The ground cherry（cerasus fruticosa Pall）.a new kind of edible cherry for cold and dry regions of China

We have conducted some studies on 3 ground cherry cultivars‘ artaskaja‘,‘Bushkaja‘ and Maksmorfikaja‘ introduced from Russia,The results indicated that these cultivars could survive temperature-40℃ during severe winter in Harbin,China and had high drought and disease resistance,the average weight of each fruit reached 2.78g,the contents of Vc and soluble solid exceeded 30mg/100g and 12%,respectively.Not only does the fruits suit for fresh market,but also for processing.Ground cherry is a promising new fruit crop in cold region.     

2015年全球非洲猪瘟流行状况分析

2015年全球共有16个非洲国家和7个欧洲国家暴发了2 500多起家猪和野猪的非洲猪瘟疫情。非洲地区以家猪疫情为主,欧洲地区频发野猪疫情;带毒野猪与家猪交叉感染,导致病毒在欧洲出现循环传播,且在秋冬季节集中暴发。非洲猪瘟从非洲和欧洲传入我国的风险在不断增加,提示我国应时刻提高警惕,加强防范。     

小肽吸收机制及在动物生产中的应用

传统的经典蛋白质营养理论即氨基酸营养理论认为,动物采食的日粮蛋白质在消化道内经蛋白酶和肽酶作用降解为小肽和游离氨基酸,游离氨基酸可被动物直接利用,而小肽只有进一步降解为游离氨基酸才能被利用。但在后来的一些研究中发现,用纯合日粮或低蛋白质平衡氨基酸日粮饲喂动物,并不能达到最佳生产性能。Agao等(1953)首先观察到肠道能完整地吸收转运双甘肽。Neway等(1960)的研究为小肽能被完整吸收提供了证据。Hara等(1984)在小肠黏膜上发现了小肽载体。Garder(1984)研究也表明,大量小肽能直接被吸收,进入体循环。Webba(1989)研究表明,蛋白…     

Three‐dimensional culture system can induce expression of casein in immortalized bovine mammary epithelial cells

Primary bovine mammary epithelial cells (BMECs) are not ideal models for long‐term studies of lactation mechanisms because these cells in a monolayer culture system cannot be polarized to simulate the physiological functions in vitro. We investigate the effects of different culture models and karyotypes on casein expression in a three‐dimensional (3D) culture system. The immortalized cells' karyotypes were analyzed at passages 10, 20, 30 and 40 to detect the effects of chromosome stability. Western blotting examined that whether or not the immortalized cells at passages 5, 10, 20, 30, 40 and 50 could induce expression of casein in a 3D culture system. The proper polarization of the acinar structures was monitored. BMECs were successfully immortalized. The cell karyotype at passage 30 remained at 60 chromosomes and the average value was 57.1 ± 0.40 after passage 40. The polarized protein's levels were up‐regulated in 3D culture compared to 2D culture. Expression of αs1, β and κ‐casein could be detectable in a passage range in 3D culture. Expression of αs2‐casein was undetectable in all experimental groups. However, all casein expressions were barely detectable in traditional 2D culture system. Therefore, 3D culture system is an important tool for the long‐term study of lactation mechanisms in vitro.     

德化黑鸡的肌肉品质分析

对150日龄、180日龄的德化黑鸡肌肉的肉品质指标(肉色、失水率、嫩度、pH值、水分、粗蛋白质、粗脂肪、肌苷酸、脂肪酸、肌纤维直径、肌纤维密度、黑色素)进行了测定。通过对德化黑鸡肉品质客观指标的综合分析,德化黑鸡具有市场需求的优良肉质和风味。     

Expression of steroidogenic enzymes and synthesis of steroid hormones during development of ovarian follicles in prepubertal goats

Expression of mRNAs encoding cytochrome P450 side-chain cleavage (P450scc), cytochrome P450 17 -hydroxylase (P450c17), and cytochrome P450 aromatase (P450arom) were characterized by the RT-PCR technique and concentrations of progesterone (P4), testosterone (T0) and estradiol (E2) were measured by radioimmunoassay during follicular development of prepubertal goats. Synthesis of mRNAs encoding P450scc and P450c17 began in preantral follicles, but mRNA encoding P450arom was not detectable until early antral formation. While mRNA for P450scc was expressed in both theca and granulosa cells, mRNA for P450c17 was expressed only in theca cells while P450arom mRNA only in granulosa cells. In nonatretic follicles from prepubertal ovaries, the relative quantity of mRNA expression of all the three enzymes increased with follicle size; however, while the concentration of P4 and E2 increased, that of T0 decreased with follicle size. While expression of mRNA encoding P450scc was unaffected, that of P450c17 mRNA decreased to the lowest level and mRNA for P450arom became undetectable following atresia; accordingly, while the concentration of P4 increased in the atretic medium follicles, that of T0 and E2 decreased to the lowest level after atresia. While the adult follicular stage follicles showed a similar cytochrome expression as the nonatretic follicles of prepubertal goats, the former contained higher levels of E2 and P4 than the latter. The presence of corpus luteum in an ovary decreased expression of P450scc, significantly in large follicles while it increased concentration of P4. These findings indicated that (1) similar to other species, changes in follicular steroid production in goats were explained in large measure by changes in steroidogenic enzyme expression; (2) while mRNA expression was similar, activities of some of the steroidogenic enzymes may differ between sexually mature and immature goats.     

齿爪式粉碎机监督抽查的技术标准

齿爪式粉碎机是国家实施生产许可证制管理的农机产品,企业必须严把质量关,质量技术监督部门要严格质量监督.同时质量监督应依据相关技术标准,确定主要检验项目,遵循监督抽查规范程序和规则.     

不同生育期光合碳在水稻-土壤系统中的分配

通过盆栽试验方法,采用13C脉冲标记技术和稳定同位素质谱分析技术,研究了三个生育期(返青期、分蘖期和抽穗期)光合碳在"水稻-土壤"系统中的同化率、分配比率及其在土壤中增加率的动态变化,探讨三个生育期光合碳在"水稻-土壤"系统中的运转、分配规律,为明确稻田生态系统中碳素循环过程提供理论依据。结果表明,分别在返青期、分蘖期和抽穗期进行一次13C脉冲标记(持续5 h)后,光合碳在"水稻-土壤"系统中的总同化率均随标记后天数的延长呈逐渐下降趋势,从标记后2 d至收获时,总同化率分别为75.92%~39.53%、70.01%~52.02%、86.38%~69.60%,且收获时与2 d时的同化率差异均达显著水平(p0.05),其被同化光合碳的损失率分别为47.93%、25.70%和19.43%;抽穗期光合碳同化率明显高于返青期和分蘖期,被同化光合碳的损失也明显低于返青期和分蘖期。三个生育期被同化的光合碳向水稻地上部分和地下部分(包括根和土壤)的运转呈互相消长关系,但向水稻地上部分的分配比率(平均为85.04%~73.10%)远大于向根的分配比率(平均为12.50%~22.04%)和土壤的分配比率(平均为1.70%~5.04%),且抽穗期光合碳向水稻地上部分中的分配比率大于分蘖期和返青期,向地下部分的分配比率则正好相反;此外,三个生育期被同化的光合碳在土壤中的增加率分别为0.08%~0.21%、0.09%~0.17%和0.19%~0.27%,抽穗期土壤中光合碳的增加率要大于返青期和分蘖期,且光合碳在土壤中也相对稳定。     

几种有机肥对玉米光合特性及土壤酶活性的影响

为了比较研究有机肥、化肥对玉米生产能力的影响,为北方黑土地区有机肥与化肥的施用提供科学依据.大田条件下对玉米施用4种有机肥和传统化肥,测定玉米产量、叶片光合特性、土壤酶活性以及丛枝菌根真菌(AMF)侵染情况等指标.结果表明:超效有机肥(T4)处理下的玉米产量为9800kg/hm2,相比于传统化肥(CK)增产11.53％...