盐碱地柽柳全冠移植技巧

就怪柳移植要求与改碱技术以及移植后的根系护理与出现症状的抢救措施展开论述,以供同行参考。     

大树移植施工及养护技术

为了提高移植大树的成活率和绿化效果,详细介绍大树起挖、包装、运输、卸下、移植等方面的施工技术要点,探讨大树移植后的具体养护管理措施,总结提高移植大树成活率的技术要点。     

确保大规格银杏成活率及美观度的全冠移植技术

以灵山胜境3期绿化工程为例,从银杏的生态习性出发,阐述了大规格银杏全冠移植在水分平衡、养分平衡、温度、改善透气性、光照、兼顾美观度等方面采取的一系列技术措施,为今后类似的园林工程施工积累成功的经验并提供借鉴。     

Assisted reproductive techniques for canines: preservation of genetic material in domestic dogs

Assisted reproductive techniques (ARTs), such as artificial insemination, in vitro fertilization, and cryopreservation of gametes/zygotes, have been developed to improve breeding and reproduction of livestock, and for the treatment of human infertility. Their widespread use has contributed to improvements in human health and welfare. However, in dogs, only artificial insemination using frozen semen is readily available as an ART to improve breeding and control genetic diversity. A recent priority in sperm cryopreservation is the development of alternatives to egg yolk, which is widely used as a component of the sperm extender. Egg yolk can vary in composition among batches and is prone to contamination by animal pathogens. The latter can be a problem for international exchange of cryopreserved semen. Low-density lipoprotein and skim milk are promising candidates for use as extenders, to ensure fertility after artificial insemination. Although not tested for its effects on fertility following artificial insemination, polyvinyl alcohol may also be a useful alternative to egg yolk as an extender. The development of cryopreservation techniques for canine embryos lags behind that for other mammals, including humans. However, given the success of non-surgical embryo transfer in 2011, studies have sought to refine this approach for practical use. Research on sperm cryopreservation has yielded satisfactory results. However, investigation of other approaches, such as cryopreservation of oocytes and gonadal tissues, remains insufficient. Techniques for the efficient induction of estrus may aid in the development of successful canine ARTs.     

轻简化基质育苗棉苗栽前离床期耐受生理特性研究

【目的】明确棉花轻简化基质育苗技术下的幼苗离床耐受生理相关特性,为其安全存放和运输保护提供理论支持。【方法】设置了育苗基质添加保水剂和不添加保水剂的处理,以中棉所50为材料,研究了29 d苗龄的幼苗不同离床和复水条件下的相关生理指标变化。【结果】室内条件下棉苗离床的耐受过程中,幼苗叶片逐步失水,引起从叶片外部表层细胞结构到内部生理的一系列变化,最终影响移栽成活率。其中,离床3 d内是安全期,叶片含水量的损失不到5%,且及时复水后能达到幼苗离床前初始状态的98%以上,移栽成活率均在99%以上;此时叶片表层细胞结构相对完整,细胞连接相对平滑,保卫细胞相对饱满。离床5 d为临界期,此时复水仅能达到初期的93%左右;第5至7天叶片失水最快,这个阶段相对含水率日均下降15百分点;当失水降到50%以下(11 d后)时,叶片表层细胞皱缩较严重,细胞壁皱褶明显,气孔塌陷较深,复水后恢复能力弱。失水过程中真叶内脯氨酸、丙二醛含量和过氧化物酶活力随离床时间增加而上升/增加,过氧化氢酶和超氧化物歧化酶活力变化在前5 d上升,5 d后开始下降。【结论】保水剂有利于维持离床棉苗体内水分,缓解离床期干旱胁迫。     

Supplementing media with NAD+ precursors enhances the in vitro maturation of porcine oocytes

In vitro maturation (IVM) is an important reproductive technology used to produce embryos in vitro. However, the developmental potential of oocytes sourced for IVM is markedly lower than those matured in vivo. Previously, NAD⁺-elevating treatments have improved oocyte quality and embryo development in cattle and mice, suggesting that NAD⁺ is important during oocyte maturation. The aim of this study was to examine the effects of nicotinic acid (NA), nicotinamide (NAM) and nicotinamide mononucleotide (NMN) on oocyte maturation and subsequent embryo development. Porcine oocytes from small antral follicles were matured for 44 h in a defined maturation medium supplemented with NA, NAM and resveratrol or NMN. Mature oocytes were artificially activated and presumptive zygotes cultured for 7 days. Additionally, oocytes were matured without treatment then cultured for 7 days with NMN. Supplementing the IVM medium with NA improved maturation and blastocyst formation while NAM supplementation improved cleavage rates compared with untreated controls. Supplementing the IVM or embryo culture media with NMN had no effect on maturation or embryo development. The results show that supplementing the maturation medium with NA and NAM improved maturation and developmental potential of porcine oocytes.     

牛早期胚胎体外发育条件的研究

本试验研究了精卵共育时间和培养液等因素对牛早期胚胎体外发育的影响。精卵共育6～12h能显著提高受精卵的囊胚发育率,受精卵的囊胚发育率为23．2％～25．3％,共育时间为24h时,囊胚发育率降低,但精卵共育6h时卵裂率较低;TCM199、mBECMaa、mSOFaa均能支持体外受精卵的发育,其囊胚发育率分别为18％、30．7％和29．2％。试验结果表明：精卵于BM受精液中共育9h后,将其置于添加5％OCS的mBECMaa或mSOFaa中培养,能得到较高的体外生产胚胎的囊胚发育率。     

牛胚胎生产的全程质量控制

本文介绍了供体牛的准备、供体牛同期发情处理、供体牛的超排和配种以及胚胎回收、胚胎质量评定、胚胎冷冻等牛胚胎生产的各个环节中应采取的全程质量控制措施。     

大别山黄牛胚胎移植技术应用效果分析

选择120头大别山黄牛进行胚胎移植,84头进行同期发情处理,结果,发情67头,发情率79.7%,可移植的大别山黄牛69头,妊娠29头,妊娠率为42%,达到实际应用水平,经济效益显著。     

甘蓝型油菜硫苷组分的胚、细胞质和母体遗传效应分析

利用甘蓝型油菜4个显性纯合两用系与7个恢复系配制不完全双列杂交组合，采用广义种子遗传模型分析甘蓝型油菜硫苷组分的胚、细胞质和母体植株3套遗传体系的基因主效应和基因型×环境效应。结果表明硫苷组分性状受制于基因主效应，基因型×环境互作效应作用较小。2-羟-3-丁烯基、3-丁烯基以胚主效应为主，分别占75.21%和58.25%。4-羟-3-吲哚甲基、苯乙基以细胞质效应为主，分别占74.19%和69.54%。4-戊烯基由胚主效应和细胞质效应共同控制，分别占50.29%和38.12%。在基因型×环境互作方差中，4-羟-3-吲哚甲基仅受制于细胞质互作效应，其余硫苷组分均以显著的胚互作效应和细胞质互作效应为主。5个硫苷组分均以普通狭义遗传率为主，互作狭义遗传率较低。在普通狭义遗传率中，2-羟-3-丁烯基、3-丁烯基以胚遗传率为主，分别为71.61%和53.76%。4-羟-3-吲哚甲基和苯乙基以细胞质遗传率为主，分别为68.21%和68.47%。4-戊烯基以胚遗传率和细胞质遗传率为主，分别为47.81%和36.24%。在互作狭义遗传率中，5个硫苷组分以细胞质互作遗传率为主，均达到了显著水平。亲本遗传效应值预测表明，选用D3AB、D21R作为硫苷品质改良亲本有利于降低杂种后代油菜籽中2-羟-3-丁烯基和3-丁烯基的含量。