添加不同酵母培养物对瘤胃纤维分解菌群和纤维素酶活的影响

用3种酵母培养物(YC- 1、YC 2和YC- 3)分别饲喂4头带有永久性瘤胃瘘管的肉牛,研究培养物对瘤胃发酵、纤维分解酶活性和3种纤维分解菌数量的影响,结果表明:YC 2处理的乙酸、丙酸、丁酸和总 VFA浓度显著高于对照组(P<0 .05),YC 1和YC 3处理的乙酸/丙酸比例显著降低(P<0 .01);各处理均能显著提高瘤胃内羧甲基纤维素酶、水杨苷酶和木聚糖酶的活性(P<0 .01);各处理都显著提高黄化瘤胃球菌的相对比例(P<0 .01),16SrRNA特异性寡聚核苷酸探针杂交法分析测定结果表明 3 种纤维分解菌在瘤胃细菌中所占比例为 3. 80%±0 .2%。     

中国荷斯坦牛部分乳房结构特性对泌乳性能的影响

本研究对规模化场奶牛乳房结构部分性状进行评价和测定,旨在分析其影响因素及其与泌乳性能的关系。现场评价和测定我国北方6个规模化奶牛场荷斯坦牛的乳房均衡(2 030条)、乳头长度(1 551条)和乳头位置评分(分前、后乳头,2 839条),使用SAS 9.2 GLM过程采用固定效应模型分析影响上述3个乳房性状的因素,同时分析3个单项性状对校正日产奶量和体细胞评分的影响。结果表明:场和胎次对3个乳房性状影响极显著(P0.01);前、后乳头位置和后乳头长度对校正日产奶量有显著影响(P0.05),校正日产奶量与前乳头位置评分值呈正比,与后乳头位置评分值呈反比;前乳头位置和长度对体细胞评分有显著影响(P0.05),体细胞评分随前乳头位置评分的增大而减小;5~5.5 cm的乳头长度对于校正日产奶量和体细胞评分都最佳。本研究结果为通过乳房性状选择、淘汰并提高奶牛的生产性能、乳房健康提供了参考。     

大豆突变体库构建研究进展

大豆突变体库是大豆农艺性状变异的重要来源,可以作为选育新品种资源和大豆基因功能研究的基础。综述了几种常用大豆突变体库的构建方法及其构建特点和应用范围,介绍了一些突变体库构建的新方法及其优缺点,并对这些新方法在大豆突变体库构建应用中进行了展望,为大豆育种实践和基因功能研究拓宽思路和提供参考。     

Reproductive barriers to hybridizations between narrow-leaf and broad-leaf Anoectochilus roxburghii

Narrow-leaf and broad-leaf Anoectochilus roxburghii were used as reciprocal parents to explore the reason for low seed setting rate. Pollen-pistil interaction was observed by fluorescence microscopy and hybrid embryo development by paraffin section technology. The results indicated that pollen tube growth could reach the embryo sac, and double fertilization could be completed. These findings showed that a pre-fertilization barrier was not the major factor in the cross of narrow-leaf and broad-leaf A. roxburghii. The endosperm development of the hybrid was abnormal and eventually promoted abortion of the embryos. A post-fertilization barrier appears to be the major factor for low seed setting rate in the cross of narrow-leaf and broad-leaf A. roxburghii. In addition, an efficient protocol of embryo rescue, the development of which is reported elsewhere, was used to compare the time needed for rescue between the reciprocal crosses.     

枣抑制消减cDNA文库构建与分析

枣树具有独特的开花结果特性,为获得枣花发育基因,以金丝4号枣不同发育时期的花蕾和同时期的叶片cDNA互为试验方和驱动方,利用抑制消减杂交技术分别构建了枣花和枣叶抑制消减杂交cDNA文库(SSH文库)。枣花和枣叶SSH文库重组率分别是92.05%和90.26%,插入片段长度均介于200~2 000 bp之间,主要集中于1 000 bp左右。分别从枣花和枣叶SSH文库中随机挑选1 000个阳性克隆进行DNA测序、组装拼接,结果显示枣花SSH文库中获得96条unigene,其中contigs 43个,singletons 53个,96条unigene预测得到73个ORF,经过同源比对分析获得有注释的序列20条,按功能分为7类;枣叶SSH文库中获得86条unigene,其中contigs 45个,singletons 41个,86条unigene预测得到70个ORF,经过同源比对分析获得有23条注释的序列,按功能分为6类。     

瘦肉型猪组合配套杂交效果研究

为探索瘦肉型猪组合配套杂交方法和效果而进行试验。试验采用HN121（温氏杜洛克猪）、HN212（法系皮特兰♂×温氏杜洛克♀）为父本,以HN204（温氏大白♂×美系长白♀）为母本,对HN323（HN121×HN204）和HN424（HN212×HN204）两个组合配套进行研究。结果表明,HN424组合与HN323组合相比母猪的窝产仔数、窝产活仔数、仔猪初生窝重、21日龄仔猪成活率、21日龄窝重等繁殖性状差异不显著（P>0.05）;HN424组合仔猪的体重、背膘厚降低5.63%（P<0.05）,瘦肉率提高4.95%（P<0.05）,眼肌面积增大33.08%（P<0.01）,肉色评分降低7.19%（P<0.05）,大理石纹评分降低11.30%（P<0.01）,滴水损失率提高10.63%（P<0.01）,其他遗传性状差异不显著;HN424组合与HN204二元母系相比,日增重提高9.26%（P<0.05）,背膘厚减少16.41%（P<0.01）,料肉比减少8.02%（P<0.05）;HN323组合与HN204二元杂交母系相比,日增重提高7.20%（P<0.05）,背膘厚减少11.43%（P<0.01）,料肉比降低5.35%（P<0.05）。说明采取四元杂组合和三元杂交组合均对“大×长”（HN204）二元杂交有显著的遗传改良作用,“皮×杜×长×大”四元杂组合可显著提高猪的瘦肉率、眼肌面积,但肉色、大理石纹、滴水损失率等肉质指标变差,建议在“皮×杜×长×大”四系组合配套杂交中加入能改良肉质基因的猪种。     

猪轮回杂交的杂种优势之辩证

文章辩证地分析了猪轮回杂交的利与弊。作者指出：畜禽经济杂交在实践中应用的各类方法都有其适用范围和局限性。只要掌握了杂种优势的基本原理以及获得杂种优势的方法,就能在生产实践中扬长避短,将轮回杂交的缺点降到最低,并将其优点发挥到极致。     

苜蓿原生质培养及体细胞杂交技术的应用

阐述了植物原生质体培养和体细胞杂交技术以及苜蓿Medicago spp.体细胞胚胎发生特性,综述了该技术在苜蓿育种研究中的应用状况,同时介绍了我国苜蓿研究领域原生质体培养和体细胞杂交技术的研究进展.     

Natural hybridization between wheat (Triticum aestivum L.) and its wild relatives Aegilops geniculata Roth and Aegilops triuncialis L.

BACKGROUND

Cultivated bread wheat (Triticum aestivum L.) spontaneously hybridizes with wild/weedy related Aegilops populations, but little is known about the actual rates at which this hybridization occurs under field conditions. It is very important to provide reliable empirical data on this phenomenon in order to assess the potential crop–wild introgression, especially in the context of conducting risk assessments for the commercialization of genetically modified (GM) wheat, as gene flow from wheat to Aegilops species could transfer into the wild species genes coding for traits such as resistance to herbicides, insects, diseases or environmental stresses.

RESULTS

The spontaneous hybridization rates between wheat and A. geniculata and A. triuncialis, which are very abundant in the Mediterranean area, have been estimated for the first time in the northern part of the Meseta Central, the great central plateau which includes the largest area of wheat cultivation in Spain. Hybridization rates averaged 0.12% and 0.008% for A. geniculata and A. triuncialis, respectively. Hybrids were found in 26% of A. geniculata and 5% of A. triuncialis populations, at rates that can be ≤3.6% for A. geniculata and 0.24% for A. triuncialis.

CONCLUSION

The detection of Aegilops spp.–wheat hybrids in Aegilops populations indicates that gene flow can occur, although wheat is considered a crop with a low-to-medium risk for transgene escape. These data on field hybridization rates are essential for GM wheat risk assessment purposes. © 2023 Society of Chemical Industry.     

籼稻体细胞胚胎发生特异性蛋白质研究

以籼稻Oryza sativa L.subsp. indica品种“广陆矮4号”幼穗和种子为外植体，在含有2，4-D2.0mg/L的MS培养基上，分别形成胚性和非胚性愈伤组织，建立体细胞胚胎发生实验系统。应用Native/SDS双向凝胶电泳分析，结果表明，非胚性愈伤组织分化培养前后均存在一种分子量为45kD的非胚性蛋白质N1，另一种非胚性蛋白质N2（54kD）仅