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1.
Summary The establishment and development of vesicular-arbuscular mycorrhizal (VAM) fungi were studied in three cultivars of potato, which differed in susceptibility to Late blight, in a field experiment on a lateritic sandy-loam during two growing seasons (1980 and 1981). The cultivars SSC 1174 (highly resistant) and Kufri Jyoti (resistant) showed an earlier establishment and more rapid development of VAM fungi than up-to-date (highly susceptible). The first mycorrhizal infection in both SSC 1174 and Kufri Jyoti was observed after 12 days in 1980 and 8 days in 1981, whereas in up-to-date it was observed after 19 and 12 days respectively. The mycorrhizal infection increased with the age of the plants in all the three cultivars.  相似文献   

2.
Summary We have synthesized 2(3)-O-(glycyl)-adenosine-5-(O-methylphos-phate), an analogue of the 3-terminus of aminoacylated tRNA. A 0.4M solution of this compound maintained at pH 8.2, yields 5.5% of diglycine and 11.5% of diketopiperazine, in addition to the hydrolysis products glycine and adenosine-5-(O-methylphosphate). Under the same conditions, glycine ethyl ester reacts much more slowly, but ultimately gives similar yields of diglycine and diketopiperazine.The aminolysis of 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) by free glycine is relatively inefficient, but serine reacts 20 times more rapidly and yields up to 50% of N-glycylserine. The prebiotic significance of these reactions is discussed.Abbreviations MepA adenosine-5-(O-methylphosphate) - MepA-gly 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) - MepA-bis-gly 2,3-O-(bis-glycyl)-adenosine-5-(O-methylphosphate) - DKP diketopiperazine - gly Et glycine ethyl ester - gly-ser N-glycylserine - O-gly-ser O-glycylserine - O-(gly)-gly-ser O-(glycyl)-glycylserine - Boc-gly N-tert-butyloxycarbonylglycine - MepA-Boc-gly 2(3)-O-(Boc-glycyl)-adenosine-5-(O-methylphosphate) - MepA-bis-Boc-gly 2,3-O-(bis-Boc-glycyl)-adenosine-5(O-methylphosphate) - (gly)2 diglycine - (gly)3 triglycine  相似文献   

3.
On age morphological changes of males of Chydoridae (Cladocera)   总被引:2,自引:2,他引:0  
N. N. Smirnov 《Hydrobiologia》1967,30(3-4):555-571
Summary Young and adult males of 11 species of Chydoridae are studied, their figures being published here (fig. 1–15). The necessity is stressed to distinguish young forms of males and gynandromorphic individuals.Pleuroxus balatonicus is considered to be described from the population ofPleuroxus unicatus having under Balaton Lake conditions retarded transformation of young males into adult form, and accordingly having unusually numerous young males. \qO\qs\qn\qo\qv\qn\qy\ye \qr\ye\qz\qu\ql\Qj\qt\qa\qt\qy 11 (. 1–15). . , Pleuroxus uncinatus , Pleuroxus balatonicus.  相似文献   

4.
Summary In the Far East two types of -thalassemia genes, namely -thalassemia1 (-thal1) and -thalassemia2 (-thal2) exist. Definite diagnosis of the -thal1 and -thal2 traits is very difficult because their hematological findings are minimally abnormal or normal. This study attempts to characterize the heterozygotes by hemoglobin chain synthesis in reticulocytes from obligatory cases of the -thal1 and -thal2 traits. Twelve parents of babies with hemoglobin Bart's hydrops fetalis (obligatory -thal1 trait) had the mean total radioactivity / ratio of 0.76±SD 0.04, while that of 7 normal controls was 1.06±SD 0.04. The / globin chain ratios of 16 cases, who were either parents or offspring of patients with hemoglobin H disease, were found to segregate into 2 groups, i.e. 0.78±SD 0.03 (10 cases) and 0.92±SD 0.03 (6 cases), probably representing the -thal1 and -thal2 traits respectively. The hematological data of the first group showed definite hypochromic microcytic red cells, similar to thoseof the parents of the hydrops. The second group had significantly higher mean corpuscular hemoglobin than the first group, compatible with -thal2 trait. Our globin chain synthesis study thus appears to be capable of discriminating normal, -thal1 and -thal2 traits.A preliminary report of the results was presented at the XV Congress of the International Society of Haematology, Israel, September, 1974.  相似文献   

5.
We have identified seven different -thalassemia mutations and one -thalassemia determinant (the Sicilian type) in 32 members of 17 Hungarian families. The most common mutation is the IVS-I-1 (GA) change; its high frequency is comparable to that observed in neighboring Czechoslovakia. Additional mutations are of Mediterranean origin. One rare mutation (initiation codonATGGTG) was identified as an independent mutation because of the absence of known polymorphisms in the -globin gene. One new frameshift at codon 51 (-C) was observed in a single individual; hematological data were as expected for a °-thalassemia heterozygosity.  相似文献   

6.
Genic variation was examined with starch and polyacrylamide gel electrophoresis at 14 loci in 12 populations of Peromyscus maniculatus nubiterrae from a small part of the Appalachians in eastern Tennessee and western North Carolina. Polymorphism was observed at eight loci with no significant correlations between frequency of common genotypes or alleles and altitude. Average individual heterozygosity (\-H) values were low for P. maniculatus whether using only slow evolving loci (mean = 3.0%) or both slow and fast evolving loci (mean = 4.9%). No significant correlation was present between altitude and \-H. Interlocality variation of \-H was as great in this study as previously reported for P. maniculatus over larger geographic areas. Rogers' coefficients of genetic similarity of paired combinations of populations based on slow evolving loci (range of 0.941 to 0.997) or based on slow and fast evolving loci (range of 0.858 to 0.974) showed all populations to be highly similar. Ranges of similarity values observed in the present study were as great as those previously reported for P. maniculatus over a larger geographic area.  相似文献   

7.
By means of reaction calorimetry we measured the apparent enthalpy change, Happ, of the binding of Mn2+-ions to goat -lactalbumin as a function of temperature. The observed Happ can be written as the sum of contributions resulting from a conformational and a binding process. In combination with the thermal unfolding curve of goat -lactalbumin, we succeeded in separating the complete set of thermodynamic parameters (H, G, S, Cp) into the binding and conformational contributions. By circular dichroism we showed that NH 4 + -ions, upon binding to bovine a-lactalbumin, induce the same conformational change as do Na+ and K+: the binding constant equals 98 ± 9 M–1.Abbreviations BLA bovine -lactalbumin - GLA goat -lactalbumin - HLA human -lactalbumin - CD circular dichroism Offprint requests to: H. Van DaelDeceased  相似文献   

8.
Summary Thirteen spontaneously occurring chlorophyll deficient phenotypes have been described and their genetic basis was established. Ten of these — white, white tipped green, patchy white, white virescent, white striping 1, white striping 2, white striping 4, fine striping, chlorina and yellow virescent showed monogenic recessive inheritance and the remaining three — yellow striping, yellow green and light green seedling phenotypes showed digenic recessive inheritance. The genes for (i) white tipped green (wr) and yellow virescent (yv) and (ii) patchy white (pw) and white striping 1 (wst 1) showed independent assortment. Further, the genes for white (w), white tipped green (wr) and yellow virescent (yv) were inherited independently of the gene for hairy leaf margin (Hm).In the mutants — white tipped green, patchy white, white striping 1, white striping 2, fine striping, chlorina, yellow virescent, yellow striping, yellow green and light green phenotypes total quantity of chlorophyll was significantly less than that in the corresponding controls, while in white virescent there was no reduction in the mature stage. For nine of the mutants the quantity of chlorophyll was also estimated in F1's (mutant x control green). In F1's of six of the mutants — white tip, patchy white, chlorina, yellow virescent, fine striping and yellow striping the quantity of chlorophyll was almost equal to the wild type. In the F1's of three of the mutants — white striping 1, white striping 2 and light green an intermediate value between the mutant and wild types was observed. In yellow virescent retarded synthesis of chlorophyll, particularly chlorophyll a was observed in the juvenile stage. Reduced quantity of chlorophyll was associated with defective chloroplasts. In the mutants — white tipped green, white virescent, fine striping, chlorina, yellow striping, yellow green and light green defective plastids were also observed. In patchy white secondary destruction of chlorophylls and the presence of defective plastids were found to be associated with reduced chlorophyll quantity at maturity.Paper chromatographic studies of leaf flavonoids revealed some variation between the inbreds, but there were three common spots, 7, 8 and 9, except for PDP in which the spot 8 was absent. Chlorophyll deficient mutants differed from their respective controls in the absence of one or more of the spots present in the controls and in the presence of new spots in some of the mutants.Most of the chlorophyll mutants showed higher survival rate in the Kharif season than in Rabi season which was attributed to the higher mean day temperature and longer day light period in the Kharif season than in Rabi season.  相似文献   

9.
Phoma tracheiphila is the causative agent of the disease mal secco. Citrus cultivars differ substantially in respect to their sensitivity to the pathogenP. tracheiphila and its toxin. Some cultivars (e.g., Femminello lemon) are inherently sensitive while others (e.g., Tarocco orange) are tolerant. Cell lines derived from nucellar tissue of Femminello, Tarocco and a cell line selected for tolerance to the fungal toxin (Femminello-S) were used to study host-pathogen interaction. Our results showed that calli or conditioned media of Tarocco and Femminello-S inhibited the size of co-cultivated fungal colonies when compared to Femminello. In addition, conditioned medium of Tarocco as well as FemminelloS, but not Femminello, promoted bursting of hyphal tips. A ten-fold increase in chitinase and glucanase enzymatic activity, as evaluated by radiometric assay and laminarin hydrolysis respectively, was detected in Femminello-S extracellular extracts as compared to Femminello. An increase in chitinase was also shown by immunoblot analysis. Our findings suggest a positive correlation between the presence of chitinase and glucanase in the conditioned media of the cultured cells and the tolerance of those cells toP. tracheiphila toxin.  相似文献   

10.
A novel syrup containing neofructo-oligosaccharides was produced from sucrose (Brix 70) by whole cells of Penicillium citrinum. The efficiency of fructo-oligosaccharides production was more than 55% and those of the main carbohydrate components, 1-kestose (Fruf 21Fruf 21 Glc), nystose (Fruf 21Fruf 21 Fruf 21 Glc) and neokestose (Fruf 26 Glc12 Fruf), were 22, 14 and 11%, respectively.  相似文献   

11.
Summary A method has been developed which enables the estimation of the plant gene flow parameters p (pollen dispersal), s (seed dispersal) and t (outcrossing rate) from a selection-free continuously structured population in equilibrium. The method uses Wright's F-coefficients and introduces a new F-function which describes the genetic similarity as a function of the spatial distance. The method has been elaborated for wind pollinated plant species but can be modified for insect pollination and for animal species. In practice allozymes will provide for the necessary neutral genetic variation. The more loci used and the more intermediate the gene frequencies, the more reliable the results. For the estimation of p and t together (when the outcrossing rate is not known) at least two chromosomally unlinked loci are required. The method for estimating s depends on whether the plant species is annual or perennial. The mechanism of selfing has been analysed by the explanation of the value of t by three components: population density (d), pollen flow (p) and relative fertilization potential of own pollen (Z). The concepts of neighbourhood size and isolation by distance, developed by Wright, who used a single gene flow parameter , have been extended to the situation which is realistic for seed plants, using all three parameters p, s and t. When p is large with respect to s, s largely determines the value of the neighbourhood size, whereas p is the most dominating factor in isolation by distance. The use of local effective population size and mean gene transport per generation instead of neighbourhood size and neighbourhood area, respectively, is proposed to avoid confusion. Computer simulations have been carried out to check the validity and the reliability of the method. Populations of 200 plants, using two or three loci with intermediate allele frequencies, gave good results in the calculation of p with known value of t and of s and Ne. With unknown t, especially with lower values of t, larger populations of at least 1,000 plants are necessary to obtain reasonably accurate results for p and mean gene transport per generation M.Grassland Species Research Group Publication No. 81  相似文献   

12.
    
In order to obtain further information on the role played by phenyl ring position in the C-methylated -amino acid side chain on peptide preferred conformation, the crystal-state structural preferences of C-methyl, C-phenylglycine peptides have been determined by X-ray diffraction. This study shows that either the fully extended conformation or the -bend/310-helical structures are adopted by peptides characterized by this C-methylated, -branched, aromatic -amino acid.  相似文献   

13.
Summary -Thalassemia exists at a high prevalence in several regions of Saudi Arabia. The restriction endonucleases Bam HI and BglII were used to investigate the molecular basis of deletion type of -thalassemia in 226 subjects from the eastern and 61 subjects from the northwestern regions of the country. The arrangements-/ and-/- were common. BglII digestion revealed the existence of rightward deletion in a majority of the cases. Leftward deletions, both homozygous and heterozygous, were also identified. Triple -gene arrangements -/ and -/- were observed at a low frequency in both regions.  相似文献   

14.
Ni  Zhang-Lin  Wang  Da-Fu  Wei  Jia-Mian 《Photosynthetica》2002,40(4):517-522
The conserved residue Thr42 of -subunit of the chloroplast ATP synthase of maize (Zea mays L.) was substituted with Cys, Arg, and Ile, respectively, through site-directed mutagenesis. The over-expressed and refolded -proteins were purified by chromatography on DEAE-cellulose and FPLC on mono-Q column, which were as biologically active (inhibiting Ca2+-ATPase activity and blocking proton gate) as the native subunit isolated from chloroplasts. The T42C and T42R showed higher inhibitory activities on the soluble CF1(–) Ca2+-ATPase than the WT. The T42I inhibited the Ca2+-ATPase activity of soluble CF1 and restored photophosphorylation activity of membrane-bound CF1 deficient in the most efficiently. Far-ultraviolet CD spectra showed that the portions of -helix and -sheet structures of the three mutants were somewhat different from WT. Thus the conserved residue Thr42 may be important for maintaining the structure and function of the -subunit and the basic functions of the -subunit as far as an inhibitor of Ca2+-ATPase and the proton gate are related.  相似文献   

15.
Cryopreservation has been recognized as a practical and efficient tool for long-term storage of vegetatively propagated plants. This study was conducted to investigate effects of modified vitrification techniques on cryopreservation of potato. In vitro plants of potato cultivars Superior and Atlantic were cold acclimated, and axillary buds were precultured, osmoprotected, exposed to PVS-2 solution, plunged into liquid nitrogen, thawed, and finally planted in the regeneration medium. In the modified vitrification technique an ice-blocking agent, Supercool X1000, was added with PVS-2 solution. Cold acclimation affected survival of cryopreserved shoot tips, and the highest survival (46.7%) was obtained after 3 weeks of acclimation at 10°C. Shoot tips exposed to 2M glycerol plus 0.6M sucrose for 40 min gave 51.5% and 11.7% survival in Atlantic and Superior at 10°C, respectively. Cold acclimated and osmoprotected shoot tips were dehydrated with PVS-2 containing different concentrations of Supercool X1000 prior to a plunge into liquid nitrogen. Treatments with 0.1% and 1% of Supercool X1000 significantly improved survival by 55% in Superior and 71.3% in Atlantic, respectively. After cryopreservation, vitrified shoot tips resumed growth within a week in a medium (1 mg l–1 GA3, 0.5 mg l–1 zeatin, and 0.1 mg l–1 IAA) with a low level of Pluronic F-68 (0.005%) and survival was 33.7% higher in Atlantic and 14.7% higher in Superior than the control (without Pluronic F-68).  相似文献   

16.
Zusammenfassung Bei der diploiden hohen Garten-Iris cv. Floridor (Cayeux 1929) wurde als bisher einziger Sorte ein neues Delphinidinglycosid Floridorin aufgefunden. Seine chemische Konstitution wurde als Delphinidin-3-Glukose-Rhamnose-p-Cumarsäure aufgeklärt. Es fand sich zusammen mit dem schon von uns aufgeklärten Anthozyan Tulipanin (Delphinidin-3-Glucose-Rhamnose). Das Hauptanthozyan der anderen Garten-Iris ist das von uns neuerdings nachuntersuchte Violanin. Die Untersuchungen wurden mit bereits von uns angegebenen neueren Methoden ausgeführt, wie der stufenweisen Hydrolyse und dem oxidativen Abbau. Das neue Floridorin zeigte bei den diploiden Garten-Iris einen monohybriden rezessiven Erbgang gegen Violanin. Die Blüten der Sorten, die Floridorin enthalten, sind schon mit dem Auge an einem charakteristischen taubenblauen Farbton zu erkennen.
On the constitution and inheritance of a new delphinidine glycoside Floridorin from the cultivated iris variety cv. Floridor (Cayeux 1929)Studies on anthocyanins LI
Summary The diploid tall bearded garden Iris cv. Floridor (Cayeux 1929) proved to be thus far the only variety with a different anthocyanine, called Floridorin. Its chemical structure has been found to be delphinidine-3-glucose-rhamnose-p-coumaric-acid. It occurs together with tulipanine already analyzed by us as delphinidine-3-glucose-rhamnose. The main anthocyanine of thePogoniris garden varieties proved to be violanin the structure of which has been studied by us lately. The investigations were carried out by some newer methods, such as partial hydrolysis and oxidative degradation already published by us. The new Floridorin gives a monohybrid recessive Mendelian ratio with other diploid varieties ofPogoniris colored by violanine. The varieties colored by Floridorin show a characteristic greyish blue coloration which can be recognized with the naked eye.
  相似文献   

17.
Summary The inheritance of resistance to whitebacked planthopper Sogatella furcifera (Horvath) was studied in 21 rice varieties. Reactions of F1; F2 and F3 progenies of the crosses of 21 resistant varieties with the susceptible variety TN 1 revealed that a single dominant gene governs resistance in Mushkan 41, Santhi, Siahnakidar 195, SM2-34, Tirisurkh 251, Zirijowaian 245, 18, 24A, 39, 76 S, 78, 180, 213 B, 267, 293, CI 6037-4, NP97, S39 JKW and Bansphul. In varieties 65 and 274 A, resistance is governed by one dominant and one recessive gene which segregate independently of each other. Tests for allelism with the Wbph 1 gene originally identified in N 22 revealed that the dominant gene present in all the test varieties is the same as Wbph 1. Further studies are required to determine the allelic relationships of the recessive gene found in varieties 65 and 274 A.  相似文献   

18.
Summary Analysis of -thalassemia syndromes in several German families revealed DNA deletion as well as nondeletion forms as the molecular basis for the defects. Thus, the -thalassemia haplotype was identified as the (–)3.7 rightward deletion form, and the region of the putative recombination process generating such a deletion was further characterized. In addition three different ° haplotypes, (--)MED, (--)>26, and ()T, could be detected using -and -globin gene-specific probes.  相似文献   

19.
The inheritance of host plant resistance and its effect on the relative infection efficiency for leaf blast was studied in the crosses IR36/CO39 (partially resistant × highly susceptible) and IR36/IR64 (both partially resistant). On the natural scale, gene action appeared multiplicative. After log transformation, additive effects described most of the genetic variation in the cross IR36/CO39, while additive and dominance effects were about equal in magnitude in the cross IR36/IR64. Dominance was towards increased resistance. No transgressive segregation occurred in the cross IR36/CO39. The number of genes that reduce lesion number was estimated to be zero in CO39 and five or more in IR36. The cross IR36/IR64 showed transgressive segregation in both directions, and IR36 and IR64 each contain at least one gene that is not present in the other cultivar. The heritabilities (narrow sense) in the F2 were low (range 0.06–0.16), while narrow sense heritabilities based on F3 lines were much higher (range 0.41–0.68). Lesion numbers in F3 lines were reasonably correlated with those in F5 progenies derived from the same F2 plant (r was±0.6 in both crosses). Partial resistance can be effectively improved by selecting the most resistant plants from the most resistant F3 lines.  相似文献   

20.
W. Hofmann 《Hydrobiologia》1980,73(1-3):255-258
Keratella cochlearis occurs in many Holstein lakes (northern Germany) as three well defined and separated forms: cochlearis, hispida, and tecta, each showing very little variation between the lakes. The present data show that the tecta form did not originate from a Lauterborn cycle.  相似文献   

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