Late laying hens deposit dietary antioxidants preferentially in the egg and not in the body

The allocation of nutrients in the metabolism of laying hens favors the egg over the body. It is unclear whether this programming also includes micronutrients and antioxidants. This was tested with five by seven 76-wk-old Heisdorf & Nelson Brown Nick layers. They were fed a basal diet low in antioxidants either unchanged (control) or supplemented with 40 IU of α-tocopherylacetate/kg of diet (vitamin E) or 2.5% chokeberry pomace, rose hip, or sage in the last 4 wk before slaughter. The traits measured were subjected to ANOVA. The additives did not affect ADFI, performance, egg quality, carcass, or meat quality. Yolk tocopherol contents were higher with vitamin E and sage compared with control and rose hip treatments. Oxidative stability was more affected in egg yolk powder than in the meat. After 12 wk of storage, yolks from vitamin E-treated hens were lowest in TBA levels (5.0 mg of malondialdehyde/kg), followed by chokeberry (8.7) and sage (8.8). Rose hip (18.1) and control (18.9) treatments were similar. In meat, TBA was slightly decreased after 9 d of storage in meat from chokeberry- and sage-supplemented hens (contrast analysis). In conclusion, antioxidant deposition to the egg seems to be part of the genetic determination of the hen. Adding antioxidants is therefore interesting for layer nutrition in general, and herbal additives allow performing this in a natural way. The programming for partitioning, however, renders the strategic feeding of antioxidants before slaughter, with the goal to increase oxidative stability of spent hen meat rather inefficient.     

<Superscript>15</Superscript>N uptake by mycorrhizal native and invasive plants from a N-eutrophied shrubland: a greenhouse experiment

In the coastal sage scrub (CSS) community of southern California, Artemisia californica and other native shrubs are gradually being replaced by invasive annual grasses, especially Bromus madritensis ssp. rubens. This decline may be attributed, in part, to local atmospheric N deposition, which causes elevated soil NO₃ ^–. Unaffected soils have low N with a relatively higher concentration of NH₄ ⁺ than NO₃ ^–. The objectives in this study were: (1) to compare the short-term uptake of ¹⁵NO₃ ^– and ¹⁵NH₄ ⁺ by B. madritensis and A. californica and (2) to discern whether ¹⁵NO₃ ^– or ¹⁵NH₄ ⁺ uptake is influenced by the mycorrhizal status of either plant species. Analysis of ¹⁵N concentrations indicated that both A. californica and B. madritensis took up more ¹⁵NO₃ ^– than ¹⁵NH₄ ⁺, but overall, B. madritensis took up 6–15 times more of both forms of ¹⁵N than A. californica. Mycorrhizal A. californica had an increased ¹⁵NH₄ ⁺ concentration in roots but not shoots. In B. madritensis, the only mycorrhizal response was a reallocation of ¹⁵NO₃ ^–, with mycorrhizal plants retaining a higher proportion of ¹⁵NO₃ ^– in roots. Overall, arbuscular mycorrhizae had a small effect on ¹⁵N uptake in this short-term study. However, the ability of B. madritensis to take up so much ¹⁵N may explain in part why it has been so successful in replacing A. californica in CSS.     

一串红新品种‘神州红’

 一串红新品种‘神州红’株形紧凑, 分枝性强; 直立, 矮生。花鲜红色, 总状花序长15 cm左右。春季始花期为播种后135 d, 单花序观赏期38 d; 秋季始花期为播种后91 d, 单花序观赏期29 d。耐热性较强, 适宜杭州、衢州及气候类似地区春秋两季栽培。     

PP_(333)、B_9、CCC对盆栽一串红矮化效应研究

高质量的盆花要求株型矮小、紧凑,茎杆粗壮,花繁叶茂。一串红(Salvia splen-dens Ker.-Gawl.)是各地广泛栽培,尤其是国庆节期间布置花坛美化环境的重要盆栽花卉。但在普通栽培条件下,大多株高茎瘦,花叶稀疏,脱脚现象严重,容易倒伏,影响观赏价值。目前生产上多采用反复摘心来促使分枝,控制株高,但费工费时,经济效益差。应用植物生长阻滞剂控制盆栽植物的株高是一项重要现代农业技术措施。多效唑(PP_(333))、比久(B_9)、矮壮素(CCC)为几种常用的植物生长阻滞剂,国外在金鱼草、百合和一品红等多种观赏植物上已有研究,我国也有用PP_(333)和B_9处理培养案头菊的实例。但在一串红上应用的报道甚少。为此,我们进行了用叶面喷布PP_(333)、B_9和CCC的方法促使盆栽一串红矮化的试验。 材料与方法 本试验于1989年在南京玄武湖公园进行。     

Plant extracts containing caffeic acid and rosmarinic acid inhibit zoospore germination of Phytophthora spp. pathogenic to Theobroma cacao

The three most important species of Phytophthora worldwide causing black pod disease of cacao are P. palmivora, P. megakarya, and P. capsici. Chemicals are effective in controlling this disease but more natural methods would be preferred. One alternative is to use natural plant extracts. Rosemary and lavender leaf extracts were found to be effective in reducing germination of P. capsici, P. megakarya, and P. palmivora zoospores when supplemented to agar plates at different dilutions. The extracts displayed the biggest impact on P. megakarya zoospores where it completely inhibited germination at a 25% dilution of the prepared extract. When applied to cacao leaf disks, rosemary extract reduced necrosis caused by P. megakarya zoospores. In a bioassay, pears first treated with lavender extract showed no symptoms of P. megakarya infection compared with the non-treated controls. Based upon HPLC analyses, the active compound in these extracts was determined to be caffeic acid, rosmarinic acid or some simple derivative thereof. When added to agar plates, synthetic caffeic acid and rosmarinic acid completely inhibited germination of P. capsici, P. megakarya, and P. palmivora zoospores at concentrations of 3 and 6 g l⁻¹, respectively. In addition, sage and rice bran extracts, which both contain caffeic acid, were also effective in reducing zoospore germination. In contrast, inhibition of Botrytis cinerea or Trichoderma asperellum conidia germination did not occur, displaying some level of specificity. These extracts could provide an economically safe method for reducing damage caused by black pod disease on cacao until resistant varieties are developed and released.     

一串红新品种‘红运’

一串红新品种‘红运’株形直立紧凑,分枝性强,矮生,盛花期平均株高17.3 cm,冠幅21.7 cm,叶片深绿,叶脉下陷明显,叶表面光泽度及叶柄显色程度较强;花红色,花序紧凑,花冠较长,观赏效果佳;开花早,播种至始花94 d,观赏期长;耐热性较好。适宜浙江省及气候类似地区栽培。     

Ecosystem Water Availability in Juniper versus Sagebrush Snow-Dominated Rangelands

Western Juniper (Juniperus occidentalis Hook.) has greatly expanded in the past 150 + years and now dominates over 3.6 million ha of rangeland in the Intermountain Western United States. The impacts of juniper encroachment on critical ecohydrological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as the greater sage grouse (Centrocercus urophasianus), remain poorly understood. The goal of this study is to better understand how juniper encroachment affects water availability for ecohydrologic processes and associated wildlife habitat in snow-dominated sagebrush (Artemisia spp.) steppe ecosystems. A 6-yr combined measurement and modeling study is conducted to explore differences in snow distribution, water availability, and annual water balances between juniper-dominated and sagebrush-dominated catchments. Although there is large interannual variability in both measured weather data and modeled hydrologic fluxes during the study, results indicate that juniper-dominated catchments have greater peak accumulations of snow water equivalent, earlier snow melt, and less streamflow relative to sagebrush-dominated catchments. Water delivery is delayed by an average of 9 days in the sagebrush-dominated scenario compared with the juniper-dominated scenario as a result of increased water storage in snow drifts. The delayed water input to sagebrush-dominated ecosystems in typical water years has wide-ranging implications for available surface water, soil water, and vegetation dynamics associated with wildlife habitat for sagebrush obligates such as sage grouse. Results from this study imply that the retention of high-elevation, sagebrush-dominated landscapes may become crucial for sage grouse habitat management if mid- and low-elevation precipitation continues to transition from snow to rain dominated.     

Mapping Tree Canopy Cover in Support of Proactive Prairie Grouse Conservation in Western North America

Invasive woody plant expansion is a primary threat driving fragmentation and loss of sagebrush (Artemisia spp.) and prairie habitats across the central and western United States. Expansion of native woody plants, including conifer (primarily Juniperus spp.) and mesquite (Prosopis spp.), over the past century is primarily attributable to wildfire suppression, historic periods of intensive livestock grazing, and changes in climate. To guide successful conservation programs aimed at reducing top-down stressors, we mapped invasive woody plants at regional scales to evaluate landscape level impacts, target restoration actions, and monitor restoration outcomes. Our overarching goal was to produce seamless regional products across sociopolitical boundaries with resolution fine enough to depict the spatial extent and degree of woody plant invasion relevant to greater sage-grouse (Centrocercus urophasianus) and lesser prairie-chicken (Tympanuchus pallidicinctus) conservation efforts. We mapped tree canopy cover at 1-m spatial resolution across an 11-state region (508 265 km²). Greater than 90% of occupied lesser prairie-chicken habitat was largely treeless for conifers (< 1% canopy cover), whereas > 67% was treeless for mesquite. Conifers in the higher canopy cover classes (16 ? 50% and > 50% canopy cover) were scarce (< 2% and 1% canopy cover), as was mesquite (< 5% and 1% canopy cover). Occupied habitat by sage-grouse was more variable but also had a relatively large proportion of treeless areas ($\stackrel{?}{x}$ = 71, SE = 5%). Low to moderate levels of conifer cover (1 ? 20%) were fewer ($\stackrel{?}{x}$ = 23, SE = 5%) as were areas in the highest cover class (> 50%; $\stackrel{?}{x}$ = 6, SE = 2%). Mapping indicated that a high proportion of invading woody plants are at a low to intermediate level. Canopy cover maps for conifer and mesquite resulting from this study provide the first and most geographically complete, high-resolution assessment of woody plant cover as a top-down threat to western sage-steppe and prairie ecosystems.     

一串红茎腐病的发生及防治

不少养花爱好者缺乏防治一串红茎腐病的经验,本文着重介绍了一串红茎腐病的正确识别、发病规律及防治经验,以供养花爱好者参考。     

一串红盆栽基质配方筛选正交试验分析

应用正交试验对一串红盆栽生产基质进行了研究,对一串红的13个观测指标进行主成分分析,综合为3个主成分.计算主成分综合得分,作为分析指标进行方差分析.结果表明:泥炭:珍珠岩:蛭石为2:2;2(体积比)为最佳组合.