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1.
Leonard andHegmon (1987) compare a series of dental metrics of ‘Australopithecus afarensis Johanson, White, andCoppens, 1978’ with criteria for modern apes, to test the hypothesis that ‘A. afarensis’ represents a single species. They also compare the morphology of the lower third premolar. The dental breadth of ‘A. afarensis’ shows a wide range of variation, particularly in the lower third premolar morphology which displays greater variation than in modern apes—yet the study concludes that the single species hypothesis cannot be rejected. The study is flawed by applying criteria for pongids inappropriate for a hominid. When ‘A. afarensis’ is compared with criteria for hominids, the range of variation in dental size, breadth, and third premolar morphology is greater than that in any hominid species. The single species hypothesis is, therefore, once again rejected. Moreover, the name ‘A. afarensis’ is preoccupied byPraeanthropus africanus (Weinert) and must be dropped.  相似文献   

2.
‘English’ ivy (Hedera spp.) is a complex of invasive plant pests that are separated into several distinct taxa. To better understand the invasion by ivy of Pacific Northwest native forests, we investigated the taxonomic identity of 58 selected invasive populations in the Pacific Northwest. Random amplified polymorphic DNA (RAPD) markers revealed that 83% of the 119 samples from invading populations were derived form H. hibernica (Kirchner) Bean, which has been frequently sold as English ivy, although this apparently is an incorrect common name. It is used widely in urban landscapes in the Northwest. The remaining 20 samples were either H.helix ‘California,’ ‘Pittsburgh,’ ‘Star,’ other cultivars not investigated in the study or possible hybrids.  相似文献   

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4.
The recognition of species proceeds by two fairly distinct phases: (1) the sorting of individuals into groups or basic taxa (‘discovery’) (2) the checking of those taxa as candidates for species-hood (‘justification’). The target here is a rational reconstruction of phase 1, beginning with a discussion of key terms. The transmission of ‘meaning’ is regarded as bimodal: definition states the intension of the term, and diagnosis provides a disjunction of criteria for recognition of its extension. The two are connected by a spectrum, with purely theoretical definition at one pole and purely ‘operational’ diagnosis at the other, with the more operational elements explained by the more theoretical. The current plethora of species concepts provides a good example. Accepting the Ghiselin–Hull thesis, that a species is an individual, a basic taxon is therefore also an individual with organisms as its parts. In a generalised synchronic individual its parts are conceptually integrated by an integrating principle (IP), which consists of a relation applying within a plan or rule. Fully developed, such an IP ensures the maximisation of the information content of the individual. A diachronic individual is then the set of its component synchronic parts, and its IP is provided by near-identity in an appropriate space-time (not necessarily physical). The integration of parts of an individual is illuminated by Gasking's concept of a proper group (in this case a chain-group), whose members are related by the relation serially fitting together with, the IP completed by an appropriate plan or rule. Gasking also applied the term cluster to a proper group persisting over a substantial period of time, individuated by any member acting as focus. A basic taxon is therefore a cluster of individuals, integrated by the relation significantly taxonomically similar and the rule in character-space-time. The nature of those concepts is discussed and defended. A species will inherit certain of the attributes of the preceding basic taxon (taxa). In at least the synchronic version its parts (individuals) will resemble each other significantly, providing the intuitive applicability of ‘members of’ and ‘instances of’ a species. Also, the notion that a species’ name is given by pure ostension, via a name-bearer (holotype) is empirically incoherent: the name cannot be applied in practice without an appropriate set of diagnostic traits.  相似文献   

5.
Sulfur is the oldest and most widely used fungicide in the vineyards of California, where it is used for control of powdery mildew (Uncinula necator [Schw.] Burr). For decades, sulfur use has been associated with outbreaks of Tetranychus pacificus McGregor (Acari: Tetranychidae) on cultivated grapes in the San Joaquin Valley. I undertook large-scale field studies to test this association, to evaluate the impact of sulfur on Galendromus occidentalis (Nesbit) (Acari: Phytoseiidae), a major predator of T. pacificus, and to determine if timing of sulfur applications with respect to grape bloom has an impact on T. pacificus density. The studies took place in a 32 ha vineyard in Fresno County, and all fungicide applications were made with commercial-scale equipment. In 1998 a ‘high sulfur’ treatment, a combination of wettable sulfur and sulfur dust, was compared to ‘low sulfur,’ in which demethylation inhibitor (DMI) fungicides partially substituted for sulfur. In 1999 treatments were ‘sulfur,’ ‘DMI,’ ‘sulfur pre-bloom’ (here sulfur was applied prior to grape bloom, in late May, and then DMIs were applied until mid-season) and ‘sulfur post-bloom’ (the reverse of ‘sulfur pre-bloom’). In each year, the T. pacificus population increase came after the end of fungicide applications, and results clearly show a relationship between sulfur use and T. pacificus density. In 1998, mean T. pacificus density was 2.7 times higher and mean G. occidentalis density 2.5 times higher in ‘high sulfur’ compared to ‘low sulfur.’ In 1999, the highest T. pacificus counts were in the ‘sulfur’ and ‘sulfur pre-bloom’ treatments, 4.8 times higher than ‘sulfur post-bloom’ and 2 times higher than ‘DMIs.’ Density of G. occidentalis was 2.3 times as high in ‘sulfur’ or ‘sulfur pre-bloom’ than ‘DMIs.’ The predator/prey ratio was not significantly different among treatments in 1998, but in 1999 it was highest in the ‘sulfur pre-bloom’ treatment. In 1999, density of Homeopronematus anconai (Baker) (Acari: Tydeidae) was 2.7 times higher in ‘sulfur pre-bloom’ compared to ‘sulfur,’ and higher by 2.7 times in ‘DMI’ compared to ‘sulfur post-bloom,’ suggesting a negative effect of sulfur on this tydeid. These results do not support the hypotheses that the cause of the increase in T. pacificus density is due to negative effects of sulfur on phytoseiids or tydeids. Rather, it appears that a plant-based explanation is likely, first, because of the differences in pre-bloom versus post-bloom sulfuring, and second, because of the long lag time between the end of the sulfur applications and the corresponding increase in spider mite density.  相似文献   

6.
 Random amplified polymorphic DNA (RAPD) and genomic in situ hybridization (GISH) methods have been used to verify the hybridogenic origin and to identify the parental species of some ornamental cultivars in the subgenus Melanocrommyum of the genus Allium. The cultivars had been selected from seed obtained after uncontrolled pollination in breeders’ fields. The combination of GISH analysis with RAPD markers is very suitable for testing the hybridogenic origin of plants and to ascertain the parental species of the hybrids in such cases. As suspected, A. macleanii and A. cristophii are the parental species of ‘Globemaster’. The parental species of cultivar ‘Globus’ are A. karataviense and A. stipitatum, and not A. cristophii and A. giganteum as has been assumed on morphological grounds. Cultivars ‘Lucy Ball’ and ‘Gladiator’ are of hybrid origin, though only one of the parental species, A. hollandicum, could be confirmed. The cultivars ‘Purple Sensation’, ‘Mount Everest’, ‘White Giant’, ‘Michael H. Hoog’ and ‘Mars’ are not hybrids since neither GISH nor RAPD suggest the presence of a second genome. ‘Purple Sensation’ belongs to A. hollandicum, ‘Mount Everest’, ‘White Giant’ and ‘Mars’ to A. stipitatum,‘Michael H. Hoog’ to A. rosenorum. Received: 3 July 1997 / Accepted: 9 October 1997  相似文献   

7.
Phytophthora fragariae var. fragariae is the causal agent of red stele (red core) root rot in strawberry (Fragaria spp.). The inheritance of resistance to one isolate of this fungus was studied in 12 segregating populations of F.×ananassa derived from crosses between four resistant cultivars (‘Climax’, ‘Redgauntlet’, ‘Siletz’, and ‘Sparkle’) and three susceptible cultivars (‘Blakemore’, ‘Glasa’, and ‘Senga’ Sengana’). The analysis clearly supports the hypothesis of a single segregating dominant resistance gene. It is proposed that this gene be designated Rpf2. Received 12 November 1996 / Accepted: 22 November 1996  相似文献   

8.
 We used graphical genotyping and linkage analyses with molecular markers to determine the chromosomal location of the rice stripe disease resistance gene, Stv-b i . The stripe resistance gene from the indica rice (Oryza sativa) cv ‘Modan’ was introgressed into several Japanese rice varieties. We found 4 RFLP markers in ‘Modan’, five susceptible parental rice varieties (‘Norin No. 8’, ‘Sachihikari’, ‘Kanto No. 98’, ‘Hokuriku No.103’ and ‘Koganebare’) and four resistant progeny varieties (‘St. No. 1’, ‘Aichi No. 6’, ‘Aoisora’ and ‘Asanohikari’). Graphical genotyping of the resistant progeny revealed a chromosomal segment ascribable to ‘Modan’ and associated with stripe resistance. The chromosomal segment from ‘Modan’ was located at 35.85 cM on chromosome 11. Linkage analysis using 120 F2 individuals from a cross between ‘Koshihikari’ (susceptible) and ‘Asanohikari’ (resistant) revealed another 8 RFLP markers in the same chromosome. We performed a bioassay for rice stripe resistance in F3 lines of the F2 individuals using infective small brown planthoppers and identified an 1.8-cM segment harboring the rice stripe disease resistance gene, Stv-b i , between XNpb220 and XNpb257/ XNpb254. Furthermore, Stv-b i was linked by 0.0 cM to a RFLP marker, ST10, which was developed on the basis of the results of RAPD analysis. These DNA markers near the Stv-b i locus may be useful in marker-assisted selection and map-based cloning of the Stv-b i gene. Received: 26 September 1997 / Accepted: 4 November 1997  相似文献   

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10.
‘SI1300’ is a self-incompatible Brassica napus line generated by introgressing an S haplotype from B. rapa ‘Xishuibai’ into a rapeseed cultivar ‘Huayou No. 1’. Five S-locus specific primer pairs were employed to develop cleaved amplified polymorphic sequences (CAPS) markers linked the S haplotype of ‘SI1300’. Two segregating populations (F2 and BC1) from the cross between ‘SI1300’ and self-compatible European spring cultivar ‘Defender’, were generated to verify the molecular markers. CAPS analysis revealed no desirable polymorphism between self-incompatible and self-compatible plants. Twenty primer pairs were designed based on the homology-based candidate gene method, and six dominant sequence characterized amplified region (SCAR) markers linked with the S-locus were developed. Of the six markers, three were derived from the SRK and SP11 alleles of class II B. rapa S haplotypes and linked with S haplotype of ‘SI1300’. The other three markers were designed from the SLG-A10 and co-segregated with S haplotype of ‘Defender’. We successfully combined two pairs of them and characterized two multiplex PCR markers which could discriminate the homozygous and heterozygous genotypes. These markers were further validated in 24 F3 and 22 BC1F2 lines of ‘SI1300 × Defender’ and another two segregating populations from the cross ‘SI1300 × Yu No. 9’. Nucleotide sequences of fragments linked with S-locus of ‘SI1300’ showed 99% identity to B. rapa class II S-60 haplotype, and fragments from ‘Defender’ were 97% and 94% identical to SLG and SRK of B. rapa class I S-47 haplotype, respectively. ‘SI1300’ was considered to carry two class II S haplotypes and the S haplotype on the A-genome derived from B. rapa ‘Xishuibai’ determines the SI phenotype, while ‘Defender’ carry a class I S haplotype derived from B. rapa and a class II S haplotype from B. oleracea. SCAR markers developed in this study will be helpful for improving SI lines and accelerating marker-assisted selection process in rapeseed SI hybrid breeding program.  相似文献   

11.
In this work, we have identified a chimeric pentatricopeptide repeat (PPR)-encoding gene cosegregating with the fertility restorer phenotype for cytoplasmic male sterility (CMS) in radish. We have constructed a CMS-Rf system consisting of sterile line ‘9802A2’, maintainer line ‘9802B2’ and restorer line ‘2007H’. F2 segregating population analysis indicated that male fertility is restored by a single dominant gene in the CMS-Rf system described above. A PPR gene named Rfoc was found in the restorer line ‘2007H’. It cosegregated with the fertility restorer in the F2 segregating population which is composed of 613 fertile plants and 187 sterile plants. The Rfoc gene encodes a predicted protein 687 amino acids in length, comprising 16 PPR domains and with a putative mitochondrial targeting signal. Sequence alignment showed that recombination between the 5′ region of Rfob (EU163282) and the 3′ region of PPR24 (AY285675) resulted in Rfoc, indicating a recent unequal crossing-over event between Rfo and PPR24 loci at a distance of 5.5 kb. The sterile line ‘9802A2’ contains the rfob gene. In the F2 population, Rfoc and rfob were observed to fit a segregation ratio 1:2:1 showing that Rfoc was allelic to Rfo. Previously we have reported that a fertile line ‘2006H’, which carries the recessive rfob gene, is able to restore the male fertility of CMS line ‘9802A1’ (Wang et al. in Theor Appl Genet 117:313–320, 2008). However, here when conducting a cross between the fertile line ‘2006H’ and CMS line ‘9802A2, the resulting plants were male sterile, which shows that sterile line ‘9802A2’ possesses a different nuclear background compared to ‘9802A1’. Based on these results, the genetic model of fertility restoration for radish CMS is also discussed.  相似文献   

12.
The purpose of this paper is to investigate the differential responses of flower opening to ethylene in two cut rose cultivars, ‘Samantha’, whose opening process is promoted, and ‘Kardinal’, whose opening process is inhibited by ethylene. Ethylene production and 1-aminocyclopropane-1-carboxylate (ACC) synthase and oxidase activities were determined first. After ethylene treatment, ethylene production, ACC synthase (ACS) and ACC oxidase (ACO) activities in petals increased and peaked at the earlier stage (stage 3) in ‘Samantha’, and they were much more dramatically enhanced and peaked at the later stage (stage 4) in ‘Kardinal’ than control during vasing. cDNA fragments of three Rh-ACSs and one Rh-ACO genes were cloned and designated as Rh-ACS1, Rh-ACS2, Rh-ACS3 and Rh-ACO1 respectively. Northern blotting analysis revealed that, among three genes of ACS, ethylene-induced expression patterns of Rh-ACS3 gene corresponded to ACS activity and ethylene production in both cultivars. A more dramatic accumulation of Rh-ACS3 mRNA was induced by ethylene in ‘Kardinal’ than that of ‘Samantha’. As an ethylene action inhibitor, STS at concentration of 0.2 mmol/L generally inhibited the expression of Rh-ACSs and Rh-ACO in both cultivars, although it induced the expression of Rh-ACS3 transiently in ‘Kardinal’. Our results suggests that ‘Kardinal’ is more sensitive to ethylene than ‘Samantha’; and the changes of Rh-ACS3 expression caused by ethylene might be related to the acceleration of flower opening in ‘Samantha’ and the inhibition in ‘Kardinal’. Additional results indicated that three Rh-ACSs genes were differentially associated with flower opening and senescence as well as wounding.  相似文献   

13.
Four new and one unidentified species of Neohaliotrema Yamaguti, 1965 were obtained from the gills of the Indo-Pacific sergeant Abudefduf vaigensis (Quoy & Gaimard) off Pulau Langkawi, Malaysia. The five species, N. malayense n. sp., N. bombini n. sp., N. andamanense n. sp., N. parvum n. sp. and an unidentified Neohaliotrema sp. (similar to N. macracanthum Zhukov, 1976), are described and distinguished based mainly on features of the haptor. Species of this genus are divisible into two groups, the ‘maomao group’, with two pairs of morphometrically modified ‘marginal’ hooks and a fenestrated haptor, and the ‘gracile group’, with morphologically similar marginal hooks and an entire haptor. With the exception of N. bombini n. sp., the species described fit within the ‘maomao group’. It is suggested that the more complex Neohaliotrema species of the ‘maomao group’ have modified hooks 1 and 2 on a haptoral ‘isthmus’ between two large apertures, i.e. ‘windows’, whereas the less complex species lacking these features are those of the ‘gracile group’. Neohaliotrema spp. have only a single pair of pigmented eye-spots. A fenestrated haptor is unique to the Neohaliotrema spp. of the ‘maomao group’. The generic diagnosis of Neohaliotrema is amended to include new data and a key to its known species is presented.  相似文献   

14.
Mating disruption treatments for the tufted apple bud moth (TABM),Platynota idaeusalis (Walker), were tested in small plot trials in apple orchards in Pennsylvania. Treatments were evaluated by fruit injury and by capture of male TABM in traps baited with synthetic pheromone sources or virgin females. The TABM pheromone is a two component isomeric blend ofE-11-tetradecen-1-ol (E11-14:OH) andE-11-tetradecenyl acetate (E11-14:Ac). A 50∶50 ratio of these two components was used in standard monitoring septa and in mating disruption treatments released from either hollow fibers (‘fiber’) or PVC tubes (‘PVC’). Other pheromone blends tested included a 90∶10 ratio of E11-14: Ac and E11-14:OH (‘EAc’) and its reverse (‘EOH’), mixture ‘EAc’ with 30% of the Z-isomers (‘low AEc’), and a blend similar to the preceding with 2% Z9-12:Ac (‘generic’). These other blends were released from multi tube tape (‘tape’) or Shin-Etsu type rope (‘rope’) dispensers. Seasonal dispenser release rate in mg ha−1 h−1 was ca. 30 for the ‘rope’ dispensers, 14 for ‘PVC’ and 6 for ‘fiber’. ‘EAc-tape’ and ‘EOH-tape’ were equally effective in reducing catches of males in traps baited with synthetic lures and in traps baited with virgin females. Both treatments also reduced fruit injury. ‘EAc-rope’, ‘fiber’ and ‘PVC’ also were generally effective; whereas, the ‘low EAc’ and ‘generic’ treatments reduced trap capture less than 90% and did not reduce fruit injury. Dispenser density was positively correlated with reduction in trap capture for the ‘low EAc-rope’ and ‘genericrope’ treatments. Traps loaded with ‘fiber’ dispensers captured more male TABM than the other treatments in non-pheromone permeated environments. Trap capture of other tortricids was reduced in pheromone treatments. ‘EAc-rope’ and the ‘TABM’ treatments provided mean (s.e.) percent reduction in trap catch of 99.5 (0.4) and 42.9 (10.1), respectively, for the redbanded leafroller,Argyrotaenia velutinana (Walker), and 90.4 (6.8) and 90.4 (1.3), respectively, for the obliquebanded leafroller,Choristoneura rosaceana (Harris).  相似文献   

15.
An incompletely dominant gene conferring resistance to Puccinia hordei, Rph14, identified previously in an accession of Hordeum vulgare, confers resistance to all known pathotypes of P. hordei in Australia. Knowledge of the chromosomal location of Rph14 and the identification of DNA markers closely linked to it will facilitate combining it with other important leaf rust resistance genes to achieve long lasting resistance. The inheritance of Rph14 was confirmed using 146 and 106 F3 lines derived from the crosses ‘Baudin’/‘PI 584760’ (Rph14) and ‘Ricardo’/‘PI 584760’ (Rph14), respectively. Bulk segregant analysis on DNA from the parental genotypes and resistant and susceptible DNA bulks using DArT markers located Rph14 to the short arm of chromosome 2H. DArT marker bPb-1664 was identified as having the closest genetic association with Rph14. PCR based marker analysis identified a single SSR marker, Bmag692, linked closely to Rph14 at a map distance of 2.1 and 3.8 cm in the ‘Baudin’/‘PI 584760’and ‘Ricardo’/‘PI 584760’ populations, respectively.  相似文献   

16.
Fourteen of 200Lactobacillus isolates from African fermented foods,viz. ‘wara’, ‘kenkey’, ‘ugba’, ‘ogi’, ‘kunuzarki’, ‘fufu’ and ‘iru’ were found to produce bacteriocins againstL. plantarum and only three bacteriocinogenic isolates inhibited some of the food pathogens. Plasmid analysis of the 14 bacteriocin-producing lactobacilli showed that only 5 isolates harbored plasmids ranging in size from 3.1 to 55.5 kb.  相似文献   

17.
Eight native Iranian almond species from three sections, ‘Euamygdalus’ (Prunus communis; Prunus eleagnifolia and Prunus orientalis); ‘Lycioides’ (Prunus lycioides and Prunus reuteri) and ‘Spartioides’ (Prunus arabica, Prunus glauca and Prunus scoparia) were in vitro screened for drought tolerance using sorbitol and polyethylene glycol (PEG) as an osmoticum. Different levels of water stress were induced using five concentrations of either sorbitol or polyethylene glycol in Woody Plant Medium (WPM). Water potential of various media ranged from −0.80 to −2.05 MPa and water stress in culture medium adversely affected plantlet growth. Wild species from ‘Spartioides’ were less affected than ‘Lycioides’ and ‘Euamygdalus’. At the same level of water potential, sorbitol had lower adverse effects than PEG; the latter being severe. Prunus × sorbitol and Prunus × PEG interactions were significant. At 0.2 M sorbitol and 0.003 M PEG, ‘Spartioides’ produced significantly more roots with higher total root length and root volume, as well as root-dry weight than those of ‘Lycioides’ and ‘Euamygdalus.’ It is concluded that in vitro screening of native Iranian almond species under specific and limited water-stress conditions may provide a system for effectively differentiating the wild species of almond for their expected root mass production under field conditions.  相似文献   

18.
Summary Anthers and ovaries of six grapevine cultivars (three Vitis vinifera L., two V × Labruscana L. H. Bailey, and one complex hybrid) were extracted from flower buds over 2 yr and cultured on three media reported to promote somatic embryogenesis in Vitis tissues. The highest percent embryogenesis from the hybrid ‘Chancellor’ and V. vinifera ‘Chardonnay’, ‘Merlot’, and ‘Pinot Noir’ occurred on medium C [Nitsch and Nitsch, 1969, basal medium with 3.0% (w/v) sucrose, 0.01% (w/v) inositol. 0.3% (w/v) Phytagel, 2.5 μM 2.4-dichlorophenoxyacetic acid, 2.5μM β-naphthoxyacetic acid, 5.0μM N-(2-chloro-4-pyridyl)-N′-phenylurea, and 0.05% (w/v) glutamine]. Regardless of the media, the labrusca cultivars ‘Concord’ and ‘Niagara’ produced soft non-embryogenic callus that was sometimes mixed with well-developed somatic embryos. Nine vinifera genotypes were further tested for several different years on medium C. Embryogenic cultures suitable for transformation were obtained from all genotypes in more than 1 yr. The average percent embryogenesis from ovaries was 7-fold higher than from anthers. There was significant annual variation in percent embryogenesis, demonstrating the need for media comparisons to be replicated for more than one season. Suspension cultures suitable for use in genetic transformation were initiated from ‘Chardonnay’, ‘Merlot,’ and ‘Pinot Noir’ pro-embryogenic masses. ‘Chardonnay’ suspension cultures plated and grown under conditions developed for recovery of plants after biolistic transformation yielded approximately 500 non-transformed embryos per plate after 4 mo. of culture, with 68.6% of the embryos converting to plants. This is the first reported protocol for embryogenesis from ‘Concord,’ ‘Cabernet Franc,’ and ‘Pinot Noir’ grapevines.  相似文献   

19.
The compositions of leaf monoterpenoids from 11 species in the Juniperus section (Juniperus chinensis var. chinensis,J. virginiana, J. communis var. montana,J. rigida, J. chinensis var. globosa,J. chinensis var. sargentii,J. chinensis ‘Kaizuka Variegata’,J. squamata ‘Wilsonii’,J. x media ‘Shimpake’,J. x media ‘Plamosa Aurea’, andJ. squamata ‘Aloderi’) were comparatively analyzed by GC-MS. Of the 24 compounds identified, α-pinene, myrcene, limonene, terpinolene, and bornyl acetate were common to all, but particular combinations differed remarkably among taxa. The simplest composition (eight compounds) was found in.J, chinensis var. chinensis; the most complex (19 compounds), inJ. x media ‘Shimpake’. Cluster analysis generated four distinctive clades within the Juniperus section. The minimum spanning network revealed thatJ. squamata ‘Wilsonii’ andJ. x media ‘Shimpake’ were most similar in their chemical makeup.  相似文献   

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