number of introgressed I. fulva alleles located throughout the genome, while survivorship in the reciprocal BCIF hybrids was heavily influenced by two epistatically acting QTL of opposite effects. These results demonstrate the potential for adaptive trait introgression between these two species and may help to explain patterns of genetic variation observed in naturally occurring hybrid zones.     

大花萱草对镉的耐性及积累特性

通过盆栽试验研究了大花萱草对镉(Cd)的耐性及积累特性。结果表明:Cd浓度为0.5mg·kg-1时刺激大花萱草的生长,大于5mg·kg-1时抑制大花萱草生长,Cd浓度小于5mg·kg-1时延长了大花萱草的绿期和花期;随着Cd浓度的增大,大花萱草根系活力、叶绿素含量和含水量逐渐降低,游离脯氨酸和可溶性糖含量先升高后降低,细胞膜透性逐渐升高;Cd在大花萱草体内分布为根系>地上部分,随着Cd浓度的增大,大花萱草根系和地上部分Cd含量逐渐升高、富集系数和转运系数逐渐降低;Cd浓度为20mg·kg-1时大花萱草对Cd的积累量最大,为1.489mg·株-1。综合分析大花萱草的生长、生理变化及富集Cd的能力,大花萱草适用于浓度小于1mg·kg-1的Cd污染土壤的修复。     

Comprative Studies on Karyotypes of Some Species of Hemerocallis (Liliaceae)

Some species of Hemerocallis were cultivated in the campus of Futan University, including the evergreen H. aurantiaca Baker. The original plant of H. aurantiaca was introduced from Zhangzhou, southeastern Fukien Province. The karyotype formula of H. aurantiaca is 2n=33=12m+9sm+3st+3T+6m(sat). The karyotype differs from those of summer-green or evergreen H. fulva (k(2n)=33=3M+21m+6sm +3T) and H. fulva var. kwanso (K(2n)=33=3M+l8m+6sm+3st+3T). The vouchers are kept in FUS.