甘蔗茎皮硬度,开化及产糖量性状的遗传方差与遗传进度     

kang  M.S 王建南 《国外农学:甘蔗》1991,(2):8-11

  相似文献   

有盾蚁巢伞菌丝体培养过程中β—葡糖苷酶的产生     

Sengu  S 王谦 《国外农学:国外食用菌》1993,(1):34-38

  相似文献   

辣椒新雄性不育系P-MS的选育     

S·矢泽  H·米田  M·细川 《辣椒杂志》2003,1(1):51-52

辣椒杂种一代的制种迄今几乎全靠人工授粉进行，需要花费大量的人工或劳动力。利用雄性不育繁制杂交种子已在不少农作物和园艺作物上得到利用，至于辣椒雄性不育的研究于1958年曾有过报道(Peterson，1958)。辣椒细胞质雄性不育由与S细胞质互作的隐性基因rf控制，但雄性不育的表达对温度敏感，在冷凉条件下会产生可育花粉(Peterson，1958；Shifriss ＆ Guri 1979；Shifriss，1997)。  相似文献   

油脂在提高公猪生产力和生育力上的潜在作用     

潘雪男  P.C.Penny  R.C.Noble  A.Maldjian  S.Cerolin 《国外畜牧学(猪与禽)》2001,(2):24-29

精子及其相关精浆中所含的脂肪成分在组成和脂肪酸成分上是非常独特的。长链多不饱和脂肪酸 (即具有 2 0或 2 2个碳原子并含三个以上双键的脂肪酸 )在绝大多数主要组织所含脂肪中的含量非常有限 ,但在精子和精浆中的含量相当高 ,并具有明显的种属特异性。油脂的这种特性现在日益被认为是使受精最终成功所特别需要的。本综述根据最近一的些研究结果撰写而成 ,从精液质量和功能的一系列决定因子的角度论述了使现代种公猪精子中脂肪 /脂肪酸参数最佳化的可能性 ,可见人们对一系列参数所作的一系列重要研究 ,产生了使公猪和母猪的繁殖能力都得到提高的高度有益结果。文章还从主要的营养学特性和化学特性方面对研究结果进行了讨论 ,并与其它家畜进行了比较 ,还讨论了其对猪繁育部门可能的商业应用价值。  相似文献   

小蔗螟抗性的广义遗传力、遗传相关和选择指数及其与产量损失的关系     

S．B．Milligan  向平 《国外作物育种》2004,23(1):61-62

由Diatraea saccharalis引起的小蔗螟对甘蔗造成了严重的损害，因而培育抗性品种非常重要。小蔗螟幼虫通过在茎秆节间钻洞和化蛹来损害甘蔗。通过机械钻洞，营养物质输送中断，直接减少了茎秆重量，严重时造成茎秆毁损。这种机械损毁作为病原体传入的通道，造成茎秆重量和品质的进一步下降。  相似文献   

品种和年龄对猪的基础免疫特性、血液皮质醇浓度及生长性能的影响     

M.A.Sutherland  S.L.Rodriguez-Zas  M.Ellis  J.L.Salak-Johnson 《饲料工业》2005,(20)

试验的目的是要证实不同品种的猪之间存在着基础免疫和生长特性的差异,这些差异是由猪的日龄不同引起的。分别选取4、8、12周龄的波克夏猪(36头)、杜洛克猪(18头)、梅山猪(54头)、长白和约克夏的杂交后代白猪(36头)、约克夏猪(36头)来进行基础免疫,血浆中的皮质醇浓度和生长性能差异的试验。所有试验猪均在17～21d之间断奶,并且转移到同样环境下的仔猪舍中待试验。试验检测指标包括:白细胞的数量和差异性、血浆中皮质醇的浓度、免疫球蛋白的浓度、吞噬细胞、嗜中性嗜菌细胞和细胞的趋化性。在所有各日龄的猪中,梅山猪的皮质醇浓度最高,而约…  相似文献   

Recovery of Mycoplasma spp. from the Reproductive Tract of the Mare during the Estrous Cycle          下载免费PDF全文

Bermudez V  Miller R  Johnson W  Rosendal S  Ruhnke L 《The Canadian veterinary journal. La revue veterinaire canadienne》1987,28(8):519-522

The sites in the genital tract from which mycoplasmas could be recovered at various stages of the estrous cycle were studied in five Standardbred mares naturally infected with Mycoplasma. Mycoplasma equigenitalium and Mycoplasma subdolum were most frequently isolated from the clitoral fossa as compared to the vagina, cervix, and uterus. The lowest isolation prevalence was observed in the uterus. The recovery of Mycoplasma spp. from the clitoral fossa did not differ at any stage of the estrous cycle; however, recovery from the vagina, cervix, and uterus was variable during the cycle and more organisms were recovered on the day of ovulation than at any other time. From these results it was concluded that the clitoral fossa is the most likely “ecological niche” for Mycoplasma spp. in the mare. Ureaplasmas were not isolated.  相似文献   

Ivermectin toxicity in small animals          下载免费PDF全文

Bauck S 《The Canadian veterinary journal. La revue veterinaire canadienne》1987,28(9):563-564

  相似文献   

Laser manipulation of atoms and particles     

Chu S 《Science (New York, N.Y.)》1991,253(5022):861-866

A variety of powerful techniques to control the position and velocity of neutral particles has been developed. As examples of this new ability, lasers have been used to construct a variety of traps, to cool atoms to temperatures below 3 x 10(-6) kelvin, and to create atomic fountains that may give us a hundredfold increase in the accuracy of atomic clocks. Bacteria can be held with laser traps while they are being viewed in an optical microscope, and organelles within a cell can be manipulated without puncturing the cell wall. Single molecules of DNA can now be stretched out and pinned down in a water solution with optical traps. These new capabilities may soon be applied to a wide variety of scientific questions as diverse as precision measurements of fundamental symmetries in physics and the study of biochemistry on a single molecule basis.  相似文献   

Atomic force microscopy of atomic-scale ledges and etch pits formed during dissolution of quartz     

Gratz AJ  Manne S  Hansma PK 《Science (New York, N.Y.)》1991,251(4999):1343-1346

The processes involved in the dissolution and growth of crystals are closely related. Atomic force microscopy (AFM) of faceted pits (called negative crystals) formed during quartz dissolution reveals subtle details of these underlying physical mechanisms for silicates. In imaging these surfaces, the AFM detected ledges <1 nanometer (nm) high that were spaced 10 to 90 nm apart. A dislocation pit, invisible to optical and scanning electron microscopy measurements and serving as a ledge source, was also imaged. These observations confirm the applicability of ledge-motion models to dissolution and growth of silicates; coupled with measurements of dissolution rate on facets, these methods provide a powerful tool for probing mineral surface kinetics.  相似文献