几种牧草对河西走廊盐渍化土壤改土培肥的效应研究

在河西走廊盐渍化土地上种植老芒麦、扁穗冰草、碱茅和紫花苜蓿4种优质牧草,对盐渍化程度均有一定的改良效果.其中碱茅对盐渍化土壤的改土培肥效果最好,建植3年后的碱茅,与对照比较,0～20 cm土层中自然含水量增加125.99 g/kg,总孔度增加16.14%,容重降低0.27 g/cm3,pH值由8.43降到8.10,全盐含量降低52.90 g/kg,脱盐率达到76.12%,有机质增加3.67 g/kg,碱解氮含量增加18.63 mg/kg,速效磷和钾亦随之增加.     

抗鸡传染性腺胃炎酶标抗体的制备和应用

在前期从患病鸡腺胃内分离到呼肠孤病毒的基础上，以该病毒为免疫原对兔进行免疫制备高免血清，分离纯化IgG，进行辣根过氧化物酶（HRP）标记，并用ELISA双抗体夹心法对山东省青岛、枣庄、泰安等地区采集的传染性腺胃炎的腺胃样品进行检测，结果表明制备的抗鸡传染性腺胃炎呼肠孤病毒的酶标抗体检测传染性腺胃炎特异性强、灵敏度高、较简便。     

人参提取液体外抑制IHNV作用效果研究

探究人参提取液体外抑制CCB细胞感染IHNV的能力,构建体外CCB细胞模型,运用RTCA技术和MTT法测得不同浓度人参提取液对IHNV抑制作用曲线,并从阻断病毒复制和杀灭病毒两方面讨论人参提取液作用效果。结果表明,4%人参提取液对IHNV具有明显抑制作用,能够在16 h内保护细胞不受IHNV病毒的侵染,其中2 h时对病毒灭活抑制率最高达到51.5%,1~12 h内对病毒复制有持续抑制作用。研究可为IHVN防治药物的研发提供新的思路及参考。     

小黑麦与黑麦花序结构和籽粒特性比较

植物的花序结构及其形态特征是影响种子生产性能的重要因素。对于禾本科植物而言,其花序大小、小穗数、小花数及小花的外稃、内稃和芒的性状特征直接影响种子形成和产量。本研究通过测定小黑麦品系C2、C35和黑麦品系C13、C33的花序结构特征,得到以下结果:小黑麦花序[(14.30±0.52) cm×(1.24±0.09) cm]明显大于黑麦[(13.20±0.35) cm×(0.82±0.02) cm],小黑麦花序长而粗,黑麦花序短而细;小黑麦花序的小穗数[(21.35±1.47)个]少于黑麦[(30.20±0.79)个];小黑麦每个小穗的小花数较多,为3~4朵,黑麦的小花数趋于稳定,每个小穗有2朵小花。从花序中部小穗的小花结构看,小黑麦下位护颖长[(1.27±0.11) cm]和宽[(0.26±0.03) cm]、上位护颖长[(1.30±0.09) cm]和宽[(0.23±0.04) cm]均显著大于黑麦下位护颖长[(1.04±0.05) cm]和宽[(0.08±0.01) cm]、上位护颖长[(0.94±0.10) cm]和宽[(0.06±0.01) cm];小黑麦中部小穗第1小花的外稃宽[(0.32±0.03) cm]、外稃高[(0.24±0.03) cm]和芒长[(8.35±0.51) cm]、第2小花的外稃宽[(0.35±0.04) cm]、外稃高[(0.25±0.05) cm]和芒长[(8.37±1.19) cm]极显著大于黑麦相应值[(0.26±0.01),(0.15±0.01),(5.50±0.19),(0.25±0.01),(0.17±0.01)和(5.18±0.23) cm];第1和第2小花的外稃长[(1.35±0.06),(1.37±0.06) cm]和内稃长[(0.84±0.04),(1.41±0.06) cm]均小于黑麦的外稃长[(1.49±0.05),(1.47±0.05) cm]和内稃长[(1.45±0.05),(1.47±0.04) cm]。小黑麦的穗粒数[(52.50±1.80)粒]显著低于黑麦[(58.50±2.50)粒] (P<0.05),但其穗粒重[(2.08±0.04) g]、粒重[(0.04±0.00) g]和籽粒宽[(3.04±0.32) mm]均极显著高于黑麦 (P<0.01),每个花序的籽粒不仅体积大,而且质量较重,其籽粒的生产性能高于黑麦。小黑麦籽粒呈椭圆形或长卵圆形,浅黄色,表皮皱缩,饱满度差;黑麦籽粒呈窄纺锤形,青灰色,表皮光滑,籽粒饱满。小黑麦和黑麦花序结构与籽粒性状的Pearson相关分析表明,小黑麦花序宽和花序基部小穗数与籽粒长显著正相关(P<0.05),花序长与籽粒宽极显著正相关(P<0.01),花序中部小穗的下、上位护颖宽分别与穗粒重和穗粒数极显著正相关(P<0.01);黑麦花序中部小穗第2小花的内稃长与籽粒长显著正相关(P<0.05),外稃高与穗粒数极显著负相关(P<0.01)。研究小黑麦和黑麦的花序结构和籽粒特征,对正确区分二者和了解其籽粒的生产性能具有重要意义,同时有利于小黑麦的示范推广。     

UV‐light and dietary vitamin D and their effects on ionized calcium and 25‐OH‐D plasma concentrations in captive gentoo penguins (Pygoscelis papua)

In this study, the effect of ultraviolet (UV) light and dietary vitamin D on calcium metabolism in permanently indoor‐housed gentoo penguins (Pygoscelis papua ) was investigated. The study consisted of three periods, each completed with blood samples to analyse plasma concentrations of 25‐OH‐D, 1,25‐(OH)₂‐D, ionized (iCa) and total calcium (tCa). During the first study period (D), animals were housed under routine conditions without UV‐light and fed a diet of different fish species, supplemented with 1,000 IU vitamin D per animal and day. The following study period (Baseline) of 28‐day duration consisted of the same diet without any vitamin D supplementation and without UV‐light. During the study period (UVB) artificial UV‐light was added for 3 weeks. The vitamin D content of fish was measured by high‐performance liquid chromatography. It varied between fish species and between facilities, ranging from no measurable content in capelin (Mallotus villosus ) to 7,340 IU vitamin D/kg original matter (OM) in herring (Clupea spp). The average dietary vitamin D content was 311 IU/kg OM at facility 1 and 6,325 IU/kg OM at facility 2, resulting in a vitamin D intake per animal and day without supplementation of 130 IU (25.5 IU/kg body weight BW) and 2,454 IU (438.2 IU/kg BW) respectively. The supplementation of vitamin D elevated significantly the plasma concentrations of 25‐OH‐D by an intraindividual difference of 15 (range ?2 to 59) nmol/L and tCa by 0.1 (0.0–0.3) mmol/L only at facility 2. The exposure to UV‐light raised the blood concentrations of tCa at facility 2 by 0.15 (0.1–0.2) mmol/L, and of iCa and tCa for females at facility 1 by 0.23 (0.13–0.41) mmol/L and 1.8 (1.1–2.5) mmol/L respectively. No significant influence of the study periods (D) and (UVB) was found for the concentrations of 1,25‐(OH)₂‐D at both facilities.     

Efficacy of essential oils combination on performance,ileal bacterial counts,intestinal histology and immunocompetence of laying hens fed alternative lipid sources

This study was carried out to assess the effects of a blend of herbal essential oils (namely Thymus vulgaris, Mentha piperita, Rosmarinus offisinalis and Anethum graveolens) and different dietary lipid sources on the performance, ileal bacterial enumeration, intestinal histological alterations and immune responses in laying hens. For this purpose, a total of 150 laying hens were randomly allocated to six experimental treatments with five replicates of five birds each. Dietary treatments consisted of three levels of a mixture of essential oils (0, 100 and 200 mg/kg) and two sources of lipid (soybean oil and fish oil containing different ratios of n‐6 to n‐3 fatty acids) fed to the animals during an 80‐days feeding trial. Findings indicated that dietary administration of fish oil not only increased significantly the spleen relative weight (p < 0.01) and the antibody titre against Newcastle virus (p < 0.05) but also led to reductions in liver relative weight (p < 0.05) and feed conversion ratio (p < 0.05). Moreover, the mixture of herbal essential oils brought about declines in hepatic relative weight, heterophile to lymphocyte ratio (p < 0.05) and intestinal pathogen populations (p < 0.01). Mention must also be made of the improvements it made in spleen weight (p < 0.01), antibody titres against SRBC (p < 0.01) and Newcastle virus (p < 0.05), villus height to crypt depth ratio (p < 0.01), goblet cell numbers (p < 0.05), lamina propria lymphatic follicle diameters (p < 0.01) and feed conversion ratio (p = 0.06). It may be claimed that the enhancements observed in the performance of laying hens fed fish oil and 200 mg/kg of the blend of essential oils could have potentially been associated with improved intestinal health indices as well as cellular and humoral immune responses.     

Effect of parental origin on early life history traits of European eel

Establishment of European eel (Anguilla anguilla) hatchery production will rely on selectively bred individuals that produce progeny with the best traits in successive generations. As such, this study used a quantitative genetic breeding design, between four females and nine males (four wild‐caught and five cultured), to investigate the effect of paternal origin (wild‐caught vs. cultured) and quantify the relative importance of parental effects, including genetic compatibility, on early life history (ELH) performance traits (i.e. fertilization success, embryonic survival at 32 hr post‐fertilization, hatch success and larval deformities at 2 days post‐hatch) of European eel. Wild‐caught males had higher (56%) spermatocrit values than cultured males (45%), while fertilization success, embryonic survival, hatch success and larval deformities were not significantly impacted by paternal origin. This demonstrates that short‐term domestication of male eels does not negatively affect offspring quality and enables the consideration of cultured male broodstock in future breeding programmes. Moreover, paternity significantly explained 9.5% of the variability in embryonic survival, providing further evidence that paternal effects need to be taken into consideration in assisted reproduction protocols. Furthermore, maternity significantly explained 54.8% of the variation for fertilization success, 61.7% for embryonic survival, 88.1% for hatching success and 62.8% for larval deformities, validating that maternity is a major factor influencing these “critical” ELH traits. At last, the parental interaction explained 12.8% of the variation for fertilization success, 8.3% for embryonic survival, 4.5% for hatch success and 20.5% for larval deformities. Thus, we conclude that eggs of one female can develop more successfully when crossed with a compatible male, highlighting the importance of mate choice for successful propagation of high‐quality offspring. Together, this knowledge will improve early offspring performance, leading to future breeding programmes for this critically endangered and economically important species.     

High-throughput screening reveals small molecule modulators inhibitory to Acidovorax citrulli

Acidovorax citrulli is a seed-transmitted gram-negative bacterium that can cause substantial economic yield loss in watermelon and melon production worldwide. Four small-molecule libraries containing 4,952 compounds were selected for high-throughput screening against A. citrulli wild-type strain Xu3-14 by evaluation of growth inhibition. One hundred and twenty-seven molecules (2.5% hit rate) were identified as bactericidal or bacteriostatic against A. citrulli at 100 μM. Secondary screens indicated that 27 candidate compounds were more effective against A. citrulli Group II strains than Group I strains (classified using repetitive element PCR). Several compounds were inhibitory to other pathogenic bacteria, including Clavibacter michiganensis subsp. michiganensis and Xanthomonas campestris pv. campestris, but did not affect the growth of plant beneficial bacteria Pseudomonas fluorescens and Bacillus subtilis. More than half of the compounds did not inhibit germination of Arabidopsis or watermelon seeds. The effect of small molecules on A. citrulli seed-to-seedling transmission was evaluated by applying each compound to inoculated watermelon seeds and assessing seedling infection. Nine compounds were chosen for further investigation based on their reduction of percentage seedling infection and compiling scores on their specificity, sensitivity, and phytotoxicity obtained in the secondary screens. The five best compounds were selected (thiamphenicol, nadifloxacin, pipemidic acid, ciclopirox, and zinc pyrithione) for greenhouse tests and were found to effectively reduce the seed-to-seedling transmission of A. citrulli in both artificially and naturally infested seeds. These top five compounds provide a basis for future development of an A. citrulli-specific bactericide.     

江苏盐城首次记录到彩鹮

2020年5月4日在江苏盐城大丰麋鹿国家级自然保护区(120°47′—120°53′E,32°59′—33°03′N)记录到3只彩鹮。栖息地为一处浅滩水塘,3只彩鹮于水中觅食。以往曾宣布彩鹮在国内绝迹,本次记录填补了彩鹮在本地区的分布空白,证实了彩鹮在江苏省仍有分布。这一纪录或许说明本地区栖息地得到了有效的改善。