Correlated Response to Selection for Protein Yield in Oats After Three Cycles of Recurrent Selection

Three oat (Avena saliva L.) populations (i.e., lines of descent), high grain yield (HG), high protein content (HP), and high protein yield per se (HGP), each developed by three cycles of S, recurrent selection, were evaluated for the effect of selection for groat-protein yield upon other agronomic traits. Selections making up the HG line of descent had high protein yield primarily due to high grain yield, and those selected for HP had high protein yield due to both high protein content and high grain yield. Selection in HGP was on the basis of protein yield per se. Selection caused increases in bundle weight, harvest index, vegetative growth rate, and seed number in all lines of descent. Heading date, plant height, and seed weight were unaffected, whereas groat percentage and test weight were decreased in HP and HGP. Heritabilities were high for heading date, plant height, test weight, and seed weight, moderate for harvest index and bundle weight, and low for groat percentage. Genetic variability generally declined from CO to C3 for all traits. Groat-protein yield and amount of protein per groat increased in all lines of descent. In HG, the increase in groat weight was due primarily to increases in the nonprotein fraction, with groat-protein content actually decreasing. In HGP, groat weight increased due to increases in protein and nonprotein fractions, and groat protein content remained constant. In HP, groat weight and amount of nonprotein per groat decreased, thus increasing groat-protein content. Three cycles of recurrent selection resulted in oat lines with groat-protein yields significantly higher than the highest lines from CO. Utilization of index selection may be desirable to obtain populations of greater breeding value.     

猪血浆蛋白(酶)多态性与杂种优势的关系

为探讨血浆蛋白 (酶 )多态性与杂种优势的关系 ,测定了杜洛克、长白、大白、杜×长大、大×长大、长×大、大×长共 7个品种 (组合 )的 8个血浆蛋白 (酶 )位点的多态性及部分生长和胴体性状 ,计算了平均基因杂合度与部分经济性状实测值和杂优率的相关关系 .结果表明 ,平均基因杂合度与遗传距离呈正相关 ,与日增重、屠宰率、背膘厚、后腿比例的实测值或杂优率呈正相关 ,与眼肌面积的实测值和杂优率呈负相关 .平均基因杂合度和亲本间遗传距离可为预测杂种优势提供依据 .     

跑车带锯机列的电气改造

本文通过对木工跑车带锯机列摇尺制动和摇尺操纵的电器改造，实现了摇尺自控和跑车摇控。提高了木材出材率，改善了工人的劳动条件。     

乳酸菌与中药合生元对肉鸡生长性能及饲料利用率的影响

本试验分别向肉仔鸡日粮中添加等量的抗生素和乳酸菌与中药合生元制剂,通过测定肉仔鸡的各项生长指标和饲料利用率指标,探讨乳酸菌与中药合生元在肉鸡生长和饲料利用率方面替代抗生素的优势.结果表明,试验组与对照组在生长性能和饲料利用率上各指标均差异不显著（P〉0.05）,说明乳酸菌与中药合生元可以替代抗生素饲喂给肉仔鸡.     

基于果实相关性状的桃品种初级核心种质取样策略研究

以国家种质资源圃(北京)编目的558份桃品种的18个形态学和农艺学性状为基本数据,研究了桃品种初级核心种质构建的取样策略,包括总体取样比例的确定及取样方案的选择,以获得最佳的初级核心种质。本试验共设10%～90%9个总体取样比例;取样方案研究包括分组原则和组内取样比例的确定。结果表明,桃初级核心种质的适宜总体取样比例为10%;按品种类群分组结合多样性比例取样为构建桃初级核心种质的最佳取样方案;利用此取样策略从558份桃品种中提取56份作为核心样本,对其代表性进行检测表明所构建的初级核心种质能够很好地代表桃原始种质的遗传多样性。     

小麦远缘杂交后代节燕98-2分离类型贮藏蛋白的研究

采用A-PAGE和SDS-PAGE聚丙烯酰胺凝胶电泳方法,对远缘组合分离出来的节燕98-2类型入选11个遗传性基本稳定的具有高产、多抗的小麦株系的醇溶蛋白和高分子量谷蛋白亚基进行了分析.结果表明,在A-PAGE电泳分析中,11个供试株系具有11种不同的醇溶蛋白带型.在SDS-FAGE电泳分析中,出现了7种不同的高分子量谷蛋白亚基(HMW-GS)及6种亚基组合类型,优质亚基及亚基组合所占的比例较少,品质评分偏低,其变幅为5～8分,平均为6.36分.但在所分析的材料中,出现了一个少见的特殊亚基:2 10 12.并研究了这些HMW-GS和组合频率及特点.11个株系中7个具有45 10优质亚基和2个具有2*亚基,它们可供小麦优质育种利用.研究表明,通过远缘杂交能够选育出具有高产、抗病和优质的小麦新材料.     

干旱区20个紫花苜蓿品种抗旱性研究

该试验测定了20个苜蓿品种的水势、总含水量、自由水量、束缚水量、束/自比以及渗透调节物质.从植物水分生理与生化方面,测试各品种的抗旱性,并结合产草量、品质进行综合评价.从中选出5～6个抗旱性较强、产草量高、品质较好的苜蓿品种,为干旱区选择适宜的苜蓿品种提供具有实用价值的基础资料.     

Patterns of silver eel (Anguilla anguilla L.) sex ratio in a catchment

Abstract –  Changes in the numbers and size-class structure of European silver eels, Anguilla anguilla , in the River Frémur (France) were examined over a 9-year period after installation of downstream eel passes. The number of silver eels migrating downstream peaked in 1999, then decreased strongly and steadily after 2000, reaching relatively low levels. At the same time, a gradual shift in the silver eel sex ratio from a dominance of males (size from 270 to 442 mm, age from 3 to 6 years) to females (size from 366 to 1112 mm, age from 4 to 9 years) was recorded. Possible explanations for the escapement patterns observed are environmental sex determination and the installation of eel passes on the main hydraulic engineering structures in 1992 and 1996.     

低蛋白质氨基酸平衡饲粮对早期断奶仔猪腹泻和生产性能的影响

本研究选用１８头２８±１日龄断奶的杂交仔猪（平均体重约５．５ｋｇ），研究低蛋白质氨基酸平衡饲粮对早期断奶仔猪腹泻和生产性能的影响。试验结果显示：（１）低蛋白质氨基酸平衡饲粮使仔猪血浆挥发性盐基氨含量、血浆尿素氨含量和腹泻指数降低（Ｐ＜０．０５或０．０１）。（２）采食全植物蛋白型氨基酸平衡饲粮（ＣＰ１８．３％）的仔猪，其平均日增重（ＡＤＧ）、平均日采食量（ＡＤＦＩ）和料肉比（Ｐ／Ｇ）与采食复合蛋白型对照饲粮（ＣＰ１９．７％）的仔猪差异不显著（Ｐ＞０．０５），但前者的增重成本比后者降低（Ｐ＜０．０５）３１％。（３）采食复合蛋白型氨基酸平衡饲粮（ＣＰ１８．４％）的仔猪的生产性能优于采食复合蛋白型对照饲粮（ＣＰ１９．７％）的仔猪，前者的ＡＤＧ和ＡＤＦＩ分别提高（Ｐ＜０．０５）６１％和３２％，Ｆ／Ｇ和增重成本分别下降（Ｐ＜０．０５）２４％和３７％。（４）采食全植物蛋白型氨基酸平衡饲粮的仔猪，其ＡＤＧ和ＡＤＦＩ低于（Ｐ＜０．０１）采食复合蛋白型氨基酸平衡饲粮的仔猪。前者的Ｆ／Ｇ和增重成本趋于高于后者，但差异不显著（Ｐ＞０．０５）。以上结果表明，低蛋白质氨基酸平衡饲粮可显著降低仔猪断奶后腹泻和提高仔猪生产性能。复合蛋白型?     

SS-1型声速实验仪的研制

本文阐述了SS—1型声速实验仪的原理、结构和测量方法。波动学和分子物理学是物理学中的重要组成部分,"声速的测量"和"Y值的测量"两个实验有助于学生对波动相位的空间分布、谐振动的合成、李萨育图、能量按自由度均分原