一种适用于单胎动物多品种选择的基因组关系矩阵

旨在提出一种新型基因组关系矩阵并验证其在多品种联合群体中的模拟应用效果。本研究利用QMsim软件模拟牛的表型数据和基因型数据;利用Gmatrix软件构建常规G阵;利用R语言构建新型G阵,新型G阵在常规G阵的基础上,将多品种联合群体的非哈代-温伯格平衡位点考虑在内;利用DMU软件使用“一步”法模型计算基因组估计育种值（estimated genomic breeding value,GEBV）;比较不同情况下使用两种G阵的GEBV预测准确性。结果表明,在不同遗传力及QTL数下,不对新型G阵使用A₂₂阵加权就能达到常规G阵使用A₂₂阵加权时的GEBV预测准确性。在系谱部分缺失时,新型G阵不加权较常规G阵加权时GEBV预测准确性高。证明,在系谱有部分缺失时,新型G阵对多品种GEBV的预测有一定优势。     

The value of incorporating carcass trait phenotypes in terminal sire selection indexes to improve carcass weight and quality of heavy lambs

Genetic selection for carcass traits is paramount to maximize the profitability and long‐term sustainability of any meat‐producing livestock species. The main objectives of this research were to evaluate the efficiency of indicator traits for the genetic improvement of lamb carcass traits and to determine the value of including carcass traits into terminal sire selection indexes for the Canadian sheep industry. The carcass traits included hot carcass weight (HCW), fat depth at the GR site (FATGR) and average carcass conformation score (AVGCONF), and were measured on heavy lambs (slaughter age less than 365 days and HCW greater than 16.3 kg) in commercial abattoirs. Growth traits were found to be moderately efficient indicator traits for the genetic improvement of HCW but selection on ultrasound traits was necessary to substantially improve the carcass quality traits (FATGR and AVGCONF). Economic selection indexes were designed by adding various combinations of carcass traits into the Canadian Sheep Genetic Evaluation System terminal indexes. Records measured on individuals and progeny were assumed to be the sources of information for live animal and carcass traits, respectively. The changes in index accuracy, efficiency and expected correlated response were used to assess the value of their inclusion. HCW was found to have a large economic value, and its inclusion into terminal selection indexes was expected to substantially increase their accuracy (0.08–0.12 points) and efficiency (20%–30%). However, further including FATGR (measured 110 mm from the carcass midline over the 12th rib) and AVGCONF had little impact on the accuracy (≤0.03) and efficiency (1%–7%) of the proposed indexes. Thus, the inclusion of carcass traits into the existing terminal selection indexes could be beneficial for the genetic improvement of HCW, but further research is needed to determine optimal methods of increasing carcass fatness and muscularity.     

农业推广方法选择研究——以陕西省三原县为例

本文以陕西省三原县为例,采用典型调查方法,运用问卷调查、农户访问等资料搜集手段,研究各种因素对农业推广方法选择的影响.研究结果表明:推广对象的经济状况、采用创新的不同阶段以及推广对象的文化程度等都影响到农业推广方法的选择,而要最大限度地提高推广效果需要综合采用多种农业推广方法.     

中华卵索线虫人工室内培养技术

为室内大量繁殖中华卵索线虫Ovomermis sinensis,采用个体由大到小的斜纹夜蛾Spodoptera litura、棉铃虫Helicoverpa armigera和黏虫Mythimna separata作为宿主,测定被中华卵索线虫寄生后3种宿主的体长和体重,研究宿主种类对中华卵索线虫有效率、雌雄比和体长的影响以及寄生强度对线虫雌雄比的影响。结果显示,被中华卵索线虫寄生后,斜纹夜蛾、棉铃虫和黏虫生长减缓。在相同感染比例下（除宿主与线虫比为1∶15外）,3种宿主的线虫有效率之间差异不显著。当寄生强度为5时,3种宿主体内脱出的中华卵索线虫均为雌线虫;当寄生强度从10增到40时,斜纹夜蛾、棉铃虫和黏虫所脱出的雌性比分别由100.0%、90.0%、83.9%降为0;相同寄生强度下,从斜纹夜蛾体内脱出的雌性比显著高于从棉铃虫与黏虫体内脱出的雌性比。斜纹夜蛾、棉铃虫和黏虫体内脱出雌线虫和雄线虫平均体长分别为14.8、13.8、12.8 cm和8.0、7.5和7.5 cm。当中华卵索线虫与宿主按照比例20∶1～25∶1侵染斜纹夜蛾、按照15∶1侵染棉铃虫和黏虫时,能获得线虫最适雌雄比（1∶1...     

Decision Making for Vendor Selection With AHP and Random Disposal of DEA

The vendor selection directly relatives to the procurement quality and influences the competition of the corporation in the supply chains. It is important and practical to study the vendor selection method. The measuring criteria and the method for vendor selection are analyzed. The authors put forward an new method which is combined with both the advantage of analytic hierarchy process (AHP ) and random disposal of data envelopment analysis ( DEA) for vendor selection. It introduces a random variable which solves the disadvantage of the weigh value in DEA which convert subjective estimation to objective opinion in the course of the vendor selecting. The method can improve the reliability of the vendor selection.     

小麦轮回选择的初步实践

利用太谷核不育小麦,开展以抗锈和矮秆丰产为主要目标的轮回选择,选择压分别为5.6%和4.7%.抗锈群通过一轮混合选择,条锈病反应型0—1级的抗病株率和严重度25%以下的轻病株率较基础群体分别提高12.5%和5.1%.矮秆丰产群采用两种轮选方案.经两轮选择看出,改良半姐妹法其群体的株高比基础群体明显降低6.2厘米,其余性状有向选择目标集中的趋势;混合选择法其群体除穗粒数外,其余性状进展趋势与上相同.     

介电式脱绒棉种分选机的研制

为了提高棉花种子的发芽率，采用了先进的计算机控制技术，研制了介电式棉种分选机，达到了利用种子的介电特性进行分选的目的。试验表明，该机工作稳定可靠，操作方便．完全满足种子精选的要求，具有广泛的推广前景。     

小黄鱼热泵干燥工艺及设备选型分析

研究了不同热泵干燥温度下小黄鱼的干燥特性,并对其干燥品质进行分析。结果表明在干燥温度55℃、铺放密度为6.48 kg/m2的条件下干燥时间为13.5 h,干燥品质最优。在综合考虑能耗、企业加工条件和产品品质的前提下,将生产工艺参数确定为:干燥温度60℃、铺放密度为6~7 kg/m2,干燥时间为10~12 h。根据企业日处理量5.5~6.0 t的加工要求,通过对产能核算及加工成本计算,确定设备选型方案为:1台GHRH-510型热泵干燥机与2台GHRH-340型热泵干燥机,该方案投资回报期短,社会效益明显。     

叶用型沙棘育种研究--“蒙×中”沙棘F1代雄株变异特性与选优标准的研究

通过对蒙古沙棘亚种优良品种与中国沙棘亚种优良类型F1代雄株的变异特性分析,建立了选择优 良单株的标准,为叶用型沙棘选择育种提供了科学依据。