Enhancing mucosal immunity in mice by recombinant adenovirus expressing major epitopes of porcine circovirus-2 capsid protein delivered with cytosine-phosphate-guanosine oligodeoxynucleotides

A recombinant replication-defective adenovirus expressing the major epitopes of porcine circovirus-2 (PCV-2) capsid protein (rAd/Cap/518) was previously constructed and shown to induce mucosal immunity in mice following intranasal delivery. In the present study, immune responses induced by intranasal immunization with a combination of rAd/Cap/518 and cytosine-phosphate-guanosine oligodeoxynucleotides (CpG ODN) were evaluated in mice. The levels of PCV-2-specific IgG in serum and IgA in saliva, lung, and intestinal fluids were significantly higher in the group immunized with rAd/Cap/518 and CpG ODN than animals immunized with rAd/Cap/518 alone. The frequencies of IL-2-secreting CD4⁺ T cells and IFN-γ-producing CD8⁺ T cells were significantly higher in the combined immunization group than mice immunized with rAd/Cap/518 alone. The frequencies of CD3⁺, CD3⁺CD4⁺CD8^-, and CD3⁺CD4^-CD8⁺ T cells in the combined immunization group were similar to that treated with CpG ODN alone, but significantly higher than mice that did not receive CpG ODN. PCV-2 load after challenge in the combined immunization group was significantly lower than that in the phosphate-buffered saline placebo group and approximately 7-fold lower in the group treated with CpG ODN alone. These results indicate that rAd/Cap/518 combined with CpG ODN can enhance systemic and local mucosal immunity in mice, and represent a promising synergetic mucosal vaccine against PCV-2.     

不同密度对玉米新品种“华玉”518植株性状及产量的影响

为了探索玉米新品种“华玉”518最佳种植密度,2020年在运城市盐湖区进行了密度比较试验。结果显示,植株特征特性表现出随密度加大株高、穗位均增高,穗长、千粒重降低,对产量影响显著。当密度为6万株/hm²,其产量最高,6.75万株/ hm²次之,因此最佳适宜密度为6万株/ hm²左右。     

西瓜新品种“苏蜜518”及其配套栽培技术

苏蜜518是江苏省农业科学院蔬菜研究所根据江苏省生态环境特点和结合西瓜种植的地理条件,经科学培育而成的西瓜新品种。2020、2021年在江苏西瓜主产区东台地区试验、示范栽培,综合表现出长势稳健、耐低温弱光、易坐果、畸形果发生率低、外观美、口感品质好等优点;每667 m²产量在4 000 kg以上,产值1.5万元左右,高于同期当地主栽品种早佳84-24。综合田间生产实践,重点介绍了品种特点和优势及其育苗、定植、温光肥水管理、病虫害防治等配套栽培技术。     

超级稻H优518不同播、插期的机插栽培技术研究

以超级晚稻H优518为试验材料,进行播期和秧龄的双因素试验。结果表明,该品种可在同生态区域作双晚机插,最迟安全播种期在7月1日前后,秧龄15~20 d移栽,可在武汉市"寒露风"的常年出现日期9月18日前后安全齐穗;播、插期越早,安全性越高,丰产性越好,最高单产可达723.4 kg/667 m~2。     

家蚕灰黑蛾夏秋用品种517×518的育成

将家蚕暗化型灰黑蛾基因(m ln)导入实用品种,育成强健型灰黑蛾中系品种517,与常规日系强健型白蛾品种518组配成夏秋用品种517×518,利用蛾色差异,可使杂交率提高到99%以上。该品种强健好养,眠起齐,耐粗食,茧丝长1 096 m,解舒率71.84%,茧丝纤度2.874 dtex,洁净95.89分,已通过安徽省桑蚕品种审定委员会审定。     

机插双季晚稻不同秧龄栽培试验研究

以H优518和陆两优996为供试材料，研究了不同秧龄处理对机插秧秧苗素质、生育期、分蘖能力及经济性状的影响。结果表明：不同秧龄对机插双季晚稻的秧苗素质、生育期及产量等均有一定影响，在该试验条件下，H优518和陆两优996作双季晚稻机插栽培时，秧龄以17 d为最适宜，产量分别为577.3和541.7 kg/667m2。并在试验的基础上，提出了水稻机插栽培的几点注意事项。     

不同种植密度、施氮量及栽培方式对玉米品种桂糯518产质量的影响

【目的】探索玉米新品种桂糯518最佳种植密度、施氮量和栽培方式等优质高效栽培技术。【方法】试验设种植密度（36000、42000、48000、54000和60000株/ha）、施氮量（0、75.0、150.0、225.0、300.0和375.0kg/ha）和栽培方式（常规栽培、宽窄行栽培、温棚育苗移栽和直播地膜覆盖）3个水平,均为随机区组设计。调查出苗期、采收期、生育期、株高、穗长和产量等性状,并将筛选出的桂糯518优质高效栽培技术在广西北海、南宁、都安、贵港4个点进行示范,测定产量及品质性状。【结果】随着种植密度的增加,株高整体呈下降的趋势,穗长变短。种植密度为54000株/ha时,桂糯518产量最高;随着施氮量的增加,桂糯518表现略为晚熟,株高略有增高,施纯氮300.0kg/ha时,桂糯518鲜食产量最高;直播地膜覆盖处理时,玉米鲜食产量最高,宽窄行栽培处理次之,温棚育苗移栽处理产量最低;桂糯518在4个示范点平均比常规栽培增产7.68%,综合品质略优于常规栽培。【结论】桂糯518采用宽窄行栽培方式,种植密度48000~54000株/ha,施纯氮量300.0kg/ha左右时,产量及品质较高。     

菌株518鉴定及其次生代谢产物的生防特性与分离

经形态学与分子生物学鉴定,菌株518为淡紫拟青霉。对其进行液体发酵处理,发酵产物对番茄灰霉病有很好的防治效果,同时起到一定的促生长作用。菌体固体发酵后,从中分离得到4种化合物。初步鉴定分别为麦角甾醇、D-甘露糖醇、麦角甾-7,22（E）-二烯-3β,5α,6β-三醇（又称酵母甾醇）、白僵菌素。