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91.
92.
对采集自我国12个不同分布区的105个野生披碱草属(Elymus)牧草居群的14项穗部形态指标进行研究,结果表明,我国披碱草属牧草种质资源穗部遗传多样性丰富,居群内多样性指数(H′)在0.784~1.652,平均多样性指数为1.396;居群总平均多样性指数为1.936,居群间表型分化系数为27.89%。14项穗部形态性状在居群内多样性、居群总多样性以及变异系数变化不完全一致,居群内H′最高的为旗叶与穗基部长度(1.648),居群总H′最高的为小穗长(2.054),变异系数最大的为第一颖芒长(58.932%),平均变异系数为31.22%,表明穗部形态性状均存在较大的变异,F检验差异极显著。引起居群形态差异的性状与种子产量密切相关,主要包括穗长、穗宽、第一颖芒长、第一外稃长、第一内稃长、第一外稃芒长、每穗轴小花数、第一颖长和第一颖宽。我国野生披碱草属牧草的多样性和分布格局是相关的,我国西北部是野生披碱草属牧草分布中心,也是披碱草属牧草的多样性中心。此外,提出了我国披碱草属牧草保护的策略。 相似文献
93.
Miriam S Martin Michael D Kleinhenz Lily N Edwards-Callaway Terry E Engle Octavio Guimaraes David W Schafer Shawnee R Montgomery Andrew K Curtis Mikaela M Weeder Devin R Jacobs Johann F Coetzee 《Journal of animal science》2022,100(3)
Hot-iron branding uses thermal injury to permanently identify cattle causing painful tissue damage. The primary objective was to examine the physiological and behavioral effects of oral meloxicam (MEL), compared to a control, administered at the time of hot-iron branding in Angus and Hereford steers and heifers. The secondary objectives were to investigate breed and sex effects on pain biomarkers. A total of 70 yearlings, consisting of 35 heifers and 35 steers (Angus, Hereford, or Angus × Hereford), were enrolled in the study. Animals were blocked by sex, randomized across weight, and assigned to receive MEL (1 mg/kg) or a placebo (CON). Biomarkers were assessed for 48 h after branding and included infrared thermography (IRT), mechanical nociceptive threshold (MNT), accelerometry and a visual analog scale (VAS), and serum cortisol and prostaglandin E2 metabolites (PGEM). Wound healing was assessed for 12 wk. Hair samples to quantify cortisol levels were taken prior to and 30 d post-branding. Responses were analyzed using repeated measures with calf nested in treatment as a random effect, and treatment, time, treatment by time interaction, breed, and sex as fixed effects. There was a treatment by time interaction for PGEM (P < 0.01) with MEL having lower values than CON at 6, 24, and 48 h (MEL: 18.34 ± 3.52, 19.61 ± 3.48, and 22.24 ± 3.48 pg/mL, respectively; CON: 32.57 ± 3.58, 37.00 ± 3.52, and 33.07 ± 3.48 pg/mL; P < 0.01). MEL showed less of a difference in maximum IRT values between the branded (2.27 ± 0.29 °C) and control site (3.15 ± 0.29 °C; P < 0.01). MEL took fewer lying bouts at 0–12 h (4.91 bouts ± 0.56) compared with CON (6.87 bouts ± 0.55; P < 0.01). Compared with Hereford calves, Angus calves exhibited greater serum but lower hair cortisol, greater PGEM, more lying bouts, and less healed wound scores at 3, 4, and 5 wk. Compared with heifers, steers exhibited lower PGEM, lower branding site and ocular IRT, higher MNT, and lower plasma meloxicam levels. Steers spent more time lying, took more lying bouts and had greater VAS pain, and more healed wound scores at 5 wk than heifers. Meloxicam administration at branding reduced branding and control site temperature differences and reduced lying bouts for the first 12 h. Breed and sex effects were observed across many biomarkers. Changes from baseline values for IRT, MNT, lying time, step count, VAS pain, and wound scoring all support that branding cattle is painful. 相似文献
94.
美国杏李不同栽培模式适应性评价 总被引:1,自引:0,他引:1
本文通过对不同品种不同栽培模式美国杏李生长和林地土壤含水量动态变化分析表明:栽培模式3抗旱性好,在研究地可广泛应用;栽培模式2在研究地比较适合在有一定灌溉条件的地区应用;栽培模式1抗旱性适中,可在研究地土壤水分条件尚好的地区应用;栽培模式5可在研究地土壤水分条件尚好的地区控制应用;栽培模式4在研究地不宜采用。 相似文献
95.
Martin Körschens 《Archives of Agronomy and Soil Science》2013,59(2):77-92
Im Statischen Düngungsversuch Bad Lauchstädt werden nach Erweiterung der Versuchsfrage seit 1978 die Prüffaktoren: Stalldung (2 Stufen), Corg‐Gehalt im Boden (6 Stufen) und Mineral‐N‐Mengen (5 Stufen) in der Fruchtfolge Kartoffeln, Winterweizen, Zuckerrüben, Sommergerste geprüft. Nur bei Sommergerste konnte eine Ertragswirkung des Stalldungs im Vergleich zu ausschließlicher Mineraldüngung nachgewiesen werden. Die jährlichen Veränderungen der Corg‐ und Nt‐Gehalte im Boden betrugen bei jeweils extremen Änderungen des Düngungsregimes bis zu 0, 012% Corg bzw. 0,0013% Nt. 相似文献
96.
97.
A 140-day laboratory incubation, using surface soil from a long-term soybean tillage study, evaluated tillage influence on [14C]metribuzin degradation. Higher plant residue conditions in no-tillage (NT) soil inhibited metribuzin mineralization to [14C]carbon dioxide as compared to metribuzin degradation patterns observed in conventional tillage (CT) soil. At 140 days, relative abundance of extractable 14C components in NT included polar metabolites > metribuzin = deaminated metribuzin (DA) = deaminated diketometribuzin (DADK), while in CT, components included metribuzin > polar metabolites > DADK?DA. Conditions in NT apparently inhibited polar 14C degradation, and resulted in its accumulation, while in CT polar 14C degradation proceeded relatively rapidly. For both NT and CT, more 14 C was measured in an unextractable fraction than in any other fraction. A greater portion of the unextractable fraction in NT was associated with decomposed plant residue than in CT. Surface accumulation of crop residue, such as occurs under NT, provided a soil environment which altered metribuzin degradation patterns. 相似文献
98.
Christian Martin Pierre Davet Danielle Vga Camille Coste 《Pest management science》1991,32(4):427-438
When 42 field trials, carried out from 1975 to 1989 in the Perpignan region (France) for control of lettuce drop caused by Sclerotinia minor, were compared, a decrease in the field effectiveness of cyclic imides was perceptible, beginning approximately in 1985. Moreover, in 15 out of 46 commercial lettuce fields surveyed in 1988 and 1989, the effectiveness of iprodione was less than 80%, the level of acceptability for the growers. In these fields, fungicide degradation, estimated by 3,5-dichloroaniline formation, was faster than in soils in which S. minor was adequately controlled. Statistical analyses showed that the iprodione degradation index was strongly linked to the history of fungicide treatment and was weakly correlated to soil pH or clay content. All the fields characterized by low iprodione effectiveness were associated with high levels of fungicide treatment and high degradation index. Moreover, we observed that soil from a field which had received iprodione for more than ten years did not degrade vinclozolin quickly, while soil from another part of the same field which had been treated with vinclozolin for eight years degraded vinclozolin faster than iprodione. 相似文献
99.
The effectiveness of the Californian model Bugoff2 for Cydia pomonella was tested in Germany (4 years) and Italy (2 years), the Italian results confirming the German findings. In the first codling moth generation (air temperatures normally below 30 C) good agreement was found between field observations of egg hatching and the model's forecast. However, the model gave notable differences for the second generation, i.e. 3 weeks in Germany and 1 week in Italy, and a significant difference for the third generation in Italy. These divergencies arise from an overestimation of the development rate of the codling moth in Bugoff 2's heat unit table whenever air temperature exceeds the upper limit for development. As a result of modifications to Bugoff 2, an example of a better simulation of the codling moth egg hatch in Germany and Italy is discussed. 相似文献
100.
The standard ELISA method for detection of PVY in dormant potato tubers was compared with recently developed methods: (1) a hybridization technique, using a complementary DNA-probe to PVYN; (2) three modifications of ELISA (standard monoclonal, Flegg & Clark polyclonal or monoclonal). Sap of six Dutch cultivars secondarily infected with PVY was subjected to these methods directly after lifting and after six subsequent one-week intervals during storage at 20°C. During storage the detectability of PVY decreased, irrespective of the diagnostic method applied. However, decrease was less in susceptible than in resistant cultivars. Although the hybridization technique yielded slightly better results than the standard ELISA procedure, it was time-consuming and involved hazardous reagents. The modifications of ELISA investigated were not, in general, more sensitive than standard ELISA. 相似文献