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41.
Splenic lymphoma in a short-beaked echidna (Tachyglossus aculeatus)   总被引:1,自引:1,他引:0  
A 23-year-old, male short-beaked echidna ( Tachyglossus aculeatus ) housed at a North American zoo was successfully treated for flea-associated anaemia, but subsequently died. Cause of death was presumptive septicaemia secondary to splenic lymphoma. This is only the fifth case of neoplasia reported in this monotreme species, and the first from outside of Australia.  相似文献   
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Summary The responses of two potato cultivars, Crystal and Norgold Russet, to a standard protoplast regeneration procedure were examined. Both cultivars yielded protoplasts that survived and grew in the initial plating medium. Protoplast-derived callus tissue also grew on the callus proliferation medium. The cultivars differed most in their ability to survive on the shoot induction medium; changes in its growth regulator content and the quantity of agar increased shoot production of Crystal from 1% to 30% and that of Norgold Russet from 7% to 24% on modified medium under low light intensity. Journal Series Paper 1699 of the North Dakota Agricultural Experiment Station.  相似文献   
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Several important postharvest characteristics were evaluated in protoplast-derived somaclones after two consecutive growing seasons (1987, 1988). None of the somaclones had tuber yields significantly greater than the protoplast donor Crystal mother clone (MC), however, 8 of 37 clones had significantly lower yields. Of the 25 somaclones selected forErwinia soft rot resistance testing, 1 clone demonstrated significantly elevated resistance to soft rot while 12 clones were found to be significantly more susceptible relative to MC. Over half (20) of the 33 somaclones tested showed significant improvement in resistance to tuber bruising while only a single clone was more susceptible than MC. Based upon Agtron color analysis, 5 somaclones showed significantly enhanced chip color when processed directly out of cold storage (6 C). Six clones had significantly improved chip color after a reconditioning period (20 C). Four of the clones with significantly better cold processing characteristics were also among the 6 with significantly enhanced processing quality after reconditioning. Some clones showed improvement in two or more characteristics. Clone 72–93 had significantly elevated resistance to both bacterial soft rot and tuber bruising while the bruise resistant clones 74-14, 71-41, 71-18 and 71-2 demonstrated significant improvement in both cold and reconditioned processing characteristics.  相似文献   
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‘Dakota Rose’ is a medium-maturing, white-fleshed, red-skinned cultivar that retains its bright red color in storage. Tubers have very smooth skin with an oblong shape. Yields are equivalent, or superior, to ‘Red Norland’, but lower than ‘Red Pontiac’, a late-maturing cultivar. Dakota Rose produces a high percentage of U.S. No. 1 tubers and few oversized tubers. Sensory evaluation scores for baked, boiled, and microwaved potatoes are similar to Red Norland and Red Pontiac, standard red tablestock cultivars. The specific gravity averaged about 1.067 across irrigated and non-irrigated sites, a typical value for a red tablestock cultivar. Adequate skin set for handling has often been difficult to achieve; application of nitrogen early in the growing season, coupled with chemical vinekill 3 weeks prior to harvest aids in minimizing the problem. Dakota Rose was released by the North Dakota Agricultural Experiment Station on 17 November 2000.  相似文献   
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Changes in the oomycetePhytophthora infestans in the United States and other parts of the world pose a significant threat to potato production. A continual evaluation of potato clones for resistance to late blight is necessary to identify clones with resistance and to monitor the stability of resistance in light of the emergence of new and more aggressive strains of this pathogen. Twentytwo potato clones (10 cultivars and 12 selections) were evaluated in 1997 for late blight resistance at seven U.S. locations. Seven late blight differentials (R1R2R3R4, R1R2R4, R1R3R4 R3, R8 R10, and Rmulti) were also included in the test at five of these locations. The US-8 strain of P.infestans was present at all locations. Percent infected foliage was recorded at approximately weekly intervals following the onset of disease. Area under the disease progress curve (AUDPC) was calculated. The nonparametric stability statistics mean absolute rank differences (S i (1) ) and variances of the ranks (S i (2) ) were used to analyze phenotypic stability. Although neither of these statistics was significant for individual clones, both of these statistics were significant when summed over clones, indicating the importance of genotype × environment interactions on the rankings of these clones across locations. The most late blight-resistant and susceptible clones were the most stable; clones in the intermediate ranges were most subject to rank changes due to genotype × environment interactions. The most late blight-resistant clones were AWN86514-2, B0692-4, B0718-3, and B0767-2. The most susceptible clones were B0811-13, B1004-8, Nor-Donna, and Krantz. AUDPC was very low for the late blight differentials R8 and Rmulti, moderately low for R10 and very high for the remaining differentials. This study is important in characterizing the reaction of potato clones to new strains of P.infestans.  相似文献   
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Ribavirin (virazole) treatment of cultured axillary bud tips (3-4 mm) was tested as a method of eradicating potato virus Y (PVY) and potato virus S (PVS) from two potato cultivars, Norchip and Desiree. Ribavirin treatment was phytotoxic at all concentrations tested, but cultivars treated at 5 mg/1 were visually similar to the nontreated control cultures after 20 weeks. The buds treated with ribavirin at 20 mg/1 had a survival rate of only 30–40%. Virus assays indicated that 2,74,82, and 89% of the plants were free of PVY, and 1, 71, 83 and 90% were free of PVS, 20 weeks following treatment with 0, 5, 10, and 20 mg/1, respectively. Virus assays indicated that 2, 74, 82, 89% of the plants were free of PVY, and 1, 71, 83 and 90% were free of PVS, 20 weeks following treatment with 0, 5, 10, and 20 mg/1 ribavirin treatment respectively for cultivar Norchip. Desiree cultivar assayed 2, 69, 80 and 86% free of PVY and 2, 74, 85 and 93% free of PVS, 20 weeks following treatment with 0, 5, 10, and 20 mg/1 ribavirin treatment respectively.  相似文献   
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Crystal is an oblong to round white-skinned cultivar with high yielding ability. It has medium total solids and is medium late in maturity. Chipping tests have shown that Crystal is comparable to Kennebec in chip color but not as good as Norchip. It has resistance to infection by Potato Virus X and to some strains of common scab (Streptomyces scabies).  相似文献   
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