甘肃省杂优猪杂交父本的合成研究——杂交猪DA、DB、DC肉用性能的同期比较

在同一条件下研究比较杜洛克（Ｄ） 与Ａ、Ｂ、Ｃ３ 个新品系猪杂交后代的肉用性能。结果显示, ＤＡ、ＤＢ、ＤＣ 的生长速度分别为７５７－３２ 、７１８－８１ 、６８６－６７ ｇ／ｄ 。料重比依次为３－５８ 、３－５４、３－７０ 。屠宰测定, ＤＡ、ＤＢ 的胴体瘦肉率比ＤＣ分别高７－５１ ％ （ Ｐ＜ ０－０５） 和１３－３８ ％ （ Ｐ＜ ０－０１） ,脂肪率ＤＣ比ＤＡ、ＤＢ 分别高１４－８４ ％ （ Ｐ ＜ ０－０５） 和３１－１５％ （ Ｐ ＜ ０－０１） , ＤＡ 和ＤＢ 无显著性差异。其它胴体性状水平各组间无显著性差异。ＤＡ、ＤＣ 的肉质性能良好, ＤＢ 表现轻度的ＰＳＥ 肉     

Effects of dietary lipid levels on lipid deposition and activities of lipid metabolic enzymes in hybrid tilapia (Oreochromis niloticus × O. aureus)

This study was designed to investigate the effects of dietary lipid levels on growth performance, lipid deposition and activities of lipid metabolic enzymes in hybrid tilapia (Oreochromis niloticus × O. aureus). Four isonitrogenous (300 g/kg crude protein) experimental diets containing graded levels of lipid (25, 55, 85 and 115 g/kg) were randomly assigned to triplicate groups of 180 juvenile fish. Fish were fed twice daily for 8 weeks. At the end of the experiment, the growth performance and proximate composition of fish were determined. The activities and gene expression of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) were assessed as well. Fish fed the diets with 55 and 85 g/kg lipid had a significantly (p < 0.05) higher body weight gain than those fed the diets with 25 and 115 g/kg lipid. The whole-body and liver lipid contents were significantly (p < 0.05) elevated with increasing dietary lipid levels. Moreover, the activities and mRNA abundances of LPL and HSL in the liver, dorsal muscle and fat tissues were markedly altered by dietary lipid levels. Our data demonstrate a profound influence of dietary lipid levels on the growth and lipid deposition in hybrid tilapia, which is likely associated with the regulation of lipid metabolic enzymes including LPL and HSL.     

桑树喷施磷酸二氢钾替代春季摘芯效果试验

通过试验得出，春期桑园喷施磷酸二氢钾不仅可以提高桑叶产量和实力利用率，还可以改善桑叶叶质。较春叶摘芯起到更好的效果。本文还提出了该药剂的实用喷施方法。     

施用镁肥对桑叶产量和叶质的影响

试验表明在Ｋ／Ｍｇ相对较高的酸性土壤,施用镁肥可提高桑叶产量和改善桑叶品质,在生产上可以施用钙镁磷肥或喷施２％硫酸镁溶液。     

全模拟自然生态条件下杂交野猪繁育与肥育性能测定

为了研究杂交野猪的生长性能、繁育水平与养殖环境、运动量、饲料配制的关系,根据野猪生活习性,对杂交野猪放养区内生活环境进行模拟(包括野猪巢穴、生态环境、植被),使杂交野猪能够有更多的运动范围和获取野外食物的机会。结果表明,放养模式下的杂交野猪产仔率(P<0.05)、仔猪存活率(P<0.01)均高于圈养模式杂交野猪,但增重速度显著(P<0.05)低于圈养模式下饲养杂交野猪。由试验结果可以得出,圈养模式下杂交育肥野猪增重速度显著高于放养杂交野猪,饲养管理难度较低,适合集约化大规模饲养。     

川牧土鸡的杂交试验

用川牧土鸡与固始鸡青脚系、乌骨系进行正反杂交,以测定F1代的生产性能。试验结果表明,川牧土鸡(♂)×固始鸡青脚系(♀)杂交组,受精率达93.04%,受精蛋孵化率88.03%,F1代90日龄成活率92.31%,公母均重1790.09g,料肉比3.01∶1,优于其他杂交组。     

加拿大披碱草-野大麦三倍体杂种加倍植株同工酶分析

分析了加拿大披碱草-野大麦三倍体属间杂种F₁加倍植株的同工酶酶谱特征。结果显示:同一生育阶段杂种自然加倍植株与加倍F₁代植株在EST、POD和SOD酶带的数目、位点及强弱方面具有一致性和遗传稳定性,而与杂种F₁代及亲本的酶带表型差异显著,从酶蛋白分子水平证明该杂种F₁染色体加倍是真实的;加倍植株抽穗期旗叶的EST、POD酶谱中分别呈现9和4条酶带,分蘖期幼叶的EST、POD、SOD酶谱内分别呈现8、4和4条酶带,有多态性位点的特征酶带可作为杂种加倍后代育性恢复鉴定的遗传标记的候选位点;对供试材料不同生育阶段做同工酶酶谱对比分析,比单一生育阶段更能反映其酶带表型的遗传差异性,提高同工酶电泳技术鉴定结果的准确性。     

20个龙须草种质资源叶片解剖特征

主要采用扫描电子显微镜技术,对收集的20个龙须草(Eulaliopsis binata)种质资源叶片进行电镜扫描,结果表明,不同种质资源叶片形态中的叶长、叶宽、叶面积,以及叶解剖结构中的叶片表皮厚度、叶片厚度、叶片气孔密度、叶片气孔长、叶片气孔宽、叶片纤维细胞直径、胞壁厚度、腔径、腔壁比等均呈现出显著或极显著差异,以优选造纸材料中重要指标壁腔比进行聚类分析,可将供试龙须草种质资源造纸性能分为最优、较好、较差和最差4类。试验结果可为中国南方丘陵区龙须草种质资源良种选育和开发利用研究提供依据。     

Factors responsible for levels of male sterility in photoperiod-sensitive cytoplasmic male sterile (PCMS) wheat lines

A `two-line system' using photoperiod-sensitivecytoplasmic male sterility (PCMS) caused by Aegilops crassa cytoplasm has been proposed as a newmeans of producing hybrid wheat. The PCMS line ismaintained by self-pollination under short-dayconditions (14.5 h light period), and F<sub>1</sub> seedscan be produced by outcrossing of the PCMS line witha pollinator under long-day conditions (15 h lightperiod). As the levels of male sterility in PCMSlines under the long-day conditions is a crucialfactor in determining hybrid purity of the F<sub>1</sub>seeds, a study was conducted into the effect ofseeding rate on male sterility in PCMS lines. Threedifferent density levels were tested using analloplasmic line of Japanese wheat cultivar `Norin 26'which exhibits PCMS. Levels of male sterility of thePCMS line increased at sparse planting, because tiller(ear) number per plant increased at low seedingdensity and late-appearing ears tended to exhibithigher levels of male sterility than early-appearingears. On the other hand, male sterility levels of thePCMS lines depended on genotype, e.g., the PCMS`Fujimikomugi' was completely male sterile, whereasthe PCMS `Norin 26' showed partial male sterility. APCMS line showing complete male sterility, such as thePCMS `Fujimikomugi', should produce F<sub>1</sub> seeds withhigh purity. However, the PCMS `Fujimikomugi' showeda lower female fertility. For practical use, it isnecessary to produce PCMS lines having high malesterility with high female fertility under long-dayconditions.     

萨杜湖杂交羊生长性能、羊毛品质及血液生理生化指标测定

为研究萨福克羊×杜泊羊×湖羊杂交羊(萨杜湖杂交羊)生长发育情况及其对当地生态环境的适应能力,采用生产性能常规测定、显微测定和全自动血液生理生化分析仪分别测定了不同年龄阶段萨杜湖杂交羊的体重、体尺指标、羊毛品质(包括不同部位羊毛的净毛率、细度、有髓毛和无髓毛占比、自然长度和伸直长度等指标)和成年羊血液生理生化指标。结果表明:萨杜湖杂交羊早期生长速度较快,初生阶段及周岁时公羊体斜长均显著高于母羊(P<0.05);3月龄时公羊体高、体斜长和胸围均显著高于母羊(P<0.05);6月龄时母羊体重极显著高于公羊(P<0.01),成年时期公羊体重和体高均显著高于母羊(P<0.05);其余各生长阶段内,公母羊间体重及体尺差异不显著(P>0.05)。其成年时平均净毛率较低,为45.21%;长度适中:平均自然长度为4.55cm,伸直长度为6.22cm;细度良好,为17.60μm。公母羊血液生理生化指标及其同国内绵羊参考值相比存在一定的差异,其中母羊血小板总数(PLT)和血小板压积(PCT)均极显著高于公羊(P<0.01),公羊甘油三酯(TG)和白蛋白(ALB)含量显著高于母羊(P<0.05),其余各项指标均无显著差异(P>0.05)。综上所述,萨杜湖杂交羊在生长发育等方面都有不同程度的改进和提高,本试验结果可为该品种杂交羊进一步开发利用提供参考依据。