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101.
为探索红枣GSTU类基因在红枣抗逆中的分子作用机制,本研究以狗头枣枣树叶片的DNA为模板,根据枣GSTU基因的序列(HM345954.1)设计引物,采用PCR方法获得GSTU基因序列,并利用生物信息学手段对其所对应蛋白的结构域、功能域、理化特性、跨膜区、二级结构及亚细胞定位等进行分析。结果表明:克隆到的DNA序列全长838 bp,具有2个外显子和1个内含子,内含子在292~460 bp碱基处,该序列与GenBank中枣的GSTU核苷酸序列和氨基酸序列的同源性分别为99.85%和100%,表明成功的克隆了狗头枣的GSTU基因。该序列编码222个氨基酸,分子量为25.268 kD,理论等电点(pI)为6.10;亲水性的平均数为-0.242,表明该蛋白是亲水性蛋白。二级结构主要以α-螺旋为主,其次是无规则卷曲,不存在信号肽,表明该蛋白可能为非分泌性蛋白,该蛋白可能位于内质网(膜)和质膜上。本研究获得的狗头枣GSTU基因在基因结构上含有1个内含子,在核酸序列及氨基酸序列上与GenBank中枣的GSTU基因同源性高,并对其理化性质、结构等进行了预测与分析,为进一步研究红枣抗逆分子机制提供理论基础,同时为红枣品种的选育提供理论支持。  相似文献   
102.
为探索石灰岩山地不同林分类型中空气细菌的动态变化规律及其影响因素,筛选出抑菌效果较好的林分,选取徐州石灰岩山地4种典型林分为试验材料,采用自然沉降法研究林分中细菌含量的季节变化和日变化,同步监测温湿度、风速、PM2.5和空气负离子浓度,分析空气细菌含量及其之间的关系。试验结果表明:(1)细菌含量季节性变化表现为春季秋季夏季冬季,除冬季日变化呈现"早晚低,中午高"的变化趋势,其他季节表现为"早晚高,中午低";(2)不同林分类型空气细菌含量存在显著差异(P0.05),总体来看,苦楝林对细菌的抑制效果最好;(3)细菌含量与空气湿度和PM2.5呈极显著正相关关系,与空气负离子呈极显著的负相关关系。综上,苦楝林的抑菌效果最好,湿度、PM2.5和负离子是影响空气细菌含量的主要因素。本研究可为此地城市保健林的营建以及生态旅游规划提供科学依据。  相似文献   
103.
有机粪肥施入与秸秆还田已经成为改良黑土性状的重要途径。以30年长期定位试验为研究平台,探讨了长期有机物料投入对土壤理化性质的影响。研究共包含4个处理:(1)不施肥(CK);(2)单施化肥(NPK);(3)有机粪肥部分替代化肥(NPKM);(4)秸秆部分替代化肥(NPKS)。研究结果指出,与NPK处理相比,NPKM与NPKS处理分别提高58.7%和10.7%的土壤有机碳含量、66.4%和18.5%的全氮含量、27.6%和25%的全钾含量(P<0.05);在土壤全磷含量方面,NPKM处理提高了56.6%的全磷含量(P<0.05),而NPKS处理对土壤全磷含量无显著影响。NPK处理中土壤pH最低,为5.97,NPKM与NPKS处理土壤pH分别为7.26和7.99,显著高于NPK处理(P<0.05)。与NPK处理相比,NPKM和NPKS处理分别降低了17.9%和13.8%的土壤容重(P<0.05)。在作物产量方面,与NPK处理相比,NPKM处理显著提高了9.6%的玉米产量(P<0.05),而NPKS处理对作物产量无显著影响。综上所述,长期有机粪肥与秸秆施入可以有效...  相似文献   
104.
Common wheat(Triticum aestiuum L.)is one of the most important crops because it provides about 20%of the total calories for humans.T.aestiuum is an excellent modern species for studying concerted evolution of sub-genomes in polyploid species,because of its large chromosome size and three well-known genome donors.Establishment of common wheat genome reference sequence and development of high-density SNP chips provide an excellent foundation to answer questions of wheat evolution and breeding at the genomic level.By genotyping more than 600 accessions of common wheat and their diploid and tetraploid ancestors using a Wheat660 K SNP array,we found dramatic genome changes due to tetraploidization and hexaploidization,in contrast to weaker influences of domestication and breeding on them.Further,since common wheat was introduced in China in 1500 BCE,Chinese landraces formed two subgroups(T.aestiuum-L1 and T.aestiuum-L2)with considerably diverse geographic distributions and agronomic traits.T.aestiuum-L2,mainly distributed in central and east China is found to have more but smaller oval grains with early maturity characteristics.We found that variation and selection in intergenic regions of the A and B sub-genomes dominated this differentiation,in which chromosomes 7 A and 3 B took the leading roles due to the existence of putative genes related to defense responses and environmental adaption in the highly differentiated regions.Large haplotype blocks were detected on 3 B(232.6-398.3 Mb)and 7 A(211.7-272.9 Mb)in the landraces,forming two distinct haplotypes,respectively.We discovered that artificial crosses in breeding promoted recombination in the whole genome,however,this recombination and differentiation was highly asymmetric among the three sub-genomes in homoeologous regions.In addition,we found that the wide use of European and northern American cultivars in breeding at early era,led dramatic changes in Chinese wheat genome,whereas,the recent breeding functioned to optimize it.This study will provide the insight for reconsideration of wheat evolution and breeding,and a new strategy for parent selection in breeding.  相似文献   
105.
Platycodi radix is widely used in traditional herbal medicine for the treatment of bronchitis, asthma, pulmonary tuberculosis, hypertension, hyperlipidemia, and diabetes. This study aimed to investigate cell proliferation (Ki-67) and apoptosis (Caspase-3) potential in squamous cell hyperplasia of the stomach induced by a Platycodi radix water extract in a subchronic toxicity study. One hundred formalin-fixed, paraffin-embedded stomach tissues of rats treated with Platycodi radix at doses of 0, 500, 1,000, and 3,000 mg/kg body weight/day were used for the analysis. They were conventionally stained using hematoxylin and eosin (H&E) and immunohistochemically (IHC) stained using caspase-3 and Ki-67 antibodies. The incidence of squamous cell hyperplasia was significantly increased in the 3,000 mg/kg b.w./day treatment group in both sexes (p<0.01). However, the hyperplastic change was completely repaired after 4 weeks of recovery period. Ki-67 expression was similar in all groups, with no statistically significant differences among the groups. Caspase-3 expression was significantly increased in both sexes in the 3,000 mg/kg b.w./day treatment group (p<0.01), compared with the vehicle control groups, and then reduced to normal levels in the recovery groups in both sexes. In conclusion, this study showed that squamous cell hyperplasia induced by the Platycodi radix water extract in the limiting ridge of the stomach is not considered to be abnormal proliferative change; as a result, squamous cell hyperplasia is considered to be a non-adverse effect when induced by the oral administration of the Platycodi radix water extract once daily for 13 weeks in rats.  相似文献   
106.
WNT7A and β-catenin localisations and roles in regulating periimplantation ovine conceptus development under natural estrous conditions have been elaborated.However,their locations and expression patterns have not been reported under induction of oestrus.The localisation,expression and function of WNT7A and β-catenin in the uterine tissues of the early pregnant and non-pregnant sheep on days 10,12,14,16 and 18 following artificial induction of oestrus were investigated by means of in situ hybridisation,real-time RT-PCR,immuno-histochemistry and western blotting methods.WNT7A and β-catenin mRNA and protein were both restricted to the apical surfaces of the uterine luminal epithelium (LE) and glandular epithelium (GE).In pregnant sheep,protein localisation of WNT7A and β-catenin was observed both in the endometrial LE and GE.Their staining presented on day 10,increased between day 12 and day 16,and decreased on day 18.WNT7A and β-catenin mRNA and protein expression increased initially and then decreased from day 10 to day 18,peaking on day 16,and β-catenin reaching a peak on day 18 in the uterine tissues of pregnant sheep (p0.05).By contrast,no significant changes in WNT7A and β-catenin mRNA and protein expression levels were observed from day 10 to day 18 of the oestrus cycle in the uterine tissues of non-pregnant sheep (p0.05).Additionally,WNT7A and β-catenin mRNA and protein expression levels in the uterine tissues of the early pregnant sheep were significantly higher than those of non-pregnant sheep (p0.05).Treatment of endometrial epithelial cells with WNT7A increased the mRNA expressions of β-catenin,c-myc and Cyclin D1.These results provided an underlying mechanism of periimplantation ovine conceptus development under induction of oestrus.  相似文献   
107.
通过对木材进行封闭处理,在木材表面进行真空磁控溅射镀膜金属试验,在保持木材本身天然特性的同时,使其具有抗电磁辐射功能。对桐木胶合板进行单侧面和双侧面镀铜、铝膜试验,测试其电磁屏蔽效能。结果表明:三聚氰胺甲醛树脂与硅烷偶联剂混合物质对木材进行封闭,真空室的真空度10-2~10-4MPa,靶材温度为200℃,溅射时间为90s的工艺参数理想,获得的薄膜厚度为30μm,木材表层镀铜或是镀铝,双侧镀还是单侧镀,在30MHz~1.5GHZ频段之间,电磁屏蔽效能都能达到30dB以上,满足电磁屏蔽要求。双侧面的效果大于单侧面的效果,镀铜的效果大于镀铝的效果。  相似文献   
108.
盐胁迫下栽培大豆黑农40不同器官中抗氧化酶活性的变化   总被引:1,自引:0,他引:1  
付畅  关旸 《大豆科学》2007,26(3):343-346,354
通过对盐胁迫下栽培大豆黑农40的根、茎、叶等不同器官中主要的抗氧化酶活性的测定与分析,探讨了大豆耐盐性的机理.结果表明,黑农40叶片中的SOD、POD和APX活性水平明显高于根部和茎部.叶片中的POD和APX在高盐胁迫下的应答反应都比在低盐时快速.盐胁迫时间的延长引起根、茎、叶中的SOD和POD活性发生明显的下降,在高盐胁迫下这种下降比在低盐时更为急剧.  相似文献   
109.
太阳能-土壤源热泵空调系统研究   总被引:2,自引:0,他引:2  
提出了太阳能—土壤源热泵空调系统的概念,研究了该系统的工作原理。对地源热泵和热管式太阳能集热器的热力计算方法进行了理论分析;结合工程实例,介绍了太阳能地源热泵空调系统的设计思路和运行方式。  相似文献   
110.
玉米大豆间作对玉米主要病虫害发生及其产量的影响   总被引:4,自引:2,他引:2  
为明确玉米大豆间作模式对玉米主要病虫害发生及其产量的影响,利用2017-2018年2年的田间小区试验及2019年的大田试验,在作物生长期对亚洲玉米螟Ostrinia furnacalis、东方黏虫Mythimna seperata和玉米大斑病等主要病虫害发生情况进行调查和统计分析,并于收获期对间作作物产量进行测定.结果...  相似文献   
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