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1.
Gene frequencies, estimated by electrophoretical analysis, were compared between sympatric populations of ninespine sticklebacks,Pungitius pungitius, P. tymensis andP. sinensis, in Hokkaido, Japan. The loci examined wereLdh- E,Sod, Pgm andMp. Consequently, significant differences were detected betweenP. tymensis and other species in all rivers examined. This result strongly suggests thatP. tymensis is reproductively isolated from the other species even when they coexist, although a few natural hybrids betweenP. pungitius andP. tymensis were found through its heterozygosity in esterase isozyme patterns and inPgm. On the other hand, no significant difference was detected betweenP. pungitius andP. sinensis populations in the Biwase River of eastern Hokkaido. Therefore, it is suggested that they possibly belong to a single interbreeding population.  相似文献   

2.
Penicillia species were isolated from postharvest decays of fruits of pear, apple, grapes, strawberry, melon, pepper, eggplant and tomato, after 3–5 days' shelf-life following cold storage.Penicillium cyclopium was the most common species in storage and was isolated from all fruits except eggplants. Next in frequency wereP. expansum, P. puberulum, P. viridicatum andP. brevi-compactum, naturally occurring on various types of stored fruits.P. expansum, P. stecki andP. cyaneo-fulyum showed the highest pathogenic potential, being capable of infecting all inoculated tested fruits.P. cyclopium, P. puberulum, P. viridicatum, P. crustosum andP. granulatum were also among the non-selective species, capable of infecting all fruits except eggplant or pepper.P. citrinum, P. purpurogenum, P. frequentans, P. chrysogenum, P. stolonifer, andP. italicum constitute a category characterized by both limited natural distribution and selective pathogonicity after artificial fruit inoculations. Fruit tissues of pears, grapes and tomatoes were found the most suitable for colonization and development of the Penicillia, whereas those of eggplant and pepper were most resistant to infection.  相似文献   

3.
Psathyrella hypertropicalis, a new species, is described from a high mountain (Cofre de Perote) in the State of Veracruz, Mexico above the subtropical zone. This species is intermediate betweenP. velutina of the temperate regions andP. sepulchralis from the subtropical regions of Mexico. A list of the 26 species ofPsathyrella of Mexico is presented, of which 21 are from the tropics and subtropics, three from the temperate regions (P. velutina, P. spadicea, andP. hypertropicalis), and two with a broad distribution (P. candolleana andP. disseminata). Eleven are only known from Mexico.  相似文献   

4.
《Experimental mycology》1992,16(1):22-34
Twenty-five isolates representing fivePythium species collected from diverse hosts and geographic origins were evaluated using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. DNA regions coding for the small-subunit ribosomal RNA (SrDNA) and the internal transcribed spacer (ITS) were amplified and analyzed by restriction enzyme digestion. The amplified SrDNA was about 1800 bp long and uniform in length among the five species. However, restriction digestion revealed three polymorphic groups. They areP. arrhenomanes andP. graminicola,P. irregulare andP. spinosum, andP. ultimum. The amplified-ITS region showed three different lengths which corresponded to the three polymorphic groups of SrDNA. Each length variant of the ITS showed distinct banding patterns after restriction enzyme digestion. In addition,P. irregulare andP. spinosum each showed distinct banding patterns after digestion with enzymesHinfI andMboI. Physical maps of the restriction sites in the SrDNA and the ITS were determined. Length variation occurred primarily in the spacer between the SrDNA and 5.8 S rDNA; although, it also was detected in the ITS-2 region. Little intraspecific variation was observed in the SrDNA and ITS, and species could be reliably distinguished by RFLP analysis of the amplified rDNA regions. Data presented do not support the maintenance ofP. arrhenomanes andP. graminicola as distinct species. Results indicate that PCR-RFLP can be used as a simple and speedy taxonomical tool for ecological studies ofPythium species.  相似文献   

5.
《Experimental mycology》1990,14(1):18-31
The extent of intraspecific mitochondrial DNA (mtDNA) diversity was investigated in isolates ofPhytophthora capsici,P. citricola, P. citrophthora, P. megakarya, P. palmivora, andP. parasitica that represented a wide range of host plants and geographic origins. Phenograms were constructed following the analysis of restriction fragment patterns that were generated by several endonucleases. The six species showed different degrees of mtDNA diversity. Restriction fragment patterns inP. palmivora andP. parasitica were very uniform. Distinct subgroups could be distinguished inP. megakarya andP. citrophthora that correlated with the geographic origin or the host plant, respectively. These subgroups did not seem to be closely related to each other. High degrees of diversity were also evident inP. citricola andP. capsici. Although some isolates ofP. capsici had identical mtDNA patterns, no distinct subgroups were found that could be correlated with either a specific host plant or geographic origin. InP. capsici andP. parasitica variation in nuclear DNA was much more pronounced as compared to mtDNA. InP. capsici both types of analysis correlated well. Because of very limited variation of mtDNA inP. parasitica a comparison between the two phenograms was difficult.  相似文献   

6.
7.
The geographic distribution of the mesopsammobiont gastropod genusPseudovermis is reconsidered.P. papillifer andP. schulzi were found for the first time in the Northern Adriatic near Rovigno.P. kowalevskyi andP. boadeni are described. A taxonomic survey and a determination key are presented for allPseudovermis species known thus far.  相似文献   

8.
Panicum amarum andP. amarulum exhibit north-south clinal variation and are virtually indistinguishable in the southern part of their range. Cytological evidence indicates thatP. amarum (2n = 54) is probably an autohexaploid derivative ofP. amarulum (2n = 36). The minor morphological differences, the apparent close genetic relationship, and the close ecological and chemical affinities between these two taxa indicate thatP. amarum andP. amarulum should have varietal rather than specific rank.  相似文献   

9.
Andrew M. Torres 《Brittonia》1969,21(4):322-331
Philactis (Compositae-Heliantheae) is a genus of three species, all of limited distribution. A revision is presented, based upon herbarium specimens and field work. Cytological data are from bud material fixed in the field, and from root tips of seedlings. The basic chromosome number appears to be 14.P. nelsonii andP. liebmannii are tetraploid (2n = 56), andP. zinnioides is hexaploid (2n = 84).  相似文献   

10.
In the most recent monograph of the genus in North America,Physalis lanceolata was considered to be a hybrid betweenP. heterophylla andP. virginiana. Comparative morphological and Chromatographic studies indicate, however, thatP. lanceolata is not intermediate between its supposed parents. This evidence plus its high pollen viability and seed set indicate that the species is not a hybrid. Natural hybrids betweenP. heterophylla andP. virginiana are sterile and are intermediate between these species in morphology and Chromatographic pattern.  相似文献   

11.
Noel H. Holmgren 《Brittonia》1978,30(4):416-425
Penstemon goodrichii of sect.Cristati andP. navajoa andP. moriahensis of sect.Glabri are described, illustrated and mapped. Their relationships to kindred species are discussed.  相似文献   

12.
A systematic review of the Colombian species of the tribe Pterideae (Pteridaceae) resulted in the discovery of two new species ofPteris:P. muricatopedata andP. albertiae, both in the Deflexa group. Two species are reported for the first time from Colombia:P. bakeri C. Chr. andP. lechleri Mett.  相似文献   

13.
Bryosedgwickia is considered a synonym ofPlatygyriella and the following transfers are proposed:P. aurea, P. aureoides, P. densa, P. fragilifolia, P. kirtikarii andP. pringlei. A key is provided to the accepted species ofPlatygyriella. Excluded species are treated asHondaella entodontea (C. Müll.) Buck andIsopterygium jamaicense (Bartr.) Buck.  相似文献   

14.
Ginseng is a well-known medicinal plant that has been used as an anti-aging agent for many years in East Asia. In the genusPanax, only three species,P. ginseng (Oriental ginseng),P. quinquefolius (American ginseng) andP. notoginseng (Chinese ginseng), are currently considered to be important medicinal herbs. Despite the increase in their breeding value, molecular cytogenetic information on the species is not available. To analyze the genomic relationships among thePanax species, FISH (fluorescencein situ hybridization) and GISH (genomicin situ hybridization) techniques were applied. FISH analysis revealed that the 45S and 5S rRNA genes ofP. notoginseng (2n=2x=24) andP. ginseng (2n=4x=48) cluster on a single locus on different chromosomes, whileP. quinquefolius (2n=4x=48),P. japonicus (2n=4x=48), and Korean wild ginseng (2n =4x= 48) had one locus of the 45S rRNA gene and two loci of the 5S rRNA gene, respectively. GISH analysis using genomic DNA as a probe detected strong cross-hybridization of genomes betweenP. ginseng andP. quinquefolius. GISH analysis of other species showed weak or no distinct signals on the chromosomes. Our data revealed thatP. ginseng andP. quinquefolius showed the highest degree of homology, indicating that these species diverged in most recent years.  相似文献   

15.
David J. Keil 《Brittonia》1984,36(1):74-80
Four new species ofPectis are described:P. ericifolia from Barbuda,P. luckoviae from west-central Mexico,P. arida from Ecuador and Peru, andP. cajamarcana from Peru. Chromosome counts forP. ericifolia (n=48) andP. luckoviae (n=12) are presented. Relationships of the newly described taxa are discussed.  相似文献   

16.
We studied degree of variability and relationships among populations belonging to five species of the section Strombocarpa of the family Leguminosae, namelyProsopis ferox, P. torquata, P. pubescens, P. strombulifera andP. reptans, by isozyme electrophoresis. The genetic similarity betweenP. reptans andP. strombulifera is high enough for the two to be considered subspecies or geographic races ofP. strombulifera instead of good taxonomic species. As expected these species cluster withP. pubescens, all belonging to series Strombocarpae. This group is different isoenzymatically from the remaining species,P. torquata andP. ferox. Comparison of our results with those obtained earlier for species of the section Algarobia showed that genetic variability in the section Strombocarpa is lower than in the section Algarobia, while the species divergence is much higher. These results suggest different adaptive strategies between these sections.  相似文献   

17.
18.
A study is presented of germination inPotamogeton angustifolius, P. acutifolius, P. obtusifolius, P. crispus, P. lucens, P. natans, P. pectinatus, P. pusillus andP. trichoides, and the possibility of overcoming dormancy in these species under laboratory conditions. Three of the species, viz.Potamogeton pectinatus, P. pusillus andP. trichoides have been examined in greater detail. Impermeability of the fruit coat appears to be the main reason for the dormancy of these species. The lowest percentage of the impermeable achenes has been recorded inPotamogeton crispus.  相似文献   

19.
David J. Keil 《Brittonia》1974,26(1):30-36
Pectis minutiflora,P. papposa var.grandis, andP. purpurea var.sonorae are described as new. A new combination,P. purpurea var.lancifolia also is included. Chromosome counts (n = 12) are reported forP. papposa var.grandis andP. purpurea var.sonorae.  相似文献   

20.
The effect of different prey mite species on development of the immature stages and on survival and oviposition of adult predator femalePhytoseiulus longipes Evans was studied.P. longipes completed its development onTetranychus pacificus McGregor,Oligonychus punicae (Hirst), andPanonychus citri (McGregor), but not onPetrobia harti (Ewing). Females oviposited while feeding onT. pacificus andO. punicae, but not onP. citri orP. harti. The highest percent survival was observed onT. pacificus, followed byO. punicae andP. citri. The longevity ofP. longipes onP. harti (vial arenas) and on pollen (leaf arenas) was the same as that on leaves with no food. The provision of 10% sucrose solution and clover honey doubled the longevity ofP. longipes females compared with no food.  相似文献   

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