EMS诱变玉米自交系郑58后代变异分析及应用评价

种子是农业的“芯片”,是保障粮食安全的根本,农业种质资源又被称为“种业芯片”。因此,引进、创制和丰富种质资源是攻克“卡脖子”技术的关键,通过人工诱变是种质资源创新的一个重要途径。利用0.67 mg/L EMS诱变玉米自交系郑58花粉,构建1 650个株系的玉米突变体库,从M₂和M₃后代筛选到包括生育期、株型、叶型、穗型、粒型、叶色、轴色、育性等多个农艺性状突变体,表型变异率约为9.6%。结果表明,具有育种应用潜能的代表性材料有Z330、Z641和Z1433等,可供用于选育矮秆、低穗位、耐密植、抗倒伏型新品种;Z636、Z848和Z930等新种质材料可用于测配或改良玉米穗型、粒型、轴色、粒色及品质性状。     

不同品种公猪精液品质调查

为了研究品种不同的种公猪的精液品质之间存在的差异,本试验通过对长白、大白、杜洛克等3个品种的成年种公猪的精液品质进行统计学方法分析和比较。结果显示:长白公猪的精子活率最好(75.03%),然后依次是大白(71.62%)、杜洛克(70.36%),长白与大白及杜洛克之间差异显著(P<0.05),但大白与杜洛克之间差异不显著(P>0.05);长白种公猪的精液量(337.60mL)与大白(380.00mL)之间差异不显著(P>0.05),但均与杜洛克(251.74mL)之间差异显著(P<0.05)。三个品种精子活率由高到低依次为长白、大白、杜洛克;平均精液量大小依次为大白、长白、杜洛克,综合评价,长白猪的精液品质最好。     

乾华肉用美利奴羊新品种种质特性的研究

乾华肉用美利奴羊是正在培育的绵羊新品种,对该品种的产区的自然生态条件、品种体型外貌和生产性能指标进行观测和分析,旨在为进一步选育提高提供理论依据和技术参考。结果表明:乾华肉用美利奴羊对东北农牧交错区的自然条件具有良好的适应性;具有优良的生长发育性能、产肉性能、繁殖性能和产毛性能;该品种成年公、母羊的体重可达124.78、103.25 kg,原毛产量和净毛率分别为6.68 kg、49.15%,4.67 kg、48.83%;育成羊和成年羊的羊毛的自然长度均超过9 cm,体侧部的羊毛纤维直径集中在20.32~21.45μm;育成公、母羊的屠宰率和胴体净肉率分别为51.65%和75.45%、51.28%和74.251%;初产和经产母羊的产羔率分别为125.23%和150.21%,羔羊成活率分别为93.12%和95.26%。     

日本樱花品种观赏性状多样性考察

日本樱花的原始分布种即野生种通常认为有9种：‘山樱’、‘大山樱’、‘霞樱’、‘江户彼岸’、‘丁子樱’、‘深山樱’、‘大岛樱’、‘豆樱’、‘高岭樱’。无论来自哪个种，凡山野自生的品种称为山樱。种间杂种、野生种的突然变异形成的品种、人工育成品种等统称为里樱。现有品种估计500个左右，观赏性状多样性丰富，双季花品种约有十数个。花瓣数量在60枚以上的菊(瓣)樱品种30余个，其中300枚以上的品种4个。黄色或绿色品种6个。芳香品种总数约30个左右，多数来自‘大岛樱’系统。垂枝型品种20个左右，曲枝型品种2个。自主选育适合地方风土条件的优良品种，形成性状互补的品种群体，是我国樱花产业健康、可持续发展的基础条件。     

Laminitis: Risk Factors and Outcome in a Group of Danish Horses

Recent systematic reviews have highlighted the lack of quality information with respect to the epidemiology of equine laminitis. The objectives of this study were to identify in Denmark, the risk factors for new (i.e., not believed to have suffered from laminitis previously) cases of laminitis (NL) and to look at the outcome and incidence of repeated episodes of laminitis in these animals as well as those which had previously suffered an episode of laminitis (i.e., chronic cases) over the following 12 months. Information was obtained from 110 veterinary diagnosed cases of laminitis (69 new and 41 chronic) and 80 control animals (the next nonlaminitic horse/pony seen by that participating practice). All animals were followed for up to 1 year. Univariable and multivariable conditional logistic regression was conducted for the NL case-control pairs. Variables were retained within the final multivariable models if the likelihood ratio P value was <.05. There was no association between sex or gender and laminitis. A recent change of grass, being on what was considered high-quality grass and being a cold-blooded type, <149 cm (i.e., Shetland, Fell, Welsh, or Dartmoor pony, Icelandic horse, Norwegian fjords, or a mix of these breeds) were all significant risk factors for laminitis. Although cresty neck score and body condition score were significantly associated with NL at the univariable screening stage, they were found to be confounders of breed and each other during the multivariable model building process. Other factors such as weight and estimated starch intake were not found to be significant. Thirty-three percent of all the laminitis cases had been humanely destroyed within 12 months of diagnosis, mainly for laminitis-associated reasons, compared with only 7.5% of the controls (none for laminitis associated reasons). This study confirms the importance of grass turnout and breed on laminitis risk. Horses in work at the time of diagnosis as well as those diagnosed in the winter and spring were more likely to be humanely destroyed within the next 12 months than those not in work or diagnosed in the autumn and summer.     

Heart disease as a cause of death in insured Swedish dogs younger than 10 years of age

BACKGROUND: Population-based information on disease occurrence is paramount in clinical decision making and in designing preventative measures, but such information is scarce. HYPOTHESIS: The risk of cardiac death is higher in certain breeds and mortality varies by age and sex. DOGS: Dogs that were life insured by an animal insurance company between 1995 and 2002. METHODS: The mortality pattern for heart disease in insured dogs up to 10 years of age was studied. The influences of sex, age, breed, month, and geographic location were investigated by means of incidence rates, proportions, and survival proportions. Cox proportional hazards regression was used to model time to heart disease. RESULTS: 405,376 dogs contributed to a denominator of 1,431,933 dog-years at risk (DYAR) and 3,049 dogs had been assigned a cardiac-related diagnosis as cause of death. The cardiac-related mortality for dogs <10 years of age, was 21.3 deaths per 10,000 DYAR. This mortality in males and females was 27.3 deaths and 15.4 deaths per 10,000 DYAR, respectively. Twelve of 54 breeds had a point estimate above the overall rate. The 3 breeds with the highest point estimates were: Irish Wolfhounds, Cavalier King Charles Spaniels, and Great Danes (rates of 356, 247, and 179 deaths per 10,000 DYAR, respectively). CONCLUSIONS AND CLINICAL IMPORTANCE: Breed, age, and sex affect cardiac mortality in certain breeds of dogs, but no effects of month and geographic location were identified. These findings can assist clinicians in establishing diagnoses, and can assist breeders in defining priorities for preventative measures.     

山西芦芽山国家级自然保护区黑啄木鸟的种群密度和繁殖习性

2008～2010年,在山西芦芽山国家级自然保护区对黑啄木鸟的生态习性进行了观察,采用常规路线统计法,统计其种群密度,并对其繁殖生态进行观察。结果表明该鸟在本地为留鸟,主要栖息于山区针阔混交林中,种群密度最大为0.417只/km,平均种群密度为0.261只/km。繁殖后比繁殖前种群密度增长了32%。繁殖期为4～6月,营巢期9～10 d,窝卵数为4～5枚,平均卵重12.1 g,大小为36.1 mm×24.3 mm。卵为椭圆形,白色光滑无斑。孵化期为13～15 d,雏鸟晚成性,24～25 d离巢,孵化率为86.36%,繁殖成功率为84.21%。主要以昆虫为食,且多为农林害虫,为森林益鸟,应加以保护。     

Effects of breed, sex and halothane genotype on fatty acid composition of triacylglycerols and phospholipids in pork longissimus muscle

The objective of this study was to estimate the effects of breed, sex, and halothane (HAL‐1843^TM) genotype on fatty acid composition of triacylglycerols (TAG) and phospholipids (PL) extracted from porcine longissimus muscle (LM). Purebred Yorkshire (n = 131), Duroc (n = 136), Hampshire (n = 49), Spotted (n = 35), Chester White (n = 74), Poland China (n = 51), Berkshire (n = 169) and Landrace (n = 82) pigs (n = 727; 427 barrows and 300 gilts) from the 1994 and 2001 National Barrow Show Sire Progeny Tests were used. For statistical analyses, a mixed model was used that included fixed effects of breed, sex, HAL‐1843^TM genotype, year, slaughter date within each year, interaction of breed × sex and random effects of sire and dam within breed. Breeds and sex were significantly associated with the percentages of the majority fatty acids in TAG. Duroc pigs had greater total saturated fatty acids (SFA) and lower total monounsaturated fatty acids (MUFA) (p < 0.05) contents than did pigs of all other breeds except Berkshire (p > 0.05). The concentration of total polyunsaturated fatty acids (PUFA) was the greatest in Hampshire pigs (p < 0.05). The content of total SFA was greater (p < 0.01), whereas the concentrations of total MUFA and PUFA were lower (p < 0.01) in barrows than those in gilts. The contents of major SFA in PL did not differ significantly among pigs from different breeds and sex groups. However, breed and sex significantly affected the concentrations of major MUFA and PUFA in PL and strong negative correlation between the total contents of MUFA and PUFA in PL was observed in the current study. Chester White pigs had greater total MUFA and lower total PUFA contents (p < 0.05) in PL than did pigs of all other breeds except Spotted (p > 0.05). In contrast to breed and sex effects, the concentrations of fatty acids in PL were more affected by HAL‐1843^TM genotype than those in TAG. The content of C16:0, a major SFA in PL, differed significantly in pigs with different HAL‐1843^TM genotypes. In conclusion, these results suggest that breed and sex are important sources of the variations for fatty acid composition of TAG and PL in LM.     

大通牦牛新品种的育成及推广经验

简要阐述了利用野牦牛作为父本培育新品种牦牛的理论及实践.并对育种中遇到的技术难点作了介绍.最后重点谈了大通种牛场在推广中总结的四点经验.     

Effect of breed on fatty acid composition and stearoyl-CoA desaturase protein expression in the Semimembranosus muscle and subcutaneous adipose tissue of cattle

The present study investigated (i) the effect of breed on the expression of stearoyl-CoA desaturase (SCD) protein and fatty acid composition in Semimembranosus muscle and subcutaneous adipose tissue of beef cattle and (ii) the relationship between SCD expression, cis-9, trans-11 conjugated linoleic acid (CLA) content, and monounsaturated fatty acid (MUFA) level. The study was conducted on the following breeds: Longhorn (L), Charolais cross with Holstein–Friesian (CX), Hereford (H), Belted Galloway (BG) and Beef Shorthorn (BS). Significant breed differences in the total fatty acid content, saturated fatty acid (SFA) level, MUFA and n−3 PUFA content were observed in subcutaneous adipose tissue but not in muscle. In the case of CLA, the breed differences were observed in both muscle and subcutaneous adipose tissue, with the highest level in L and the lowest level in H. In the case of subcutaneous adipose tissue, the breed with the highest CLA content (L) also had the highest SCD protein expression. The breed-specific pattern of SCD expression in subcutaneous adipose tissue was similar to the breed-specific pattern of one of the products of an SCD-catalysed reaction, C16:1 (BS < BG < H < CX < L). It has been concluded that (i) the mechanisms regulating SCD protein expression and CLA level in beef cattle are tissue-specific; (ii) breed-specific variations in SCD expression might contribute to breed variations in MUFA and CLA content in subcutaneous adipose tissue but not in Semimembranosus muscle.