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1.
Carotenogenic mutants ofPhycomyces, which accumulate excess β-carotene or its intermediates, always failed in zygospore development. No improvement occurred when such mutants were mated together with a helper wild type of the same mating type against the wild type of the opposite mating type. Addition of excess synthesized pheromone, trisporin B, also failed to improve the zygospore development, though the mating response was significantly activated in the early stages and abundant zygophores were formed. Exceptional acceleration of the zygospore development under these experimental conditions occurred in a regulatory albino mutant (carA), which does not accumulate excess intermediate carotenoids. Chemically- or genetically-induced ovarproduction of β-carotene or lycopene also inhibited the zygospore development. These results imply that the zygospore development ofPhycomyces is maximal when the intracellular amount of β-carotene is optimal (=wild type), and that pheromones act mainly in the early stages of mating, while other factors such as the cell-to-cell recognition system may also be involved in the later stages. Intracellular accumulation of excess β-carotene or its intermediates probably disturb such later-stage factors.  相似文献   

2.
A detailed analysis of chloroplast DNA restriction fragment length variation was undertaken to reconstruct the maternal phylogeny of 18 taxa from both sections of the papilionoid tropical forage legume genusStylosanthes. Data were analysed by means of the computer program PAUP, using an heuristic search with Wagner parsimony. The resulting cladogram dividedStylosanthes into four separate clades, which comprised: (i) theS. guianensis complex and related species (i.e.S. gracilis, S. grandifolia andS. montevidensis); (ii)S. hispida, tetraploidS. hamata s. l.,S. sympodialis, S. humilis, S. leiocarpa, S. angustifolia and certain accesions ofS. scabra; (iii)S. calcicola, S. viscosa, diploidS. hamata s. str., andS. fruticosa, plus accessions ofS. scabra, S. capitata and one accession ofS. grandifolia; and (iv)S. macrocephala and other accessions ofS. capitata not included within clade 3. Results are generally congruent with previously established interspecific relationships and, moreover, enabled identification of putative maternal progenitors for four tetraploid taxa:S. humilis was identified as a likely maternal parent of bothS. sympodialis andS. hamata s. l.,S. viscosa as a maternal parent ofS. scabra, andS. macrocephala as a maternal parent ofS. capitata.  相似文献   

3.
Two species ofMenziesia, M. katsumatae andM. yakushimensis, are described as new to science. The former is characterized by having a long axis of the inflorescence with 15–20 bracts while the other species has a short axis with about ten bracts.M. katsumatae is restricted to the Hakusan range extending northward to Mt. Hōdatsuzan in the Noto Peninsula.M. yakushimensis has been considered asM. purpurea Maxim. in Kyūshū, but it is clearly distinguishable from the latter by the color and shape of the corolla and the presence of fasciculate glandular-hairs at the base of the corolla lobes. It is endemic to the higher altitudes of Yaku-shima Island, Kagoshima Prefecture.  相似文献   

4.
We describe short-term changes in foraging behavior by wild Yakushima macaques (Macaca fuscata yakui),which inhabit a warm-temperate broad—leaved forest on Yakushima Island (30°N, 131°E), Japan. Rapid changes of dietary composition, activity budget, and range use by the monkeys occurred from May to June, apparently associated with changes in the availability of the fruit of Myrica rubraBefore the fruit ripened, monkeys spent less time moving and more time feeding on many species of leaves, which accounted for 40% of feeding time. However, when M. rubrabegan to ripen, they fed intensively on the fruit, which accounted for three-fourths of feeding time,though the activity budget remained unaffected As fiuit of M. rubradecreased,the monkeys fed more on the fruit of other species and on insects, and spent more time moving at higher speeds. There marked shifts in foraging pattern occurred within only two months. In terms of moving cost and dietary quality,Yakushima macaques shifted their foraging pattern according to the availability of M. rubrafrom a “low-cost, low-yield” strategy to a “low-cost, high-yield” strategy, and then to a more costly strategy. The ability to make such rapid shifts in foraging pattern may allow the macaques to effectively use the highly variable food supply within their small range.  相似文献   

5.
The germ tubes ofColletotrichum lagenarium showed negative phototropism to UV-blue (300–520 nm) and far-red (>700 nm) regions with maximum in the near ultraviolet (NUV) region, while monochromatic radiations of 575–700 nm (yellow-red region) induced positive phototropism with maximum in the red region. Green light (520–575 nm) was ineffective. Negative phototropism-inducing wavelength regions inhibited germ tube growth and positive phototropism-inducing wavelength regions promoted it significantly.Bipolaris oryzae did not show any phototropic response and light did not affect the germ tube growth. These results indicate that the lens effect, in combination with the light growth reaction and light growth inhibition, is the mechanism of the phototropism of germ tubes ofC. lagenarium. NUV radiation, which induced negative phototropism ofC. lagenarium, promoted appressorium formation, while red light, which induced positive phototropism, suppressed it significantly. In the case ofB. oryzae, light did not affect the infection structure formation. These results indicate that negative phototropism of germ tubes ofC. lagenarium favors the infection process by facilitating the contact of the tips of germ tubes with the host surface, while positive phototropism has the opposite effect.  相似文献   

6.
Asexual and sexual reproductive cyries are described and illustrated for a cultured homothallic strain of Mougeotia transeaui Collins. Reproduction is by aplanospores and zygospores. Aplanospore formation precedes zygospore formation and continues longer with regreening of older cultures occurring regularly from precocious germination of aplanospores. Aplanospores typically form when most of the protoplast moves into the central swollen region of a cell and two new cross walls form to delimit an aplanosporangium. Conjugation is scalariform without the movement and fusion of well-organized gametes. During zygospore maturation, three new cross walls form in the receptive gametangium and conjugation tube to produce a zygosporangium.  相似文献   

7.
Glycerol formation ofDunaliella cells in non-growing media was investigated.Dunaliella tertiolecta andD. bioculata grew well in a NaCl medium but not at all in a LiCl or a MgCl2 medium. When the cells originally suspended in a medium containing 0.5 M NaCl were transferred to media which contained one of 1 M NaCl, 1 M LiCl or 0.7 M MgCl2, the intracellular glycerol content increased.D. tertiolecta cultured in either a 1 M LiCl or a 0.7 M MgCl2 medium did not multiply, but maintained abilities to evolve O2 in the light and absorb O2 in thedark even after about a 5 day culture. From these results, it can be concluded that the halotolerance ofDunaliella to different kinds of salts is not directly related to osmoregulation by the glycerol formation.  相似文献   

8.
In vitro rearing of the aphid endoparasitoidLysiphlebus fabarum (Marshall) (Hymenoptera, Braconidae) was attempted. Successful permanent cultures ofAphis fabae Sc. andMyzus persicae Sulz. cells were not obtained. Therefore, parasitoid larvae were reared in 2 unnatural media rone of which included cells ofCeratitis capitata Wied. (Diptera, Trypetidae). A group of larvae was reared in a substrate to which parasitoid teratocytes had been added. SinceLysiphlebus fabarum females did not oviposit into paraffin droplets including the substrates, the larvae were directly transferred from parasitized aphids into the rearing media. Several larvae reached the final instar, but only 2 out of the 48 tested in the 3 substrates became adults. The meaning of teratocytes inin vitro rearing of Aphidiine, Braconids is discussed. This work was supported by a grant from the italian Ministry of Education (M.P.I. 40%).  相似文献   

9.
Takahashi  Haruki 《Mycoscience》1999,40(1):73-80
Two lignicolous species ofMycena (Agaricales, Basidiomycetes) are described and illustrated from eastern, Japan:Mycena auricoma sp. nov., forming ephemeral coprinoid basidiomata and belonging to sectionRadiatae, was found on a dead fallen twig ofQuercus serrata. It appears to close to a Malaysian species,“Trogia” crinipelliformis. Mycena spinosissima in sectionSacchariferae, new to Japan, was collected from dead bark ofAphananthe aspera, a dead fallen inflorescence ofCryptomeria japonica, and a dead fallen twig ofQuercus serrata.  相似文献   

10.
Mammillaria species are the most numerous within Cactaceae family, and some of them are threatened with extinction as a result of human activities. In this work, results of in vitro propagation are presented for ten Mammillaria species, testing 20 combinations of indole-3-acetic acid (IAA) and kinetin. Best results on shoot formation were obtained using kinetin at two levels: 27.9 and 46.5 μM. All IAA levels tested were able to induce de novo shoot formation in M. bocasana, M. densispina, M. hahniana, M. hutchisoniana, M. orcutii, M. pectinifera, M. perbella, M. picta, M. rhodantha, and M. zephyranthoides. Depending on the IAA level tested, four responding groups were observed concerning their highest shoot-formation number. For all species, the highest average of shoot formation was achieved with 5.7:46.5 or 11.4:46.5 μM IAA/kinetin, yielding 4.8 and 4.7 shoots per explant, respectively, in 60 d. Rooting of regenerated shoots was achieved by leaving the explants in their shoot-induction medium or transferring them to half-strength MS medium. Hardening of regenerated plants was successfully achieved by planting them in peat moss substrate after a desiccation treatment at room temperature for 3 d.  相似文献   

11.
R. Kaspi 《BioControl》2000,45(4):463-468
Chiracanthium mildei, a common sac spider (Clubionidae) in Israel, is an important predator of pest insects in citrus and apple orchards. Field observations indicate that the females of this hunting spider are attracted to traps containing the parapheromone trimedlure and males of the Mediterranean fruit fly (Ceratitis capitata),which were caught in these traps. Laboratory testsshow that C. mildei females are attractedto olfactory cues from male C. capitata, but notto trimedlure. This suggests that C. mildeimay be an important nocturnal predator of C.capitata.  相似文献   

12.
Bleaching is generally expected to produce detrimental impacts on coral reproduction. This study compared the fecundity of bleached and unbleached colonies of the Hawaiian coral Montipora capitata. It was hypothesized that bleaching would have no effect on reproduction because previous studies have shown that Montipora capitata can increase heterotrophic feeding following bleaching. Reproductive parameters, total reproductive output (bundles released ml−1 coral colony), number of eggs bundle−1, and egg size, measured in the summer of 2005 did not differ between colonies that bleached or did not bleach during 2004. These data were collected following a single bleaching event and cannot be used to predict the outcome should bleaching episodes become more frequent or severe.  相似文献   

13.
From the blue seed coats ofOphiopogon jaburan, a new flavonol glycoside was isolated as needles and determined to be kaempferol 3-O-β-d-galactoside-4′-O-β-d-glucoside (OK-2) by UV and NMR spectral analyses. OK-2 and kaempfrol 3, 4′-di-O-β-d-glucoside (OK-1), which was detected previously, in the blue seed coat were present in a molar ratio of about 13:7. OK-2 was newly found as a factor causing the blueing effects on ophionin which is a main anthocyanin in the blue seed coats. The mixture of 4.8×10−3 M OK-2 and 2.5×10−3 M ophionin in Mcllvaine's buffer solution (pH 5.6) showed stable blue color, and the absorption spectrum of the mixture showed two absorption peaks and a shoulder in visible reasion, coinciding with that of the fresh blue seed coat. The effect of ophionin and OK-2 co-pigmentation on the blue color of seed coat ofO. jaburan was discussed.  相似文献   

14.
Medicago intertexta andM. ciliaris have been controversially recognized as separate species. The only reliable diagnostic character, gland-tipped trichomes on the fruits inM. ciliaris, is controlled by presence of a single dominant allele, and such one-character taxonomies are debatable. Contributing to the difficulty,M. muricoleptis andM. granadensis, the other two species ofMedicago sectionSpirocarpos subsectionIntertextae, are sometimes confusingly similar toM. intertexta or to each other. Allozyme differences provided 95% verification of the suitability of the gland-tipped trichome character for separatingM. intertexta andM. ciliaris, thus corroborating their recognition as separate taxa. Several measures of allozyme variation indicated thatM. intertexta is more polymorphic than its sister species. Heterozygosity was also highest inM. intertexta, suggestive of a higher outcrossing rate, which is also consistent with larger floral size. Heterozygosity ofM. intertexta was concentrated in Sicily and nearby countries. Taxonomic difficulties in identifying SicilianM. intertexta are well known, and may be the result of interspecific hybridization and introgression.Medicago muricoleptis differed from the above two species in the frequency of several alleles, whileM. granadensis possessed numerous unique alleles consistent with its complete absence of genetic exchange with the other three substantially interfertile species.  相似文献   

15.
16.
The virulence of two isolates of the hyphomycete fungi, Beauveria bassianaand B. brongniartii, and additional fungal species isolated from diseased Bactrocera oleae pupae and Sesamia nonagrioideslarvae were assessed against adults of the olive fruit fly B. oleae and the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae). Contact and oral bioassays revealed that moderate to high mortality rates for the olive fruit fly occurred when the adults were exposed to conidia of Mucor hiemalis, Penicillium aurantiogriseum, P. chrysogenum and B. bassianaisolates. A strain of M. hiemalis isolated from S. nonagrioides larvae was the most toxic resulting in 85.2% mortality to the olive fruit fly adults. B. brongniartiiand B. bassiana were the most pathogenic to the C. capitataadults causing 97.4 and 85.6% mortality. Metabolites collected from the M. hiemalis and P. chrysogenum isolates were toxic to adults of both species.  相似文献   

17.
This study investigated the morphology, severity, and distribution of growth anomalies (GAs) in the coral, Montipora capitata, from Wai‘ōpae tide pools, southeast Hawai‘i Island. A macro-image analysis of skeletal microstructure placed GAs into two definable categories; Type A and Type B. Type A GAs had polyp density reduced by 43.05 ± 0.80% (mean ± SE) compared to healthy M. capitata tissue, with many fused and protrusive tuberculae. Type B GAs had no discernable polyps or calices and fused protuberant coenosteum. The prevalence of Type A and Type B GAs among all M. capitata colonies (n = 1,093) in 8 tide pools at Wai‘ōpae was 22.1% (range 2.8–33.7%) and 8.2% (range 0.0–16.9%), respectively. The proportion of colony surface area occupied by GA (relative GA cover) was quantified to assess the severity of this disease among all surveyed colonies. The relative GA cover was significantly greater on colonies larger than 1 m in diameter than smaller colonies and in the central portion of colonies than in the periphery. Furthermore, relative GA cover was negatively related to water motion (R 2 = 0.748, P < 0.01). Developing field diagnostic criteria of M. capitata GA allowed for a detailed epizootiological assessment that determined several cofactors associated with disease severity. Such epizootiological analysis is applicable to future studies of GAs elsewhere.  相似文献   

18.
The monkeys on the island of Sulawesi (Celebes), Indonesia, comprise seven species ofMacaca, that isM. maura, M. tonkeana, M. hecki, M. nigrescens, M. nigra, M. ochreata, andM. brunnescens. Hemoglobins from 248 individuals of these seven species were analyzed by isoelectric focusing electrophoresis (IEFE) and by starch gel electrophoresis in the presence of urea (USGE). Eighteen phenotypes consisting of eight molecular types were identified by IEFE analysis. The speciestonkeana inhabiting the central part of the island revealed 11 phenotypes, while peripheral species such asnigrescens andbrunnescens carried only 3 and 2 phenotypes, respectively. On USGE, three α chains and three β chains were identified and named α1, α2, and α6, and β1, β3, and β5, respectively. The α1 chain has the same mobility as the α chains of other macaques, while the α2 chain is less positively charged than α1, and α6 is the least positive among these α chains. The α2 chain is widely distributed in the Sulawesi macaques as the major component. Four species,ochreata, tonkeana, maura, andnigrescens, carried the α1 and α6 chains as minor components. The electrophoretic mobility of β1 was the same as that of other macaques, while β3 and β5 were more positively charged and less positively charged than β1, respectively. All of the Sulawesi species had β3 in high or low gene frequencies and inmaura, tonkeana, andbrunnescens, this type was most abundant. β5 chain existed in the species of the northern peninsula, as the major type. The subordinate type was β3 innigra andnigrescens and β1 inhecki. On the other hand, β1 was most frequently observed inochreata.  相似文献   

19.
The particle gun, cocultivation withAgrobacterium tumefaciens, and imbibition in DNA solutions were compared as methods to transfer DNA into mature and immature pollen ofNicotiana tabacum. Bombardment of mature pollen with the β-glucuronidase gene cloned behind the pollen-specific PA2 promoter of the chalcone isomerase gene ofPetunia hybrida resulted in the expression of the β-glucuronidase gene in 0.025% of the pollen grains. Bombardment of younger stages followed byin vitro maturation also resulted in the formation of mature pollen that expressed β-glucuronidase, although at a lower frequency. Cocultivation of pollen duringin vitro maturation orin vitro germination withAgrobacterium tumefaciens did not yeild β-glucuronidase-expressing pollen. In these cases, an intron-containing β-glucuronidase gene was used which effectively prevented β-glucuronidase expression in the bacteria. Imbibition of mature, dry pollen in various DNA solutions of the same constructs also did not lead to the formation of β-glucuronidase expressing pollen.  相似文献   

20.
Based on collectors' measurements of 1,040 specimens, variation of relative tail length [RTL = (tail length/head and body length) × 100] has been studied inMacaca fascicularis andM. mulatta, two closely related species that replace one another in tropical Asia and subtropical Asia, respectively. RTL usually is greater than 90 inM. fascicularis and usually is less than 60 inM. mulatta; intermediate values occur in only 3.5% of specimens studied. Within each species, RTL is approximately equal in females and males. From infancy to adulthood, RTL tends to decline in both species. InM. fascicularis, RTL generally decreases with increasing latitude; inM. mulatta, RTL is approximately constant latitudinally. Where the geographic ranges of these two species meet at ca. 15°N in the Indochinese Peninsula, a few specimens have been collected in which RTL and dorsal pelage color are intermediate between those inM. fascicularis andM. mulatta. The observed pattern of variation suggests that the ranges ofM. fascicularis andM. mulatta formerly were separated by a zoogeographic barrier — perhaps during a Pleistocene glacial interval. After disappearance of the postulated barrier, the ranges of these two species apparently became contiguous and limited hybridization has occurred.  相似文献   

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