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101.
Summary The chloroplast DNA of 27 potato cultivars and 2 wild species has been examined by Southern blotting using probes representing
the entire chloroplast genome of barley. 16% of the probe × enzyme combinations detected polymorphism between the potato cultivars.
Cvs Maris Piper, Croft, Shelagh, Stormont Enterprise and Estima and the wild species could be distinguished from the other
cultivars by their chloroplast DNA restriction patterns. These results are discussed in relation to cytoplasmic diversity
and potato improvement. 相似文献
102.
Precision Agriculture - Soil acidification is a growing problem in semi-arid agroecosystems. In the state of Montana, USA, soil pH levels below 5.5 have been documented in nearly half of the... 相似文献
103.
D G Powell 《Veterinary Clinics of North America: Equine Practice》2000,16(3):389-403, vii
Examples of equine disease surveillance at the local, regional, national and international level are discussed in this article. Reporting systems at each level are also considered, and the increasing importance of laboratory confirmed diagnoses is emphasized. The need to develop national disease reporting systems is addressed, particularly with respect to conforming to international trading standards. 相似文献
104.
J R Strickland D L Cross T C Jenkins R J Petroski R G Powell 《Journal of animal science》1992,70(9):2779-2786
The objective of this research was to measure the effects of endophyte-infected tall fescue seed extract and various alkaloids associated with the endophyte on in vitro prolactin secretion by rat hemipituitaries. Rat anterior pituitaries (AP) were dissected into halves and placed in temperature-controlled culture chambers (37 degrees C). The tissue was perfused with culture media at a flow rate of 12 mL/h. After perfusion for at least 90 min with control media, AP halves were exposed to their respective treatments for 15 min before they were returned to the control media. The treatments for Exp. 1 were .01 micrograms of alpha-ergocryptine/mL of culture medium, .01 microgram of ergonovine/mL of culture medium, .01 gram-equivalents of endophyte-infected tall fescue seed/mL of culture medium, and .01 gram-equivalents of endophyte free tall fescue seed/mL of culture medium. Treatments for Exp. 2 consisted of 10(-4), 10(-6), and 10(-8) M concentrations of perloline, N-formyl loline, N-acetyl loline, N-methyl loline, and alpha-ergocryptine. alpha-Ergocryptine suppressed (P less than .10) prolactin secretion in both experiments. Ergonovine and perloline both stimulated (P less than .10) prolactin secretion. The loline alkaloids (N-formyl loline, N-acetyl loline, N-methyl loline) had no effect on prolactin secretion. The endophyte-infected seed extract treatment suppressed (P less than .10) prolactin secretion. The endophyte-free seed extract treatment had no effect on prolactin secretion. In Exp. 2, prolactin secretion from AP responded to alpha-ergocryptine treatment in a dose-dependent fashion.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
105.
106.
In 1980 and 1981, pitfall traps and an insect vacuum net were used to sample polyphagous predators in plots of winter wheat treated or not treated with herbicides. Dense populations of broad-leaved and grass weeds occurred in untreated plots. Significantly more large carabids (Pterostichus melanarius and P. madidus) were caught in pitfall traps in treated than in untreated plots, where their activity may have been reduced by the vegetation. Numbers of the carabids Loricera pilicornis, Agonum dorsale and Amara species, of the staphylinids Philonthus cognatus, Tachinus signatus, Tachyporus species and Aleocharinae and of larvae of both families were significantly reduced by herbicide treatments. Some species were unaffected by the treatments. Cereal aphids were sparse during the trials and their numbers were unaffected by herbicide treatments. In 1981, more Sitobion avenae occurred on the cultivar Maris Huntsman than on Kador. 相似文献
107.
G H Turnwald J J McClure M D Powell K P Shao 《American journal of veterinary research》1988,49(12):2076-2080
Peanut agglutinin (PNA) and surface immunoglobulin (SIg) were investigated as markers for T and B lymphocytes in blood and lymphoid tissues of dogs of various ages. In the blood study, 4 age groups (n = 8 dogs/group) were used. The mean (+/- SD) percentages of PNA-positive (PNA+) cells were 68.4 +/- 8.6% (group 1, less than 1 year old), 70.3 +/- 9.2% (group 2, 1 to 2 years old), 72.0 +/- 3.7% (group 3, 5 to 6 years old), and 63.8 +/- 10.1% (group 4, 10 to 11 years old). The mean percentages of SIg-positive (SIg+) cells in blood were 32.1 +/- 10.6% (group 1), 43.2 +/- 7.0% (group 2), 34.3 +/- 4.8% (group 3), and 35.0 +/- 6.8% (group 4). The mean total percentages of PNA+ and SIg+ cells were 100 +/- 6.0% (group 1), 113.5 +/- 4.9% (group 2), 106.3 +/- 5.3% (group 3), and 98.9 +/- 9.2% (group 4). The proportions of PNA+ and SIg+ cells in dogs of group 2 were significantly (P less than 0.05) different from those in dogs of the other groups. Serial changes in PNA+ and SIg+ cells were investigated in blood of 6- to 29-week-old pups (n = 8). A significant (P less than 0.05) transient decrease in PNA+ cells and a corresponding increase in SIg+ cells was observed in pups between 14 and 17 weeks old. Lymphoid tissue specimens and blood samples were obtained from 2- to 6-month-old dogs (n = 11) and from 6- to 12-month-old dogs (n = 10).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
108.
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110.