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1.
Phylogenetic and populational study of the Tuber indicum complex   总被引:1,自引:0,他引:1  
When examined using SEM, Chinese samples of Tuber indicum and T. sinense displayed the same ascospore ornamentation as that of T. pseudohimalayense, T. indicum, collected in India by Duthie in 1899, and samples renamed T. himalayense in 1988. The different authors who named the four taxa (T. indicum, T. himalayense, T. sinense, T. pseudohimalyense) described differences in the surface of the peridium which could be considered as usual variations within a single species. We consider T. indicum, T. himalayense, T. sinense and T. pseudohimalayense as one species, T. indicum. Within this T. indicum complex, according to ITS and β-tubulin sequences, there are two groups in China, which could be considered as geographical ecotypes. This study is the first to identify a genetic and phylogeographical structure within the Chinese Tuber species.  相似文献   

2.
The ecological impact of introduced biological control agents on native species of arthropods is a matter of considerable debate. This study investigated the ability of the non-native predatory mite Neoseiulus californicus to feed on the native Typhlodromus pyri and vice versa, as both species now co-occur in UK orchards. Typhlodromips montdorensis is a candidate for introduction into the UK as a glasshouse biological control agent. The ability of T. montdorensis to feed on the widely used N. californicus was investigated to identify possible intraguild predation, which might influence the effectiveness of either or both species as predators of Tetranychus urticae. Both N. californicus and T. pyri consumed larval stages of each other, but in choice experiments both showed a preference for T. urticae. Both N. californicus and T. montdorensis also fed on each other, but whereas N. californicus again showed a preference for T. urticae, T. montdorensis fed equally on T. urticae and N. californicus. Interactions between N. californicus and T. pyri and N. californicus and T. montdorensis are discussed in relation to their effectiveness as biological control agents in the glasshouse and the natural control of spider mite in the field.  相似文献   

3.
Collection of 1327 ticks sampled throughout Greece, Bulgaria, Romania and Croatia, from 211 tortoises belonging to three species, Testudo marginata Schoepff, T. graeca Linnaeus, and T. hermanni Gmelin, revealed the presence of four species of ixodid ticks, namely Hyalomma aegyptium (Linnaeus), Haemaphysalis sulcata Canestrini and Fanzago, H. inermis Birula and Rhipicephalus sanguineus (Latreille). Study confirmed the strong dominance of all life stages of H. aegyptium among ticks parasitizing west Palaearctic tortoises of genus Testudo Linnaeus. Furthermore, a considerable portion of ticks collected from tortoises in southwestern Bulgaria represent larvae and nymphs of H. sulcata. At the same area we collected as exception one larva and one nymph of H. inermis from a single specimen of T. hermanni. Our findings of four adults of R. sanguineus is the first record of this species from reptilian host. According to our results achieved on localities with syntopic occurrence of two tortoise species, T. marginata and T. graeca represent in the Balkans the principal hosts of H. aegyptium, whereas T. hermanni serves only as an alternative host in the areas close to range of either T. marginata or T. graeca.  相似文献   

4.
5 new taxa are described and illustrated; their position within the subgenus is discussed:T. hirta W. Till & L. Hromadnik,T. cotagaitensis L. Hromadnik,T. caliginosa W. Till, andT. gilliesii Baker subsp.polysticha W. Till & L. Hromadnik are members of a group includingT. myosura Grisebach exBaker,T. mandonii E. Morren exMez in DC.,T. retorta Grisebach exBaker em.Grisebach andT. andicola Gillies exBaker. T. brealitoensis L. Hromadnik is related toT. angulosa Mez in DC. but distinct and possibly of hybrid origin.
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5.
The responses of root aerobic respiration to hypoxia in three common Typha species were examined. Typha latifolia L., T. orientalis Presl, and T. angustifolia L. were hydroponically cultivated under both aerobic and hypoxic growth conditions to measure root oxygen consumption rates. Hypoxia significantly enhanced the root aerobic respiration capacity of the two deep-water species, T. orientalis and T. angustifolia, while it did not affect that of the shallow-water species, T. latifolia. T. angustifolia increased its root porosity and root mass ratio, while T. latifolia increased its root diameter under the hypoxic growth conditions. The relative growth rates in biomass of T. orientalis and T. angustifolia were 59 and 39% higher, respectively, under the hypoxic growth conditions than under the aerobic growth conditions. In contrast, that of T. latifolia did not differ between the two conditions. In T. orientalis and T. angustifolia, enhanced root aerobic respiration rates under the hypoxic growth conditions would have increased the nutrient uptake, and thus higher relative growth rates were obtained. For the deep-water species, T. orientalis and T. angustifolia, the root aerobic respiration capacity was enhanced, probably in order to maintain the generation of respiratory energy under hypoxia.  相似文献   

6.
Tick-borne diseases in horses are caused by the intraerythrocytic protozoan parasites Theileria equi and Babesia caballi. Although T. equi is highly endemic in Latin America, the New World vector of this important parasite is controversial. The aim of this study was to test the ability of nymph Amblyomma cajennense ticks acquire infection by T. equi following feeding on infected horses. Three experiments were performed: tick acquisition of T. equi from an experimentally infected horse, tick acquisition of T. equi from naturally infected foals and tick acquisition of T. equi from a chronically infected horse. A. cajennense adults were dissected and salivary glands were collected in aliquots. Methyl green pyronin staining of the salivary glands did not show the presence of hypertrophy of acini or cell nuclei normally suggestive of Theileria spp. infection. The pools of salivary glands were negative for Theileria DNA in nested PCR assays. Histopathological analysis failed to detect sporoblast and sporozoites of T. equi in salivary gland acini. This study was not able to observe infection of the A. cajennense by T. equi.  相似文献   

7.
Tetranychus evansi Baker and Pritchard and Tetranychus urticae Koch (Acari: Tetranychidae) are important pests of Solanaceae in many countries. Several studies have demonstrated that T. urticae is an acceptable prey to many predatory mites, although the suitability of this prey depends on the host plant. T. evansi, has been shown to be an unfavorable prey to most predatory mites that have been tested against it. The predator Phytoseiulus fragariae Denmark and Schicha (Acari: Phytoseiidae) has been found in association with the two species in Brazil. The objective of this work was to compare biological parameters of P. fragariae on T. evansi and on T. urticae as prey. The study was conducted under laboratory conditions at 10, 15, 20, 25 and 30°C. At all temperatures, survivorship was lower on T. evansi than on T. urticae. No predator reached adulthood at 10°C on the former species; even on the latter species, only about 36% of the predators reached adulthood at 10°C. For both prey, in general, duration of each life stage was shorter, total fecundity was lower and intrinsic rate of population increase (r m ) was higher with increasing temperatures. The slower rate of development of P. fragariae on T. evansi resulted in a slightly higher thermal requirement (103.9 degree-days) on that prey than on T. urticae (97.1 degree-days). The values of net reproduction rate (R 0), intrinsic rate of increase (r m ) and finite rate of increase (λ) were significantly higher on T. urticae, indicating faster population increase of the predator on this prey species. The highest value of r m of the predator was 0.154 and 0.337 female per female per day on T. evansi and on T. urticae, respectively. The results suggested that P. fragariae cannot be considered a good predator of T. evansi.  相似文献   

8.
The growth strategy of an emergent plant, Typha orientalis Presl, was examined in experimental ponds in comparison with two other Typha species distributed in Japan, Typha latifolia L. and Typha angustifolia L. T. orientalis showed the greatest ability of vegetative reproduction at the expense of growth in height. T. orientalis started to produce new ramets earlier than T. latifolia and T. angustifolia. These results suggest that T. orientalis should be a rather pioneer-like species and would be restricted to disturbed habitats.  相似文献   

9.
The phylogeny of the four genera of Aizoaceae subfamily Sesuvioideae (Sesuvium, Cypselea, Trianthema and Zaleya) is elucidated employing internal transcribed spacer (ITS) sequences and 23 morphological characters. Phylogenetic analysis based on ITS sequences and a combined molecular-morphological analysis provide largely congruent results. The monophyly of Sesuvioideae and its close relationship to Aizooideae s.l. and Mesembryanthemoideae is confirmed. Zaleya is placed within Trianthema and Cypselea within Sesuvium by ITS analysis, but in the combined analysis, Zaleya forms an unresolved polytomy with the two Trianthema clades and Cypselea, as well as two Sesuvium species, remain unresolved. Sesuvium sesuvioides and S. hydaspicum, previously treated as synonyms, are closely related, but molecular data do not support conspecifity. The Trianthema triquetra complex needs further intensive study because the African T. triquetra sample is closer to the NE African-Arabian T. sheilae than to Australian samples of T. triquetra. The close relationship of four species of Trianthema (T. patellitecta, T. rhynchocalyptra, T. megasperma, and T. pilosa) from Australia based on molecular data is supported morphologically by the exclusive possession of a well-developed indumentum in these taxa.  相似文献   

10.
Chromosome complements and 2C DNA amounts of six species ofTerminalia have been studied.Terminalia oliveri, T. myriocarpa andT. arjuna are diploid (2n = 24),T. chebula andT. bellirica are tetraploid (2n = 48),T. muelleri shows a triploid number (2n = 36). Two well demarcated groups of species are recognizable on the basis of chromosome length and 2C DNA values which range from 3.60 pg (T. oliveri) to 12.80 pg (T. bellirica) showing a 3.5-fold difference. Differences of DNA per basic genome or per chromosome are greatest (1.97-fold) betweenT. oliveri andT. arjuna. Two species groups (1)T. oliveri andT. chebula, and (2)T. myriocarpa, T. arjuna, T. muelleri, T. bellirica, therefore are well differentiated by DNA per basic genome, irrespective of polyploidy. The mean values of the two groups are 1.81 pg and 3.34 pg, respectively, showing a 1.84-fold difference. Within diploids and tetraploids there is 1.97-fold and 1.76-fold variation, respectively.  相似文献   

11.
王文采 《广西植物》2022,42(1):10-13
该文描述了自四川西部发现的毛茛科二新种,包括四川乌头属一新种,即泸定乌头(Aconitum ludingense W.T.Wang),此新种隶属于乌头属乌头亚属,以及四川唐松草属一新种,即狭药唐松草(Thalictrum stenantherum W.T.Wang),给出了此新种与其近缘种六脉萼唐松草之间的形态区别.  相似文献   

12.
The fresh waters of the Mekong basin are inhabited by five species of the pufferfish genusTetraodon Linnaeus, 1758 (sensu lato): the widely distributedT. leiurus Bleeker, 1851; two previously described species endemic to the Mekong,T. baileyi Sontirat, 1989 andT. suvattii Sontirat & Soonthornsathit, 1985; one new species endemic to the Mekong basins.Tetraodon baileyi has now been collected numerous times but only in or near rapids;T. abei, T. barbatus andT. suvattii are often but not exclusively associated with rapids or at least swift flowing streams; whileT. leiurus is found in almost all habitats except rapids.Tetraodon abei andT. barbatus are closely related toT. leiurus, from which they differ most strikingly in coloration.Tetraodon survattii differs from all of the others in having a strongly upturned mouth and light and dark stripes or spots radiating outwards from the eye.Tetraodon baileyi, the most distinctive Mekong pufferfish, has head and body more or less extensively covered with dermal cirri and is entirely scaleless.  相似文献   

13.
Here we describe the natural infection rate in China of Haemaphysalis qinghaiensis with four Piroplasma species, namely Theileria uilenbergi, T. luwenshuni, T. sinensis and Babesia motasi. Specifically, a nested PCR was designed based on 18S ribosomal RNA genes and its specificity and sensitivity were established. The result showed that 62 flat adult field H. qinghaiensis ticks (27 females and 35 males) out of 136 (55 females and 81 males) were infected by one or more parasites. All 62 (45.6%) were infected with T. uilenbergi; nine (five males and four females; 6.6%) were infected with T. luwenshuni; two (1.5%) females were infected with T. sinensis; and one (0.7%) male was infected with B. motasi. Twelve (19.4%) were infected with more than one pathogen. There was no significant difference in infection rate between males and females. The high figure 45.6% Theileria infection rate indicates the serious prevalence of theileriosis; while the presence of T. sinensis and B. motasi implies the potential existence of the corresponding diseases in the area studied.  相似文献   

14.
Tillandsia carminea is a new, morphologically and ecologically distinct species, related toT. stricta Solander, which occurs in the Serra dos Orgaos near Teresopolis, Brazil. It has been taken forT. rosea Lindley, but new investigations have shown thatT. rosea is a synonym toT. stricta and thatT. carminea is a good and distinct species.
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15.
Tamarix aphylla is an evergreen tree that has invaded the drawdown zone of Lake Mead, a large reservoir on the Lower Colorado River. We performed competition experiments between T. aphylla and T. ramosissima, and between T. aphylla and the native tree Salix gooddingii. Root:shoot ratios and biomass were higher in S. gooddingii than both Tamarix species, and T. ramosissima grew taller than T. aphylla and S. gooddingii when treatments with single plants and no competition were compared. Tamarix aphylla outcompeted the native S. gooddingii, but had competitive abilities that were slightly inferior to T. ramosissima. The competitive abilities of T. aphylla may and help explain why this species is not as widespread as its congeners, although because of T. aphylla's larger size, the species may be as serious a threat to native riparian ecosystems as T. ramosissima. These results indicate that management actions should be taken to ensure that T. aphylla does not further invade riparian ecosystems in the southwestern United States.  相似文献   

16.
Micromorphological investigation of the types, dimensions and distribution of characteristic trichomes in leaves and stems in Teucrium L. species (T. arduini L., T. chamaedrys L., T. flavum L., T. montanum L., T. polium L., and T. scordium L. subsp. scordioides Schreb.) distributed in Croatia was carried out as part of the taxonomical study of the genus Teucrium. Secretory types of hairs, peltate and capitate hairs were observed on the epidermis of stems and leaves of all investigated species. Non-secretory, acicular hairs were almost completely lacking on stems of T. scordium subsp. scordioides. Flagelliform hairs were not found in T. flavum and T. polium. Cladose hairs were present only in T. polium. The largest micromorphological variability was established between wild and cultivated samples of T. arduini and T. scordium subsp. scordioides, while cultivated and wild specimens of T. polium were almost identical. Differences were primarily observed in trichome dimensions and much less in micromorphological features.  相似文献   

17.
In choice test experiments on strawberry leaf disc arenas the phytoseiid mites Neoseiulus californicus and N. cucumeris were more effective than Typhlodromus pyri as predators of the phytophagous mites Tetranychus urticae and Phytonemus pallidus. There were no preferences shown for either prey by any of these predators. In multiple predator leaf disc experiments both Phytoseiulus persimilis and N. cucumeris significantly reduced numbers of T. urticae eggs and active stages; this effect was seen when the two species were present alone or in combination with other predator species. Neoseiulus californicus was less effective at reducing T. urticae numbers, and T. pyri was not effective; no interaction between predator species was detected in these experiments. When T. urticae alone was present as prey on potted plants, P. persimilis and N. californicus were the only phytoseiids to significantly reduce T. urticae numbers. These two predator species provided effective control of T. urticae when P. pallidus was also present; however, none of the predators reduced numbers of P. pallidus. There were no significant negative interactions when different species of predators were present together on these potted plants. In field experiments, releases of both P. persimilis and N. cucumeris significantly reduced T. urticae numbers. However, there was a significant interaction between these predator species, leading to poorer control of T. urticae when both species were released together. These results show the importance of conducting predator/prey feeding tests at different spatial scales.  相似文献   

18.
A clinical isolate from a black-dot ringworm lesion of a 28-year-old female Japanese was investigated by morphological and biochemical analyses as well as molecular analyses. The isolate grew well onthiamine enriched agar and did not produce violetpigment, macroconidia or microconidia on Sabouraud's dextrose agar. Approximately 620-bp genomic DNA fragments of the CHS1 gene were amplified from Trichophyton mentagrophytes, T. rubrum, T. tonsurans and T. violaceum by polymerase chain reaction (PCR) and sequenced. The chitin synthase 1 (CHS1) nucleotide sequences of the clinical isolate showed more than 97% similarity to that of T. violaceum and less than 96% similarity to that of T. mentagrophytes, T. rubrum and T. tonsurans. The phylogenetic analysis of their sequences revealed that the clinical isolate was genetically close to T. violaceum and distinct from T. mentagrophytes, T. rubrum and T. tonsurans. Therefore, the isolate was confirmed as T. violaceum by mycological examination and molecular analyses. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

19.
分布在我国西南地区的横坑切梢小蠹,云南切梢小蠹和短毛切梢小蠹同域危害寄主云南松,给林业生产带来巨大损失。为探讨同域切梢小蠹种群在共存下对其空间分布格局的影响,采用传统聚集指标法和地统计学方法研究了三者在梢转干期不同受害云南松纯林树冠中的空间分布型。结果表明重度受害样地中云南切梢小蠹种群密度显著高于横坑切梢小蠹,在轻度受害样地则相反;传统聚集指标法结果显示同域共存的3种切梢小蠹种群在不同受害程度云南松中均为聚集分布,横坑切梢小蠹和云南切梢小蠹聚集是由环境因素和昆虫本身的聚集习性引起;地统计学结果表明除重度受害样地中短毛切梢小蠹呈随机分布外,其余切梢小蠹在不同种群密度下均呈聚集分布;除重度受害样地横坑切梢小蠹外,其他小蠹的空间依赖范围为4.01—7.45 m。横坑切梢小蠹和云南切梢小蠹在不同受害林分中拟合的半变异函数模型在球形模型和高斯模型之间转换。同域共存关系不影响不同种群密度下的切梢小蠹种群空间分布类型,但影响其半变异函数模型和理论参数。  相似文献   

20.
Male and pupa of Tanytarsus calorifontis sp. n. are described. Diagnoses, hypopygium drawings for the examined species and distribution are given for: Tanytarsus akantertiusSasa & Kamimura, T. angulatus Kawai, T. atagoensis Tokunaga,T. bathophilusKieffer, T. boninensis Tokunaga, T. formosae (Kieffer), T. formosanusKieffer, T. infundibulusChaudhuri & Datta, T. kikuchiiSasa, Kawai & Ueno, T. konishii Sasa & Kawai, T. mcmillani Freeman, T. mendax Kieffer, T. miyakobrevis Sasa & Hasegawa, T. monstrosus Chaudhuri et al., T. ogasaquartus Sasa & Suzuki, T. ogasatertius Sasa & Suzuki, T. okuboi Sasa & Kikuchi, T. oscillans Johannsen, T. ovatus Johannsen, T. oyamai Sasa, T. pollexus Chaudhuri & Datta, T. shouautumnalis Sasa, T. shoudigitatus Sasa, T. takahashii Kawai & Sasa, T. tamaundecimus Sasa, T. tonebeceus Sasa & Tanaka, T. tusimatneousSasa & Suzuki, T. unagiseptimus Sasa, T. uraiensis Tokunaga, T. yakuheiusSasa & Suzuki and T. yunosecundus Sasa. Tanytarsus ikiefeus Sasa & Suzuki is a new junior synonym of T. konishii. Tanytarsus ikifegeus Sasa & Suzuki, T. miyakoflavus Sasa & Hasegawa,T. oyabepallidus Sasa, Kawai & Ueno, T. simantoopeus Sasa et al. and T. tusimatheius Sasa & Suzuki are new junior synonyms of T. okuboi. Tanytarsus nippogregarius Sasa & Kamimura is a new junior synonym of T. bathophilus. Tanytarsus cultellus Chaudhuri & Datta and T. sibafegeus Sasa et al. are new junior synonyms of T. oscillans.Tanytarsus insulus (Guha et al., 1985) is a new junior synonym of T. ovatus. Tanytarsus sakishimanus Sasa & Hasegawa, T. vinculus Chaudhuri et al., T. parvistylus Chaudhuri & Datta, T. fusciabdominalis Guha et al. and T. euformosanus Kikuchi & Sasa are new junior synonyms of T. formosanus. Tanytarsus tsutaprimus Sasa, T. tokarajekeus Sasa & Suzuki, T. tusimatlemeus Sasa & Suzuki, T. tusimatopeus Sasa & Suzuki and T. yakugeheuus Sasa & Suzuki are new junior synonyms of T. shouautumnalis. Tanytarsus togasiroidus Sasa & Okazawa is a new junior synonym of T. shoudigitatus. Tanytarsus tusimatjekeus Sasa & Suzuki and T. tusimatkeleus Sasa & Suzuki are new junior synonyms of T. akantertius, and Tanytarsus tusimatpequeus Sasa & Suzuki is a new junior synonym of T. tusimatneous. Virgatanytarsus toganiveus (Sasa & Okazawa), Cladotanytarsus utonaiquartus (Sasa) and Zavrelia tusimatijeus (Sasa & Suzuki), all previously placed in Tanytarsus, are new combinations.  相似文献   

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