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排序方式: 共有606条查询结果,搜索用时 31 毫秒
1.
研究了箭舌豌豆不同器官对种子产量的贡献,结果表明:箭舌豌豆种子利用花后光合产物较多,不同器管对箭舌豌豆种子产量的贡献是复叶〉茎〉托叶,叶片对种子产量的贡献与其所在位置有关,花后叶因离荚果较近,其光合产物易于向荚果运输。  相似文献   
2.
The current paper describes aspects of local immunity in the ovary and oviduct, and the significance of immunity to reproductive functions in hens. The immunocompetent cell populations in the ovary and oviduct change with a positive correlation to sexual activity, and gonadal steroid is one of the key factors in the increase. Local immune responses mediated by major histocompatibility complex class II and T cell subsets occur in response to infection by Salmonella enteritidis, which may contaminate eggs. In the ovary, immunocompetent cells are also suggested to play roles in the regulation of ovarian functions. Macrophages and T cells are likely to enhance the regression of atretic follicles to maintain the ovarian tissue microenvironment. Autoantibodies to ovarian tissues appeared in the hens with low egg laying frequency, suggesting that the auto‐antibodies may be one of the factors in the decline of egg production. In the oviduct, local immunity possibly has a role in the selection of sperm, though the immunoreactions may also affect sperm survival leading to the decline in fertility. The concentration of yolk IgY, which plays a role in maternal immunity transmission, significantly decreases with the aging of birds, whereas it is significantly increased by estrogen. Therefore, the immune system plays significant roles not only in defense against infection, but also in the functions of reproductive organs. Investigations on the local immune system in the reproductive organs and factors affecting it are of importance for the production of sterile eggs and improvement of reproductive functions.  相似文献   
3.
用商品益生素和自制益生素分别灌服1日龄雏鸡,灌服益生素后1、4、7、10、18d测定胸腺、脾脏、法氏囊的器官指数动态变化,用间接酶联免疫吸附试验(ELISA)方法测定泪液、气管液、胆汁和肠液的IgA、IgM、IgG相对含量的动态变化,结果发现服用商品益生素的雏鸡免疫器官指数在第7天高于未服用益生素的对照雏鸡,上述4种体液的IgA、IgM、IgG相对含量在服用益生素后7~10d高于未服用益生素的对照雏鸡,服用自制益生素的雏鸡上述4种体液的IgA、IgM、IgG相对含量在服用益生素后4~7d高于未服用益生素的对照雏鸡。表明益生素对雏鸡的免疫系统有一定的影响,能够促进免疫器官的生长发育,提高雏鸡呼吸道和消化道局部体液的免疫球蛋白相对含量。  相似文献   
4.
随着探索提高植物整体光合能力相关研究的不断开展,麦类作物穗部器官等植物非叶绿色器官光合潜力挖掘逐渐得到关注。本研究在成都平原秋播美达、贝勒、莫尼卡、摄政王、泰克和甜燕60等6个品种燕麦,设置遮穗、去颖2个试验处理,比较分析了各品种间穗部特征、穗部光合贡献率、颖片光合贡献率和茎光合物质转移率等差异。结果表明,燕麦穗部器官光合贡献率为28.56%~49.05%,其中甜燕60最高;6个品种燕麦的颖片光合贡献率为11.03%~36.88%,茎光合物质转移率为6.65%~35.81%。燕麦穗部器官对籽实增重表现了较高的光合贡献,当燕麦穗部器官光合受到限制时,燕麦单粒种子重和单穗种子数显著降低,尤其是影响双粒小穗数。  相似文献   
5.
【目的】研究不同生境和收获时间对圆齿野鸦椿不同部位总三萜类化合物积累的影响情况,为其药用价值和科学栽培的研究奠定基础。【方法】选择3个低海拔地区的8年生圆齿野鸦椿,分别于2014年11月和2015年3月采集其叶片、枝条和果实,选择高海拔地区6年生的野鸦椿和圆齿野鸦椿,于2014年8月分别采其叶片和枝条,对其总三萜类化合物含量进行了测定和比较分析。【结果】1)8月采集的叶片中三萜类化合物的含量,野鸦椿高于圆齿野鸦椿,且其含量差异呈显著性水平;但是,8月采集的枝条中三萜类化合物含量,野鸦椿低于圆齿野鸦椿。2)圆齿野鸦椿不同部位的总三萜类化合物含量存在差异,且2个月份采集的含量高低顺序均为叶片>枝条>果皮>种子,均以叶片中的含量为最高,依次为9.06%(农大)、7.14%(清流)和6.85%(邵武)。3)11月采集的圆齿野鸦椿样品中的三萜类化合物含量高于3月所采样品中的含量,其叶片中的总三萜类化合物含量最多可提高172.91%。4)圆齿野鸦椿叶片、果皮和种子中的三萜类化合物含量与试验地的海拔高度、年降水量均表现出极显著的负相关关系,与年均气温存在极显著的正相关关系,其叶片中的三萜类化合物含量还与年均无霜期呈正相关关系,其枝条中的三萜类化合物含量与各地理和气象因素之间的相关性均不显著。【结论】圆齿野鸦椿的叶片采收期长于野鸦椿;低海拔、较少降水量和年均气温较高有利于圆齿野鸦椿植株对三萜类化合物的累积,这3个因子可以作为圆齿野鸦椿适宜栽培区域的划分指标;夏季采摘野鸦椿叶片,秋冬季采摘圆齿野鸦椿叶片,所采叶片的总三萜类化合物的含量均较高。  相似文献   
6.
用免疫组化SABC法,对斯氏艾关耳球虫感染后兔肝脏、脾脏和肝门淋巴结中球虫抗原的分布进行了观察。结果表明,在肝脏窦状隙、胆管上皮细胞、肝门淋巴结和脾脏内可见到明显的呈棕黄色阳性反应区,表明在这些区域和部位有相应的E.stiedai孢子囊、裂殖子或子孢子抗原存在,且抗原数量以肝脏内最多,其次为脾脏,最少者为肝门淋巴结;显微镜下还可见到大量坏死的肝细胞、淋巴细胞以及朗罕氏巨细胞,说明多核巨细胞也参与了对球虫的吞噬和处理过程。  相似文献   
7.
The introduction of new hybrids and integrated crop-soil management has been causing maize grain yield to increase. However, less attention has been paid on the nutrient concentration of the grain; this aspect is of great importance to supplying calories and nutrients in the diets of both humans and animals worldwide. Increasing the retranslocation of nutrients from vegetative organs to grain can effectively increase the nutrient concentration of grain and general nutrient use efficiency. The present study involved monitoring the dynamic change of macro- and micronutrients in different organs of maize during the grain filling stage. In addition, the mobility of different elements and their contribution to grain nutrient content were evaluated in a 2-year experiment under low (LN, no N supplied) and high N (HN, 180 kg N ha−1) supply. Under HN supply, the net remobilization efficiency (RE) of the vegetative organs as a whole (calculated as nutrient remobilization amount divided by nutrient content at silking) of N, P, K, Mn, and Zn were 44%, 60%, 13%, 15%, and 25%, respectively. The other nutrients (Mg, Ca, Fe, Cu, and B) showed a net accumulation in the vegetative organs as a whole during the grain filling stage. Among the different organs, N, P, and Zn were remobilized more from the leaves (RE of 44%, 51% and 43%, respectively) and the stalks (including leaf sheaths and tassels) (RE of 48%, 71% and 43%, respectively). K was mainly remobilized from the leaves with RE of 51%. Mg, Ca, Fe, Mn, and Cu were mostly remobilized from the stalks with the RE of 23%, 9%, 10%, 42%, and 28%, respectively. However, most of the remobilized Mg, Ca, Fe, Mn, Cu, and Zn were translocated to the husk and cob, which seemingly served as the buffer sink for these nutrients. The REs of all the nutrients except for P, K, and Zn were vulnerable to variations in conditions annually and were reduced when the grain yield and harvest index were lower in 2014 compared with 2013. Under LN stress, the RE was reduced in P and Zn in 2013, increased in Cu and unchanged in other nutrients. The concentration of these nutrients in the grain was either unchanged (P, K, Ca, Zn, and B) or decreased (N, Mg, Fe, Mn, and Cu). It is concluded that grain N, P, K, Mn, and Zn, but not Mg, Ca, Fe, Cu, and B concentration, can be improved by increasing their remobilization from vegetative organs. However, enhancing the senescence of maize plant via LN stress seems unable to increase grain mineral nutrient concentration. Genetic improvement aiming to increase nutrient remobilization should take into account the organ-specific remobilization pattern of the target nutrient.  相似文献   
8.
以内蒙古锡林郭勒盟苏尼特右旗短花针茅荒漠草原为对象,采用随机区组放牧试验设计,结合对比分析、线性回归分析以及结构方程模型等数据分析方法,探讨荒漠草原主要种群与植物群落地上现存量的关系及在放牧条件下的变化特点。结果表明:随放牧强度增大,短花针茅、无芒隐子草和碱韭主导种群地上现存量占植物群落地上现存量的比例下降,且主导种群与植物群落地上现存量的线性关系减弱;不同年度间主导种群占植物群落地上现存量比例以及线性关系会产生变动;短花针茅种群对荒漠草原植物群落的影响强于无芒隐子草种群和碱韭种群,但无芒隐子草种群在降雨较好年份具有补偿作用。  相似文献   
9.
To understand the background value of phosphorus in chickens, the quantitative distribution of different phosphorus forms, including total phosphorus (TP), free phosphate (FP) and phospholipid (PL), in viscera, blood and bones of broiler chickens was investigated. Results showed that phosphorus contents exhibited significant differences in different parts of chickens. TP content of breast and thigh meat was over 5.0 g/kg, in which most of the phosphorus was in the form of water‐soluble phosphates. TP content in viscera was higher than that in meat, and spleen was observed to contain the highest amount of phosphorus (10.0 g/kg). In all tested organs, FP and PL contents in liver were the highest, ranging between 1207–1989 and 81–369 mg/kg respectively. TP content in chicken bone was in the range of 52 716–136 643 mg/kg, and FP content in the bone was relatively lower than that in chicken meat.  相似文献   
10.
从鸡胸腺、脾脏、哈德氏腺、外周血液和法氏囊等免疫器官中分离淋巴细胞,应用RT-PCR对这些免疫器官中鸡CD4分子mRNA的表达进行了研究。同时,用RT-PCR对鸡脾淋巴细胞CD4分子cDNA进行了克隆和序列测定。结果表明,在上述器官中,法氏囊淋巴细胞不表达鸡CD4分子mRNA,其他器官中均有表达。通过序列分析表明,本试验扩增得到的基因为编码鸡CD4分子的基因。  相似文献   
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