植物多样性水平对豆禾混播群落根系形态及叶面积指数的影响

以羊草、无芒雀麦、紫花苜蓿和扁蓿豆为材料,按照1、2、4物种梯度,构建3个多样性水平的人工草地,分析多样性水平对豆禾混播群落根系形态及叶面积指数的影响.结果 表明,直径0～1mm的根系主要分布于地下0～28cm土层,根长随着物种多样性的增加而增加;直径1～2mm的根系主要分布于28～56cm土层.禾本科牧草的根长随着物...     

冰草形态学与细胞学的研究

冰草(Agropyron cristatum)是异花授粉植物,种群内株丛间变异较大,存在着丰富的遗传多样性。研究表明,冰草形态方面存在多种变异类型,地下茎形成了疏丛型、疏丛-根茎型、根茎型3种类型;叶片表皮被毛有上下表皮均密被刺毛,上表皮被较密微毛、下表皮被较少微毛,上表皮被少微毛、下表皮光滑无毛变异类型;种子外稃有密被长柔毛、疏被短柔毛、光滑无毛变异类型。染色体研究查明,冰草染色体存在二倍体和四倍体2个倍性水平,二倍体冰草染色体为14条,核型公式为2n=14=10m(1sat)+4sm(2sat),核型类型为1A型;四倍体冰草染色体为28条,核型公式为2n=28=22m+6sm,核型类型为1A型。     

不同育苗基质下咖啡种间嫁接苗生长及光合特性

以大粒种咖啡(Caffea liberica)1号为砧木、中粒种咖啡(Caffea canephora)热研1号高产无性系为接穗形成种间嫁接苗,以棕榈叶+表土、棕榈叶+椰糠和椰糠+表土不同比例配置基质,比较不同处理下嫁接苗的根系形态、光合特性、生物量及苗木质量指数,筛选适宜育苗基质.结果表明:以棕榈叶+表土体积比1:0...     

暖地泥炭藓(Sphagnum junhuhnianum)孢子形态及发育过程探讨

描述了暖地泥炭藓(Sphagnum junhuhnianum)孢蒴从翠绿色透明状球体历经黄绿色、淡褐色、褐色、具光泽的深咖啡色球体到最后喇叭状过程中孢子的形态特征.成熟孢蒴中孢子的数量(71 631±12 751)个.成熟孢子四面体结构清晰,极面观呈圆三角形,赤道面观呈近扇形,直径(23.27±1.05)μm,均出现三裂隙结构,唇状,稍细,长为极半径的2/3,裂隙表面布满疣状颗粒物,近极端三面凹陷无褶皱,分布少量疣状颗粒物,远端面不平整,布满疣状颗粒物.     

Nutrient availability and corn growth in a poultry litter biochar‐amended loam soil in a greenhouse experiment

Nutrient‐rich biochar produced from animal wastes, such as poultry litter, may increase plant growth and nutrient uptake although the role of direct and indirect mechanisms, such as stimulation of the activity of mycorrhizal fungi and plant infection, remains unclear. The effects of poultry litter biochar in combination with fertilizer on mycorrhizal infection, soil nutrient availability and corn (Zea mays L.) growth were investigated by growing corn in a loam soil in a greenhouse with biochar (0, 5 and 10 Mg/ha) and nitrogen (N) and phosphorus (P) fertilizer (0, half and full rates). Biochar did not affect microbial biomass C or N, mycorrhizal infection, or alkaline phosphomonoesterase activities, but acid phosphomonoesterase activities, water‐soluble P, Mehlich‐3 Mg, plant height, aboveground and root biomass, and root diameter were greater with 10 Mg/ha than with no biochar. Root length, volume, root tips and surface area were greatest in the fully fertilized soil receiving 10 Mg/ha biochar compared to all other treatments. The 10 Mg/ha biochar application may have improved plant access to soil nutrients by promoting plant growth and root structural features, rather than by enhancing mycorrhizal infection rates.     

银杏-杜仲叶发酵物对脂多糖应激肉仔鸡的肠道功能和免疫反应的影响

本试验旨在研究饲粮中添加银杏-杜仲叶发酵物（FGEL）对脂多糖（LPS）应激肉仔鸡的生长性能、肠道结构、消化吸收功能和免疫反应的影响，并与未发酵银杏-杜仲叶（GEL）进行比较。采用2×3双因子试验设计，即2种免疫应激处理（腹腔注射LPS或注射等量生理盐水）和3种饲粮处理（基础饲粮及在基础饲粮中添加0.40%GEL或0.40%FGEL的试验饲粮）。选取1日龄健康爱拔益加（AA）肉仔鸡360只，随机分为6个处理，每个处理均设6个重复，每个重复10只鸡。试验期为21 d。在试验第13、15、17、19和21天，3个应激处理的试鸡腹腔注射500μg/kg BW的LPS，其他3个处理注射等量的生理盐水。在试验第21天最后1次注射后2～4 h进行屠宰取样。结果表明：1）与对照饲粮相比，饲粮添加FGEL的肉仔鸡料重比（F/G）有显著改善（P=0.024），饲粮添加FGEL显著缓解了LPS应激肉仔鸡平均日增重（ADG）(P=0.023)和血清D-木糖的含量（P=0.011）的降低。2）与对照饲粮相比，饲粮添加FGEL显著缓解了LPS应激肉仔鸡十二指肠（P=0.011）和空肠（P=0.030）的相对重量...     

贺兰山野生大型真菌孢子多样性分析

为探讨贺兰山野生大型真菌孢子的多样性,2012-2016年在内蒙古贺兰山南寺和哈拉乌沟两地进行取样,每个样地分别由5人从沟谷入口处进行拉网式调查,共获得4 000余份样品,经过微观形态观察和基因ITS序列比对,鉴定出8目25科69属189种大型真菌,主要对其孢子形态特征、表面特征及长宽比进行分析,得到如下结论:质量性状上,孢子形态特征和表面特征相互独立;数量性状上,大小孢子长宽比、孢子极端比和平均比均具有一致性和关联性,显示孢子数量特征的稳定性;菌种间孢子质量性状和数量性状具有很强的多样性;按照孢子多样性低、中、高分类,贺兰山野生大型真菌物种数分别为152种、26种和11种;孢子多样性分类为大型真菌鉴别、分类提供了基本依据。     

Single layer centrifugation of stallion spermatozoa consistently selects the most robust spermatozoa from the rest of the ejaculate in a large sample size

Reasons for performing study: An improvement in sperm quality after single layer centrifugation (SLC) has been seen in previous studies using small sample sizes (for example, n = 10 stallions). There is a need to investigate whether this improvement is repeatable over several breeding seasons with a larger number of stallions (n ≥ 30 stallions). Objective: To make a retrospective analysis of the results of SLC performed on more than 250 sperm samples (176 ejaculates) from 31 stallions in 3 consecutive breeding seasons. Methods: Sperm quality (motility, proportion of morphologically normal spermatozoa and the proportion of spermatozoa with undamaged chromatin) was assessed before and after SLC. Results: All parameters of sperm quality examined were significantly better in sperm samples after SLC than in their unselected counterparts (P<0.001 for each parameter). The yield of spermatozoa obtained after SLC was influenced by the type of extender used and also by the concentration of spermatozoa in the original ejaculate, with fewer spermatozoa being recovered when the loading dose contained a high concentration of spermatozoa. The optimal concentration was approximately 100 × 10⁶/ml. Sperm concentration in the samples loaded on to the colloid influenced the sperm yield while the type of semen extender affected sperm quality and survival. Furthermore, the scaled‐up SLC method was found to be suitable for use with a range of ejaculates, with similar sperm kinematics being observed for standard and scaled‐up preparations. Conclusions: SLC consistently improved the quality of stallion sperm samples from a large number of ejaculates. The method could be scaled‐up, allowing larger volumes of ejaculate to be processed easily from a wide range of stallions.     

Assessment of age-related morphological changes in the testes of post-hatch light ecotype Nigerian indigenous chicken

The age-related morphological changes of the testes in light ecotype Nigerian indigenous chicken were evaluated in this study using gross anatomical, histological and histomorphometric techniques. The results showed that the testes of 3- to 9-month-old birds were light pink while testes of sexually mature chicken were creamy white in colour. The left and right testicular weight, length, diameter, circumference and the organosomatic indices increased significantly (p < .05) with increasing age across the groups. Although the mean tubular diameter and epithelial height of the left and right seminiferous tubules increased significantly (p < .05) with age, the tubular diameter, epithelial height and luminal diameter did not vary significantly (p > .05) between the left and right testes of all the groups. The one-cell layer thick germinal epithelium of the left testes at 3 to 6 months old showed islands of cell proliferation that contained spermatogonia and spermatocytes. At 6 to 9 months, the left testes exhibited numerous early spermatids with occasional occurrence of late stage spermatids while the right testes showed scanty early stage spermatids. At 12 to 18 months, the germinal epithelia of both left and right testes were characterized by the presence of Sertoli cells, spermatogonia, primary spermatocytes, numerous early and late stage spermatids as well as spermatozoa. In conclusion, the morphological features highlighted in the present study show that at pre-pubertal periods, the left testes may develop faster than the right testes. However, both left and right testes may participate actively in the production of spermatozoa during the post-pubertal life.