姜黄素吸收代谢及其对家禽繁殖调控作用研究进展

姜黄素是从姜科植物（如姜黄）、天南星科植物根茎中提取出来的多酚类化合物,主要在动物肠道中进行吸收代谢,具有抗炎、抗氧化、抗凋亡、抗衰老、神经保护、免疫调节及代谢调控等作用。姜黄素在动物体内生物利用度差,为提高姜黄素的利用度,通常将其制成多种制剂及配型（如膜制剂、纤维制剂、乳制剂、水凝胶制剂、胡椒碱、半萜类化合物、环糊精、葫芦巴膳食纤维和卵磷脂）。不同的制剂及配型可增加姜黄素产物稳定性,保障姜黄素的有效利用。家禽主要通过下丘脑 - 性腺轴负反馈调节机制来调控生殖细胞发育,实现繁殖调控。此外,家禽的繁殖性能易受外部因素影响,其中光照的影响最大。光照刺激产生的褪黑素具有强抗氧化性,能通过缓解卵巢和睾丸组织的线粒体功能障碍来抑制凋亡和衰老,保障下丘脑 - 性腺轴负反馈调节机制的稳定和氧化应激状态下的卵泡发育。肠道微生物产生的血清素是褪黑素的前体物质,可以影响褪黑素的生成;其次肠道微生物刺激肠上皮细胞中的传入神经直接影响下丘脑分泌促性腺激素释放激素;最后,肠道内产生的雌二醇（E2）可以通过血液进入卵巢组织,并促进卵巢发育。研究发现,姜黄素可通过肠道微生物产生的短链脂肪酸在体内发挥功能作用,但姜黄素是否通过肠道微生物产生的短链脂肪酸来影响家禽的繁殖性能亟待探究。该文综述了姜黄素的生物活性、代谢方式、产品研发利用以及对家禽繁殖调控的作用机制及相关研究进展,旨在为姜黄素作为饲料添加剂在家禽生产中的合理应用提供理论参考。     

宁波市杜鹃属植物资源调查

2012-2018年采用典型地块、典型线路详查为主,全面踏查为辅的方式对宁波市杜鹃属植物资源进行调查.结果 表明,宁波市共有野生及习见栽培的杜鹃属植物9种1变种1变型,其中野生种6种1变种1变型,习见栽培种4种.从水平分布看,有广域种、区域种、局域种和微域种4种类型;从垂直分布看,只分布于海拔700 m以上的有华顶杜鹃...     

长春市广场树木生长状况与园林植物多样性相关关系的研究

对长春市广场树木生长状况和园林植物多样性之间的关系研究表明:广场树木生长状况的数量化值与用Shannon-Wiener指数表示的园林植物多样性之间有良好的相关关系,相关方程为:G=1.972 2 2.667 86Ht-0.644 7Ht2,相关系数R=0.908 57,估计可靠性P=99.9%。     

北京八达岭植物群落多样性特征分析

根据34个样地的调查资料,分析了该地区森林植物群落物种多样性的特征:群落内各层物种丰富度指数的大小为草本层>灌木层>乔木层;多样性指数的大小为乔木层<灌木层和草本层。灌木层与草本层的多样性指数随林分郁闭度变化而变化,在林分郁闭度为25%的侧柏黄栌混交林中,灌木层的多样性指数和丰富度指数小于草本层;在郁闭度53%的杂木林中,灌木层和草本层的多样性指数接近;在郁闭度53%以上的各个群落内,草本层的多样性指数和丰富度指数基本上都大于灌木层。人工林中的物种多样性变化多样,明显低于天然林,林分层次单一,更新不良,缺乏灌木层和地被植物,生态系统很不稳定。     

不同红蓝LED光照时间对冰菜生长和品质的影响

[目的]研究不同红蓝光照时间对冰菜生长发育的影响,分析其生长发育规律.[方法]以冰菜为研究对象,以红蓝光为人工光源,在植物工厂及水培条件下,采用可循环营养液(EC2.8 dS/m,pH6.5),待冰菜幼苗长至4片叶后移植到水培立体培养系统中,设置红光与蓝光比例为(3:1),光强统一设定为300μmol/(m2·s),补...     

白蜡树属树种的园林应用探讨

目前对城市环境的要求越来越高,而提高环境质量的诸因素中,搞好园林绿化是最直接最有效的措施。构成园林绿化的主要材料是园林植物,其主体是树木。作为1个城市,当然是园林树木品种越多,越能构成丰富多彩的园林空间。但是由于地域、气候、科技、经济与自然因素和人为因素的制约,园林树木品种的利用也受到了限制。园林树种的选择不仅要适合本土生长,还要形成地方特色和风格。     

Amelioration of a highly degraded tropical alfisol by planting I. Changes in soil physical and chemical properties 1989-91

This paper examines soil amelioration by planting 15 leguminous and graminaceous plant species, including herbaceous annuals, perennials and biennials, and woody perennials and biennials. Disturbed and undisturbed natural regrowth were planted with leguminous species, in some cases with fertilizer applied at planting (400 kg ha⁻¹ of 15:15:15 NPK). The studies were made on two highly degraded sites in southwestern Nigeria which had been subjected to intensive mechanized cropping for a period of 10 years. Changes in soil physical and chemical properties were monitored from 1989 to 1991. Acacia difficilis, Brachiaria lata and Mucuna utilis had the lowest survival rates by the following growing season. Soil fertility and compaction levels differed between sites. Planting had no effect on the latter. The decreases in compaction (i.e. macroporosity) between 0.00 and 0.10 m depth at both sites one month before and five and 17 months after planting were 43, 59 and 61 per cent, respectively were attributed to exclusion of heavy machinery from the sites. Large decreases in fertility occurred at both sites and were attributed to a combination of nutrient extraction and to leaching. Between fallow species, exchangeable Ca, pH and the cation-exchange capacity (CEC) were greater and total acids lower for herbaceous cover compared with woody perennials, and was attributed to a higher Ca demand by the latter. Highest and lowest values of Ca, CEC and pH occurred in plots where plant material was returned to the soil (i.e. by cutting or die-back) and in cropped plots, respectively. Natural regrowth was as effective or better than planted species in improving soil physical and chemical properties. Therefore the use of exotic plant species for ameliorating highly degraded alfisols is unnecessary. Amelioration of highly degraded alfisols may be best effected by allowing natural regrowth to occur while excluding all mechanized traffic from the site.     

Comparative performance of the highly invasive Mimosa invisa and its less invasive subspecies under different nutrient and light conditions

Invasive plants may be more plastic than non‐invasive plants and maintain high fitness under various environmental conditions. Previous studies mainly focused on the comparisons between invasive and native plants, and comparisons between highly invasive and less invasive exotic species are still relatively rare, especially for comparisons at the subspecies level. This study examined the effects of nutrient addition and shading on the performance of the highly invasive Mimosa invisa and its less invasive subspecies M. invisa var. inermis under either isolated or competitive conditions. Nutrient addition increased biomass and plant height and decreased root‐to‐shoot ratio (R/S). Shading decreased biomass and R/S and increased plant height. Under isolated conditions, the two invaders did not differ in R/S, plant height and plasticity of these traits in response to nutrient addition or shading, and the two invaders also did not differ in biomass production under each of the nutrient and light treatments. When the two invaders competed with each other, M. invisa outcompeted M. invisa var. inermis under high soil nutrient conditions, and the two invaders did not differ in performance under other growth conditions. Thus, only considering competition may we find out the difference between highly invasive species and their closely related, less invasive subspecies. Management of M. invisa should focus on habitats with high soil nutrient availability, in which M. invisa is more likely to dominate.     

Site‐specific management is crucial to managing Mikania micrantha

Increasingly, weeds have been taking on global distributions. With the proliferation of invasive weeds has come the challenge of managing these species over broad geographical regions, with diverse habitats and political jurisdictions. Here, we review the management of Mikania micrantha Kunth (Asteraceae; mile‐a‐minute) throughout its invaded range, extending through most of the Pacific islands and southern and south‐east Asia. Context matters when determining the best course of action for managing M. micrantha, as it has invaded a large variety of agricultural and natural systems. In Queensland, Australia and Florida, USA, M. micrantha has been targeted in relatively successful eradication campaigns, highlighting the importance of early detection and rapid response methods, while elsewhere in its invaded range, populations are either still increasing or showing limited signs of decline. An inter‐regional approach to research and management should incorporate successful management strategies employed throughout the invaded range including, but not limited to, chemical and cultural control practices, manual and mechanical control, classical biological control using the rust fungus Puccinia spegazzinii, plant–plant competition and integrated approaches utilising two or more control methods concurrently. Additional knowledge of M. micrantha genetics is required to determine if management approaches could be fine‐tuned for particular populations. Countries bordering the Mekong River formed a network in 2011 to co‐ordinate the management of invasive species such as M. micrantha. Expanding such a collaborative approach to other regions could further reduce populations of M. micrantha and limit its spread.     

Considering the preferences for nitrogen forms by invasive plants: a case study from a hydroponic culture experiment

Although preference for NH₄⁺, NO₃^? or a combination of the two often differs among species, we know little about the responses of invasive plants to different inorganic N forms. Furthermore, many studies have suggested that an increase in N availability may facilitate further invasions. However, most of these studies predicted the positive feedback without considering the preference for N forms of invasive plants. Therefore, we cultivated four common invasive species (Mikania micrantha, Ipomoea cairica, Wedelia trilobata and Bidens pilosa) in South China with hydroponic media containing different forms of N (i.e. NO₃^?, NH₄NO₃ and NH₄⁺) at equimolar concentrations. Our results showed that the N forms significantly affected the growth, biomass allocation and physiological traits of the plants. All four invasive plants supplied with NO₃^? alone had better performance and greater allocation to root biomass than did plants that were supplied with NH₄⁺ alone. Moreover, the photosynthetic rate, pigment content and photosystem II activity of plants supplied with NO₃^? or NH₄NO₃ were significantly higher than those of plants supplied with NH₄⁺alone. The results suggested that all four invasive plants preferred NO₃^? rather than NH₄⁺, and changes in NO₃^? played an important role in furthering the invasions of these plants than did changes in NH₄⁺. Our results implied that decreasing NO₃^? may be a useful tool for controlling and managing invasive plants preferring NO₃^?. In addition, this study highlighted the importance of considering plant N form preference to better understand plant invasions.