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241.
Gabriella Sonnante Angela R. Piergiovanni Quat N. Ng Pietro Perrino 《Genetic Resources and Crop Evolution》1996,43(2):157-165
Summary Isozyme variation in 25 accessions of wild and cultivated Vigna unguiculata, 49 accessions of seven wild species belonging to section Vigna, and 11 accessions of V. vexillata (subgenus Plectrotropis) was scored at 17 putative loci to assess genetic relationships within and among species. The wild species selected for this study are among those which carry important agronomical traits useful in cowpea (V. unguiculata) breeding programs. Allelic frequencies were calculated and Nei's genetic distances were obtained. Low levels of intraspecific variation were observed for V. heterophylla, V. luteola and V. racemosa, whereas the other species showed a higher polymorphism. Vigna unguiculata possessed intraspecific genetic distances comparable to those previously found by other authors. Most of the isozyme variation was apportioned among species. Although V. luteola and V. marina had an interspecific genetic distance resembling the range observed at intraspecific level, all the other species showed very high interspecific distances. Vigna unguiculata was relatively closer genetically to V. vexillata than to the species belonging to section Vigna.Abbreviations AUS
Australia
- BDI
Burundi
- BRA
Brazil
- BWA
Botswana
- CAF
Central African Republic
- GHA
Ghana
- CMR
Cameroon
- COG
Congo
- RI
Costa Rica
- EGY
Egypt
- ETE
Ethiopia
- GAB
Gabon
- GRC
Greece
- ITA
Italy
- KEN
Kenya
- MOZ
Mozambique
- NER
Niger
- NGA
Nigeria
- PAN
Panama
- RWA
Rwanda
- TCD
Chad
- TZA
Tanzania
- ZAF
South Africa
- ZAR
Zaire
- ZMB
Zambia 相似文献
242.
An investigation was carried out to assess the effects of weather on the occurrence and magnitude of the periparturient rise
(PPR) in trichostrongylid nematode egg output in breeding Dorper ewes. The study was conducted over three breeding seasons
on a ranch in the semi-arid area of Kajiado District in Kenya between June 1999 and December 2001. During each breeding season
20 ewes randomly selected from the breeding stock and 20 others selected from the unmated yearlings were monitored for faecal
strongyle egg counts every 3 weeks. The lambing seasons were timed to coincide with the onset of the short rains (October–November
1999), the mid-short rains (November–December 2000) and the end of the dry season (September–October 2001). In each season
higher egg outputs were recorded in the peri-parturient ewes compared to the unmated yearlings. The highest PPR occurred in
September 2001, when lambing coincided with the end of the dry season, possibly as a result of maturation of hypobiotic larvae.
The lowest PPR occurred in November 2000 when the onset of lambing coincided with the mid-short rains, possibly owing to low
pasture infectivity associated with a long dry spell between January and October of the same year. The results of this study
indicate that PPR occurred when lambing coincided with both the wet and the dry seasons. However, the magnitude was greatly
influenced by the season when lambing occurred. It was also influenced by resumption of development of hypobiotic larvae and
the nutritional status of the ewes. Not only should control of gastrointestinal nematode parasites in this area aim at preventing
the occurrence of PPR by treating ewes 2–3 weeks before they are to lamb and during lactation, but the anthelmintic used must
also eliminate hypobiotic larvae. In addition, the animals must be given supplementary feeding during this period. 相似文献
243.
Azad K. Kaushik Marcus E. Kehrli A. Kurtz S. Ng M. Koti F. Shojaei Surinder S. Saini 《Veterinary immunology and immunopathology》2009,127(1-2):106-113
Antibody diversification in IgM and IgG antibodies was analyzed in an 18-month old bovine (Bos taurus) suffering from naturally occurring chronic and recurrent infections due to bovine leukocyte adhesion deficiency (BLAD). The BLAD, involving impaired leukocyte β2 integrin expression on leukocytes, develops due to a single point mutation in conserved region of the CD18 gene resulting in substitution of aspartic acid128 with glycine (D128G). Twenty four VDJCμ and 25 VDJCγ recombinations from randomly constructed cDNA libraries, originating from peripheral blood lymphocytes, were examined for the variable-region structural characteristics in IgM and IgG antibody isotypes. These analyses led to conclude that: (a) expression of exceptionally long CDR3H is isotype restricted to cattle IgM antibody; (b) VDJ recombinations encoding IgM with exceptionally long CDR3H undergo clonal selection and affinity maturation via somatic mutations similar to conventional antibodies; (c) somatic mutations contribute significantly to both IgM and IgG antibody diversification but significant differences exist in the patterns of ‘hot spot’ in the FR1, FR3 and CDR1H and, also, position-dependant amino acid diversity; and (d) transition nucleotide substitutions predominate over transversions in both VDJCμ and VDJCγ recombinations consistent with the evolutionary conservation of somatic mutation machinery. Overall, these studies suggest that both somatic mutations and exceptional CDR3H size generation contribute to IgM and IgG antibody diversification in cattle during the development of immune response to naturally occurring chronic and multiple microbial infections. 相似文献
244.
C. J. Ng’ang’a N. Maingi P. W. N. Kanyari W. K. Munyua 《Tropical animal health and production》2009,41(6):921-926
The effects of anthelmintics treatments in controlling gastrointestinal nematodes in breeding ewes in a semi-arid area of
Kenya were determined. The study carried out during two breeding seasons, between June 2000 and December 2001 where albendazole
was administered to groups of ewes, 2 weeks before mating, 3 weeks to lambing and mid lactation indicated significantly lower
nematode egg counts in treated than untreated groups of ewes. In the first breeding season, reduced rainfall resulted in pasture
scarcity and weight loss in both groups of ewes through out the gestation period, but losses were higher for the untreated
group. In the second season, both groups of ewes showed a steady increase in weight gain during the gestation period and post-partum,
but weight gains were higher in the treated group. In lambs, weight gains at 6 weeks were higher for treated ewes than control
groups, in both breeding seasons. The results of this trial indicate that anthelmintic treatments in breeding ewes in the
study area are beneficial in reducing gastrointestinal nematode infections and improving performance of the ewes and their
lambs. In addition to the treatments, breeding ewes should be given feed supplementation particularly during periods of pasture
scarcity. 相似文献
245.
A rapid method for detecting Trichinella spiralis larvae in pork using a monoclonal antibody-latex conjugate 总被引:1,自引:0,他引:1
A simple, non-microscopic method was developed for the direct detection of Trichinella spiralis in pork. Samples of meat were treated with pepsin for 2 h to liberate the larvae, and sonicates were made from the deposit and used in an antigen detection system. In this system, latex particles, sensitized with a parasite-specific monoclonal antibody, were utilized in a slide or tube agglutination test. The efficiencies of these immunological methods were compared with that of trichinelloscopy in the examination of 102 pork specimens, 35 of which contained varying numbers of larvae after enzymatic digestion of 2 g of the meat. Trichinelloscopy detected 77.1% of these positive samples, but this was lower (55.5 and 41.7%) for those samples with a low larval burden (less than 50 or less than 10 larvae g-1 tissue, respectively). Better results (88.6, 76.5 and 60.0%) were obtained with the slide latex agglutination technique. The efficiency of detection was further improved (100%) using the more sensitive tube agglutination method. However, this was based on a small number (20) of samples examined and the limit of detection of this technique was subsequently found to be three larvae in total. No false-positives were seen with the latex agglutination methods from a total of 67 uninfected specimens examined. 相似文献
246.
M. Tanaka D. C. H. Yap C. K. Y. Ng 《The Journal of Horticultural Science and Biotechnology》2013,88(5):632-638
SummaryCymbidium plantlets were grown in vitro under conditions of high CO2 and low photosynthetic photon flux density using the Miracle Packt culture system. Shoots and roots of plantlets showed differential growth characteristics. Shoot growth was not different in plantlets cultured under CO2-enriched (CDE) and non-enriched (NCDE) conditions. Root growth was promoted in plantlets cultured under CDE in the presence or absence of 2% sucrose (S) with rockwool (R) as the supporting material. Growth was poor in plantlets cultured in 1% agar. Root growth was best in plantlets cultured under CDE R+S. Sucrose is still an important component for root growth under CDE conditions even though CO2 can be used as an alternative carbon source. Photosynthetic measurements (CO2 uptake and total Rubisco activity) showed the presence of active and operational photosynthetic machinery in plantlets cultured under CDE and NCDE conditions. The apparent lack of photoautotrophy (as evident from the lack of starch grains in chloroplasts) in plantlets cultured under NCDE conditions is not the result of a lesser potential for photoautotrophy; rather it is a consequence of sub-optimal CO2 concentrations within the culture vessels. 相似文献
247.
Fourteen bread wheat near-isogenic lines (NILs) with different alleles at 1B- and 1D-chromosome loci Glu-1, Glu-3 and Gli-1 coding for high molecular weight glutenin subunits (HMW-GS), low molecular weight-GS, and gliadins, respectively, were grown in replicated plots to investigate the individual and combined effects of glutenin and gliadin components on the rheological properties of dough as determined by the Chopin alveograph. NILs did not reveal significant differences in seed yield, protein content, kernel weight, test weight, flour yield, and starch damage. On the contrary, they had a large variation in alveograph dough tenacity P (55–93 mm), swelling G (17–26 mL) and strength W (140–252 J × 10-4). The null alleles at the Gli-D1/Glu-D3 loci, and allele Glu-D1d (HMW-GS 5+10) were found to have a strong positive influence on dough tenacity and a remarkable negative influence on dough swelling (extensibility) when compared to alleles Gli-D1/Glu-D3b and Glu-D1a (HMW-GS 2+12), respectively. On the other hand, alleles Glu-B1c (HMW-GS 7+9) and Gli-B1/Glu-B3k gave greater G values than alleles Glu-B1u (HMW-GS 7*+8) and Gli-B1/Glu-B3b. The effects of individual Glu-1, Gli-1, or Glu-3 alleles on P and G values were largely additive. The impact of the null allele at Gli-D1/Glu-D3 on gluten strength was highly positive in NILs possessing HMW-GS 2+12, and negligible or negative in NILs containing HMW-GS 5+10, suggesting that there is scope for improving dough quality by utilizing this allele in combination with HMW-GS 2+12. Gli-D1/Glu-D3-encoded prolamins were shown to play a major role in conferring extensibility to dough, and could account for the superior breadmaking characteristics of bread wheat as compared to durum wheat. 相似文献
248.
The variability in thermal properties among 62 S3 lines derived from a high-yielding exotic corn (Zea mays) population, Antigua 1 (PI 484990), was evaluated by differential scanning calorimetry (DSC). The S3 lines were grown in Puerto Rico (1990–1991) and Georgia (1994). Separate single-kernel starch extractions for five kernels (five replicates) from each line grown in each location were performed, and the starch was analyzed. The DSC values reported included gelatinization onset (ToG), range (RG), enthalpy (ΔHG), and peak height index (PHI) and retrogradation onset (ToR), range (RR), enthalpy (ΔHR), and percent retrogradation (%R) (an indication of the stability of gelatinized starch after storing at 4°C for 7 days). Significant differences (P < 0.05) were found among the 62 lines of Antigua 1 for ToG, RG, and PHI and highly significant differences (P < 0.01) were found for ΔHG. The starches from plants grown in Georgia (1994) had significantly (P < 0.05) greater ToG, ΔHG, and PHI but a significantly lower RG than those from Puerto Rico (1990–1991). These data suggest that the starch from plants grown in Georgia (1994) might have a greater degree of crystallinity than that from Puerto Rico (1990–1991). None of the retrogradation values were significantly different among starches of the 62 lines of Antigua 1 and the starches from plants grown in the two locations. 相似文献