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91.
92.
(1) Mannitol fermentation is a reasonably reliable method for the detection of coagulase positive staphylococci in milk. This reliability can be improved if mannitol fermentation is carried out under anaerobic conditions.
(2) Among hemolytic strains of staphylococci isolated from milk, beta hemolytic staphylococci predominate. Bovine and sheep blood agar plates give similar hemolytic patterns, but the hemolysis is more pronounced on sheep blood agar.
(3) Gelatin liquefaction cannot be relied upon for the selection of coagulase positive staphylococci in milk.
(4) Urease production is a feature of the majority of coagulase positive staphylococci isolated from milk.
(5) Tellurite Glycine agar medium is not satisfactory for the selection of coagulase positive staphylococci in milk.
相似文献93.
Investigations on interspecific crossability in two species of the genus Citrullus were studied based on their morphology, chromosome pairing and pollen fertility in their hybrids resulting from 12 combinations(including
reciprocals). These have been utilized for tracing the phylogenetic relationship between the taxa and factors responsible
for their differentiation. A collective evaluation of data on cross compatibility,morphology, chromosome association and pollen
fertility indicated a close phylogenetic relationship between the species C. colocynthis (wild2n = 22) and C. vulgaris (cultivated 2n = 22). Significant differences for crossability and pollen fertility were observed between hybrids of C. colocynthis × C. vulgaris and reciprocals. Meiotic analysis of F1 hybrids revealed that these two species are freely crossable and provide normal chromosome association, involving an average
of 9 to maximum 11 pairs of chromosomes. This indicated the possibility of high recombination and thereby genetic introgression
of desirable traits. As both the species are of economic significance, breeding strategies can be developed for the genetic
improvement of these species.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
94.
Inheritance of resistance to spot blotch caused by Bipolaris sorokiniana in spring wheat 总被引:1,自引:0,他引:1
Three F1 progenies and their families in the segregating generations (F3, F4, F5 and F6), obtained after crossing resistant × susceptible wheat genotypes were studied in the field to determine the genetics of resistance to spot blotch caused by Bipolaris sorokiniana. Spot blotch scores in the F1 generation showed absence of dominance. Individually threshed F2 plants were used to advance the generations. Progenies (200‐250) of resistant genotypes Acc. No. 8226, Mon/Ald, Suzhoe#8 crossed with susceptible ‘Sonalika’ were evaluated in the F3, F4, F5 and F6 generations under induced epiphytotic conditions. Based on disease score distribution in individual progeny rows, F3 progenies were grouped into four classes: homozygous resistant, homozygous susceptible, segregating resistant and segregating susceptible. Resistance appeared to be under the control of three additive genes. The presence of three genes was also noted in the distribution of F4 and F5 lines. In the case of F6 progeny rows, both quantitative and qualitative models were used to estimate the number of segregating genes based on a 2‐year trial. It appeared that resistance to spot blotch was controlled by the additive interaction of more than two genes, possibly only three. 相似文献
95.
Leaf rust resistance genes were identified in the common wheat variety ‘HUW 206’ and line HUWL 39 by inoculating their seedlings with 20 pathotypes of diverse avirulence–virulence combinations. The inheritance patterns and allelic relationships were studied by crossing these wheats with ‘Agra Local1 and a set of Thacher’ near-isogenic lines with genes for resistance. Seedling resistance studies revealed the presence of genes Lr1, Lr10 and Lr26 in ‘HUW 206’ and genes Lr10 and Lr26 in HUWL 39. The presence of genes Lr1 and Lr10 was confirmed indirectly by testing for the linked genes Sr31 and Yr9. An F1 test for progressive necrosis in crosses of the lines with ‘Spica’ revealed the absence of Lr13. 相似文献
96.
Seedling Peroxidase and IAA Oxidase Activities in Relation to Hybrid Vigour in Pearl Millet (Pennisetum americanum L. Leeke) 总被引:1,自引:0,他引:1
A. K. Joshi S. V. Chanda P. N. Krishnan P. P. Vaishnav Y. D. Singh 《Journal of Agronomy and Crop Science》1986,157(3):156-168
Seedlings of three hybrids and their parental lines were analyzed for growth, and peroxidase as well as IAA oxidase activities in cytoplasmic and salt-extracted ionically bound fractions with a view to evaluate heterosis in pearl millet. The hybrid vigour was manifested in roots and shoots of all the three hybrids clearly for growth and activities of peroxidase and IAA oxidase except the wall-bound IAA oxidase. Either better parental or mid-parental heterosis was discernible. The role of peroxidase and IAA oxidase systems in meristematic activity and removal of excessive auxin levels to bring about maximal growth response in the hybrids is discussed. 相似文献
97.
The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor 总被引:1,自引:0,他引:1
GM Keating SW Bougher RW Zurek RH Tolson GJ Cancro SN Noll JS Parker TJ Schellenberg RW Shane BL Wilkerson JR Murphy JL Hollingsworth RM Haberle M Joshi JC Pearl BJ Conrath MD Smith RT Clancy RC Blanchard RG Wilmoth DF Rault TZ Martin DT Lyons PB Esposito MD Johnston al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676
The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere. 相似文献
98.
99.
R. Gupta S. Gupta K. Joshi N.K. Ganguly 《Comparative immunology, microbiology and infectious diseases》1997,20(4):299-307
The contribution of iron towards the free radical generation leading to renal tissue damage was assessed using a non-obstructive ascending mouse model for chronic pyelonephritis. The parameters studied include luminol dependent chemiluminescence (LDCL), histopathology and some biochemical investigations. We found that iron enhanced the renal tissue damage and led to renal scarring, an end point in chronic renal inflammation, irrespective of the bacterial strain studied. In addition a role of iron chelation therapy as a treatment for chronic renal inflammation is also suggested. 相似文献
100.