In Situ Hybridisation Analysis of the X-Linked Genes in the Species of the Virilis Group of Drosophila

When estimating the level of DNA sequence variation within and between populations or when planning QTL analysis, it is essential to know the location of the genes under study. In the present work, five X chromosomal genes, earlier localised in Drosophila virilis and D. littoralis, were mapped by in situ hybridisation on the larval polytene chromosomes of four other virilis group species, D. a. americana, D. flavomontana, D. lacicola and D. montana. Conjugation of X chromosomes of the most interesting species pairs was studied in interspecific hybrids. Three of the marker genes were used as RFLP markers to examine the occurrence of recombination in D. flavomontana and D. montana hybrid females. The gene arrangement of all species studied, appeared to be different at the proximal end of the X chromosome, which prevented normal conjugation along the most part of the X chromosome. The data illustrating the locations of five X chromosomal marker genes are presented for D. a. americana, D. flavomontana, D. lacicola and D. montana.     

Effect of the air pollution component ammonium sulphate on the VAM infection rate of three heathland species

Three heathand species, Antennaria dioica, Arnica montana and Hieracium pilosella, were artificially rained with ammonium sulphate solutions at increasing concentrations in a greenhouse experiment. The same species were also artificially rained with increasing ammonium sulphate solutions under field conditions. Dry weights of the plants in the field experiments did not change with increasing ammonium sulphate applications. Nor did the dry weights of plants in the greenhouse experiments change with increasing ammonium sulphate concentrations, except for Arnica montana, which showed an increase in dry weight. VAM infection percentage of Antennaria dioica increased in both the greenhouse and the field experiment. The results of the field experiment show that VAM infection rates are reduced after two years of artificial rain in the plant species Arnica montana, which grows naturally under nutrient poor conditions and is presently declining in its natural habitat in the Netherlands. In the greenhouse experiment, VAM infection of Arnica montana did not change with increasing ammonium sulphate concentrations. VAM infection rates of Hieracium pilosella, which presently is not declining, did not change with increasing ammonium sulphate concentrations.     

西藏东南部发现桐庐铁线莲

毛茛科的桐庐铁线莲(Clematis tongluensis)原知分布于尼泊尔、不丹、印度东北部和孟加拉,2019年夏天在中国西藏东南部被发现.桐庐铁线链与绣球腾(Clematis montana)在亲缘关系上接近,两者的区别在于桐庐铁线莲的萼片呈长圆形,顶端尾状渐尖和表面被毛,背面无毛.     

Reproductive success and clonal genetic structure of the rareArnica montana (Compositae) in The Netherlands

In a medium-sized population ofArnica montana, a threatened species in The Netherlands, the breeding system, reproductive success and genetic clonal structure were studied. Pollination experiments suggested thatA. montana is largely self-incompatible. Inbreeding depression was observed for seedling weight but not for fruit weight and germination rate. Although genetic variation is rather low in this population, the data suggest an outcrossing mating system. Analysis of the genotype of all mapped rosettes in a plot of 100 m² indicated that dense clusters often consist of identical genotypes, suggesting a clonal structure. Open clusters frequently contained several different genotypes. This may be caused by limited fruit dispersal, since seedlings were found mainly within or in the near surroundings of the clusters.     

Variation and repeatability of courtship song characters among wild-caught and laboratory-rearedDrosophila montana andD. littoralis males (Diptera: Drosophilidae)

InDrosophila montana andD. littoralis (species of theD. virilis group), females use male courtship song in their mate choice in wild preferring males which produce short and dense sound pulses (Aspi and Hoikkala, 1995). In the present study these song characters were found to be repeatable among overwintered males. Male progenies of wild-caught flies reared in the laboratory, and inD. montana also the males collected in wild before overwintering, exhibited very little variation between males in these characters. Contrary to pulse characters, pulse train characters measured forD. montana song varied significantly between laboratory-reared males. Our findings suggest that inD. montana andD. littoralis song characters playing a part in sexual selection in the wild are more condition dependent than song characters which are not the direct targets of female choice.     

One- and two-dimensional polyacrylamide gel analysis of the heat shock proteins of the virilis group of Drosophila

The heat shock proteins of the virilis group of Drosophila are analyzed by one- and two-dimensional polyacrylamide gel analysis. This group consists of the two closely related but distinct virilis and montana phylads. The analysis reveals that some of the heat shock proteins are highly conserved among the two phylads while others are not. The 83-, 72-, and 69-kdalton proteins comigrate in all species examined. There is, however, a noticable trend toward greater molecular weight variability in the smaller heat shock proteins. In general, the heat shock protein patterns within each phylad follow the proposed phylogenetic relationships with some exceptions. D. ezoana and D. littoralis, both members of the montana phylad, exhibit heat shock protein patterns more similar to those of the virilis phylad. The data also demonstrate that the montana phylad has almost two times the heat shock allele members that the virilis phylad has. It is also shown that F₁ and F₂ hybrid flies of crosses between Drosophila species having different patterns of heat shock proteins show Mendelian segregation of alleles. After several generations of inbred growth, however, the pattern of heat shock protein synthesis in reciprocal hybrids each resembles that of the paternal parent. The implications of these findings are discussed.This research was supported in part by Damon Runyon-Walter Winchell Grant DRG-233F to R.M.S. and NIH Grant GM 27611 to R.V.S. R.V.S. is the recipient of an NIH Research Career Development Award.     

Evidence for introgression in differentiated North-American and Finnish <Emphasis Type="Italic">Drosophila montana</Emphasis> populations

The virilis group species Drosophila montana is widely distributed around the northern hemisphere. Here we show that it consists of at least two well differentiated populations (Finnish and North-American populations) that have been diverging for the last 0.55–0.95 My. These populations show significant chromosomal, behavioural and morphological differences, but no apparent postzygotic isolation. Evidence for introgression is found for both Finnish and North-American populations at two out of the three X-linked genes (fused, elav and su(s)) studied here. In the light of these findings, previously reported evidence for selective sweeps in D. montana populations is re-evaluated.     

A critical evaluation of reproductive barriers between closely related species using DNA markers - a case study in Pinus

Former controlled crosses between twelve Pinus montana var. rostrata (Pinus mugo complex) and eight P. sylvestris clones revealed that only two P. sylvestris had efficiently fertilised P. montana. Two species-diagnostic chloroplast DNA markers were applied to verify the species purity of the parental clones. All maternal P. montana were unambiguously confirmed to belong to the P. mugo complex at both chloroplast DNA marker loci. Six P. sylvestris clones carried the `sylvestris' haplotypes. However, the same two P. sylvestris clones that had efficiently fertilised P. montana displayed the chloroplast haplotypes diagnostic to the P. mugo complex. The patterns of highly polymorphic cpDNA microsatellite markers in parents and offspring ruled out contamination by foreign pollen. We concluded that the two clones successful in the crosses represent fertile hybrids between the two species with P. mugo as the pollen donor. Consequently, DNA markers are proposed for verifying or falsifying the success of artificial fertilisation in general. The existence of crossing barriers between the two Pinus species, meaningful to the postulated natural hybridisation and the evolution of their populations in sympatric stands, was indicated and is newly discussed.     

广西葛根内生细菌的分离鉴定及其促生特性

【背景】植物内生菌长期与宿主共生,对宿主生长发育产生影响。葛根作为重要的药食两用作物,葛根内生菌的研究具有重要实践意义。【目的】对广西葛根根部内生细菌进行分离、鉴定及促植物生长特性分析,旨在了解该药食同源植物内生细菌种群结构及其促生特性,为分析内生菌群体在药食同源植物产量和品质形成的作用及其内生细菌资源的开发利用提供参考。【方法】采用6种不同的培养基从广西葛根的根瘤、根系和根愈伤组织分离内生细菌,16S rRNA基因测序和系统发育分析内生细菌的分布特征和遗传多样性,采用生理生化方法测定分离菌株的固氮活性、溶磷特性、产生嗜铁素、分泌吲哚乙酸(indole-3-aceticacid,IAA)等促生特性。【结果】从葛根根瘤、根系和根部愈伤组织中共分离得到223个菌株,16S rRNA基因测序鉴定这些菌株隶属于2门4纲10科19属,其中芽孢杆菌属、假单胞菌属、土壤杆菌属、肠杆菌属为葛根优势菌群;内生细菌数量和群落组成存在明显的组织特异性,其数量表现为根瘤>根系>根愈伤组织,但其种群多样性表现为根愈伤组织>根系>根瘤。不同培养基分离出的细菌种群丰富度有差异。从供试菌株中筛...     

Inclination of sun and shade leaves influences chloroplast light harvesting and utilization

Light harvesting and utilization by chloroplasts located near the adaxial vs the abaxial surface of sun and shade leaves were examined by fluorometry in two herbaceous perennials that differed in their anatomy and leaf inclination. Leaves of Thermopsis montana had well-developed palisade and spongy mesophyll whereas the photosynthetic tissue of Smilacina stellata consisted of spongy mesophyll only. Leaf orientation depended upon the irradiance during leaf development. When grown under low-light levels, leaves of S. stellata and T. montana were nearly horizontal, whereas under high-light levels, S. stellata leaves and T. montana leaves were inclined 60⁰ and 30⁰, respectively. Leaf inclination increased the amount of light that was intercepted by the lower leaf surfaces and affected the photosynthetic properties of the chloroplasts located near the abaxial leaf surface. The slowest rates of quinone pool reduction and reoxidation were found in chloroplasts located near the adaxial leaf surface of T. montana plants grown under high light, indicating large quinone pools in these chloroplasts. Chloroplasts near the abaxial surface of low-light leaves had lower light utilization capacities as shown by photochemical quenching measurements. The amount of photosystem II (PSII) down regulation, measured from each leaf surface, was also found to be influenced by irradiance and leaf inclination. The greatest difference between down regulation monitored from the adaxial vs abaxial surfaces was found in plants with horizontal leaves. Different energy dissipation mechanisms may be employed by the two species. Values for down regulation in S. stellata were 2–3 times higher than those in T. montana, while the portion of the PSII population which was found to be Q_B nonreducing was 4–6 times lower in high light S. stellata leaves than in T. montana. All values of Stern-Volmer type nonphotochemical quenching (NPQ) from S. stellata leaves were similar when quenching analysis was performed at actinic irradiances that were higher than the irradiance to which the leaf surface was exposed during growth. In contrast, with T. montana, NPQ values from the abaxial leaf surface were up to 45% higher than those from the adaxial leaf surface regardless of growth conditions. The observed differences in chloroplast properties between species and between the adaxial and abaxial leaf surfaces may depend upon a complex interaction among light, leaf anatomy and leaf inclination.     

Light and electron microscopical studies onHafniomonas gen. nov. (Chlorophyceae,Volvocales), a genus resemblingPyramimonas (Prasinophyceae)

Based on light and electron microscopical studies ofPyramimonas reticulata the genusPyramimonas is shown to contain a number of unrelated flagellates.P. reticulata andP. montana are transferred to the new genusHafniomonas, cells of which differ fromPyramimonas in shape, in the absence of scales and hairs on the body and flagellar surfaces, in details of the chloroplast, the position of the nucleus, the Golgi apparatus, the internal structure of the flagellar apparatus, and in cell division. The prasinophytePyramimonas contains a characteristic association of a large microbody and a rhizoplast, situated on the nuclear surface. A similar association is being found in an increasing number of prasinophycean flagellates, but is absent inHafniomonas, which is considered related to chlorophycean rather than prasinophycean flagellates. The phylogenetic position ofHafniomonas is discussed, based in particular on details of the unique flagellar apparatus.     

Acidification effects on vesicular-arbuscular mycorrhizal (VAM) infection, growth and nutrient uptake of established heathland herb species

A greenhouse experiment was carried out to determine whether the decline of Arnica montana L. in heathland vegetation in the Netherlands could be caused by a detrimental effect of soil acidification on vesicular-arbuscular mycorrhiza of this species. Arnica montana and two non-declining species from the same habitat, Hieracium pilosella L. and Deschampsia flexuosa (L.) Trin., were grown with and without the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum (Thaxter sensu Gerdemann) Gerd. and Trappe in pots with an extremely nutrient-poor, sandy soil. They were percolated weekly with nutrient solution with different pH values, viz. 5.5, 4.5, 3.5 and 2.5. At intervals of three weeks and up to 12 weeks, measurements were made on growth, nutrient uptake and VAM infection.In the most acid treatments growth and nutrient uptake were reduced in all species. VAM infection decreased only slightly with decreasing pH of the treatments. Without VAM, Arnica montana died and Hieracium pilosella hardly grew at the most acid treatments. Therefore it is concluded that VAM decreased the stress caused by the most acid treatments. Leachate from the most acid treatment had a pH of approximately 4, and contained considerable amounts of aluminium, dissolved from the solid phase of the soil. This might have played a role in the detrimental effects on the plants in the case of the most acid treatment. No evidence was found in this experiment that the decline of Arnica montana was due to detrimental effects of soil acidification on VAM of this species.     

CYTOLOGICAL STUDIES IN LACCARIA (AGARICALES). I. MEIOSIS AND POSTMEIOTIC MITOSIS

In the genus Laccaria, basidial formation, dikaryotic basidia, karyogamy, and meiosis were generally similar to structures and phenomena reported for other Agaricales. The haploid nuclei of dikaryotic basidia resided side by side in the basidium prior to karyogamy. Following karyogamy a single nucleolus was observed in L. montana (four-spored species); several nucleoli remained in the nucleus of L. tortilis (two-spored species). The haploid number of chromosomes for L. montana appeared to be n = 9. Postmeiotic mitosis typically occurred in the basidiospores resulting in binucleate basidiospores for four-spored species and quadrinucleate basidiospores for two-spored species. Postmeiotic mitosis sometimes occurred in the sterigmata and basidia proper. In instances where postmeiotic mitosis occurred in basidia, mature basidiospores were not formed and the basidia were collapsed, and contained up to eight nuclei.     

Light acclimation of four native tree species in felling gaps within a tropical mountain rainforest

Ecuadorian mountain rainforests are declining dramatically due to deforestation. Exploitation of remaining forests has led to low abundances of native, valuable timber species. Enrichment planting of selected native tree species into forest gaps is a strategy that may increase their abundance and maintain biodiversity. However, the development of successful planting strategies requires knowledge of environmental demands on, and ecological requirements of, native species during their establishment. This knowledge is currently lacking for mid- and late-successional species in Central American forests. Two deciduous, mid-successional (Cedrela montana, Tabebuia chrysantha) and two evergreen, late-successional native tree species (Nectandra membranacea, Podocarpus sprucei) were planted into felling gaps. Photosynthetic performance and growth in height of these species were assessed along light gradients during seedling establishment to test whether species-specific light responses were related to plant successional traits. Both mid-successional species benefited from higher light levels in gaps up to 30% canopy openness_60°. In larger gaps, C. montana exhibited a significant decline in growth. As expected, growth of the late-successional species was only marginally increased at higher light levels. Nevertheless, the photosynthetic apparatus of N. membranacea displayed rapid acclimation to higher light conditions in gaps. Plant response to felling gaps may not always be predicted based on successional status. Our results suggest that the four investigated species may coexist in the same gap by occupying different niches along light gradients. This arrangement may offer an ecological basis to increase the abundance of valuable timber species through enrichment planting in Ecuador mountain rainforests.     

Light-dependent PER-like proteins in the cephalic ganglia of an apterygote and a pterygote insect species

Antibodies targeted to a highly conserved tetradecapeptide region of the pivotal biological clock protein PER detect in the firebrat Thermobia domestica a 115-kDa protein and in the cockroach Periplaneta americana a 110-kDa protein that are present in the cytoplasm of a small set of brain cells. A similar cytoplasmic reaction occurs with antisera to the whole PER protein of Drosophila melanogaster, but these antisera also react with numerous cell nuclei. On western blots, they detect an 80-kDa antigen in T. domestica and 70- and 80-kDa antigens in P. americana. No indication of antigen translocation between cell nuclei and cytoplasm was found. Nuclear staining is maintained at a high constant level in T. domestica held at a 12:12 h light:dark photoperiod (LD) or in continuous light, but disappears rapidly in response to extended darkness. In P. americana under LD conditions, the number of immunoreactive nuclei and their staining intensity fluctuate in parallel, with maximal staining late in the day. The circadian changes are maintained in continuous light but all staining vanishes in continuous darkness. A 6-h light pulse in early night of an LD cycle induces maximal staining after about 10 h, suggesting that the effect of light on nuclear PER-like expression is indirect. The behaviour of nuclear antigens is opposite to that of the cytoplasmic PER-like proteins that persist in constant darkness and disappear in constant light. Under LD conditions, the cytoplasmic PER-like antigen cycles in T. domestica but remains at a steady level in P. americana. The sensitivity to photoregime suggests that both the nuclear and the cytoplasmic PER-like antigens are components of the biological clock.R. Závodská and H. Sehadová contributed equally to this work     

鱼藤属植物优异物种筛选及引种栽培研究

为了解粉垄“145”模式在新植蔗上的应用效果,解析其生理生态基础,该研究以桂柳05136为材料,设置常规耕作(CK)和粉垄“145”模式(FL145)2个处理,通过大田试验研究粉垄“145”模式对土壤性质以及新植蔗农艺性状、光合特性和产量品质的影响,并分析其经济效益。结果表明：(1)与CK相比,FL145的0～20 cm、20～40 cm根区,土壤容重显著降低1.25%～5.98%,土壤孔隙度显著提高1.08%～4.77%,土壤含水量显著提高1.78%～8.23%。(2)FL145促进新植蔗根系生长,出苗效果和农艺性状表现良好,株高显著增加2.20%～7.86%。(3)FL145的新植蔗单株叶面积显著增大15.88%,叶绿素含量、净光合速率、气孔导度、胞间CO₂浓度分别显著提高1.41%、6.84%、18.67%、10.06%,光合能力增强,单株干物质积累量显著增加9.26%。(4)收获时,FL145的新植蔗有效茎数、茎长、茎径显著增加,理论产量和实际产量分别显著提高5.07%和5.11%,蔗汁蔗糖分和锤度分别显著提高1.61%和1.50%,还原糖分显著下降12....     

Mating behavior and the evolutionary significance of mate guarding in three species of crane flies (Diptera: Tipulidae)

Three species of crane flies-Dactylolabis montana, Limonia simulans,and Antocha saxicola-gather near streams to mate and oviposit. All species are polygamous and sex ratios at these sites are male-biased. After a short mating bout, males guard females by standing over them during oviposition. Sperm competition appears to be intense and to follow last-male advantage, based on the packing of sperm within the two elongate spermathecae. Males of A. saxicolasuccessfully defend against rivals over 85% of the time. In contrast, defending males of D. montanaand L. simulanslose the female over 65% of the time during interactions with rivals. Despite the high frequency of loss, defending males gain additional oviposition time by engaging rivals in combat while the female continues to oviposit. Thus, a guarding male does not have to retain the female for guarding to be adaptive. Legs and claws of all species are sexually dimorphic and play an important role in guarding and defending.     

Secondary Metabolites,Glandular Trichomes and Biological Activity of Sideritis montana L. subsp. montana from Central Italy

Sideritis montana subsp. montana is a small annual herb occurring in countries bordering the Mediterranean and Balkan regions. The secondary metabolism of this plant has not been fully explored so far. The aim of the present study was to understand the complex mixture of secondary metabolites and the type of secretory structures. The polar constituents were isolated by column chromatography from the ethanolic extract, and their structure was elucidated by NMR and MS. The essential oil was isolated by hydrodistillation and analysed by GC/MS. The plant indumentum was studied by light and scanning electron microscopy. To complete the work, the essential oil antioxidant activity and cytotoxicity on tumor cells were evaluated by DPPH, ABTS, FRAP, and MTT methods. Four different classes of secondary metabolites were isolated, namely flavonoids, caffeoylquinic derivatives, glycosidic hydroquinones and iridoids. The essential oil was mainly characterized by sesquiterpenene hydrocarbons. Peltate and long‐capitate hairs were the main sites where terpenes and polar constituents are produced. The secondary metabolites found in S. montana subsp. montana are of chemotaxonomic interest, some of them being typical of the genus Sideritis. The trichomes types observed partially differ from those described in other members of the genus Sideritis. The essential oil showed noteworthy inhibition on tumor cells.     

Pollen morphology of Stachys (Lamiaceae) in Iran and its systematic implication

Pollen grains of 30 taxa of the genus Stachys (29 spp. and one subsp.), representing 9 of the currently recognized sections and 1 species of the closely related genus Sideritis (Si. montana) distributed in Iran were examined by light and scanning electron microscopy. Twenty-eight taxa are studied for the first time under aspects of pollen morphology. The basic shape of the pollen grains in most taxa studied is prolate-spheroidal, but subprolate, spheroidal and oblate-spheroidal pollen grains can also be found in few species. The grains are usually tricolpate (the amb triangular), but also tetracolpate (the amb circular to more or less square) in some species (S. iberica, S. atherocalyx and Si. montana). The surface is microreticulate (the frequent type), reticulate, perforate, foveolate-psilate or foveolate. The lumina are separated by smooth or sinuate muri which make them polygonal, more or less rounded and elongate. Major pollen morphological features of the taxa studied are compared and discussed on the basis of taxonomical concepts. In some cases, these characters are useful in delimitation of formerly introduced sections while they mostly provide further characters in separating related species from each other. For example, all members of S. sect. Aucheriana are characterized by elongated lumina. Based on the oblate-spheroidal shape of its pollen as well as tetracolpate aperture type, the results of the present study confirm sect. Pontostachys as including S. angustifolia, S. iberica, S. sparsipilosa as well as S. atherocalyx. Our results also suggest that although some species like S. fruticolosa and S. lavandulifolia are morphologically well characterized, they cannot be separated from other species of Stachys based on pollen morphology.