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KM Morton SL Catt FK Hollinshead WMC Maxwell G Evans 《Reproduction in domestic animals》2004,39(6):454-461
Cumulus-oocyte complexes from hormone-stimulated 3-4-week-old (n=43) and 6-7-week-old (n=12) prepubertal lambs were matured in vitro and incubated with unsorted, or X- or Y-spermatozoa separated with a high-speed cell sorter (SX MoFlo)frozen-thawed. Presumptive zygotes were then cultured to the blastocyst stage, and transferred to recipients fresh or after cryopreservation (frozen). Oocyte cleavage was higher (p <0.05) with unsorted (515/926, 55.6%) than X- or Y-spermatozoa (261/672, 38.8% and 229/651, 35.2%, respectively) and blastocyst formation (% zygotes) by Day 9 of in vitro culture was lower (p <0.05) for X- (102/261, 39.1%) than unsorted spermatozoa (249/515, 48.3%), but did not differ between Y-spermatozoa (103/229, 45.0%) and unsorted spermatozoa, or between X- and Y-spermatozoa (p >0.05). For fresh embryos, survival to term was 50.0% (3/6) for unsorted, 0.0% (0/6) for X- and 16.7% (1/6) for Y-spermatozoa-derived embryos (p >0.05), and for frozen embryos was 4.0% (2/50) for unsorted, 9.1% (2/22) for X- and 2.9% (1/34) Y-spermatozoa-derived embryos (p >0.05). Of the two lambs born from X-spermatozoa-derived embryos, one was female (50%), and from the two Y-spermatozoa-derived lambs, both were male (100%), demonstrating that lambs can be produced after the transfer of fresh and cryopreserved IVP embryos derived from prepubertal lamb oocytes and frozen-thawed sex-sorted sperm. 相似文献
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试验设喷施百菌清推荐剂量(2 400g/hm2,T1)、加倍剂量(4 800g/hm2,T2)、喷清水(对照)3个处理。探讨蔬菜上百菌清残留量的安全性,开展番茄中百菌清残留的消解规律试验。结果表明,百菌清在番茄上的自然消解速度随施药剂量的增大而减慢。喷药后24h内消解最快,T1处理和T2处理施药后1d的消解率分别为60.22%和27.58%,7d的消解率达91.72%和46.67%,其半衰期分别为4.3d和18.0d。按推荐剂量施药1d后采摘,番茄中百菌清残留量为0.370mg/kg,符合国家相关标准的规定;从人体健康风险角度分析,如果按规范施药,百菌清在番茄上施用安全,产品食用无健康风险。 相似文献
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Richtmyer FK 《Science (New York, N.Y.)》1927,65(1695):617-619
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小麦骨干亲本生选6号的赤霉病抗性遗传分析 总被引：1，自引：0，他引：1
为研究生选6号对黄淮麦区小麦赤霉病抗性改良效果,以黄淮麦区矮抗58、周麦25、周麦27、兰考161等4个主栽品种(系)为母本,以生选6号为父本,配制杂交组合,分别在长江中下游地区(上海崇明、安徽滁州)和黄淮地区(河南兰考)对4个组合F2群体进行赤霉病抗性鉴定。结果表明,4个组合的F2群体赤霉病抗性较感病亲本均显著提高,平均病小穗率在18.4%~31.2%之间,均达到中抗水平。4个群体的个体抗性级别主要集中在抗病和中抗,平均约占80%;而中感、感病和高感很少,平均占比20%左右。矮抗58/生选6号F2群体在滁州和兰考两个不同生态区域的抗性差异显著,虽然两地均达中抗水平,但滁州点抗性明显优于兰考点。主要表现为兰考点高感单株数是滁州点的7.4倍,中抗单株数却不到滁州点的1/2。同时,兰考点抗感比为65∶35,而滁州点为89∶19,这种现象应该与当年两地气候差异有关,可能黄淮冬麦区当年气候更适合赤霉病发病,也与长江中下游品种大多中抗以上而黄淮品种大多为高感品种的事实相一致。此外,抗性单株从F2到F3,发生了接近3∶1的抗感分离,F3抗性单株的平均病小穗率为20.2%,仍保持较强赤霉病抗性。上述结果表明,生选6号可以作为骨干亲本,广泛用于黄淮冬麦区小麦赤霉病抗性的改良。 相似文献