引进肉用绵羊品种的杂交利用研究进展

文章综述了从国外引进优良肉用绵羊品种对国内不同地方绵羊品种杂交改良方面的研究应用情况,重点介绍了萨福克羊、杜泊羊、无角陶赛特羊、美利奴羊、特克塞尔羊等优良绵羊品种与我国不同地方绵羊品种杂交,其杂交后代在生长发育性能、产肉性能、胴体品质等方面的表现,旨在总结中国肉用绵羊的杂交改良工作,为推动中国肉用绵羊杂交改良,提高地方绵羊的生长性能和肉用性能,扩大我国肉羊的生产规模,促进我国畜牧业的健康发展和动物性肉食结构平衡提供借鉴。     

A combination of Lactobacillus buchneri and Pediococcus pentosaceus extended the aerobic stability of conventional and brown midrib mutants–corn hybrids ensiled at low dry matter concentrations by causing a major shift in their bacterial and fungal community

We evaluated the effects of applying a combination inoculant to four corn hybrids harvested at high moisture on their nutritive value and microbial populations. The treatment design was the factorial combination of corn hybrids ensiled with (INO) and without (CON) inoculant. The hybrids were TMF2R737 (MCN), F2F817 (MBR), P2089YHR (PCN), and PI144XR (PBR), ensiled at dry matter (DM) concentrations of 30.5%, 26.3%, 31.1%, and 31.5%, respectively; MBR and PBR were brown midrib mutants (BMR). The inoculant contained Lactobacillus buchneri and Pediococcus pentosaceus (4 × 10⁵ and 1 × 10⁵ cfu/g of fresh corn). The experiment had a complete randomized design with treatments replicated six times. Corn was treated or not with inoculant, packed into 7.6 L bucket silos, and stored for 100 d. At d 0, the relative abundance (RA, %) of Enterobacteriaceae was lower in PBR vs. the other hybrids [51.3 vs. x¯ = (average of) 58.4] and in the case of fungi, incertae sedis (i.s.) Tremellales and Mucoraceae were more and less abundant, respectively, in conventional hybrids vs. BMRs (x¯= 25.8 vs. x¯ = 13.9 and x¯ = 3.64 vs. x¯ = 7.52; P < 0.04). After ensiling, INO had higher LAB (9.3 vs. 7.1 log cfu/g of fresh corn) and acetic acid (3.44% vs. 1.32% of DM) and lower yeast (3.1 vs. 4.6) and molds (1.5 vs. 3.0), and also extended the aerobic stability (582 vs. 111 h) but decreased DM recovery (95.6% vs. 97.4%) vs. CON (P < 0.02). Inoculation reduced bacterial phylogenetic diversity (6.75 vs. 14.4) but increased fungal observed taxonomical units (46 vs. 20) vs. CON (P < 0.01). Also, a higher relative abundance (RA) for Lactobacillaceae (99.2% vs. 75.7%) and lower for Enterobacteriaceae (0.28 vs. 9.93) was observed due to inoculation (P < 0.001). For fungi, INO had a lower RA compared to CON for Monascaceae (12.6 vs. 44.7) and increased i.s. Tremellales (8.0 vs. 1.2) and i.s. Saccharomycetales (6.4% vs. 0.3%; P < 0.006). Inoculation changed the diverse bacterial community found in the phyllosphere across hybrids to a taxonomically uneven one dominated by Lactobacillaceae. In the case of fungi, INO application increased the fungal diversity at d 100 mainly by reducing the dominance of Monascaceae vs. CON. In conclusion, the INO treatment overwhelmed the disparate microbial populations found across BMR and conventional hybrids ensiled at low DM concentrations and ensured a significant concentration of acetic acid that modified fungal populations and in turn extended the aerobic stability of all hybrids.     

六种哺乳动物细胞系染色体制片条件优化研究

为提高胞核学检验的检查效率,采用6种具有种属代表性的常用传代细胞系对影响检验的关键步骤(染色体制片条件)进行优化,并对这六种传代细胞系的染色体数目进行了统计。实验以CHO、BHK-21、ST、OA3.Ts、MDBK、RK-13六种疫苗生产中常用的传代细胞系作为材料,对影响染色体制片效果几个主要条件(秋水仙素浓度、KCl浓度及低渗处理时间)进行了优化,并对这六种细胞染色体数目分布进行了检查。结果发现,在细胞用25 cm~2细胞培养瓶1∶2比例传代24～48 h时,秋水仙素浓度为1μg/mL,处理60 min后处在中期分裂相的细胞最多,视野中染色体长度适中;用0.4%KCl溶液低渗处理40 min,细胞中染色体在载玻片上形态最佳,分散度最好。优化后的染色体制片条件,可适用于多种细胞的染色体制片,结果重复性好,染色体形态和分散度均满足胞核学检验要求,可为胞核学检验的流程标准化制定提供有益参考。     

“假黄牛”或“假牦牛”精母细胞减数分裂及精子发生的研究

黄牛与牦牛种间杂交的F3代杂种公牛,精母细胞减数分裂及精子发生的水平,与F1和F2代相比,呈现明显的渐进性改善。但个体间睾丸发育状况及减数分裂与精子发生水平仍有较大差异,且仍能观察到一些异常现象。F3代公牛虽能产生数量较多的精子,但大多仍是畸形或有缺损,这可能是其仍无生育力的主要原因。     

高加索三叶草×白三叶胚萌发条件的探索

以六倍体高加索三叶草Trifolium ambiguum与四倍体白三叶T.repens为亲本,通过远缘杂交,采用组织培养手段对杂交胚的萌发条件进行探索.结果表明:以高加索三叶草为母本、白三叶为父本,在花期8:00-9:00授粉,授粉后12～13 d取胚,用质量分数10%NaClO灭菌6.5～7 min,在不加任何外源激素的改良MS培养基上,胚萌发率最高,达8%.高频扩繁时,再附加0.25 mg/L 2,4-D+0.50 mg/L 6-BA可获得较高萌发率.     

鸭茅的营养价值评定

以宝兴鸭茅(Dactylis glomerata L.)为对照,对鸭茅新品系YA02-116、YA01-101、YA01-103、02123、01071的营养价值及其刈割影响进行了评价。结果表明:刈割对鸭茅营养有直接影响,刈割后再生草的蛋白质含量较初次刈割材料有明显下降,纤维含量显著升高(P<0.05),营养价值降低。通过隶属函数法对所有供试材料综合评价表明,材料YA 02-116、YA 01-101的营养价值较好,高于对照品种宝兴鸭茅,具有一定开发利用价值,为鸭茅新品种的选育提供了参考。     

南瓜新品种科栗1号的选育

科栗1号是以S31-1为母本、S4-1为父本配制而成的南瓜一代杂种。植株蔓生,长势中等;分枝较少,叶小,节间短;第1雌花节位第9节左右;嫩瓜扁圆形,瓜皮绿色覆绿色斑点和浅色纵条斑纹,老瓜皮墨绿色。嫩瓜单瓜质量0.5~1.5kg,果实横径9cm左右,纵径13cm左右,糯性好,粉质,品质佳;春季露地和秋季设施栽培嫩瓜产量1500~2000kg·(667m2)-1,早春设施栽培嫩瓜产量3000kg·(667m2)-1左右。适宜浙江省及栽培条件相似的地区推广种植。     

秋冬萝卜新品种晋萝卜4 号的选育

晋萝卜4 号是以雄性不育系4-01A 为母本，自交系03-37-1 为父本配制而成的秋冬萝卜一代杂种，生育期80 d（天）。地上部叶丛半直立，叶片稀疏，肉质根圆柱形，表皮光滑，出土部分皮绿色，入土部分皮白色，近1/2 露出地面。含水量适中，肉质甜脆，商品性好。肉质根纵径30 cm，横径7～8 cm，单根质量1.5 kg，每667 m² 产量5 000 kg 左右。适宜山西省及其周边地区种植。     

水果萝卜新品种京脆1 号的选育

京脆1 号是由两个自交不亲和系05132 和05177 配制而成的鲜食水果型萝卜一代杂种。生长期75～80 d（天），叶
片近板叶型，深绿色，半直立株型。肉质根椭圆形，尾根细，茎盘小。根长13 cm，横径12 cm，平均单根质量1.2 kg，每
667 m² 产量5 000～6 000 kg。肉质根3/4 露出地面，出土部分浅绿色，入土部分白色，肉色浅绿，肉质甜脆，VC 含量 380
mg·kg^-1（FW），硫苷含量318.8 μmol·kg^-1（FW），适合生食。田间对病毒病和软腐病的抗性强于对照满堂红。适合北京、
天津、河北、山东等地种植。     

茄子新品种京茄13号的选育

京茄13号是以优良自交系1156为母本,以1125为父本配制而成的长茄一代杂种。早熟,始花节位为第10节,植株长势强,节间短。果实顺直,长筒状,果长25~30cm,横径5~6cm,果皮黑亮,连续坐果性强,每667m2平均产量为4240kg,低温耐受性强,适合北方保护地栽培。