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1.
小麦温型现象研究   总被引:64,自引:1,他引:64  
通过多年来用红外技术对不同品种小麦群体温度进行连续观测,结果发现,小麦具有温型现象.不同温度型的小麦在外部和内部性状上各有一些鲜明特点.冷型小麦的许多重要性状较暖型小麦为优.功能叶的功能期长10.8%,每株根数多20条,旗叶的叶绿素含量、蒸腾率和净光合率分别高出0.1389g·100g-1·FW、0.0035mol·m-2·s-1和4.71μmol·m-2·s-1.由此可以认为,温度型和小麦的一系列重要性状密切相关.  相似文献   

2.
Two new parthenogenetic species of Longidorus were found in Arkansas. Longidorus grandis n. sp. is characterized by its body (5.80-8.24 mm), slightly offset head, head width 20-27 µm, odontostyle 86-100 µm, guide ring 26-35 µm posterior to the anterior end, short conoid to mammiliform tail. Longidorus grandis n. sp. is similar to L. vineacola Sturhan &Weischer, 1964; L. lusitanicus Macara, 1985; L. edmundsi Hunt &Siddiqi, 1977; L. kuiperi Brinkman, Loof &Barbez, 1987; L. balticus Brzeski, Peneva &Brown, 2000; L. closelongatus Stoyanov, 1964; and L. seinhorsti Peneva, Loof &Brown, 1998. Longidorus paralongicaudatus n. sp. is characterized by its body length (2.60-5.00 µm), anteriorly flattened and offset head region 13-18 µm wide, odontostyle length 92-127 µm, guide ring 21-30 µm posterior to the anterior end, tail elongate-conical, and c'' = 1.2-2.6. Longidorus paralongicaudatus n. sp. most closely resembles L. longicaudatus Siddiqi, 1962; L. socialis Singh &Khan, 1996; L. juvenilis Dalmasso, 1969; and L. curvatus Khan, 1986.  相似文献   

3.
A strain of Aspergillus sp. is described and proposed as a new species under the name ‘Aspergillus insulicola sp. nov.’ Montemayor & Santiago, 1973. This strain was isolated from soil samples taken in ‘Aves Island’ during a scientific expedition. — Aves Island, situated at 15°, 40′, 42″ N and 63°, 36′, 47″ W, about 665 Km of the coast of Venezuela, has very special ecological conditions. Due to its smallness: 550 m long and 40 to 120 m across and to its low profile only 3 m over sea level, it is swept by the sea during the periodical storms and hurricanes in the area. It has thus a very interesting fauna and flora. We took a series of soil samples to study its mycological flora. Forty samples were inoculated by dilution method. In this first paper a species is described and proposed as a new species because of its macroscopic and microscopic characteristics, as well as by its biological properties, under the name ‘Aspergillus insulicola sp. nov.’. In its study we have tried to follow as closely as possible the methods recommended by Kennet B. Raper & Dorothy Fenell, world authorities on the genera Aspergillus and Penicillium. The strain is being kept in USB under the number T1, and has been sent to ATCC & CBSC to be incorporated in their collections.  相似文献   

4.
Three new benthic, photosynthetic dinoflagellate species, Prorocentrum norrisianum, Prorocentrum tropicalis, and Prorocentrum reticulatum, from floating detritus and coral rubble of Central America are described from scanning electron micrographs. Species were identified based on shape, size, surface micromorphology, thecal plate ornamentation, and architecture of the periflagellar area and intercalary band. Cells of P. norrisianum are ovate with a cell size of 20–25 μm long and 13–16 μm wide. The theca is delicate, its surface smooth, pores species specific with 95 to 105 pores per valve. Pores are round with a diameter of about 0.1 μm. The periflagellar area is V-shaped, located on the right valve in a shallow depression. It has no ornamentation. The flagellar and auxiliary pores are unequal in size. The intercalary band is smooth. Prorocentrum tropicalis cells are ovoid, 50–55 μm long and 40–45 μm wide in valve view with maximum width behind the middle region, narrow at the anterior end. The periflagellar area, situated in the right valve, is a V-shaped wide triangle with a deeply indented depression; the left valve exhibits a flat ridge. The periflagellar area is unornamented, and the flagellar and auxiliary pores are unequal in size. The valve surface is rugose with evenly distributed valve poroids. Each poroid appears to have a small dome in the center. The intercalary band is rimlike around the cell margin, granulated, and horizontally striated. Prorocentrum reticulatum cells are oblong in valve view; cells are 55–60 μm long and 40–45 μm wide. Thecal surface is reticulated; it is composed of a labyrinth of ridges with alternating depressions that vary in size and shape. Each depression has a narrow, oblong-kidney-shaped opening about 0.6 μm long. The periflagellar area is a deep, V-shaped triangle. The right valve of P. reticulatum is excavated, and contains a large flagellar pore and a smaller auxiliary pore surrounded by a narrow apical collar. The left valve margin exhibits a curved flat ridge. The intercalary band is smooth.  相似文献   

5.
Two new amphimictic species of Longidorus were found in Arkansas. Longidorus biformis n. sp., found in the rhizosphere of hardwood trees along streams in sandy soil in 14 Arkansas locations, is characterized by its long body (5.42-9.50 mm), wide expanded flattened head end, head width 20.0 to 26.0 µm, odontostyle 96 to 125 µm, guide ring 29 to 38 µm posterior to the anterior end, elongate conoid tail, and c'' = 0.9-2.1. Females with 2 to 11 vetromedian supplement-like structures were found in 2 of 14 populations of this new species. Longidorus biformis n. sp. is closest to L. seinhorsti Peneva, Loof &Brown, 1998 and L. closelongatus Stoyanov, 1964. Among North American species it is closest to L. glycines n. sp. A distinguishing feature of L. biformis n. sp. is the presence of supplement-like organs in some females. Longidorus glycines n. sp., found in soybean microplots at the Main Research Station, Fayetteville, Arkansas, is characterized by its long body (6.14-8.31 mm), wide offset flattened head end, head width 20.3 to 23.3 µm, odontostyle 87.3 to 99.5 µm, guide ring 22.3 to 26.4 µm posterior to the anterior end, short conoid tail with rounded terminus, and c'' = 0.9-1.4. Longidorus glycines n. sp. is closest to L. lusitanicus Macara, 1985. Among North American species it is close to L. biformis n. sp., L. breviannulatus Norton and Hoffman, 1975, and L. crassus Thorne, 1964. Both new species are believed to have four juvenile stages; the first stage was not found for L. biformis n. sp.  相似文献   

6.
鲫鱼寄生车轮虫一新种的研究   总被引:5,自引:1,他引:4  
本文记述了寄生在鲫鱼(Carassius auratus)体表和鳃上一种新的车轮虫(Trichodina carassii sp.nov.),虫体直径70(54.6—80.4)μm,附着盘直径58(51.6—67.2)μm,齿环直径32(27.0—36.2)μm,齿体25—30个,齿环中央有7—14个旧齿体残余物形成的颗粒结构。大核马蹄形。小核短杆状,在大核一端的外侧,其位置略有变动。口沟390—400°。齿钩镰刀状,齿棘较直,侧面具有若干个缺刻,末端钝圆或平截,近锥体的后方有一个不太明显的小突起。    相似文献   

7.
Cui YD  Wang HZ 《Zoological science》2005,22(12):1353-1357
Potamothrix scleropenis sp. nov. (Tubificidae: Tubificinae) is described from the profundal zone (74 m) of Fuxian Lake, the deepest lake (up to 155 m) on the Yunnan-Guizhou Plateau in China. The new species is assigned to Potamothrix because of its short vasa deferentia and its tubular atria without ejaculatory ducts and prostate glands. It differs from congeners by its cuticularized penis sheaths; bifurcated, strongly curved spermathecal chaetae; bifurcated lower prongs of bifids; and feathered hairs. P. scleropenis appears closely related to P. cekanovskajae Finogenova, 1972 and P. tudoranceai Sporka, 1994, since all the three species have homogeneous atria without prostate glands.  相似文献   

8.
Atractomorpha echinata gen. et sp. nov. is described from isolates derived from zygotes present in a dry soil sample obtained from Texas. The new genus is distinguished from Sphaeroplea primarily by its pattern of vegetative growth. While Sphaeroplea is distinctly filamentous with numerous coenocytic cells uniseriately arranged, Atractomorpha grows as individual, multinucleate, spindle-shaped cells with sharply pointed extremities. Such cells may vary considerably in length (25–6000 μm, or more) and normally lack septa. In young, rapidly growing cultures the cells often attain lengths of 300–500 μm, but rarely exceed 1800 μm. The new species is further characterized by: (1) the regular formation of biflagellate zoospores in asexual reproduction, (2)anisogamy (occasionally oogamy) and (3) the size and ornamentation of its zygotes. Variations in vegetative morphology are discussed as are conditions for obtaining gametogenesis.  相似文献   

9.
We have investigated the role of serine 40 (Ser-40) in tyrosine hydroxylase (TH) catalysis of basal and activated enzymes by protein kinase A (PKA)-mediated phosphorylation. Wild type and mutant TH were transiently and stably expressed in AtT-20 cells, and the enzymatic activities of the recombinant enzymes were analyzed. The specific enzymatic activity of transiently expressed TH mutants Ser-40-->leucine or-->tyrosine (Leu-40m or Tyr-40m) was higher than that of the wild type enzyme or of other mutants in which Ser-8, -19, and -31 were replaced by leucine. The kinetic studies carried out with the stably expressed TH show that the Km for the cofactor 6-methyltetrahydropterine is lower and the Ki for dopamine is higher when the enzymatic hydroxylation is catalyzed by the Leu-40m or Tyr-40m than by the wild type enzyme. The kinetic parameters and the pH profile of the enzymatic hydroxylation catalyzed by the Leu-40m or Tyr-40m are similar to the enzyme activated by PKA-mediated phosphorylation. We suggest that Ser-40 in TH exerts an inhibitory influence on the enzymatic activity, and its replacement with another amino acid by site-directed mutagenesis or its modification by phosphorylation leads to a change in conformation with an increased enzymatic activity. The importance of Ser-40 in the activation of TH by PKA-mediated phosphorylation was investigated by comparing the activation of the wild type enzyme with that of Leu-40m or Tyr-40m. The findings that the enzymatic activity is increased by PKA-mediated phosphorylation of the wild type enzyme, but not of the Leu-40m or Tyr-40m, demonstrate that phosphorylation at Ser-40 is essential for activation of TH by PKA. The findings that addition of ATP plus cAMP to homogenates from transfected AtT-20 cells stimulates the recombinant wild type TH activity indicate that these cells contain endogenous cAMP-dependent protein kinase.  相似文献   

10.
Gravitational unloading causes atrophy of muscle fibers and can lead to destruction of cytoskeletal and contractile proteins. Along with the atrophic changes, unloaded muscle frequently demonstrates significant shifts in the ratio of muscle fibers expressing fast and slow myosin heavy chain isoforms. Stretching of the m. soleus during hindlimb suspension prevents its atrophy. We supposed that neuronal NO-synthase (NOS) (which is attached to membrane dystrophin-sarcoglycan complex) can contribute to maintenance of protein metabolism in the muscle and prevent its atrophy when m. soleus is stretched. To test this hypothesis, we used Wistar rats (56 animals) in experiments with hindlimb suspension during 14 days. The group of hindlimb suspended rats with stretched m. soleus was injected with L-NAME to block NOS activity. We found that m. soleus mass and its protein content in hindlimb-suspended rats with stretched m. soleus were preserved due to prevention of protein degradation. NOS is involved in maintenance of expression of some muscle proteins. Proliferation of satellite cells in stretched m. soleus may be due to nNOS activity, but maintenance of muscle mass upon stretching is regulated not by NOS alone.  相似文献   

11.
The conformational equilibrium of the title compound has been determined by correlating its n.m.r. parameters with those of its 2,2,6,6-tetradeuterio derivative and trans- and cis-2-tert-butyl-4,5-epoxytetrahydropyran. The high preference (ΔG ~ ?0.8 kcal/mol) for the half-chair conformation in which the pyranoid oxygen is furthest from the oxirane oxygen atom can be interpreted in terms of electrostatic interactions between the two oxygen atoms.  相似文献   

12.
新种大连滑刃线虫.Aphelenchoides dalianensis sp.nov.采自中国辽宁省大连市老铁山的枯死黑松.新种的鉴别特征为:体较短(雌虫:571.5~658.0 μm;雄虫:436.8~520.0μm),口针纤细(雌虫:10.0~12.7 μm;雄虫:9.2~11.8μm)具有基部球,侧线4条.雌虫阴门位于虫体60%~75%处,尾型特殊,具蜗牛触角状分叉的尾尖突;雄虫尾部向腹面弯曲成拐杖形,有1简单尾尖突,交合刺小(10.0~12.9μm),乳突3对,无交合伞.新种的近似种是大核滑刃线虫A.macronucleatus,主要区别在于大核滑刃线虫的雌虫仅具一简单尾尖突,雄虫加热杀死后呈"L"形,而非新种的"J"形.应用限制性酶切图谱(PCR-ITS-RFLP)的方法以及DNA测序为新种提供了分子生物学的证据.  相似文献   

13.
Dichomitus hubeiensis Hai J. Li & B. K. Cui sp. nov. is described from the Hubei province, central China. It is distinct in the genus by its cream to straw‐yellow pore surface and large pores (1–2 per mm), both inamyloid and indextrinoid skeletal hyphae, presence of cystidioles and dendrohyphidia in the hymenium, more or less ellipsoid basidiospores (10–14 × 5.6–7.0 µm). Dichomitus kirkii originally described from Zimbabwe was found in the Yunan province, it is new to the Chinese fungal flora, and is characterized by its buff‐yellow to cinnamon‐buff pore surface, entire to lacerate pores (1–2 per mm) and large cylindrical basidiospores (20.8–25.0 × 6.8–8.0 µm).  相似文献   

14.
New Zealand restructured its health system in 1992 with the aim of achieving greater levels of assessment and accountability in the publicly funded health sector. A committee was established specifically to advise the minister of health on the kinds, and relative priorities, of health services that should be publicly funded. One of its projects has been to develop standardised sets of criteria to assess the extent of benefit expected from elective surgical procedures. These have been developed with the help of professional advisory groups using a modified Delphi technique to reach consensus. So far the committee has developed criteria for cataract surgery, coronary artery bypass grafting, hip and knee replacement, cholecystectomy, and tympanostomy tubes for otitis media with effusion. These criteria incorporate both clinical and social factors. Use of priority criteria to ensure consistency and transparency regarding patients'' priority for surgery is required for access to a dedicated NZ$130m (pounds 57m; US$90m) pool of money, created to help eliminate surgical waiting lists and move to booking systems. The criteria will also be used in surgical outcome studies, currently in the planning phase.  相似文献   

15.
Paralongidorus bullatus n. sp. from groundnut soils in Sador''é Niger is described and illustrated. It is distinguishable from most species of the genus by its body and odontostyle lengths, knob-like head, and digitate ending of the protoplasmic region of the tail. Length of the female body is 4.4-5.5 mm, of the odontostyle 132-156 μm, and of the tail 32-44 μm. Tail terminus is conoid to broadly rounded. Uteri are well developed, without sperms. Males are not found. Xiphinema parasetariae Luc 1958, a species inquirenda, is validated and, based on measurements and tail structures, X. attorodorum Luc 1961 is proposed as a synonym of X. parasetariae. Additional measurements are given for its females and juveniles.  相似文献   

16.
Sodium bisulfite is a mutagen which can specifically deaminate more than 96% of the cytosine residues in single-stranded DNA via formation of a 5,6-dihydrocytosine-6-sulfonate intermediate. Under the same reaction conditions, only 2-3% of the 5-methylcytosine (m5Cyt) residues in single-stranded XP-12 DNA, which has 34 mole% m5Cyt, was converted to thymine (Thy) residues. In contrast, at the deoxynucleoside and free base levels, the same treatment with bisulfite and then alkali converted 51% and > 95%, respectively, of the m5Cyt to the corresponding Thy derivatives. However, the rate of reaction of m5Cyt and its deoxyribonucleoside was much slower than that of the analogous quantitative conversion of cytosine or deoxycytidine to uracil or deoxyuridine, respectively. The much lower reactivity of m5Cyt and its derivatives compared to that of the unmethylated analogs is primarily due to a decrease in the rate of formation of the sulfonate adduct.  相似文献   

17.
The morphology, life history, and the geographical distribution of Spongomorpha spiralis Sakai in Hokkaido, Japan, was studied. The thallus is characterized by its digitate tufts (bundles) of slender filaments with hooked branchlets. The diameter of the filaments is usually 20-50 μm in the basal portion, 50-130 (70-110) μm in the middle portion of main axes, and 30-150 μm in the upper portion. The diameter of the middle portion of the main axes varies from locality to locality. At Muroran, for example, the range is 70-130 μm (average approximately 100 μm), while at other localities it is 50–100 μm (average approximately 70 μm). The diameter of filaments in the upper portion decreases toward the end of the growing season. The cells are multinucleate with four chromosomes in each nucleus of the haploid plant. The manner of cell division is identical to the process reported previously for the Spongomorpha-Acrosiphonia complex. Sexual reproduction is isogamous with anteriorly biflagellate gametes. Plants are unisexual. The life history involves an alternation of heteromorphic generations: the gametophytic phase is a macroscopic, filamentous thallus and the sporophytic phase is a microscopic, ellipsoidal or club-shaped cell. Optimal culture condition for growth and reproduction of both stages was 5°C and long daylength. The gametophyte developed abnormally at 15°C. The sporophyte developed normally at 15°C, but did not produce zoospores.  相似文献   

18.
Ilexol, a new triterpenoid alcohol isolated from the barks of several species of the Genus Ilex, has now been oxidized with chromium trioxide to yield a ketone, designated as ilexone of C30H48O, m.p. 239.5–240.5°, and – 68.74°, which gives oxirne of m. p. 256.5–257.5°, 2,4-dinitrophenylhydrazone of m.p. 260–261°, and positive Zimmermann test.

On reduction with sodium and ethanol as well as with lithium aluminum hydride, it has been shown that ilexone is regenerated to yield an alcohol proved to be identical with natural ilexol.

On reduction according to the procedure of Huang-Minion, ilexone has been shown to yield an oxygen-free compound, designated as ilexene of C30H50, and m.p. 241–242°.

It seems most likely that ilexol might be a triterpenoid alcohol of C30H49OH, an alcoholic hydroxyl group of which is secondary in nature, and moreover attached at C–3 in its molecule.  相似文献   

19.
Renal mitochondrial 25-hydroxyvitamin D3-1-hydroxylase (1-hydroxylase) is sensitive to inhibition by 2 × 10?5m calcium and 5 × 10?3m phosphate when hydroxylation is supported by either malate or NADPH. This sensitivity to ion inhibition is observed in mitochondria from both vitamin D-deficient and repleted chicks and remains when mitochondria are frozen and thawed or are incubated in a hypotonic medium. The ionophore A23187 inhibits the 1-hydroxylase but partially reverses the inhibition exerted by 2, 5, or 7.5 × 10?5m calcium. Addition of a kidney soluble cell fraction (37,000g supernatant) to isolated mitochondria did not enhance the 1-hydroxylase activity under conditions of varied substrate concentration, osmolarity of the incubation medium, or mitochondrial washes. It is concluded that a soluble cellular component is not involved in the regulation of the 1-hydroxylase but that intramitochondrial calcium and phosphate may well play a role in its regulation.  相似文献   

20.
Rhabditis (Oscheius) pheropsophi n. sp., associated with cadavers of the bombardier beetle, Pheropsophus aequinoctialis, is described from material collected in Brazil. Mean body length of the female is 1,217 μm, of the male 872 μm, and of the dauer juvenile 568 μm. The female has six lips with one papilla on each lateral lip and two on each sublateral lip; stoma wall thickened dorsally, metarhabdions with warts, excretory pore near base of esophagus, tail long (c = 8), and phasmids prominent, protruding on scanning electron microscope preparations. The male has 10 pairs of bursal ribs, with the terminal pair considerably smaller than the others; spicules fused distally two-thirds of their length. The new species can be distinguished from other members of the Dolichura-group by its fused spicules.  相似文献   

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