The F38-Like Group,a New Group of Caprine Mycoplasmas?

This paper concerns the taxonomic status of the F38-like group (MacOwan), a prime determinant of contagious caprine pleuropneumonia (CCPP). Extensive biochemical and serological investigations on strain F38 are reported. Some complex serological relationships with other mycoplasma species are revealed. The results, taken in conjunction with earlier published work on geno-typic characters, lead to the conclusion that final classification of these organisms should await further comparative studies of a number of field strains with a related group of strains classified as M. capri-colum.The characterization of F38 confirms its partial relationship to the “M. mycoides group” of ovine/caprine/bovine mycoplasmas, and has also revealed a very close phenotypic relationship to the bovine mycoplasma serogroup 7, a finding of potential diagnostic and epidemiological importance.Key words: mycoplasmas, classification, F38-like group     

绵羊卵泡发育过程中关键信号通路研究进展

卵泡从原始卵泡发育为成熟卵泡，直至排卵、黄体发育等过程都受到精密的调控，产生大量的优势卵泡是绵羊产多羔及实现快速扩繁的关键因素。研究发现，相关信号通路和转录因子通过影响绵羊卵泡中卵母细胞、颗粒细胞的生长，进而调控卵泡的发育成熟，对这些信号通路进行深入了解，有助于探索卵泡发育的调控机制，早日实现绵羊高效繁育。Notch是卵泡发育过程中发挥重要作用的高度保守信号通路，PI3K/AKT/mTOR信号通路各成员都是广泛存在于细胞内的信号转导分子，在卵泡发育早期发挥了主要作用，还有间隙连接（gap junction，GJ）和跨带突触（transzonal projections，TZPs）等物理连接方式，在细胞间的交流通讯起到重要作用。作者详细介绍了Notch信号通路、PI3K/AKT/mTOR信号通路、间隙连接及跨带突触的结构功能在绵羊卵泡发育中的调控作用，为进一步探明绵羊卵泡发育的调控机制提供参考。     

以全产业链思维优化甘肃省“粮改饲”生产力布局

用全产业链思维优化“粮改饲”生产力布局具有重要的现实意义和理论价值。本文以甘肃省为例,总结甘肃省“粮改饲”工作已取得的工作成效和不足,论述了“粮改饲”构建全产业链的必要性,初步探讨了甘肃省“粮改饲”全产业链模式和布局优化,并提出完善相关支持政策、培育壮大龙头企业、高度重视品牌建设和创新科技带动引领4条对策建议。 [关键词]全产业链|粮改饲|生产力布局|甘肃省     

Determination of vc and mating types of Cryphonectria parasitica isolates by multiplex PCR and their genetic diversity in 13 chestnut-growing provinces of Turkey

Vegetative compatibility (vc) and mating types and genetic diversity of Cryphonectria parasitica isolates were determined using 183 isolates obtained from 215 infected chestnut trees growing in 13 provinces of Turkey. Based on the cultural aspects, 143 of these isolates were evaluated as virulent whereas the remaining 40 isolates were hypovirulent. When vc types of 183 isolates were classically differentiated, 135 of them matched to EU-1 (82.3%), 29 of them to EU-12 (17.6%) vc type, whereas 19 of them did not match to the two. When molecular vic markers were used, all the isolates were assigned to two EU vc types; 149 to EU-1 (81.4%) and 34 (18.5%) to EU-12. Of the majority of the isolates, 134 (73.2%) had mating-type MAT-1, while 44 (24%) isolates had MAT-2 and 5 (2.8%) isolates had both mating types. The population analysis based on two DNA marker systems, Inter-Primer Binding Site and Start Codon Targeted Polymorphism, showed no intraspecific genetic variation among the C. parasitica isolates. The prevalence of two dominant vc types revealed by this study shows that biological control with hypovirulent EU-1 and EU-12 isolates will be significant for the country. The results might be helpful to chestnut breeders carrying out resistance breeding studies to manage this disease based on hypovirulence attributed to Cryphonectria hypovirus 1.     

Approaches to pathogen-mediated resistance breeding against plum pox potyvirus in stone-fruit trees1

In a programme for developing systems which allow the transfer of foreign genes into apricot cultivars, we have tested cotyledons of immature embryos, somatic embryos and leaf discs. Apricot plants have been transformed, and then regenerated, with Agrobacterium tumefaciens strain LBA 4404 containing various binary plasmids: pBinGUSint, carrying the marker gene β-glucuronidase (GUS), and pBinPPVm, carrying the coat-protein gene of plum pox potyvirus (PPV). The marker gene GUS was used for visual evaluation of the efficiency of the transformation system. The coat-protein gene was used in the hope of introducing coat protein-mediated resistance to one of the most important stone-fruit pathogens in Europe and the Mediterranean area.     

浅谈牧草转基因育种研究进展

简要概述了牧草遗传转化方向及牧草转基因所取得的主要贡献,介绍了牧草遗传转化三种方法,并就今后的发展前景和转基因育种生物安全问题做了初步探讨。     

内蒙古阿拉善盟草原疯草危害调查

采用现场调查和资料收集相结合的方法，对内蒙古阿拉善盟的阿拉善左旗、阿拉善右旗和额济纳旗3个旗疯草的种类、分布、危害及防治对策进行了调查研究。结果表明：阿拉善盟有疯草7种，其中棘豆属有毒植物3种，黄芪属有毒植物4种，分布面积超过139．33万hm^2，危害最严重的是小花棘豆和变异黄芪，给当地畜牧业造成了极大的危害，并就如何综合利用疯草提出了几点措施。