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灌溉对高羊茅种子产量和质量的影响 总被引:7,自引:0,他引:7
以猎狗5高羊茅为材料,研究了在施肥量相同的情况下不同的灌水量和灌水时间对高羊茅种子产量和质量的影响,结果表明,从返青到种子收获,灌4次水(返青期、拔节期、抽穗期和灌浆期灌水,每次灌水量为900m^3/hm^2)生殖枝/m^2最高,小穗数/生殖枝、小化数/小穗、种子数/小穗接近最高;潜在种子产量、表现种子产量和实际种子产量最高,在种子发育早期(盛花期后7d),灌4次水种子标准发芽率最高,老化发芽率最高,种苗芽长最长,芽重最重。种子发育后期,不同的灌溉处理对高羊茅种子质量的影响不明显。 相似文献
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灌溉及多效唑对蓝茎冰草生长及种子产量的影响 总被引:2,自引:1,他引:1
在甘肃省酒泉地区研究灌溉和多效唑对蓝茎冰草(Agropyron smithii)种子产量及其构成要素的影响。结果表明,蓝茎冰草从返青到收获,返青期、拔节期、抽穗期、灌浆期、盛花期灌溉5次水的生殖枝数/m2、小穗数/生殖枝和种子产量最高,但每个时期的灌溉量不宜过于充足,以防止植株倒伏;拔节期灌溉有利于生殖枝数/m2和种子数/小穗的增加,生殖枝数/m2和种子数/小穗与种子产量之间相关性极显著;返青期一次性喷施0.022 5%的多效唑0.3 kg/hm2对提高生殖枝数/m2、小穗数/生殖枝、小花数/小穗、种子数/小穗以及种子产量效果显著;灌施多效唑有效地提高了种子数/小穗,最终也提高了种子产量。多效唑喷施的效果较灌施好。 相似文献
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灌水对新麦草种子产量及产量构成的影响 总被引:2,自引:2,他引:2
研究不同灌水次数和灌水量对新麦草(Psathy rostachys juncea)种子产量、产量构成和生长特性的影响。结果表明:不同灌水次数的小穗小花数、小穗种子数和千粒重间差异显著(P<0.05),生殖枝数和生殖枝小穗数差异不显著;从返青到收获,灌水4次(返青期、拔节期、抽穗期和灌浆期)生殖枝数和小穗种子数最高,其实际种子产量也最高,达593.3 kg/hm2;不同灌水次数对生殖枝高度和穗长影响显著(P<0.05);不同灌水量对种子产量和产量构成的影响不显著。 相似文献
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春季分施氮肥对新麦草种子产量及氮肥利用率的影响 总被引:2,自引:0,他引:2
本文研究了春季分施氮肥对新麦草(Psath yrostachys juncea(Fisch.)Nevski)肥料利用率、种子产量构成要素和种子产量的影响,旨在提高种子产量和氮肥利用效率.结果表明,在春季总施氮量为200 kg/hm2N的条件下,返青期和抽穗初期分次施肥(1:1).种子产量达到2761.8 kg/hm2,较春季不施肥处理、返青期和抽穗期一次施肥分别增产117%、113%和61%;与返青期施氮肥相比,抽穗初期施氮肥表现出小穗数/生殖枝和小花数/小穗增加,而生殖枝数/m2和种子数/小穗略有减少;而返青期和抽穗初期分施氮肥可以发挥两个时期的施氮肥效应,种子产量构成要素的各项指标均达到最高;返青期与抽穗初期分施氮肥处理的种子生产氮素利用效率与返青期一次施肥的效果相当,但其氮肥表观回收率更高,抽穗初期一次施肥处理的干物质量和种子生产效率,以及氮肥表观回收率均最低. 相似文献
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研究硼肥对热研11号黑籽雀稗(Paspalum atratum cv. Reyan 11)种子产量和品质的影响。试验设9个硼肥处理,质量分数范围为0~4.0%,分3次施入。结果表明,施硼量3.0%(3%的硼酸分3次施入:400 mL+400 mL+600 mL)的效果最好,种子产量达1 124.4 kg·hm-2。施硼肥可提高生殖枝数、小花数/小穗、可育小花数/小穗和种子千粒重,但对小穗数/生殖枝影响不显著;施硼肥能提高种子的发芽率、发芽势、发芽指数以及芽长和芽质量。施硼量3.0%可以使发芽率达到20.17%,比对照提高了30%。 相似文献
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以新麦草为材料,在河北坝上高原区种子生产实验研究中得出:在生育期中灌水6 次、磷酸二铵做种肥的条件下,施化肥对新麦草种子产量影响显著,秋施45kgN/hm2 45kgP2O5/hm2、春施90 kgN/hm2 时种子产量最高,为265.1 kg/hm2;新麦草种子产量的首要影响因素是单位面积生殖枝数,生殖枝主要由上年果前短营养枝转化,秋春施氮可以增加果前短营养枝/m2,使第二年生殖枝数/m2 增加。同一施氮量下,秋春分施氮肥与春季一次施氮处理之间,小穗数/生殖枝、小花数/小穗、种子数/小穗及种子千粒重差异不显著。 相似文献
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行距对牧草型高羊茅种子产量和产量因子的影响 总被引:1,自引:0,他引:1
试验于2009—2012年,在河西走廊地区对不同行距条件下牧草型高羊茅(Festuca arundinacea)种子产量和产量因子进行分析研究。结果表明:行距对种子产量有显著影响且随行距增大种子产量呈下降趋势,2011年30cm行距种子产量最高,为1225 kg·hm~(-2)。不同年限间种子产量差异显著,播种后第3年种子产量最高。行距和年限均是通过影响单位面积分蘖、单位面积营养枝数和单位面积生殖枝数,进而影响种子产量。小穗数/生殖枝、小花数/小穗、种子数/小穗和千粒重主要随年际变化,受行距影响较小。 相似文献
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施肥对新麦草种子产量及产量组分的影响 总被引:7,自引:0,他引:7
以新麦草为材料,在河北坝上高原区种子生产实验研究中得出:在生育期中灌水6次、磷酸二铵做种肥的条件下,施化肥对新麦草种子产量影响显著,秋施45kgN/hm^2 45kgP2O5/hm^2、春施90kgN/hm^2时种子产量最高,为265.1kg/hm^2;新麦草种子产量的首要影响因紊是单位面积生殖枝数,生殖枝主要由上年果前短营养枝转化,秋春施氮可以增加果前短营养枝/m^2,使第二年生殖枝数/m^2增加。同一施氮量下,秋春分施氮肥与春季一次施氮处理之间,小穗数/生殖枝、小花数/小穗、种子数/小穗及种子千粒重差异不显著。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献