不同年代大豆品种(系)根系生长动态的比较研究   总被引：1，自引：0，他引：1  

王智权  谢甫绨  王海英  丁雪丽  谢志涛  张惠君 《辽宁农业科学》2006,(4):9-12

不同年代大豆品种根干重积累动态可以用Logistic曲线方程进行模拟。在不同施肥水平下,根干重最大增长速率及出现的时间和平均增长速率有所不同。根干重最大增长速率出现的时间,中国当代品种、美国当代品种及中国20世纪20年代的品种间差异不显著,各品种间差异及施肥处理间差异也不显著。根干重最大增长速率,中国当代、美国当代及中国20世纪20年代的品种间差异不显著,各品种间差异也不显著,施肥处理间差异显著。平均增长速率,中国当代、美国当代及中国20年代的品种间差异显著,各品种间及施肥处理间差异也显著。不同施肥水平、不同生育时期,中国当代品种与美国当代品种根干重都比中国20年代品种大。  相似文献   

Oroville earthquakes: normal faulting in the sierra nevada foothills     

Bufe CG  Lester FW  Lahr KM  Lahr JC  Seekins LC  Hanks TC 《Science (New York, N.Y.)》1976,192(4234):72-74

Aftershocks of the Oroville, California, earthquake of 1 August 1975 define a 16- by 12-kilometer fault plane striking north-south and dipping 60 degrees to the west to a depth of 10 kilometers. Focal mechanisms from P-wave first motions indicate normal faulting with the western, Great Valley side downdropped relative to the Sierra Nevada block. The northward projection of the fault plane passes beneath Oroville Dam and crops out under the reservoir.  相似文献   

Point mugu, california, earthquake of 21 february 1973 and its aftershocks     

Ellsworth WL  Campbell RH  Hill DP  Page RA  Alewine RW  Hanks TC  Heaton TH  Hileman JA  Kanamori H  Minster B  Whitcomb JH 《Science (New York, N.Y.)》1973,182(4117):1127-1129

Seismological investigations show that the Point Mugu earthquake involved north-south crustal shortening deep within the complex fault zone that marks the southern front of the Transverse Ranges province. This earthquake sequence results from the same stress system responsible for the deformation in this province in the Pliocene through Holocene and draws attention to the significant earthquake hazard that the southern frontal fault system poses to the Los Angeles metropolitan area.  相似文献   

Biomedical research publication system     

Wang YL  Burridge K  Dembo M  Gabbiani G  Hanks SK  Hosoya H  Janmey P  Karlsson R  Lindberg U  Mabuchi I  Otey C  Rottner K  Small JV  Wang CL  Zigmond S 《Science (New York, N.Y.)》2004,303(5666):1974-1976

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Maternal characteristics of young dams representing Bos taurus and Bos indicus x Bos taurus breed types     

C M Bailey  D R Hanks  W D Foote  Y O Koh 《Journal of animal science》1988,66(5):1144-1152

Reproductive traits and preweaning growth of progeny from young Hereford, Red Poll, Hereford X Red Poll, Red Poll X Hereford, Angus X Hereford, Angus X Charolais, Brahman X Hereford and Brahman X Angus dams were evaluated. First-calf heifers were mated with Red Angus bulls; Santa Gertrudis sires were used for each cow's second and third breeding season. Herefords, Red Polls and Hereford-Red Poll crosses were below average in percentage of calves weaned, whereas Angus-sired and Brahman-sired dams exceeded the overall mean. Angus X Charolais (P less than .10), Brahman X Hereford (P less than .01) and Brahman X Angus (P less than .10) dams weaned a higher percentage of calves than straightbred Herefords. None of these breed types differed from young Angus X Hereford females in reproductive performance. Angus X Charolais calves ranked highest in 180-d calf weight, exceeding progeny from both Hereford (P less than .01) and Angus X Hereford (P less than .10) dams. Brahman X Hereford dams weaned heavier (P less than .05) calves than Herefords, but their progeny did not differ at weaning from those reared by Angus X Herefords. Calves from Brahman X Angus dams weighed 12.7 kg less (P less than .01) than Angus X Hereford progeny. Analysis of the Hereford-Red Poll diallel showed evidence of (P less than .10) maternal heterosis in 180-d calf weight.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

The responses of virus-free and virus-infected lily ‘Enchantment’ to the retardants ancymidol,chlormequat chloride,mepiquat chloride and BTS 44 584, a ternary sulphonium carbamate     

Roger Menhenett  Gordon R. Hanks 《Scientia Horticulturae》1982,17(1):61-70

The new growth retardants mepiquat chloride (a quaternary ammonium compound of the piperidinium type, coded BAS 083 00W) and a ternary sulphonium carbamate (coded BTS 44 584) were compared with ancymidol (A-Rest or Reducymol) and chlormequat chloride (Cycocel) for their ability to dwarf virus-free and virus-infected (ordinary) Mid-Century Hybrid lily cultivar ‘Enchantment’. Single compost drenches were given 3 weeks after transferring plants to the glasshouse.Compared with the virus-infected control plants, virus-free controls were 62% taller and 33% greater in leaf spread; floret number was approximately doubled and floret diameter was increased by 12%, but flowering was delayed by 6.5 days. The length of the lower stem bearing dead leaves was 15% of the total in virus-infected controls and 3% of the total in virus-free controls.Ancymidol, chlormequat chloride and mepiquat chloride were all effective growth retardants, and were without adverse side-effects. On a concentration basis, mepiquat chloride was 2–2.5 times as active as chlormequat chloride in reducing stem extension, but ancymidol was several orders of magnitude more active than both those compounds. With BTS 44 584, the maximum reduction in stem length obtained was 16% compared to controls. The decreases in stem extension were more pronounced, in both percentage and absolute terms, in the virus-free bulbs. Nevertheless, for a given retardant treatment, plants of the virus-free stock remained taller than those of the virus-infected stock. As a result, 2–3 times the amount of an active retardant was required by virus-free than by virus-infected plants in order to produce similar stem lengths at flowering. Effects of the retardants on the time of flowering, flower number, floret diameter and leaf spread were small, but increasing concentrations of all chemicals progressively increased the proportion of the stem bearing dead leaves.The effects of ancymidol, chlormequat chloride and mepiquat chloride persisted in the year after treatment.  相似文献   

Early forcing of narcissus: The effects of lifting date and stage of floral development at the start of cooling     

Gordon R. Hanks  A.R. Rees 《Scientia Horticulturae》1984,23(3):269-278

Early Narcissus flowers may be obtained if bulbs are lifted early from the field, warm-stored (35°C) and then cool-stored (9°C) before forcing in a glasshouse. The earliest satisfactory forcing was investigated, in ‘Carlton’ and ‘Fortune’, by lifting weekly from 27 May to 22 June, and storing at 17°C for 0–7 weeks between warm- and cool-storage. Storage at 17°C is usually intercalated to allow the completion of flower differentiation prior to the start of cool storage.After warm-storage, the bulbs lifted on 27 May and 22 June had reached Stages Sp and A2 of flower differentiation, respectively; 5–7 weeks of 17°C-storage were then needed to reach complete flower differentiation (Stage Pc). Cool storage was therefore begun with bulbs ranging from Stage Sp to Stage Pc. The earliest cooled bulbs had progressed only to Stage A2, and all others to Stage Pc, after 14–16 weeks of cool storage. No floral defects (e.g., split paracorolla) were noted in any treatment, but in ‘Carlton’, about half the bulbs lifted on 27 May and stored for 0 or 1 week at 17°C did not yield a flower, due to failure of the scape to elongate and death of the flower bud within the spathe.Duration of the glasshouse period was reduced by later lifting and by longer 17°C-storage, but following lifting on 15 or 22 June and 2 or more weeks at 17°C, differences were trivial. For flowering within 30 days in the glasshouse, 5 or 6 weeks' 17°C-storage was needed with 27 May lifting, reducing to 1 week at 17°C after 22 June lifting. Flowering within 21 glasshouse days was achieved only after 15 or 22 June lifts followed by 4–5 weeks at 17°C. The earliest flowers in ‘Fortune’ (7 November) were produced following 3–5 weeks at 17°C after lifting on 27 May or 1 June, or following 1–2 weeks at 17°C after later lifting. In ‘Carlton’, the earliest flowers (23 November) followed 2–3 weeks at 17°C after lifting between 1 and 15 June, or 0–1 weeks at 17°C after the last lifting date (22 June). Following the use of 3 weeks' 17°C-storage, flowering date was about equal, irrespective of lifting date. However, further extension of 17°C-storage resulted in a delay in flowering date. Scape length increased irregularly with longer storage at 17°C; scapes were taller following later lifting (8–22 June) than following earlier lifting. Differences in flower diameter between treatments were relatively small.  相似文献   

The experimental production of big liver and spleen disease in broiler breeder hens     

SK CRERAR  GM CROSS 《Australian veterinary journal》1994,71(12):414-417

SUMMARY Big liver and spleen disease (BLS) was reproduced experimentally by intravenous (IV) and oral (PO) administration of BLS inocula to susceptible broiler breeder hens 34 to 36 weeks of age. Serological and pathological signs of BLS similar to those seen in the natural disease occurred in inoculated and in-contact birds. Splenomegaly was the earliest and often the only necropsy finding, with hepatomegaly and kidney enlargement occurring in some birds later in the course of the disease. After IV administration, serum antigen was detected between 2 and 4 weeks, and antibody between 3 and 5 weeks. After PO administration, antigen was detected between 2 and 4 weeks, and antibody between 3 and 6 weeks. Antibody persisted in all birds to the end of the experiment (6 weeks), and horizontal transmission probably occurred since in-contact birds developed BLS. Liver probably contained the highest concentration of BLS agent because it had the highest infectivity.  相似文献   

The Effects of the Periodical Use of In-feed Chlortetracycline on the Reproductive Performance of Gilts and Sows of a Commercial Pig Farm with a History of Clinical and Subclinical Viral and Bacterial Infections   总被引：1，自引：0，他引：1  

C Alexopoulos  GC Fthenakis  A Burriel  E Bourtzi-Hatzopoulou  SK Kritas  A Sbiraki  SC Kyriakis 《Reproduction in domestic animals》2003,38(3):187-192

The objective of this study was to assess the effects of in‐feed chlortetracycline (CTC) as a measure of preventing or minimizing infectious problems of reproductive failure in gilts and sows. In a farm of 400 Large White × Landrace gilts and sows with a clinical history of porcine respiratory and reproductive syndrome (PRRS) virus, the animals were treated with CTC. Treatment consisted of 10 g CTC sow/day for 15 days every 3 months. It improved the health status of sows by decreasing post‐farrowing clinical mastitis and vaginal discharges, abortions, return‐to‐oestrus and irregular return‐to‐oestrus rates. These beneficial effects had a positive impact on the performance of the litter. More piglets were born live and weaned. These positive effects improved with repeated use of CTC. The serological evidence of PRRS virus, Leptospira spp. and Chlamydia spp. and the subsequent beneficial use of the antimicrobial agent indicate that reproductive failure, possibly resulting from the bacterial agents can be controlled with in‐feed use of broad spectrum antimicrobials.  相似文献   

An evaluation of new growth retardants on Mid-Century Hybrid lilies     

Gordon R. Hanks  Roger Menhenett 《Scientia Horticulturae》1980,13(4):349-359

The new growth retardants piproctanyl bromide (Alden or Stemtrol), dikegulac-sodium (Atrinal), PP 528 (a phenyl tetrazole compound) and 2,3-dihydro-5,6-diphenyl-1,4-oxathiin (coded UBI-P293) were compared with the established compounds chlormequat chloride (Cycocel), ancymidol (A-Rest or Reducymol) and chlorphonium chloride (Phosfon), for their ability to dwarf Mid-Century Hybrid lily cultivars ‘Enchantment’ and ‘Joan Evans’. Single compost drenches were given 2–3 weeks after transferring plants to the glasshouse.Piproctanyl bromide at high concentrations (2000 mg a.i. per plant) produced some dwarfing, as did chlorphonium chloride (at 250 mg a.i. per plant). Chlormequat chloride produced a similar response at 1250 mg a.i. per plant, but on a concentration basis ancymidol was by far the most active compound (only 0.25–0.50 mg a.i. per plant was required). Plant and flower quality was generally good with these 3 chemicals.Dikegulac-sodium reduced stem length but prevented the development of flower buds and the plants senesced. PP 528 also restricted stem extension but plant quality was unsatisfactory; increasing concentrations led to smaller florets, weaker stems and drooping leaves. UBI-P293 produced as great a reduction in stem length as did ancymidol, and 100 mg a.i. per plant was as active as 500 mg. However, as the concentration was raised there was a decrease in floret size and number.  相似文献