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1.
本实验对五只雌性乌苏里貉(Nycterentespyocyonoides)发情周期中阴道涂片和阴道电阻值的研究,发现乌苏里貉的排卵发生在阴道电阻值和阴道涂片中角化细胞最高峰之后的第一天至第二天。此时圆形细胞含量最低(20%左右);白细胞仍可见,但含量显著降低。根据乌苏里貉发情周期中阴道电阻及阴道涂片中细胞成分的变化特点,可以为选择人工授精的最佳时间提供理论依据。  相似文献   

2.
辛学 《技术与市场》2007,(10):34-34
一、东毕血吸虫病 1、症状:东毕血吸虫寄生于牛、羊的肠系膜静脉和肛门静脉中.一般表现为慢性,症状为逐渐消瘦,可视粘膜苍白,有的略有黄染,消化不良,多有稀便带血或粪便含粘液或血液.幼畜发育停滞,母畜往往不发情,不妊娠或流产.病畜逐渐消瘦,贫血,卧地死亡.  相似文献   

3.
以枣Ziziphus jujuba var. inermis、君迁子Diospyros lotus和拐枣Hovenia acerba等几种高Vc植物为材料,对叶片Vc含量及Vc存在形态(总Vc、氧化型Vc、还原型Vc)的年变化、日变化及随叶龄的变化进行了初步的研究.结果表明:植物叶Vc的年变化明显,枣叶Vc累积高峰在9月,君迁子叶则在5~7月,而拐枣叶Vc的存在形态变化极大.植物叶Vc亦存在日变化,总Vc积累高峰时间在中午.此外叶Vc随叶龄不同而变化,一般以稳定叶中Vc含量较高.因此,对高Vc植物Vc含量和存在形态的变化规律的认识,为科学地合理加工利用植物Vc资源提供了理论依据.  相似文献   

4.
【目的】研究香榧假种皮开裂过程中细胞壁代谢及结构的变化,为进一步探明假种皮的开裂机制和探寻促进假种皮开裂的措施提供理论依据。【方法】在种实的不同发育时期内,测定香榧假种皮的开裂率和硬度的变化,分析细胞壁组分及相关降解酶活性的变化,结合石蜡解剖结构的观察,揭示假种皮细胞壁代谢与结构变化在开裂过程中的作用;通过测定香榧种实乙烯释放率的变化,并利用外源乙烯利/乙烯作用抑制剂(1-甲基环丙烯,1-MCP)处理分析乙烯在假种皮开裂过程中的作用,探讨乙烯与假种皮开裂的关系。【结果】1)从134~154 DASP(DASP:突破种鳞后的天数),香榧假种皮的开裂率增加了10倍,硬度降低了61%,假种皮厚度增加了43%;假种皮开裂时(154 DASP),假种皮中靠近内表皮层的树脂道细胞群与其相邻树脂道细胞群之间的薄壁细胞降解,呈分离状态,且中间薄壁细胞层与内表皮层之间存在明显的分离层。2)从134~154 DASP,假种皮的水溶性果胶(WSP)总体上呈增加趋势,而CDTA可溶性果胶(SSP)和Na2CO3可溶性果胶(CSP)则呈降低趋势,其相关降解酶果胶甲酯酶(PME)和多聚半乳糖醛酸酶(PG)活性均呈...  相似文献   

5.
本文通过对不同龄级马尾松林分定点、定位、按月进行常法采脂和生长量调查,并测定针叶中可溶性糖及淀粉的含量,揭示了马尾松人工林林分的生长、发育以及内含物的变化规律。35年生马尾松的产脂力和可溶性糖含量的相关性达到极显著水平,可溶性糖与淀粉含份呈负相关。产脂力和产脂量在年龄间和月份间都存在显著性差异,高产脂类型马尾松的产脂力和产脂量较普通马尾松有明显优势。经产脂力、生长量分析,初步确定马尾松的稳定采脂起始年龄,高产脂类型为25年,普通马尾松为30年。  相似文献   

6.
低温锻炼不仅提高了毛白杨幼苗存活率和抗冻性以及RNA和可溶性总蛋白的含量 ,降低了RNase活性 ,而且能减轻低温胁迫引起的RNA和可溶性总蛋白含量的下降程度和RNase活性的提高 ,有利于幼苗在恢复过程中RNA和可溶性总蛋白水平的迅速回升以及RNase活性的降低 .进一步研究发现 ,DNA含量无论在低温锻炼中还是在低温胁迫下或是在随后的恢复生长期均保持相对稳定 ;低温锻炼所引起的RNA含量的增加 ,与RNase活性的降低呈明显的负相关 ,与可溶性总蛋白含量的增加以及幼苗抗冻性的提高成正相关 .这表明低温锻炼可能抑制RNase活性 ,有效地促进RNA含量的增加 ,而RNA可能参与了可溶性总蛋白的合成及抗冻性的诱导  相似文献   

7.
在温室内以中美山杨幼苗为材料进行砂培试验,探讨了4种不同氮素浓度(1、4、8、16 mmol/L)处理对中美山杨幼苗生物量分配以及根、茎、叶氮浓度的影响。结果表明:(1)氮素供给浓度显著影响幼苗生物量,7月份和9月份在N16水平下达最大,8月份在N8水平下达最大,从7月份到9月份,叶片中的生物量比例逐渐降低,根系的生物量比例逐渐增加。(2)随着供氮水平的提高,苗木体内根、茎、叶中氮浓度明显增加。生长末期根、茎、叶中氮浓度平均达到生长初期的1.16、1.38、1.03倍。(3)本试验可为中美山杨幼苗培育提供理论依据和技术参考。  相似文献   

8.
以新选育果叶兼用品系‘嘉陵40号’桑椹为材料,测定不同发育时期桑椹的花青素和叶绿素的含量,并分析花青素合成相关酶基因、Rubisco编码基因和脱镁叶绿酸 a加氧酶基因( PaO)的表达差异。花青素含量随着桑椹发育逐渐上升,叶绿素的含量先下降后上升。与花青素合成有关的酶基因随着桑椹发育呈现不同的表达模式, Rubisco编码基因 RBCL和 RBCS表达量逐渐降低,PaO1和 PaO2的表达量都呈先下降后逐渐上升,然后再下降的表达模式。使用ABA、乙烯利和1-MCP等试剂处理桑椹,经分析在生化上ABA和乙烯利能促进花青素合成,抑制叶绿素的合成,在基因表达上能促进花青素合成相关基因的表达,而抑制 Rubisco 编码基因的表达;1-MCP 能抑制花青素的合成,并对花青素合成基因的表达也具抑制作用。  相似文献   

9.
10.
朝鲜冷杉(Abies koreana Wils.)为常绿矮生树种,高达1 m,树冠塔型,树皮褐色,大枝轮生平展,叶条形,正面为亮绿色,背面被两条白色气孔带,具有鲜艳美丽的球果,观赏价值较高,在韩国为优良地貌风景林树种和行道树种[1],并在欧美等国家园林中已得到广泛应用,我国目前未见有引种报道.在国家林业局"948"项目的资助下,引进朝鲜冷杉的种子,但其种子具有一定的休眠习性,如不经过任何处理,发芽率仅为40%左右,且不整齐,严重抑制了种苗的生产,提高了成本.国内外学者对冷杉属(Abies Mill.)部分植物的种子休眠习性和萌发特性进行了研究.  相似文献   

11.
张洪海 《林业研究》1999,10(4):247-250
GeneraldistributionoriginaIty,wolf(CanislUPus)distributedinmostareas2o"N(Mech1974)exceptfortropicaIrainfor-estanddesert.lnatimewolfdistributedintheEurope-AsiacontinentofthenorthernsphereandtheNoFthAmericancontinentexceptforfewisIands(in-cIudingSaudiArabiaPeninsuIaandJap'n).lnNorthAmerica,thedistributionareaofwolvese\erspreadstotheSouthofMexicoadjointotheTropicofcancer(Goldman1997).ThedistributionareasofwoIveshavedecreasedgreatIysofar,especiaIlyinWestEuropeandNorthAmerica.lntheNorth…  相似文献   

12.
Food habits of the grassland wolf in Inner Mongolia of China   总被引:3,自引:0,他引:3  
IntroductionThettnIf(CanishII,us)belongstoCan1ivora.Tllcwolfdistributedinll1ncrMol1goliaisaCl1incscstIbspccics(CanishII,llscl;ancoGray).Tl1ctvoIfllasagrcatcco-logicaladaptingcapacity.Itisaln1ostdistributcdovcrtvholcCIlina.Inso111careas,tl1cwolfoftcl1doesahan11tosol11cdolllesticani1nals.TocOI1troltvolfPopuIatio11,pcoplcalwaysl11a1mgetokilltl1ettolvcs.Il1sol11crcgiOI1s,tlloscwllokilltllewolvcsarcevcnrcttardcd.n1us-cxactrolcoftlletvolfintl1cccologicalsystcl1lsI1ouldbccIarificdfortllcpr…  相似文献   

13.
半野生麋鹿秋、冬季粪堆频率分布的研究*   总被引:1,自引:0,他引:1       下载免费PDF全文
通过对江苏大丰麋鹿保护区Ⅰ、Ⅱ放养区内麋鹿粪堆频率分布的系统抽样调查,发现半野生麋鹿在秋、冬季粪堆呈聚集型分布,分布型服从负二项分布、奈曼A型分布和Thomas分布,其中以负二项分布拟合程度最好。造成粪堆聚集分布的主要原因是环境因素的影响,与麋鹿的习性关系不大。在放养区主要生境类型草地和林地中,粪堆均服从负二项分布。粪堆密度林地大于草地,但粪堆聚集指数草地却高于林地。粪堆的聚集强度与鹿群在该生境中的活动类型有关,当麋鹿粪堆在单一生境内服从负二项分布时,粪堆聚集指数与鹿群对该生境的休息利用率之间存在着明显的相关关系(r=0.988,P0.05)。粪堆频数调查显示,秋、冬季大丰麋鹿对林地的利用率高于草地。  相似文献   

14.
通过对江苏大丰麋鹿保护区Ⅰ、Ⅱ放养区内麋鹿粪堆频率分布的系统抽样调查,发现半野生麋鹿在秋、冬季粪堆呈聚集型分布,分布型服从负二项分布、奈曼A型分布和Thomas分布,其中以负二项分布拟合程度最好。造成粪堆聚集分布的主要原因是环境因素的影响,与麋鹿的习性关系不大。在放养区主要生境类型草地和林地中,粪堆均服从负二项分布。粪堆密度林地大于草地,但粪堆聚集指数草地却高于林地。粪堆的聚集强度与鹿群在该生境中的活动类型有关,当麋鹿粪堆在单一生境内服从负二项分布时,粪堆聚集指数与鹿群对该生境的休息利用率之间存在着明显的相关关系(r=0.988,P<0.05)。粪堆频数调查显示,秋、冬季大丰麋鹿对林地的利用率高于草地。  相似文献   

15.
Bamboo forest is an important forest type in subtropical China and is characterized by fast growth and high carbon sequestration capacity. However, the dynamics of carbon fluxes during the fast growing period of bamboo shoots and their correlation with environment factors are poorly understood. We measured carbon dioxide exchange and climate variables using open-path eddy covariance methods during the 2011 growing season in a Moso bamboo forest(MB, Phyllostchys edulis) and a Lei bamboo forest(LB, Phyllostachys violascens) in Zhejiang province,China. The bamboo forests were carbon sinks during the growing season. The minimum diurnal net ecosystem exchange(NEE) at MB and LB sites were-0.64 and-0.66 mg C m-2 s-1, respectively. The minimum monthly NEE, ecosystem respiration(RE), and gross ecosystem exchange(GEE) were-99.3 ± 4.03, 76.2 ±2.46, and-191.5 ± 4.98 g C m-2 month-1, respectively,at MB site, compared with-31.8 ± 3.44, 70.4 ± 1.41,and-157.9 ± 4.86 g C m-2 month-1, respectively, at LB site. Maximum RE was 92.1 ± 1.32 g C m-2 month-1 at MB site and 151.0 ± 2.38 g C m-2 month-1 at LB site.Key control factors varied by month during the growing season, but across the whole growing season, NEE and GEE at both sites showed similar trends in sensitivities to photosynthetic active radiation and vapor pressure deficit,and air temperature had the strongest correlation with RE at both sites. Carbon fluxes at LB site were more sensitive to soil water content compared to those at MB site. Both onyear(years when many new shoots are produced) and offyear(years when none or few new shoots are produced)should be studied in bamboo forests to better understand their role in global carbon cycling.  相似文献   

16.
2005年12月~2006年8月,采用瞬时扫描取样法和全事件取样法,对云南野生动物园内5只孟加拉虎行为进行了初步观察。结果表明,在观察期内,笼养孟加拉虎白昼行为时间分配上两性存在一定差异,即雌性的睡眠和卧息多于雄性的睡眠和卧息;雌性的走动和其它行为少于雄性的走动和其它行为。在活动节律上,两性有极大的相似性,只是雌虎在下午的卧息高峰值比雄虎晚约1h。  相似文献   

17.
为探讨人工柽柳林对滨海盐碱地的改善效果,以黄河三角洲滨海盐碱地区3种不同林龄(8 a、6 a、3 a)人工柽柳林为对象,采用多点混合采样法,对生长季土壤微生物量C、N及微生物数量变化进行了对比分析;同时利用LI-8100A土壤碳通量测量系统,原位监测了柽柳生长季内土壤呼吸速率的变化特征。结果表明:1)人工柽柳林土壤微生物微生物量C、N变化受林龄和季节影响明显,其中8 a林地含量最高,3 a林地最小,夏季较高,春季较低,且8 a与3 a差异显著,夏季与春季差异显著(P <0.05);不同林龄土壤微生物商生长季介于2.56~4.15%之间,其变化规律与微生物量一致。2)土壤3种微生物数量均随林龄的增大而增加,微生物数量关系为细菌>放线菌>真菌,而3种微生物数量季节变化规律不一致。3)3种林龄土壤呼吸速率的大小为8 a> 6 a> 3 a,土壤呼吸具有明显的季节变化和日变化,其中季节变化表现为夏季>秋季>春季,日变化则呈现出低-高-低的单峰曲线,最大值则出现在12:00―14:00。4)相关分析表明,土壤含盐量与土壤微生物量C和呼吸速率呈显著负相关,与细菌、真菌呈极显著负相关,是主要限制因子;土壤微生物量C、N与微生物商、土壤呼吸、土壤微生物数量均呈正相关;除土壤湿度外,土壤温度与其它指标均呈正相关;而土壤湿度与各指标间均不显著。5)综上所述,不同林龄人工柽柳林土壤微生物量、微生物数量及呼吸速率均可反映土壤环境状况,可为滨海盐碱地土壤改良和土壤质量演变规律提供理论依据。  相似文献   

18.
Although it is well known that sap exudation during early spring in temperate deciduous trees occurs in response to daytime warming and nighttime cooling, the mechanisms of the process are not yet fully understood. Previous theories suggested that changes in stress in the wood caused by daytime heating and nighttime cooling might be linked with sap flow. Consequently, a study of itaya-kaede maple (Aver mono) and shirakamba birch (Betula platyphylla var.japonica) looked at tangential strains. One-hour intervals for 3 years of the tangential strains on the inner bark of stem and root were measured in itaya-kaede maple and shirakamba birch during the sap exudation season. The measurements indicated different mechanisms of sap exudation in these two trees. During the sap exudation season in late March, when the temperature fluctuated around 0°C, the tangential strain in the root of itaya-kaede maple showed expansion in the daytime and contraction at night. Conversely, in early April the tangential strain in the root of shirakamba birch exhibited contraction in the daytime and expansion at night. The changes in tangential strains in itaya-kaede maple were attributed to conditioning, a known concept used to explain the uptake mechanism of soil water in maple and its exudation during early spring. However, because the change in tangential strain in the roots of shirakamba birch was similar to that found during the rampant season, sap exudation was not attributed to conditioning but to the plentiful supply of water from the roots. The implications of these mechanisms are that different sap harvesting techniques may be appropriate for different tree species.  相似文献   

19.
Morphological changes in the cytoskeleton, nuclei, and vacuoles were monitored during the cell death of short-lived ray tracheids in the conifer Pinus densiflora. After formation of the dentate thickenings that occurred at the final stage of formation of cell walls, organelles started to disappear in differentiating ray tracheids. First, the microtubules and vacuoles disappeared. Then actin filaments disappeared in the differentiating ray tracheids adjacent to ray tracheids that lacked nuclei, and, finally, the nuclei disappeared. These features indicate that cell death in ray tracheids might differ from the programmed cell death of tracheary elements that has been studied in vitro in the Zinnia culture system. This study was presented at the 57th Annual Meeting of the Japan Wood Research Society, August 8–10, 2007, Hiroshima, Japan  相似文献   

20.
The low availability of nitrogen (N) is believed to be one of the major limiting factors of forest regeneration in Iceland and frequently under Boreal conditions. Lutz spruce (Picea x lutzii Littl.) seedlings were nutrient loaded using four fertilization regimes in the end of nursery rotation in autumn 2008 and planted in the following spring, with or without a single dose of fertilizer, on two treeless sites in N-Iceland with contrasting soil fertility. Measurements were made after one growing season. The highest loading level without additional field fertilization increased new needle mass by 122% and 152%, for the poor and more fertile site, respectively. The highest loading level with field fertilization increased new needle mass equally, by 188% and 189%, for the poor and more fertile site, respectively. Retranslocation of N, from old needles to current needles, increased with more loading. However, it was clear that nutrient loading could not replace field fertilization, as the seedlings generally showed an additive response to field fertilization and nutrient loading; doing both always gave the best results in seedling performance. As the study only covers field establishment during the first year, the long-term effect of nutrient loading of Lutz spruce cannot be predicted. However, it was concluded that loading might provide an additional input for faster plantation establishment during the first growing season after planting.  相似文献   

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