In vitro maturation and fertilization of prepubertal and pubertal black Bengal goat oocytes

Oocytes retrieval, in vitro maturation (IVM) and fertilization (IVF) efficiency are inevitable steps towards in vitro production of embryos. In the present study, these parameters were investigated in the ovaries of prepubertal (n = 31) and pubertal (n = 61) black Bengal goats obtained from a slaughterhouse. Nuclear maturation was evaluated upon aspiration and following IVM in TCM-199 (Earle''s salt with L-glutamine and sodium bicarbonate) for 27 h at 39℃ under 5% CO₂ in humidified air. The oocytes retrieval and efficiency (mean ± SD) per prepubertal and pubertal goats were 5.2 ± 0.6 and 6.8 ± 0.6, and 77.3 ± 0.1% and 80.5 ± 0.6%, respectively. Anaphase I - telophase I stages differed significantly (7.3 ± 0.8 vs. 2.6 ± 0.2, p < 0.05) between the two groups of goats. After IVM, the percentages of metaphase II were significantly higher (66.3 vs. 60.3, p < 0.05) in pubertal goats than in their prepubertal counterparts. The percentages of normal in vitro fertilization (IVF) in Fert-Tyrode''s albumin lactate pyruvate of pubertal goat oocytes did not differ between Percoll and swim-up sperm separation methods (36.7 ± 0.9% vs. 32.7 ± 1.3%, p > 0.05). Furthermore, sperm capacitation by heparin alone or in combination with ionomycin did not lead to a significant increase in the normal fertilization rate (34.8 ± 1.7 vs. 32.2 ± 1.5%, respectively) in the oocytes of pubertal goats. In conclusion, the ovaries of pubertal black Bengal goats obtained from the slaughterhouse could be used for in vitro embryo production. However, further optimization of the IVM and IVF techniques are necessary for satisfactory in vitro embryo production.     

大口鲇仔鱼消化道的组织学观察

本研究对1～43日龄内的大口鲇仔鱼消化道组织学进行了观察;描述了大口鲇不同 发育 阶段的口裂、口咽腔、食道、胃、前肠、后肠等组织和器官的组织学结构的变化;对口裂宽 、口裂高与全长进行了比较;讨论了仔鱼消化系统的早期发育特点与摄食、营养方式的关系 。     

基于RAGA的PPC模型在黑土区玉米调亏灌溉评价中的应用

调亏灌溉作为一种行之有效的节水灌溉方式,对黑土区农业水资源的可持续高效利用具有重要意义。而调亏灌溉方案的优劣取决于它的综合效果,难以直观评价。以2013年在黑龙江省红星农场进行的玉米调亏灌溉技术效应的试验研究为基础,选取了8个评价指标,采用投影寻踪分类模型(PPC),利用基于实数编码的加速遗传算法(RAGA)优化其投影方向,根据投影函数值得到各评价指标对综合评价的贡献大小对不同调亏处理的各项指标进行排序。结果表明:苗期水分调亏程度为田间持水量60%的处理为最佳调亏灌溉方案,产量和水分利用效率比适宜调亏灌溉处理分别提高了2.11%和6.42%。研究结果可为黑土区玉米灌溉管理提供科学依据。     

4种步甲属昆虫一龄幼虫形态学特征

采用Bousquet等创立的幼虫原生刚毛标记分类法对步甲属Carabus L.切鞘步甲亚属Apotomopterus Hope中的普通步甲南岭亚种Carabus(A.)sauteri nanlingensis Deuve et Tian、舜步甲南岭亚种C.(A.)shun floridus Cavazzutiet Ratti、石坑崆步甲C.(A.)shikengkong Deuve et Tian和阿氏步甲粤北亚种C.(A.)arrowi yubeicus Deuve et Tian的一龄幼虫形态特征进行了描述,并编制了这4种步甲一龄幼虫的分类检索表.     

砂姜黑土甘薯施肥技术研究

本文研究了砂姜黑土N、P、K肥及不同K肥品种在甘薯上肥效,结果表明:适量的N、P、K均能促进甘薯的生长和产量的提高,过高的N会引起甘薯徒长,进而影响产量.当K肥用量低时,氯化钾增产效果与硫酸钾相近;高用量时,氯化钾对甘薯产量有负作用,硫酸钾增产效果高于氯化钾;氯化钾与硫酸钾配施既可提高甘薯产量,又能节约施肥成本,是K肥有效施肥技术.砂姜黑土上甘薯K肥增产效果最大,其次为P肥,N肥增产效果最小.砂姜黑土适宜施用量分别为58.2kg /hm2 N、129.5kg /hm2 P2O5、190 kg/hm2 K2O.     

黔中稻区二化螟的越冬幼虫虫口密度及其自然寄生率

为准确预测预报黔中稻区二化螟越冬后的发生提供理论依据,采用GB/T15792—2009稻桩剥查法对贵阳市花溪区、安顺市平坝县、黔南州惠水县和黔东南州麻江县等稻区二化螟越冬幼虫虫口密度及自然寄生情况进行调查。结果表明:麻江县的越冬幼虫虫口密度最高,达15 741头/667m2;其次为平坝县和惠水县,越冬幼虫虫口密度分别为10 684头/667m2和10 153头/667m2;贵阳市花溪区的越冬幼虫虫口密度最低,仅944头/667m2。大多数地区的雌雄蛹重量有显著差异。调查共采集到5种寄生蜂,包括稻螟小腹茧蜂、螟甲腹茧蜂、大螟钝唇姬蜂、菲岛抱缘姬蜂和黄眶离缘姬蜂;各稻区的寄生率均较低,平坝县二化螟幼虫被寄生率最高,达15.6%,其次为麻江县14.6%、花溪区6.7%和惠水县5.7%。     

In vitro antifungal activity of brassinin, camalexin and two isothiocyanates against the crucifer pathogens Alternaria brassicicola and Alternaria brassicae

In vitro assays investigated the responses of Alternaria brassicicola and A. brassicae isolates towards two crucifer phytoalexins and two isothiocyanates (ITC) by evaluating their potential toxic effects on different fungal growth parameters. Although variable responses towards each compound was observed within the species A. brassicicola , the results obtained confirmed the antifungal effects of camalexin, brassinin, allyl- (AlITC) and benzyl- (BzITC) isothiocyanates, at different developmental stages of both Alternaria species. Irrespective of the tested isolate, the phytoalexin camalexin exhibited the greater inhibitory effect with mean EC₅₀ values ranging from 34  µ m (germ-tube elongation) to 183  µ m (mycelial growth). Germ-tube elongation was more sensitive compared to conidial germination and mycelial growth, with mean EC₅₀ values of the former of 81  µ m , 520  µ m and 870  µ m for brassinin, BzITC and AlITC, respectively.     

不同温度对红鳍东方(鱼屯)仔、稚、幼鱼形态发育和生长的影响

通过对三个不同水温的红鳍东方纯育苗池的仔、稚、幼鱼的连续取样观察,分析比较在不同的培育水温对红鳍东方(鱼屯)的形态发育和生长的影响。通过试验分析表明,在红鳍东方纯适宜的温度范围内的增温对红鳍东方(鱼屯)稚、幼鱼的影响效果明显,且不会降低成活率,从而可缩短育苗时间,降低成本,减少风险。     

匙吻鲟仔鱼期饵料的研究

鱼类早期生长的细微差别对其存活以及整个生活史阶段的生长,有着不可估量的影响,而摄食是影响仔鱼期生长的最重要的外界影响因子之一。在水温19．5～20．5℃下,对匙吻鲟（Polyodon spathula）仔鱼的开口时间、适宜开口饵料和投饵率进行了研究。结果表明,匙吻鲟仔鱼在6日龄初次摄食,摄食率在7—8日龄迅速升高,9—10日龄达到100％,11-13日龄略有降低,14-15日龄迅速降低,不可逆点（PNR期）出现在15日龄;以轮虫作为开口饵料,仔鱼的存活率和生长优于丰年虫和颗粒饲料组;养殖水体中轮虫密度在120—150个／mL可满足仔鱼的生长需求。