Evaluation of characteristic aroma compounds of Citrus natsudaidai Hayata (Natsudaidai) cold-pressed peel oil

The characteristic aroma compounds of Citrus natsudaidai Hayata essential oil were evaluated by a combination of instrumental and sensory methods. Sixty compounds were identified and quantified, accounting for 94.08% of the total peel oil constituents. Limonene was the most abundant compound (80.68%), followed by gamma-terpinene (5.30%), myrcene (2.25%) and alpha-pinene (1.30%). Nineteen compounds which could not be identified in the original oil were identified in the oxygenated fraction. Myrcene, linalool, alpha-pinene, beta-pinene, limonene, nonanal, gamma-terpinene, germacrene D, and perillyl alcohol were the active aroma components (FD-factor > 3(6)), whereas beta-copaene, cis-sabinene hydrate and 1-octanol were suggested as characteristic aroma compounds, having a Natsudaidai-like aroma in the GC effluent. Three other compounds, heptyl acetate, (E)-limonene oxide and 2,3-butanediol, which each showed a high RFA value (>35) were considered to be important in the reconstruction of the original Natsudaidai oil from pure odor chemicals. The results indicate that 1-octanol was the aroma impact compound of C. natsudaidai Hayata peel oil.     

Chemical Diversity among the Essential Oils of Wild Populations of Stachys lavandulifolia Vahl (Lamiaceae) from Iran

The variation of the essential‐oil composition among ten wild populations of Stachys lavandulifolia Vahl (Lamiaceae), collected from different geographical regions of Iran, was assessed by GC‐FID and GC/MS analyses, and their intraspecific chemical variability was determined. Altogether, 49 compounds were identified in the oils, and a relatively high variation in their contents was found. The major compounds of the essential oils were myrcene (0.0–26.2%), limonene (0.0–24.5%), germacrene D (4.2–19.3%), bicyclogermacrene (1.6–18.0%), δ‐cadinene (6.5–16.0%), pulegone (0.0–15.1%), (Z)‐hex‐3‐enyl tiglate (0.0–15.1%), (E)‐caryophyllene (0.0–12.9), α‐zingiberene (0.2–12.2%), and spathulenol (1.6–11.1%). For the determination of the chemotypes and the chemical variability, the essential‐oil components were subjected to cluster analysis (CA). The five different chemotypes characterized were Chemotype I (germacrene D/bicyclogermacrene), Chemotype II (germacrene D/spathulenol), Chemotype III (limonene/δ‐cadinene), Chemotype IV (pulegone), and Chemotype V (α‐zingiberene). The high chemical variation among the populations according to their geographical and bioclimatic distribution imposes that conservation strategies of populations should be made appropriately, taking into account these factors. The in situ and ex situ conservation strategies should concern all populations representing the different chemotypes.     

Volatile constituents of the leaves of Siparuna thecaphora (Siparunaceae) from Turrialba,Costa Rica

The composition of the essential oil from leaves of Siparuna thecaphora (Poepp. et Endl.) A. DC. collected in Turrialba, Costa Rica, was determined by capillary GC/MS. Seventy-six compounds were identified corresponding to ca. 95% of the oil. The major components were germacrene D (32.7%), alpha-pinene (16.3%), beta-pinene (13.8%) and beta-caryophyllene (4.1%). Thirty-one minor compounds were identified for the first time in this genus of plants.     

Application of multidimensional gas chromatography to the enantioselective characterisation of the essential oil of Eupatorium buniifolium Hooker et Arnott

The qualitative and quantitative composition of the essential oil from aerial parts of Eupatorium buniifolium Hooker et Arnott (Asteraceae) has been investigated for the first time. The essential oils were obtained by steam distillation of leaves and analysed by GC-MS; 44 components were identified. Monoterpene and sesquiterpene hydrocarbons, especially alpha-pinene (14.7%), beta-elemene (12.2%), germacrene D (11.5%), trans-beta-guaiene (6.5%) and (E)-caryophyllene (4.3%), were the major constituents found in the oils. The characterisation of E. buniifolium by enantioselective GC was performed by evaluation of the enantiomeric ratios of alpha-pinene, sabinene, beta-pinene, limonene, terpinen-4-ol and germacrene D.     

Phytochemical and Cytogenetic Study of Two Centaurea Species from Croatia: the Particular Case of Diploid and Tetraploid C. salonitana

Natural wild populations of C. rupestris and C. salonitana were studied to determine possible relationships between the volatile oil (VO) composition and ploidy level. The chemical composition of the volatile oil was investigated using the GC/MS technique. The predominant components of the VO of diploid and tetraploid C. salonitana were hexadecanoic acid and α-linoleic acids, while in C. rupestris they were germacrene D and β-caryophyllene in one population and heptacosane and germacrene D, in another. The nuclear DNA amounts (2 C DNA), determined by flow cytometry, were 3.54 pg for C. rupestris, 3.39 pg for the diploid and 6.79 pg for the tetraploid population of C. salonitana. Evidence that the degree of ploidy solely influences the chemical composition of the essential oil of C. salonitana was not found. The results presented are the first data to be reported on the DNA content of the studied Centaurea populations from Croatia, as well as on the chemical composition of C. salonitana volatile oil.     

Antifungal activity of essential oil and its constituents from Calocedrus macrolepis var. formosana Florin leaf against plant pathogenic fungi

Resistance to conventional fungicides causes the poor disease control of agriculture. Natural products from plants have great potential as novel fungicide sources for controlling pathogenic fungi. In this study antipathogenic activity of the leaf essential oil and its constituents from Calocedrus macrolepis var. formosana Florin were evaluated in vitro against six plant pathogenic fungi. Chemical analysis of leaf oil by GC/MS allowed identification of alpha-pinene (44.2%), limonene (21.6%), beta-myrcene (8.9%), beta-caryophyllene (8.2%), caryophyllene oxide (2.4%), alpha-cadinol (1.6%), beta-pinene (1.2%), and T-muurolol (1.1%) as main components. Sesquiterpenoid components of the oil were more effective than monoterpenoid components of the oil. In particular, T-muurolol and alpha-cadinol strongly inhibited the growth of Rhizoctonia solani and Fusarium oxysporum, with the IC(50) values < 50 microg ml(-1). These compounds also efficiently inhibited the mycelial growths of Colletotrichum gloeosporioides, P. funerea, Ganoderma australe and F. solani. These results showed that T-muurolol and alpha-cadinol possess antifungal activities against a broad spectrum of tested plant pathogenic fungi and could be used as potential antifungal agents for the control of fungal diseases in plants.     

Population Variability of Essential Oils of Pinus heldreichii from the Scardo‐Pindic Mountains Ošljak and Galičica

The needle‐terpene profiles of two natural Pinus heldreichii populations from Mts. O?ljak and Gali?ica (Scardo‐Pindic mountain system) were analyzed. Among the 68 detected compounds, 66 were identified. The dominant constituents were germacrene D (28.7%), limonene (27.1%), and α‐pinene (16.2%). β‐Caryophyllene (6.9%), β‐pinene (5.2%), β‐myrcene (2.3%), pimaric acid (2.0%), α‐humulene (1.2%), and seven additional components were found to be present in medium‐to‐high amounts (0.5–10%). Although the general needle‐terpene profile of the population from Gali?ica was similar to those of the populations from Lov?en, Zeletin, Bjelasica, and Zlatibor‐Pe?ter (belonging to the Dinaric Alps), the principle‐component analysis (PCA) of seven terpenes (β‐myrcene, limonene, β‐elemene, β‐caryophyllene, α‐humulene, δ‐cadinene, and germacrene D‐4‐ol) in 121 tree samples suggested a partial divergence in the needle‐terpene profiles between the populations from the Scardo‐Pindic mountain system and the Dinaric Alps. According to previously reported data, the P. heldreichii samples from the Balkan‐Rhodope mountains lack β‐caryophyllene and germacrene D, but contain γ‐muurolene in their terpene profile. Differences in the terpene composition between populations growing in the three above‐mentioned mountain systems were compared and discussed.     

Determination of ploidy and nuclear DNA content in populations of Atriplex halimus (Chenopodiaceae)

Nuclear DNA contents were determined by flow cytometry for 20 populations of the perennial C₄ shrub Atriplex halimus L. (Chenopodiaceae) originating from the Mediterranean basin and Fuerteventura (Canary Islands). Two populations were also analysed for chromosome number: one (from Ibiza, Spain), with a 2C nuclear DNA content of 2.40 pg, was shown to be diploid (2 n  = 2 x  = 18), whilst the other (from Sicily, Italy), with 5.11 pg, was tetraploid (2 n  = 2 x  = 36). With respect to nuclear DNA content, two groups of populations were detected, diploids with 2.40–2.44 pg and tetraploids with 4.77–5.13 pg. The diploid populations were mainly from the western Mediterranean (Spain and France) and Fuerteventura, whereas tetraploids were generally, but not exclusively, from more arid areas in North Africa and the eastern Mediterranean. In general, the diploid and tetraploid populations corresponded to the subspecies halimus and schweinfurthii , respectively. For certain populations having morphologies intermediate between those considered typical of these two subspecies, nuclear DNA contents showed them to be tetraploid. There was significant variation in nuclear DNA content among the tetraploid populations, with greater values in the more easterly populations.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 147 , 441−448.     

Foliar and cortex oleoresin variability of silver fir (Abies alba Mill.) in Albania

Terpene composition of needle and cortical oleoresin from lateral shoots were analyzed by GC/MS for four Silver fir (Abies alba Mill.) populations scattered in natural species range in Albania. More than sixty compounds were detected in the needle oleoresin, which was characterized by a high content of alpha-pinene, camphene, beta-pinene, limonene and bornyl acetate. Three monoterpenes, alpha-pinene, beta-pinene and limonene, and two sesquiterpenes, beta-caryophyllene and germacrene D, comprised the majority of cortical oleoresin. The terpene composition differences among the populations that led to the recognition of two chemotypes. The needle oleoresin from the provinces of Puka, Bulqiza and Llogara were characterised by high amounts of beta-pinene, camphene and alpha-pinene and low amounts of limonene, while that from Drenova had high amounts of beta-pinene and limonene. A similar pattern was found in the cortical oleoresin with the exception of camphene that was a minor contributor. Geographical and seasonal variation between the populations was, also, investigated. Multivariate analysis of both needle and cortical oleoresin separated Drenova (southeastern population) from the other sites. When both major monoterpenes and sesquiterpenes were considered four chemical profiles could be attributed. Based on their chemical profiles, the populations can be divided into two groups: Populations with high content of beta-pinene and alpha-pinene but a low content of limonene (Puka, Bulqiza and Llogara), typical of most of A. alba populations in all its distribution range. Population with a high content of limonene and a moderate content of beta-pinene and alpha-pinene (Drenova).     

Essential‐Oil Composition of the Needles Collected from Natural Populations of Macedonian Pine (Pinus peuce Griseb.) from the Scardo‐Pindic Mountain System

The needle‐terpene profiles of two natural Pinus peuce populations from the Scardo‐Pindic mountain system (Mt. O?ljak and Mt. Pelister) were analyzed. Among the 90 detected compounds, 87 were identified. The dominant constituents were α‐pinene (45.5%), germacrene D (11.1%), β‐pinene (10.8%), and camphene (10.3%). The following eight additional components were found to be present in medium‐to‐high amounts (0.5–10%): bornyl acetate (5.0%), β‐phellandrene (3.4%), β‐caryophyllene (2.9%), β‐myrcene (0.9%), germacrene D‐4‐ol (0.9%), tricyclene (0.7%), (E)‐hex‐2‐enal (0.7%), and bicyclogermacrene (0.6%). Although the general needle‐terpene profiles of the populations from Mt. O?ljak and Mt. Pelister were found to be similar to those of the populations from Zeletin, Sjekirica, and Mokra Gora (Dinaric Alps), principle component analysis (PCA) of eight terpenes (α‐pinene, β‐myrcene, α‐terpinolene, bornyl acetate, α‐terpinyl acetate, β‐caryophyllene, trans‐β‐farnesene, and germacrene D) in 139 tree samples suggested a divergence between the two population groups, i.e., the samples from the Scardo‐Pindic mountain system and those from the Dinaric Alps. Genetic analysis of the β‐pinene content demonstrated a partial divergence between the two geographical groups. The profiles of both population groups differed from those published for populations from the Balkan‐Rhodope mountains system (literature results), which were characterized by high contents of bornyl acetate and citronellol (Greek populations) or δ‐car‐3‐ene (Bulgarian populations).     

Cytotype distribution at a diploid-tetraploid contact zone in Chamerion (Epilobium) angustifolium (Onagraceae)

In North America, the geographic distributions of diploid and tetraploid Chamerion (formerly Epilobium) angustifolium overlap in a narrow zone along the southern border of the boreal forest and along the Rocky Mountains. We examined the frequency and distribution of diploid and tetraploid cytotypes in a narrow (5 km) zone of sympatry across an elevational gradient and in putatively uniform diploid and tetraploid reference populations on the Beartooth Pass, in the Rocky Mountains of southern Montana-northern Wyoming. All five reference populations sampled were dominated by a single cytotype, but only one was completely uniform. In the zone of sympatry, 27 transects were sampled every 2 m for a total of 238 plants. Reproductive status (vegetative, flower buds, open flowers) was recorded, and the ploidy of each plant was determined by flow cytometry. Diploid and tetraploid plants predominated (36 and 55%, respectively) but were heterogeneously distributed among the transects. Six of the 27 transects were fixed for a single cytotype (four transects, diploid; two transects, tetraploid), and in seven others either diploids or tetraploids predominated (frequency >75%). Triploids represented 9% of the total sample and occurred most frequently in transects containing both diploids and tetraploids (G = 3.4, df = 2, P = 0.07). Diploids were more often reproductive (in bud, flower, or fruit) than either triploids or tetraploids (G = 12.0, df = 2, P < 0.001) and were the only cytotype to have produced open flowers. These results suggest that the zone of sympatry is best characterized as a mosaic rather than a cline, with diploid and tetraploids in close proximity and that the distribution of polyploidy is regulated by ecological sorting in a heterogeneous physical environment.     

Variation of chemical composition and antioxidant activity of essential oils of Mentha x rotundifolia (L.) Huds. (Lamiaceae) collected from different bioclimatic areas of Tunisia

The variation of the essential oils composition of 10 Tunisian Mentha x rotundifolia (L.) Huds. Populations and their antioxidant activity were assessed. Essential oils showed high percentages of oxygenated monoterpenes and sesquiterpene hydrocarbons. Rotundifolone, p-menthane-1,2,3-triol, β-caryophyllene and germacrene D were identified as main compounds at the species level. A variation in the essential oil composition was observed according to the populations and ecological factors. The populations 7, 8, 9 and 10 from the upper semi-arid bioclimatic zone and situated at high altitudes, exhibited the highest amount of rotundifolone. The populations 1, 2, 3, 4 and 5 from the lower humid showed a rotundifolone/β-caryophyllene/germacrene D chemotype. The population 6, situated at the lowest altitude, was characterized by the highest amount of p-menthane-1,2,3-triol. The level of antioxidant activity of the populations was linked to their chemical composition difference. The highest scavenging activity and the best ability to reduce ferric ions were recorded for the population 10. The most important capacity to inhibit β-carotene bleaching was revealed for the population 8. For all populations, the antioxidant activities were substantial but lower than antioxidant standards used (Trolox and BHT).The populations (7, 8, 9 and 10) from the upper semi-arid showed the best yields of essential oils and the highest contents of rotundifolone. Chemotypes within these populations could be selected for improvement programs.     

Correlation between distyly and ploidy level in Damnacanthus (Rubiaceae)

Somatic chromosomes were observed in 661 individuals of 14 taxa, nine species and five varieties, of Damnacanthus (Rubiaceae). Chromosome numbers are reported for the first time for 13 taxa. Diploid (2n = 22) and tetraploid (2n = 44) counts were obtained. Distyly is reported for the first time for four species, D. angustifolius, D. henryi, D. labordei, and D. officinarum. A strong correlation exists between chromosome number and occurrence of distyly. Regardless of taxa in Damnacanthus, distylous populations are diploid, and monomorphic populations are tetraploid. Flowers of the monomorphic populations observed have a long style and short stamens with few exceptions. Polyploidization may have caused the breakdown of distylous to monomorphic flowers. In D. indicus, leaves from the tetraploid populations tend to be larger than those from the diploid populations. Populations of tetraploid D. indicus were distributed in more northern areas than those of the diploid. Three types of sympatric distribution were found for the varieties of D. indicus in Japan: diploid and tetraploid, two diploids, and two tetraploids. Based on the present chromosome number study, the taxonomy of the varieties of D. indicus should be revised.     

Volatile Compounds in Fruits of Peucedanum cervaria (Lap.) L.

The volatile compounds from Peucedanum cervaria (Lap. ) L. were obtained by hydrodistillation (HD) and headspace solid‐phase microextraction techniques (HS‐SPME), and then analyzed by GC/MS methods. The composition of samples from a botanical garden was compared with plants collected in the wild. The main compounds of the essential oils of P. cervaria were identified as α‐pinene, sabinene, and β‐pinene (more than 80% of oil). The content of β‐myrcene, limonene+β‐phellandrene, and germacrene D was higher than 1%. The in vitro antibacterial activity of the essential oil was evaluated by the agar dilution method against ten reference strains of Gram‐positive and Gram‐negative bacteria.     

中国西南六种广义拂子茅属(禾本科)植物的染色体数目

广义拂子茅属（Calamagrostis）是一个世界温带广布的大属,有些作者又分为拂子茅属和野青茅属,但近期的研究表明处理为一个属较为合适。中国共有37种广义拂子茅属植物,但至今没有任何染色体的研究。本文报道了其中产于中国西南6种野青茅的染色体数目,其中Deyeuxia petelotii 4个居群,D．diffusa,D．moupinemis,D．nivicola和D．flvens各一个居群都是四倍体（2n=4x=28）,D．neglecta为六倍体（2n=6x=42）。根据广义拂子茅属植物染色体倍性特征,该属植物中至今未发现二倍体,四倍体是该属中倍性最低和最普遍的,广义拂子茅属的演化很可能是在四倍体的水平上进行的。由于以上几个四倍体种均是狭域分布的类群,所以可能是由四倍体的祖先隔离分化形成的。     

Evaluation of Characteristic Aroma Compounds of Citrus natsudaidai Hayata (Natsudaidai) Cold-Pressed Peel Oil

The characteristic aroma compounds of Citrus natsudaidai Hayata essential oil were evaluated by a combination of instrumental and sensory methods. Sixty compounds were identified and quantified, accounting for 94.08% of the total peel oil constituents. Limonene was the most abundant compound (80.68%), followed by γ-terpinene (5.30%), myrcene (2.25%) and α-pinene (1.30%). Nineteen compounds which could not be identified in the original oil were identified in the oxygenated fraction. Myrcene, linalool, α-pinene, β-pinene, limonene, nonanal, γ-terpinene, germacrene D, and perillyl alcohol were the active aroma components (FD-factor > 3⁶), whereas β-copaene, cis-sabinene hydrate and 1-octanol were suggested as characteristic aroma compounds, having a Natsudaidai-like aroma in the GC effluent. Three other compounds, heptyl acetate, (E)-limonene oxide and 2,3-butanediol, which each showed a high RFA value (>35) were considered to be important in the reconstruction of the original Natsudaidai oil from pure odor chemicals. The results indicate that 1-octanol was the aroma impact compound of C. natsudaidai Hayata peel oil.     

Genome size and base composition in Medicago sativa and M. truncatula species.

The genome size (1C value) and base composition of 14 ecotypes of two species of tetraploid and diploid Medicago have been assessed by flow cytometry. These parameters vary both between and within species. The diploid annual Medicago truncatula Gaertn. had the smallest genome of the group studied (which also covered M. sativa L. subsp. sativa, M. sativa L. subsp. caerulea (Less. ex Ledeb.) Schmalh., M. sativa L. subsp. quasifalcata Sinsk., M. sativa L. subsp. x varia (Martyn) Arcangeli; however, its ecotypes revealed substantial intraspecific variation. The smallest M. truncatula genome observed was ecotype 108-1 with 1C = 0.49 pg and 38.1% GC and the largest was Jemalong with 1C = 0.57 pg and 38.6% GC. The degree of polysomaty in these Medicago was low, although in some tissues the frequency of cells with 4C nuclei reached 50%.     

Seasonal variation of the chemical constituents of the essential oil of Santolina etrusca from Italy

The seasonal variation of the essential oil, in terms of both yield and composition, of a population of Santolina etrusca (Asteraceae) is reported in detail for different aerial parts, including sterile branches, fertile branches, and capitula. The yields generally increased from November to June, and then decreased in August and September. The main constituents of the sterile branches were 1,8-cineole and viridiflorol. The oil from fertile branches was characterized by myrcene as principal compound, whereas the essential oil obtained from the capitula contained germacrene D as the main constituent. Several compounds, as identified by GC and GC/MS, were found to prevail during the cold season.     

不同倍性盾叶薯蓣营养器官解剖结构比较

运用石蜡切片法对三个倍性盾叶薯蓣营养器官的解剖结构进行比较研究。结果表明,不同倍性盾叶薯蓣的结构差异主要表现在叶片厚度、栅栏组织厚度、栅栏组织厚度/海绵组织厚度(P/S)、栅栏组织厚度/叶片厚度(P/L)、茎维管束中导管所占比例(VR)以及根状茎周皮厚度,其中栅栏组织厚度、P/S、P/L和VR在三倍体植株中表现最高,叶片厚度和周皮厚度则是四倍体植株表现最高,多倍体植株的表现总体优于二倍体植株。     

Fitness differences among diploids, tetraploids, and their triploid progeny in Chamerion angustifolium: mechanisms of inviability and implications for polyploid evolution

Abstract. Theoretical models indicate that the evolution of tetraploids in diploid populations will depend on both the relative fitness of the tetraploid and that of the diploid-tetraploid hybrids. Hybrids are believed to have lower fitness due to imbalances in either the ploidy (endosperm imbalance) or the ratio of maternal to paternal genomes in their endosperm (genomic imprinting). In this study we created diploids, tetraploids, and hybrid triploids of Chamerion angustifolium from crosses between field-collected diploid and tetraploid plants and evaluated them at six life stages in a greenhouse comparison. Diploid offspring (from 2 x × 2 x crosses) had significantly higher seed production and lower biomass than tetraploid offspring (from 4 x × 4 x crosses). Relative to the diploid, the cumulative fitness of tetraploids was 0.67. In general, triploids (from 2 x × 4 x , 4 x × 2 x crosses) had significantly lower seed production, lower pollen viability, and higher biomass than diploid individuals. Triploid offspring derived from diploid maternal parents had lower germination rates, but higher pollen production than those with tetraploid mothers. Relative to diploids, the cumulative fitness of 2 x × 4 x triploids and 4 x × 2 x triploids was 0.12 and 0.06, respectively, providing some support for effect of differing maternal:paternal ratios and endosperm development as a mechanism of hybrid inviability. Collectively, the data show that tetraploids exhibit an inherent fitness disadvantage, although the partial viability and fertility of triploids may help to reduce the barrier to tetraploid establishment in sympatric populations.