中国沙棘属植物核型分析

本文报道了我国沙棘属植物4种5亚种的核型,对各种之间进行了比较,它们的染色体  数目都是2n＝24,全由中部着丝点和近中部着丝点染色体组成,所有种类,只有Hippophae  thibetana第8对染色体有随体,H．rhamnoidea ssp.sinensis和H．rhamnoides ssp.  mongo-  lica臂比大于2的染色体比例为0,为2A型,其余各种均为2B型。     

长筒石蒜的染色体核型分析

A karyotypic analysis of Lycoris longituba Y. Hsu et Fan was carriedout. The voucher specimen, Z. G. Mao 10501, is preserved in the Herbarium of HangchowBotanical Garden. The chromosome number in root tip cells of the species is found for thefirst time to be 16, among which 6 are large, V-shaped with submedian primary constric-tions, and the other 10 are short, rod-shaped  with terminal primary constrictions. Photomi-crograph of the chromosome complement and idiogram are given in Fig. 1-3 respectively.The karyotype formula of the species is therefore 2n=16=6m+6t+4t (SAT) in the lightof the chromosomal terminology defined by Levan and al.[5]     Based on the view stressed by Jones[3] and Brandham[4], successive fusion of the ch-romosomes should be taken as the essential mechanism for karyotype evolution and specia-tion in Lycoris. Reciprocal translocation, with the loss of one of the centromeres, might bethe mechanism of origin for a V chromosome. It is, then, suggested that the decrease in ch-romosome number as a result of fusion of the rods with terminal or subterminal primaryconstrictions has taken place in the speciation of L. longituba.     

玫瑰红石蒜的染色体核型分析

The  present paper embodies the results of a karyotypic analysis for thespecies Lycoris rosea Traub et Moldenke.  The voucher specimen, J. Z. Lin 004 is pre-served in the Herbarium of Hanchow Botanical Garden. The chromosome number in root tip cells is found for the first time to be 22, and the karyotype is shown to be an asymme-trical one with rod-shaped chromosomes. A photomicrograph, the karyotype and the idiog-ram are shown in Figs. 1-2. According to Levan et aL.[5], the karyotype formula of thespecies is 2n=22=22t. But based on the classification presented by Bose and Flory[1], thekaryotype formula should be expressed as 2n=22 =C22, and the chromosomes are all withsubterminal constrictions.      If regarding 11 as the basic number and centric fusion as the major tendency of karyo-type evolution as proposed by Inariyama[2], Stebbins[6], and Jones[3,4] in particular, L. roseawould be considered as one of the most primitive species in Lycoris from point of view ofkaryotype evolution. Reciprocal translocations and centric fusions would give rise to V-sha-ped chromosomes. Consequently, the successive decrease in chromosome number may havetaken place in the speciation of the genus under discussion. Yet further evidence seems ne-cessary for the verification of the speculation.     

沙冬青染色体数目及核型的研究

本文首次报道了沙冬青的染色体数目及核型,沙冬青  Ammopiptanthus mongolicus (Maxim.)Cheng f.染色体基数目为x＝9,其核型公式为  2n=18=4m十14sm(2SAT)。     

蜘蛛抱蛋属(百合科)的细胞分类学研究(1)——四川七个种的核型

In the work mitotic chromosomes in root-tips of 7 species native to Sichuan Pro-vince were examined and their karyotypes were analysed based on 7-8 cells at mitotic meta-phase, using Levan et al.'s (1964) nomenclature. The list of species and origin of the materialsused in this work are provided in the appendix.  The micrographs of mitotic metaphase of allthe materials are shown in Plates 1 and 2; the idiograms in Fig. 1, 1-9, and the parametersof chromosomes are provided in Tables 1-9.  All the chromosome countings and karyotypes inthis paper are reported for the first time.     Characteristics of the karyotypes may be summarized as follows:     1.  2n=38 are found in all the materials except A. sichuanensis, which has 3 cytotypes, i.e,2n=38+5B, 2n=38+lB and 2n=38+OB (Plate 2, 1-2, Fig. 1, 5-6).     2.  The karyotypes are of two major types: the karyotype of A. flaviflora falls into 3C inStebbins's (1958, 197l) classification of karyotypes and those of all the other species into 2C.The two types are also different from each other in the number of large and medium-sizedchromosomes pairs and morphology of the first pair of chromosomes (compare Plate 2, 5, Fig.1, 9 with the other micrographs and idiograms).A. flaviflora with the karyotype 3C also differsfrom the other species in a series of gross morphological characters: the species is of a yellow andcampanulate corolla.     3.  The species with caespitose leaves (A. caespitosa and A. omeiensis) have essentially thesame karyotype, which is rather different from those of the species with scattered leaves. Thereare two pairs of small sm chromosomes (arm ratio ≥1.90) in the former karyotype (Tables 1and 3), but all the small chromosomes are m or sm with arm ratio <1.80 in the latter karyotypes.     

披碱草属6种植物的核型研究

本文首次报道特产于我国青藏高原披碱草属Elymus的6种植物的染色体数目和核型。6个种的染色体数目为2n＝42,都是6倍体。它们的核型是：黑药鹅观草,2n=6x＝42=32m+10sm;糙毛鹅观草,2n=6x=42=34m+8sm;大颖鹅观草,2n=6x=42=30m+12sm;疏花鹅观,2n=6x=42=32m+10sm;青海鹅观草,2n=6x= 42＝34m十8sm;长颖鹅观草,2n=6x＝42=34m十8sm。它们的核型属1B或2B型,染色体中均未发现随体。     

九种水鳖科植物染色体数目及其核型分析

本文报道了我国产水鳖科植物5属9种染色体数目和核型,发现所有种都是二倍体,它  们的核型大部分是由中部着丝点(m)和近中部着丝点(sm)组成,少数种具有近端着丝点  (st)。它可以区分为4种核型：1A,2A和1B,2B。水筛属是原始的,黑藻属是进化的。     

国产甘草属植物的核型研究

本文对国产7种甘草属植物的核型进行了研究,其结果为：乌拉尔甘草2n＝16＝  6m+10sm;黄甘草2n＝16=8m+6sm十2st;光果甘草2n＝16=14m+2sm;胀果甘  草2n＝16＝6m十10sm;粗毛甘草2n=16=12m十4sm;云南甘草20＝16=12m十  4sm;刺果甘草2n＝16＝12m十4sm。基于对现有资料的分析,确认该属的染色体基数为  x=8,  且核型对称性程度较高。  通过对不同种核型进行比较,发现刺果甘草是本文所研究  7个种中最原始的,而黄甘草的进化程度相对较高。     

国产四种绢藓属植物的核型研究

 国产苔藓植物的核型研究,目前尚未见到任何报道。本文对中国产绢藓属4种植物进行了核型研究。观察了配子体有丝分裂中期的染色体和异染色体。4种植物的染色体数目均为11。钝叶绢藓(E．obtusatus),密叶绢藓(E．compressus),东亚绢藓(E．okamurae),的核型公式为K(n)=11＝2V(H)+2J+6(4v+2i)+m(h),陕西绢藓(E.giraldii)为K(n)＝11＝2V(H)+V+2J+5(3v+2i)+m(h)．4种植物的核型均为首次报道。     

中国含笑属核型分析

 对我国木兰科Magnoliaceae含笑属Michelia 12个种的核型进行了研究,核型公式如下:火力楠M．macclurei var．sublanea 2n=34m(2SAT)+4sm;白兰M．alba 2n=34m+4sm;多花含笑M.flori-bunda 2n=30m+8sm;黄兰M.champaca 2n=32m+6sm;石碌含笑M.shiluensis 2n=32m+6sm;阔瓣含笑M . platypetala 2n=32m+6sm(2SAT);含笑M．figo 2n=32m+6sm;深山含笑M．maudiae2n=32m+6sm;长蕊含笑M.  longistamina 2n=32m=6sm;金叶含笑M.foveolata 2n=34m=4sm;野含笑M.skineriana 2n=30m+8sm;峨嵋含笑M.wilsonii 2n=30m+8sm(2SAT)。该属核型全部为对称核型,除多花含笑为1A类型外,其他均为2A核型。含笑属种间核型具有很大相似性,核型资料对该属属以下的分类帮助不大。        

贝母属三个分类群的核型研究

本文对浙贝Fritillaria thunbergii Miq．(取材于浙江鄞县和舟山)、东贝 F.thunbergii var．chekiangensis Hsiao et K.C.Hsia和皖贝F.anhuiensis S．C.Chen et S．F.Yin的核型进行了分析比较,其中东贝和浙贝(舟山)为首次报道．浙贝的核型：取材于浙江鄞县的为2n=24=4m(1sc) l)+4st(1sc)+16t(1sc),取材于浙江舟山为  2n=24=2m+2sm+12st(1sc)+8t(2sc),东贝的核型为2n＝24=2m+2sm+8st(2sc)+12t(4sc),皖贝的核型为2n=24=2m+2sm+8st(2sc)+12t(5sc)。3个分类群均属3B核型。     

一粒小麦的核型分析

利用火焰干燥涂片方法制备染色体玻片标本。  比较了栽培一粒小麦和野生一粒小麦    10个不同材料的核型。细胞学观察表明,它们的核型很相似,可能同属小麦的A染色体组。它    们都具有7对染色体(2n＝14),  即5对中部着丝点染色体和两对亚中部着丝点染色体。所有材料的第5对染色体都带有随体。     

四川葱属一新种及其核型

本文分析了该新种的核型,其核型公式为K(2n)＝2x＝16=14m+2st(2SAT),具一对居间随体,有时该居间随体不明显。核型的不对称性为2A型。