小鼠Wip1基因的表达及其对受精能力的影响

本研究旨在探讨Wip1基因的表达及其对精子受精能力的影响,为阐明Wip1基因对雄性繁殖的影响提供新的着眼点。选取相同饲养环境、同一遗传背景的8周龄左右的野生型雄鼠,利用实时荧光定量PCR技术检测Wip1基因在心脏、肝脏、脾脏、肺脏、肾脏、脑组织及雄性生殖器官中的表达情况,利用免疫荧光技术检测Wip1蛋白在睾丸组织及精子细胞中的分布情况。以Wip1敲除型雄鼠为试验组,野生型雄鼠为对照组,利用ELISA试剂盒检测两组小鼠血清中睾酮水平;通过体外受精试验比较两组的2-细胞率及囊胚率。结果显示,Wip1基因mRNA在野生型雄鼠各组织中广泛表达,且在雄性生殖器官中表达量较高,其中睾丸中表达量最高,附睾体、附睾头、附睾尾次之;Wip1蛋白主要定位于睾丸组织中的长形精子细胞及附睾成熟精子细胞的头部。ELISA检测结果发现,与野生型雄鼠相比,Wip1敲除型雄鼠血清内睾酮含量极显著下降（P<0.01）。体外受精结果表明,Wip1敲除后2-细胞率及囊胚率均极显著下降（P<0.01）。结果表明,Wip1基因敲除能够引起雄性小鼠受精能力降低,这可能与Wip1基因在精子发生过程中发挥作用相关。     

Effect of cumulus cell removal and sperm pre‐incubation with progesterone on in vitro fertilization of equine gametes in the presence of oviductal fluid or cells

In spite of many attempts to establish an in vitro fertilization (IVF) technique in the equine, no efficient conventional IVF technique is available. The presence of oviductal fluid or oviductal cells during IVF helps to improve embryo production in vitro but is not sufficient to reach high fertilization rates. Thus, our aim was to perform equine IVF either after sperm pre‐incubation with oviductal fluid or in the presence of oviductal cells, and to evaluate the effect of cumulus removal from the oocyte or sperm pre‐incubation with progesterone. In experiments 1 and 2, IVF was performed in the presence of porcine oviduct epithelial cells. The removal of cumulus cells from equine oocytes after in vitro maturation tended to increase the percentage of fertilization when fresh sperm was used (1/33 vs. 4/31, p > 0.05) but had no effect when frozen sperm was used (1/32 vs. 1/32). Equine sperm pre‐incubation with progesterone did not significantly influence the fertilization rate when fresh or frozen sperm was used (2/14 vs. 2/18 for fresh, 1/29 vs. 1/25 for frozen). In experiments 3 and 4, IVF was performed after pre‐incubation of sperm with porcine oviductal fluid. The removal of cumulus cells tended to increase the percentage of fertilization when fresh sperm was used (1/24 vs. 3/26, p > 0.05). Sperm pre‐incubation with progesterone did not significantly influence the fertilization rate when fresh or frozen sperm was used (2/39 vs. 2/36 for fresh, 2/37 vs. 1/46 for frozen), but two 3–4 cell stage zygotes were obtained with fresh sperm pre‐incubated with progesterone. This is an encouraging result for the setting up of an efficient IVF procedure in equine.     

西北干旱灌区紫花苜蓿高产田施肥效应及推荐施肥量研究

为揭示紫花苜蓿氮、磷、钾肥效应,采用“3414”不完全正交回归设计,对紫花苜蓿氮、磷、钾肥合理配比施肥效应进行研究,同时对紫花苜蓿产量及蛋白总量进行肥效模型拟合。结果表明,氮、磷、钾对建植2年苜蓿产量的贡献为钾>磷>氮,对建植3年苜蓿产量的贡献为磷>钾>氮,建植2与3年苜蓿交互效应均表现为氮磷>氮钾>磷钾。氮、磷、钾对建植2年苜蓿蛋白总量的贡献为氮>钾>磷,对建植3年苜蓿蛋白总量的贡献为氮>磷>钾。建植2年苜蓿氮磷肥互作效应明显优于氮钾、磷钾互作;建植3年苜蓿氮磷、氮钾交互对苜蓿蛋白总量的增产效果明显大于磷钾交互。采用频度分析法,通过模拟寻优,得出建植2年紫花苜蓿目标产量大于平均产量17522kg·hm^-2时,优化施肥量为氮56.27~67.51kg·hm^-2、磷77.69~90.48kg·hm^-2、钾76.43~87.18kg·hm^-2;建植3年紫花苜蓿目标产量大于平均产量19234.1kg·hm^-2时,优化施肥量为氮46.75~57.66kg·hm^-2、磷80.15~92.28kg·hm^-2、钾57.79~69.74kg·hm^-2;建植2年紫花苜蓿目标蛋白总量大于平均2115kg·hm^-2时,优化施肥量为氮66.35~77.48kg·hm^-2、磷79.34~92.87kg·hm^-2、钾73.68~85.38kg·hm^-2;建植3年紫花苜蓿目标蛋白总量大于平均2656kg·hm^-2时,优化施肥量为氮68.44~79.50kg·hm^-2、磷72.74~85.96kg·hm^-2、钾50.68~61.61kg·hm^-2。     

施肥对苜蓿+无芒雀麦混播草地的产量影响

探讨了科尔沁地区草原2号杂花苜蓿+Carlton无芒雀麦混播草地基肥和追肥中氮,磷和钾配施对草地群落产量的影响。结果表明,氮,磷和钾合理配施有利于草原2号苜蓿和无芒雀麦生长。在配施中,草原2号苜蓿与磷肥效应最显著,无芒雀麦与氮肥和钾肥效应最显著。高钾组合与高氮组合显著降低了草原2号苜蓿产量(P<0.05)。对于春播的杂花苜蓿+无芒雀麦混播草地,为了保持混播群落组分种群的稳定性,较适宜的施肥组合是N2、P1、K2组合(基肥:尿素20 g/m2、过磷酸钙30 g/m2、氯化钾20 g/m2;追肥:尿素30 g/m2、过磷酸钙50 g/m2、氯化钾30 g/m2)。一年龄草地头茬草和二茬草中无芒雀麦产量组分比分别为44.47%和71.10%,占全年总产量的63.62%。二年龄草地三茬草中无芒雀麦产量组分比分别为39.23%,59.73%和37.76%,占全年总产量的46.64%。     

Response of apple trees to boron fertilization under conditions of low soil boron availability

The aim of the study was to examine the effect of boron (B) fertilization on the vegetative and the reproductive responses of apple (Malus domestica Borkh.) trees grown at low soil B availability. The experiment was carried out in 2005 under a greenhouse on 5-year-old ‘Jonagold’ apple trees/M.9 EMLA planted singly in 50-L containers filled with a sandy loam soil with hot water-soluble B concentration of 0.32 mg kg⁻¹. The trees were fertilized with B as foliar or soil application. Foliar B sprays were applied at the stage of pink bud, beginning of flowering, petal fall, and 10 days after flowering, at a solution concentration of 0.03%. Soil B fertilization was done at the bud break stage at a rate of 2 g per tree (27 mg B kg⁻¹ soil). The trees untreated with B served as the control. The results showed that soil B fertilization improved root development and tree vigor. Leaves of trees supplied with B to the soil had higher B concentration and chlorophyll, net photosynthetic rate, stomatal conductance, and activity of catalase and glutathione reductase than those of the control plants. Boron fertilization, regardless of application mode, increased fruit yield; the efficiency of foliar B sprays was higher than soil B application. Apple fruits of trees fertilized with B to the soil were bigger, more colored, richer in B, and had higher soluble solids concentration, and titratable acidity compared to those of the control trees.     

Long term fertilization effects on ‘Rio Red’ grapefruit yield and shape on a heavy textured calcareous soil

Fertilizer recommendations for citrus production on heavier textured, calcareous soils increase with the age of the tree up to 168 kg N ha⁻¹ year⁻¹ from a soluble source in one or two applications. Such practices may be inefficient and could cause detrimental effects on fruit quality. A variety of fertilization practices are used in South Texas, and additional evaluation is needed. Rates and sources of nitrogen (N), phosphorus (P), and a commercial program consisting of both a soil component containing organic acids and a foliar component were evaluated on grapefruit production for 6 years. Increasing rate of N application increased leaf nutrient concentration, grapefruit yield, and affected fruit shape as indicated by a decrease in the equatorial:polar diameter (E:P) ratio. Since the response to increasing N application by the E:P ratio was linear while grapefruit yield was quadratic, high N application has a negative effect on fruit shape beyond the level of increasing total yield. Phosphorus application had no effect on any parameter measured, even though soil testing indicated soil P levels were below those at which a P response would be expected. Comparisons between granular 21-0-0 applied broadcast and liquid N-32 injected in a band in the soil at the drip line showed an increase in the number of fruit per tree, but no differences in yield. The ‘Actagro’ program greatly improved available soil P levels and increased the juice brix:acidity ratio, but did not affect grapefruit yield. Phosphorus availability may therefore be a factor in improving grapefruit juice quality. The soil profile within the citrus root zone was found to contain large amounts of inorganic N, but availability of this residual N was limited since yield responses occurred at the N application rates applied in this study. The amount of N contained in the fruit harvested was a small fraction, roughly 5–10%, of the residual amount in the soil. While N uptake in the fruit increased with N fertilizer application, the increase in N taken up relative to the amount applied averaged 42%.     

水肥一体化模式下日光温室黄瓜氮磷钾优化施肥方案的研究

为了探明水肥一体化模式下日光温室黄瓜氮(N)、磷(P_2O_5)、钾(K_2O)的适宜施用量,采用三因子D–饱和最优设计,研究N、P_2O_5、K_2O用量对黄瓜产量和品质的影响,建立了以N、P_2O_5、K_2O用量为变量因子,以黄瓜产量和品质为目标函数的三元二次数学模型。通过对模型解析表明:N、P_2O_5、K_2O对黄瓜产量和品质均有显著影响;当N、P_2O_5、K_2O用量分别达到861.5 kg·hm~(-2)、306.1 kg·hm~(-2)和1 082.0 kg·hm~(-2)时,边际产量效应降至0;N、P_2O_5、K_2O用量分别达到688.4 kg·hm~(-2)、320.2 kg·hm~(-2)和1 230.2 kg·hm~(-2)时,边际品质效应降为0。通过计算机模拟运算,得出本试验条件下日光温室黄瓜产量达138 000 kg·hm~(-2)以上,同时品质综合评分达到88分以上的优化施肥方案为N 665.5~827.6 kg·hm~(-2),P_2O_5 267.9~334.3 kg·hm~(-2),K_2O 1 043.1~1 235.0 kg·hm~(-2),适宜的氮磷钾配比为1︰0.40︰1.53。     

5种缓释肥在结球甘蓝上的应用效果

采用田间试验方法,研究了5种不同种类缓释肥在结球甘蓝上的施用效果。通过对结球甘蓝田间植物学性状、产量等方面的分析,结果表明:与常规施肥方法相比,俩控缓释肥在采收期植物学性状表现优良,667 m~2较常规施肥增产6.6%,增加经济效益1728.22元;榕风缓释肥虽没有提高产量,但降低了肥料施用量,节省了生产成本,从而提高了经济效益。综合分析,俩控缓释肥及榕风缓释肥是较为经济适用的缓释肥,奥绿肥、撒作灵不适宜在结球甘蓝上施用。     

可速必宁对肉种鸡产蛋后期生产性能的影响

目的：本试验在种鸡产蛋后期料中添加可速必宁（枯草芽孢杆菌）,研究观察是否能够减缓产蛋后期产蛋率下降速度,提高种蛋的蛋壳质量、受精率及可售鸡苗率。方法：试验用2栋鸡群,各栋肉种鸡约7000羽。对照组使用常规饲料,全程试验由试验饲料与常规饲料相比,仅多添加了可速必宁,试验料每吨配合料添加300 g,其他饲料成分相同。饲喂方式皆采用自由采食,加料时间和次数每天都保持一致,并且在用常规药物预防与治疗时,药物品种、用药时间和数量相同。研究表明：肉种鸡产蛋后期料添加可速必宁有助于产蛋率稳定,提高种蛋蛋壳质量,提高受精率和鸡苗可售率。     

氮磷钾氯平衡施肥对菜心产量及品质的影响

在大棚无土栽培条件下,采用"416-B"最优混合设计研究N、P2O5、K2O、Cl配比对菜心产量和硝酸盐积累的效应及其最佳配比进行研究.结果表明:N、P2O5、K2O、Cl合理配施能提高菜心产量,降低菜心硝酸盐含量.其中N、P2O5、K2O与产量呈正效应,Cl与产量呈负效应,N与菜心硝酸盐含量呈正效应,P2O5、K2O、Cl与菜心硝酸盐含量呈负效应.综合考虑,确定高产优质菜心的最佳营养配方:N、P2O5、K2O、Cl的编码值(真实值,g/0.9 m2)分别为0.49(18.58),1.49(8.95),1.16(22.11),0.23(33.31),对应的产量707.12 g/0.9 m2,硝酸盐含量612.01 mg/kg,Vc含量170.42 mg/kg.