基于SOD和EST同工酶的19种苔藓植物种间关系排序分析

采用聚丙烯酰胺凝胶电泳的方法, 获得了金华北山苔藓植物19 个种之间酯酶(EST)、超氧化物歧化酶(SOD)的同工酶酶谱。将19 个种苔藓植物的酶谱进行量化后, 采用主成分分析(PCA)方法, 比较了19 个种种间关系的差异特点。研究表明, 苔藓植物具有很高的遗传多样性, 以同工酶酶谱资料为基础, 应用主成分分析方法能够比较直观和有效地反映出苔藓植物分类群间的系统关系。     

ANTHER MORPHOLOGY AND THE ORIGIN OF THE TETRAPLOID WHEATS

Anther morphology of various species of the genus Triticum is consistent with previous evidence that different biotypes of T. boeoticum (AA) and T. urartu (BB) contributed the respective A and B genomes to the emmer (A^eA^eB^eB^e) and timopheevi (A^tA^tB^tB^t) tetraploid complexes. Anther length of T. dicoccoides (2.8 mm) and T. araraticum (3.0 mm) is mid-way between that of T. boeoticum (3.6) and T. urartu (2.2) and the same as that of the sterile hybrid T. boeoticum X T. urartu. With respect to mode of dehiscence, post anthesis reflexion of anther lobes and twisting of the anthers, T. dicoccoides resembles T. boeoticum, whereas T. araraticum resembles T. urartu. With respect to anther apex, T. dicoccoides resembles neither T. boeoticum nor T. urartu but is identical with their F₁ hybrid. Among amphiploids involving four different Aegilops species and T. boeoticum lines, none could similarly account for the length or other diagnostic attributes of the tetraploid anthers. Anther morphology is consistent with the presumed genomic composition of the cultivated tetraploid and hexaploid wheats and seems to distinguish effectively the different genomic groups of the genus Triticum.     

CHROMATOGRAPHIC COMPARISON OF DICENTRA SPECIES AND HYBRIDS

Ten species of Dicentra were examined by two-dimensional descending paper chromatography. The flavonoid components, including anthocyanins, formed patterns which were specific to a species or a group of closely related species, and these confirmed certain natural relationships within the genus. Some of the components were hydrolyzed and close structural relationships among them were revealed. They were further characterized by spray reactions and R_F measurements in a variety of solvent systems. The inheritance of the components, especially of the anthocyanins, was studied in the hybrids. All parental substances appeared in some hybrids, but in others some parental components were missing. “Hybrid substances” which had not been present in either parent were found in certain hybrids. This is thought to represent either reconstruction of ancestral biosynthetic pathways, probably through genic complementation, or extension of existing synthetic routes through some type of interaction between parental genomes.     

CHROMATOGRAPHIC COMPARISON OF TRAGOPOGON SPECIES AND HYBRIDS

Approximately 1,700 plants representing five species of Tragopogon (Compositae) and their F₁ and F₂ hybrids were analyzed by two-dimensional descending paper chromatography. Each species, or population within a species, was chromatographically distinct. Often, however, the differences were more quantitative than qualitative. The chromatographic data generally supported the species relationships which had been determined from previous morphologic, hybridization, and fertility studies. Inheritance of the flavonoid compounds was usually additive in the F₁'s. Segregation and recombination of the genes controlling the synthesis of these compounds sometimes approximated 3:1 or 9:7 ratios in the F₂'s. Occasionally parental compounds were missing from some of the hybrids. “Hybrid” compounds which had not been found in either parent were absent from the F₁ but did occur in several F₂ populations. Two linkage groups were present. The first contains genes controlling the synthesis of three compounds and the second, four compounds.     

基于线粒体COⅠ基因DNA条形码的中国鲚属物种有效性分析

分析了150尾刀鲚Coilia nasus、湖鲚C.nasus taihuensis、短颌鲚C.brachygnathus、七丝鲚C.grayii及凤鲚C.mystus个体的COⅠ基因DNA条形码序列变异。结果显示,150条COⅠ基因条形码序列包含63种单倍型,单突变位点主要集中在100bp和600bp附近。刀鲚、短颌鲚和湖鲚群体间的遗传距离在0.253%～0.557%之间,显著低于COⅠ基因DNA条形码鉴别不同物种2%的遗传距离阈值,表明这3个群体应为同一物种。但是凤鲚两群体间的遗传距离为5.08%,大于2%的鉴别阈值,显示凤鲚两群体可能达到了种或亚种级差异水平。以日本鳀Engraulisjaponicus为外群,用邻接法、最大简约法和最大似然法构建了分子系统树显示,刀鲚、湖鲚和短颌鲚群体聚在一起,未能各自形成单系;凤鲚根据地理分布聚为两支;七丝鲚则聚成单系。研究表明COⅠ基因条形码技术可用于我国鲚属物种的鉴定。     

CHROMATOGRAPHIC INVESTIGATIONS ON THE ALKALOID CONTENT OF NICOTIANA SPECIES AND INTERSPECIFIC COMBINATIONS

Smith , H. H., and D. V. Abashian . (Brookhaven Natl. Lab., Upton, N. Y.) Chromatographic investigations on the alkaloid content of Nicotiana species and interspecific combinations . Amer. Jour. Bot. 50(5): 435–447. Illus. 1963.—Alkaloid content was analyzed by paper-partition chromatography in the following Nicotianas: (1) 52 species representing all taxonomic sections and centers of geographical distribution; (2) 35 two-species combinations including 1 species of hybrid origin, 5 F₁ interspecific hybrids, 24 amphiploids and 5 sesquiploids; (3) 14 three-species combinations including 6 hybrids between an amphiploid and a third species, and 4 different 3-species combinations with doubled chromosome number; (4) 2 four-species combinations. Most of the species contained predominantly 3 identified alkaloids: nicotine, nornicotine and anabasine. In addition, at least 6 other alkaloids, that are separable but which were not identified chemically, are characteristic of the genus and are present in varied but characteristic patterns in each species. In hybrid combinations the content with regard to the unidentified alkaloids was observed to be the same as both parents, the sum of the parental patterns, a new alkaloid appearing, or, most frequently, one or more of the parental alkaloids missing in the hybrid. Among the identified alkaloids, anabasine was most frequently dominant to the other 2 in hybrids, and nornicotine production was most frequently either dominant or partly dominant to nicotine production. No simple basis for the inheritance of alkaloidal contents was clearly evident, nor wore there clearly defined associations between phylogenetic position and the alkaloids observed. Studies on the 6 or more alkaloids, in addition to nicotine, nornicotine and anabasine, which are known to be characteristic of the genus, offer extensive materials for research on alkaloid biosynthesis.     

云南山茶花四倍体的首次发现及其科学意义

本文对分布于云南和四川金沙江河谷的云南山茶花C. reticulata及其两个近缘种(怒江山茶C.saluenensis和西南山茶C．pitardii)进行了细胞学研究。34个居群的云南山茶花中,21个居群是四倍体类型(2n=60),11个居群是六倍体类型(2n=90),另2个居群为二倍体(2n=30),云南山茶花的四倍体类型为首次发现,并且进行了核形态研究。四倍体和六倍体的花粉母细胞减数分裂染色体构型在大多数居群都为二价体(四倍体中30个二价体,六倍体中45个二价体),少数居群或是个体除二价体为主外还出现单价体和四价体,六倍体类型没有出现六价体构型。根据减数分裂的构型,我们认为,四倍体和六倍体分别为异源四倍体和异源六倍体,少数四价体的存在表明染色体有部分同源性。所有四倍体和六倍体的体细胞间期核特征和前期染色体形态特征基本相似。中海拔(1800m)以上的四倍体的云南山茶花外部形态特征与六倍体类型比较相似,而低海拔(1100～1800 m)的四倍体类型的外部形态特征则有些不同,但核形态结构是比较相似的。四倍体与六倍体类型地理分布是连续的,并与近缘的二倍体种怒江山茶、西南山茶重叠分布。     

REPRODUCTIVE ISOLATION OF TRITICUM BOEOTICUM AND TRITICUM URARTU AND THE ORIGIN OF THE TETRAPLOID WHEATS

The diploid wheats Triticum boeoticum and T. urartu are sympatric with one another throughout the geographic range of the wild tetraploids. Reciprocal crosses between ecogeographic types within each diploid species gave viable seed, but interspecific crosses consistently gave viable seed only when T. boeoticum was the female parent. Apparently urartu cytoplasm in combination with the boeoticum genome resulted in nonviable seed. The endosperm failed to develop normally despite regular endosperm fertilization. The F₁ plants obtained were completely self sterile although they showed regular intergenomic pairing (7II) at meiosis. Presumably the accumulation of cryptic differences between the two closely related genomes under reproductive isolation accounts for this sterility. The same accumulated cryptic differences could largely account for the preferential diploid pairing in the tetrapolid wheats which presumably were derived from such hybrids by chromosome doubling. The behavior of reciprocal crosses between the diploids and tetraploids suggested that T. boeoticum contributed the cytoplasm to both of the wild tetraploid species.     

TAXONOMIC REVISION OF SARGASSUM SPECIES (FUCALES,PHAEOPHYCEAE) FROM NEW CALEDONIA BASED ON MORPHOLOGICAL AND MOLECULAR ANALYSES1

Sargassum C. Agardh (1820) is a taxonomically difficult genus distributed worldwide and reported as the most species‐rich genus of the Fucales. It is especially abundant in the Pacific where decreasing species richness is reported to occur from west to east. New Caledonia has been recognized as one of the hotspots of Sargassum diversity; however, species lists available for this region are old and incomplete and have not yet been updated with regard to the latest taxonomic revisions published. This study aimed at revising Sargassum diversity in New Caledonia and to assess its geographic affinities with neighboring Pacific regions. We used combined morphological and DNA analyses on new collections and examined numerous type specimens. Although 45 taxa have been listed in the literature, most of them have been either transferred to synonymy since or misidentified, and in this study, only 12 taxa were recognized as occurring in New Caledonia. They belong to the subgenus Sargassum sect. Binderianae (Grunow) Mattio et Payri (2), sect. Ilicifoliae (J. Agardh) Mattio et Payri (2), sect. Polycystae Mattio et Payri. (1), sect. Sargassum (4), sect. Zygocarpicae (J. Agardh) Setch. (2), and subgenus Phyllotrichia (Aresh.) J. Agardh (1). New Caledonian Sargassum flora appeared as the second richest in the region after the Pacific coast of Australia, with which it has shown high similarity, and shared species with all neighboring regions. One species, S. turbinarioides Grunow, is considered as endemic to New Caledonia. The low genetic diversity detected among several polymorphic species belonging to sect. Sargassum is also discussed.     

高产油小球藻的筛选及其油脂分析

小球藻广泛分布于各种生境,特别是淡水环境中,适应性强。其同化产物主要是淀粉,但在环境胁迫条件下可显著积累中性脂,其脂肪酸类型主要为C16和C18,适合作为生物柴油的原料。我们从中国部分地区水体中分离纯化到若干株小球藻,通过薄层层析比较分析了21株产油小球藻的油脂含量,筛选到一株三酰基甘油含量较高的藻株Chlorella sp.NMX37N。其适宜生长温区为15—35℃,在25℃时生长速率最快,比生长速率为0.53/d,生长的最适光强为250μmol photons/(m2.s)。批量培养实验显示,藻细胞的三酰基甘油含量随培养时间延长而增加,并在培养的稳定期达到最大值,此时培养液中氮基本被耗尽。在批量培养条件下培养Chlorella sp.NMX37N约40d,藻细胞中总脂含量可达到33%左右,与此相比通过两步培养方式,将培养至对数后期(约20d)的藻细胞缺氮处理48h后,得到的总脂产率相当。通过两步培养方式可以大大缩短培养时间,使得该藻细胞快速有效积累油脂。另外,气相色谱分析显示,该藻的总脂和三酰基甘油的脂肪酸均以C16∶0和C18∶2为主,占总脂肪酸的70%以上,且不含C20以上的长链脂肪酸,可以作为优质的生物柴油原料。     

记几种原鼢鼠(啮齿目,鼢鼠科)及鼢鼠科的起源讨论

记述了采自甘肃秦安和内蒙古阿木乌苏中中新世晚期 -晚中新世的 4种早期原鼢鼠 :Prosiphneusqinanensissp .nov.、Pr.qiuisp .nov .、Pr.haoisp .nov .和Pr.licentiTeilharddeChardin ,1 92 6,讨论了原鼢鼠属中 7个种的相互关系及其进化趋势。Prosiphneus是鼢鼠科中最原始的属 ,目前已知最早的种是Pr.qinanensissp .nov.,最晚的种是Pr.ericksoni (Schlos ser,1 92 4 )。Prosiphneus可能起源于PlesiodipusprogressusQiu ,1 996。     

朱鹮卵壳的微观结构和成分研究

本文首次对世界珍禽——朱鹮的卵壳在电子显微镜下的微观结构进行了研究;对卵壳中的26种无机元素进行了定量分析。根据两巢卵壳所含有害元素的对比,以及两巢区土壤中有害元素含量对照情况,指出保护朱鹮自然种群、研究其环境因子,刻不容缓。     

3种北美冷杉的核型研究

本文首次报道３种北美冷杉Ａｂｉｅｓ ａｍａｂｉｌｉｓ、Ａ．ｇｒａｎｄｉｓ和Ａ．ｌａｓｉｏｃａｒｐａ的根尖体细胞核型、染色体参数及核型模式图。核型公式分别是Ｋ（２ｎ）＝２４＝１６ｍ（４ＳＣ）＋８ｓｍ、１４ｍ（２ＳＣ）＋１０ｓｍ和１８ｍ（４ＳＣ）＋６ｓｍ,染色体相对长度组成为２ｎ＝２４＝２Ｌ＋１２Ｍ２＋６Ｍ１＋４Ｓ、２Ｌ＋１２Ｍ２＋８Ｍ１＋２Ｓ和２Ｌ＋８Ｍ２＋１２Ｍ１＋２Ｓ。均为２Ａ核型类型。文中还讨     

MITOCHONDRIAL DNA ANALYSES AND THE ORIGIN AND RELATIVE AGE OF PARTHENOGENETIC CNEMIDOPHORUS: PHYLOGENETIC CONSTRAINTS ON HYBRID ORIGINS

Within the genus Cnemidophorus, parthenogenesis has arisen by hybridization several times. This provides the opportunity to investigate general features of hybridization events that result in the formation of parthenogenetic lineages. The relationships of mtDNA from all bisexual species of Cnemidophorus known to be parents of parthenogens were investigated to evaluate phylogenetic constraints on the hybrid-origin of parthenogenesis. No phylogenetic clustering of the parental species, either maternal or paternal, was apparent. However, the combination of bisexual species that have resulted in parthenogenetic lineages are generally distantly related or genetically divergent. This contrasts with the expectation if parthenogenesis in hybrids is due to the action of a single rare allele, but is consistent with the hypothesis that some minimal level of divergence is necessary to stimulate parthenogenetic reproduction in hybrids.     

兰属14种植物遗传多样性RAPD及AFLP分析

用RAPD和AFLP技术分析了14种兰属植物的遗传多样性.RAPD筛选出12个随机引物和AFLP 3对选择性引物组合均扩增出了丰富的多态性片段.分析结果按UPGMA类平均法进行聚类,所得到的RAPD和AFLP聚类结果基本一致,显示建兰与墨兰,寒兰与峨眉春蕙以及大雪兰与独占春之间的亲缘关系最近.