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1.
将从屠宰母牛卵巢上采集的水牛和黄牛的卵母细胞经 2 0～ 2 4 h体外成熟培养后 ,分别用么拉水牛或奶牛精液进行种间和种内体外受精。受精卵在体外条件下继续培养到囊胚和孵化囊胚阶段。结果表明 ,用黄牛精子受精水牛卵母细胞 (黄×水 )或用水牛精子受精黄牛卵母细胞 (水×黄 )的种间体外受精均有较高的卵裂率 (分别为 4 6.5%和 68.4 % )。但其体外囊胚发育率分别只有 3.5%和 8.7% ,显著低于种内受精组(水×水组为 1 9.9% ,黄×黄组为 2 8.0 % ,P<0 .0 5)。在受精后 2 0 h对受精卵进行固定、染色 ,发现种间受精的黄×水和水×黄组 ,分别有 36.8%和 75.0 %的受精卵形成有 1个以上原核 ,且这些受精激活卵中大部分含 2个原核以上 (分别为 80 .9%和 80 .0 % ) ,说明种间受精的精子已进入到卵母细胞内受精并形成了雄性原核。 相似文献
2.
牛分离精子对体外受精的影响 总被引：4，自引：2，他引：4
本研究的目的是测定流动细胞分离仪的精子对牛卵母细胞体外受精和胚胎发育的影响。共使用了4273个牛的卵母细胞和3种类型的精子（分离、染色未分离和未染色未分离）进行体外受精试验。这些精子分别来自于3头公牛，每头公牛重复试验3－5次，数据使用ANOVA程序进行统计分析。结果显示，用3种类型精子受精后的卵母细胞囊胚率无显著差异，分别为20．4％，22．62％和22．14％，但用分离精子受精后的卵裂率显著低于未分离的精子（53．66％比71．93％，P＜0．05）。所测度的3头公牛的卵裂率和囊胚率在不同公牛之间有所差异，H008号公牛所产生的囊胚明显低于H010号公牛组（分别为17．4％比25．1％，P＜0．05）。结果证明分离过程或染色并没有影响胚胎发育，流动细胞分离仪可以有效地用于牛胚胎的体外生产。此外，分离、染色未分离和未分离精子的受精和胚胎发育率，在不同公牛之间有差异的这一发现表明，选择能产生高质量精子的公牛精液进行精子分离，可以提高体外受精的效率。 相似文献
3.
受精液、咖啡因、精液和抗菌素对猪卵母细胞的体外受精及早期胚胎发育的影响 总被引：3，自引：0，他引：3
探讨精液的不同处理、抗菌素、受精液种类和咖啡因对体外成熟猪卵母细胞的体外受精和早期胚胎发育的影响。结果表明：(1)受精液中抗菌素添加与否对体外成熟猪卵母细胞的体外受精无显著影响，而且不添加抗菌素的受精液也无严重微生物污染；(2)用猪冷冻精液与新鲜精液进行猪卵母细胞的体外受精对早期胚胎发育无显著影响；(3)在受精液mTBM中添加5mmol／L咖啡因对猪卵母细胞体外受精后的早期发育是最好的；(4)用mTBM进行猪卵母细胞体外受精的卵裂率明显高于用mBO进行体外受精的卵裂率，但其第8d囊胚率明显低千用mBO进行体外受精的，mTBM和mBO各有优势；(5)在洗精子液含有高浓度咖啡因(15mmol／L)的情况下，无咖啡因的受精液也可进行猪卵母细胞的体外受精并发育到囊胚阶段，在受精液中添加不同浓度(0～10mmol／L)的咖啡因对猪卵母细胞体外受精后的卵裂率和第8d囊胚率都无显著影响，受精液中咖啡因对猪卵母细胞体外受精后的第6d桑椹胚 囊胚率的影响因浓度而异．其中以添加5mmol／L为最佳，随着浓度上升效果开始下降。 相似文献
4.
探讨奶牛X性控冻精的卵胞质内单精子注射(ICSI)技术的可行性及显微操作条件对奶牛X性控冻精ICSI效果的影响.结果表明,注射运动性控冻精ICSI卵的卵裂率和囊胚发育率均高于不运动组,但差异不显著(P>0.05).分别用5%、8%和10%聚乙烯吡咯烷酮(PVP)的精子操作液处理性控冻精,进行ICSI操作,ICSI卵的卵裂率差异不显著;但PVP在5%和10%时,正常卵裂率分别是78.4%和69.1%(P<0.05),囊胚率分别是29.7%和20.4%(P<0.05).精子显微注射时,将卵母细胞的极体调整在相当于时钟6点与12点的位置时,所获ICSI卵的卵裂率差异不显著,但正常卵裂率(76.4%,66.7%)和囊胚率(28.6%,19.0%)明显提高(P<0.05).结论认为,进行奶牛X性控冻精ICSI操作时,应选用运动精子,并用含5%PVP的精子操作液进行处理,而且注射在卵母细胞极体置于6点的位置,有利于ICSI卵体外发育. 相似文献
5.
为提高牛性别分离精子体外受精的效率,比较精卵共孵育8和22 h受精卵的体外发育能力,使用G- 1/G-2序贯培养液和SOFaa培养液培养牛性控受精卵,筛选出一种适合牛性控胚胎体外培养的培养液.精卵共孵育22和8h,牛性控受精卵的卵裂率分别为(55.9±4.52)％和(50.88±4.44)％,囊胚发育率分别为(35.05±5.02)％和(41.16±5.12)％,差异均不显著(P＞0.05)；精卵共孵育8h组的囊胚孵化率(52.56±6.95)％显著高于22h组(39.81±6.38)％(P＜0.05).用SOFaa和G-1/G-2培养牛性控受精卵,其体外发育率无显著差异.但G-1/G-2液中受精卵发育到第7天时囊胚内细胞数(113.9±9.46)显著高于SOFaa组(102.0±9.97)(P＜0.05).性控精子与卵子共孵育8h可提高牛性控受精卵的囊胚孵化率,G-1/G-2培养液更利于牛性控受精卵的体外培养. 相似文献
6.
试验探索重离子束辐照对绵羊卵母细胞的体外成熟及体外受精卵早期胚胎发育的影响。用不同剂量的重离子束辐照绵羊卵母细胞和精液,观察卵母细胞体外成熟率及体外受精后早起胚胎的卵裂率、桑椹胚率及囊胚率。试验结果显示:与对照组相比,1.0、1.5Gy辐射可以明显提高绵羊卵母细胞的体外成熟率(p0.01);重离子辐照绵羊精液和卵母细胞并做体外受精后,早期胚胎发育有着显著变化。当用0.5、1.0Gy剂量辐照精液时,绵羊早期胚胎的卵裂率和桑葚胚率显著升高(p0.05),囊胚率无显著变化,1.5 Gy剂量,卵裂率显著提高(p0.05),2.0 Gy剂量,卵裂率、桑葚胚率、囊胚发育率均极显著降低(p0.01);当重离子束辐照卵母细胞时,0.5、1.0Gy剂量组的卵裂率、桑葚胚率和囊胚发育率显著升高(p0.05),而2.0Gy剂量组的卵裂率和桑葚胚发育率极显著降低(p0.01),而囊胚发育率为0。结果表明低剂量的重离子辐照绵羊精液、卵母细胞,对体外受精和早期胚胎发育具有明显的促进作用,而高剂量辐照则抑制细胞的生长发育。 相似文献
7.
对不同浓度离子霉素以及不同质量(A类或混合类)的猪卵丘细胞-卵母细胞复合体(COC s)对卵孤雌发育的效果影响进行了初步研究。结果表明:(1)A类猪COC s孤雌激活后的囊胚发育率极显著的高于混合类(30.11%vs 9.09%,P<0.01);(2)采用化学方法激活体外成熟后的猪去透明带卵母细胞,离子霉素浓度为5μm o l/L组激活后得到的卵裂率(80.35%),以及激活后48 h发育到4细胞阶段的孤雌胚胎率(62.50%)均极显著高于浓度2μm o l/L组(分别为62.22%和43.33%,P<0.01)。 相似文献
8.
本研究探讨了:(1)成熟培养基中葡萄糖和丙酮酸钠剂量对猪卵母细胞体外成熟极体排放率的影响;(2)培养基中葡萄糖、谷氨酰胺、牛磺酸和亚牛磺酸的剂量对猪孤雌激活胚胎体外发育的影响,同时探讨不同浓度乙二胺四乙酸钠(EDTA-N a)对猪孤雌激活胚胎体外发育的影响。利用屠宰场猪卵巢卵母细胞,在含不同剂量葡萄糖 丙酮酸钠的成熟液中体外成熟44~48 h,计算其极体排放率(试验1),进行化学法孤雌激活后,在含不同剂量的葡萄糖 谷氨酰胺 牛磺酸 亚牛磺酸与不同浓度的EDTA-N a的培养基中体外培养,计算孤雌激活胚的第48小时卵裂率和第168小时囊胚率(试验2)。结果表明:(1)葡萄糖 丙酮酸钠在1倍剂量(浓度分别为3.05 mm o l/L和0.91 mm o l/L)时,猪卵母细胞体外成熟的核成熟率为(59.3±5.0)%,当其剂量加倍时,猪卵母细胞体外成熟的核成熟率极显著下降(P<0.01),为(51.0±4.4)%;(2)随着EDTA-N a添加浓度的增加,猪孤雌激活胚的的囊胚发育率不断上升,添加浓度达到50μm o l/L时囊胚率最高(7.2±4.1)%,超过此浓度后囊胚率开始下降,培养基中添加适当浓度(25-100μm o l/L)的EDTA-N a对猪孤雌激活胚的囊胚发育率具有有利作用(P<0.05),添加浓度达到200μm o l/L时其有利作用消失;(3)培养基中葡萄糖 氨基酸的剂量过高(葡萄糖、谷氨酰胺、牛磺酸、亚牛磺酸的浓度分别大于5.55,1.0,7.0,5.0 mm o l/L)对猪孤雌激活胚的卵裂率无显著影响(P>0.05),但对其囊胚发育率有不利作用(P<0.05)。本研究得出以下结论:(1)适当浓度(25~100μm o l/L)的EDTA-N a对猪早期胚胎体外发育具有促进作用;(2)培养基中能量基质剂量过高会抑制猪卵母细胞体外成熟;(3)培养基中能量基质 氨基酸的剂量过高会抑制猪早期胚胎的体外发育。 相似文献
9.
电脉冲激活对体外成熟猪卵母细胞卵裂率和囊胚率的影响 总被引：6，自引：0，他引：6
探索了电脉冲结合细胞松驰素B(CB)、放线菌酮(CHX)以及6-二甲基嘌呤(DMAP)等化学物质,对猪卵母细胞激活后发育的影响.在电脉冲激活时,0.6 kV/cm和1.3 kY/cm,80μs,1次电激活后,(1)用2 mmol/LDMAP处理6 h的卵裂率分别为(60.39±6.71)%和(60.35±8.95)%,差异不显著(P＞0.05),囊胚率分别为(9.51±5.93)%和(14.53±3.38)%,差异显著(P＜0.05);(2)用7.5μg/mL CB+10μg/mL CHX处理6 h的孤雌胚,卵裂率[(1.82±10.76)%vs(58.50±8.33%)]和囊胚率(8.91±4.37)%vs(14.53±3.38)%]均存在显著差异(P＜0.05).卵母细胞经1.3 kV/cm、80μs和单次电脉冲激活后,分别用7.5μg/mL CB、10μg/mL CHX、2 mmol/L DMAP、7.5μg/mL CB+10μg/mLCHX和7.5μg/mLCB+2 mmol/LDMAP处理2～8 h,结果表明CB处理4 h,CHX、CB+CHX和CB+DMAP处理6 h,DMAP处理8 h的卵裂率和囊胚率高于其它时间处理组.在电脉冲/CB、CHX、DMAP、CB+CHX和CB+DMAP 5种激活方法中,CB+CHX和CB+PMAP的卵裂率和囊胚率分别为(78.46±8.46)%、(33.13±7.84)%和(75.84±10.61)%、(39.12±7.15)%,囊胚率显著高于其它各组(P＜0.05). 相似文献
10.
探讨了不同浓度的胰岛素和葡萄糖对水牛体外受精早期胚胎体外发育的影响。结果表明,添加胰岛素浓度为5μg/mL时,水牛早期胚胎的囊胚发育率、囊胚细胞数及冷冻-解冻后胚胎的孵化率都显著高于对照组及其他浓度组(P<0.05);加入葡萄糖的浓度大于6 mm o l/L时显著影响水牛早期胚胎发育到囊胚及孵化囊胚的阶段(P<0.05);联合添加胰岛素和葡萄糖时能显著提高水牛早期胚胎的孵化囊胚率、总囊胚率和囊胚细胞数(P<0.05)。实验证实,浓度为5μg/mL胰岛素能促进水牛体外受精早期胚胎的发育;在TCM-199中单独添加葡萄糖是不必要的,联合添加葡萄糖和胰岛素能促进水牛体外受精早期胚胎的发育。 相似文献
11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响 总被引：2，自引：2，他引：0
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
12.
Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
13.
《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
14.
I.L. Boyd 《Biological conservation》2010,143(7):1664-1674
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options. 相似文献
15.
Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage 总被引：1，自引：0，他引：1
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate. 相似文献
16.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献
17.
Grete Skrede Berit Karoline Martinsen Anne-Berit Wold Stein-Erik Birkeland Kjersti Aaby 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):193-208
Abstract A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species. 相似文献
18.
Yoav Bashan Bernardo Salazar Ma. Esther Puente Macario Bacilio Robert Linderman 《Biology and Fertility of Soils》2009,45(6):585-594
To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse
trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus
were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB;
the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons
reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened
later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons
growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants,
no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi,
enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant.
In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after
30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination
only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity
to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as
compost or PGPB can either amplify the effect or else attenuate it. 相似文献
19.
Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value. 相似文献
20.
《Communications in Soil Science and Plant Analysis》2012,43(7):865-877
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils. 相似文献