梨矮化砧木——中矮1号

中矮 1号是 1980年从锦香梨自然实生中选出的紧凑型矮化砧木 ,通过嫁接鉴定、比较试验、试栽证明作中间砧能使栽培品种树体矮化、早结果、早丰产。矮砧本身具有抗枝干腐烂病、轮纹病、抗寒等特性 ,与栽培品种嫁接亲和性良好。 1998年通过专家验收与鉴定 ,1999年通过辽宁省农作物品种审定委员会审定并命名。可用作梨的矮化中间砧。     

梨品种中矮1号GA20-氧化酶基因正义和反义表达载体的构建

通过对已获得的中矮1号GA20-氧化酶基因的cDNA序列全长进行分析,选取Spe I/Bst EⅡ双酶切位点、以pCAMBIA1305为载体构建质粒。成功构建了GA20-氧化酶基因的植物正义和反义表达载体pCAMBIA1305-GAF和pCAMBIA1305-GAR,并成功转入到了农杆菌EHA105菌株中;为GA20-氧化酶基因的遗传转化和梨品种中矮1号矮化机理研究奠定了基础。     

梨矮化砧木新品种‘中矮2号’

 ‘中矮2号’是采用有性杂交技术选育而成的梨矮化砧木品种, 作梨树中间砧木或自根砧木具有促进嫁接品种树矮化、早果、早期丰产、果实品质好等特点。砧木品种本身抗寒性强, 高抗梨树枝干轮纹病或枝干腐烂病。     

梨极矮化突变体与苹果梨GA20ox基因的克隆及植物表达载体的构建

以梨极矮化突变体和苹果梨为试材,应用RT-PCR技术对GA20ox基因进行克隆及序列分析。结果表明:克隆得到梨极矮化突变体和苹果梨GA20-氧化酶基因,依次命名为PuGA20ox和PbGA20ox,其全长均为1 179bp,分别包含1个完整编码392个氨基酸的开放阅读框(ORF);对其进行序列分析,并成功构建了植物表达载体,为进一步研究梨矮化突变体和GA20-氧化酶基因功能奠定了基础。     

梨矮化砧木中矮1号绿枝扦插繁殖研究

探索梨矮化砧木中矮1号扦插繁殖难以生根的技术问题,为其在生产中作为自根砧推广应用提供理论和技术支持。以中矮1号当年生绿枝为插穗材料,研究不同基质、不同药剂配比及浓度对其扦插的影响,通过正交设计试验分析影响中矮1号绿枝扦插生根的主要因素。结果表明：5种基质中,蛭石的扦插效果最好;经过药剂处理后的插穗,扦插效果显著优于对照,相比于较高质量浓度（3 000～4 000 mg/L）的药剂处理,较低质量浓度（2 000～2 500 mg/L）的药剂更有利于插穗的生长;正交设计试验结果表明,枝条部位是影响插穗存活率、愈伤组织诱导率的主要因素,而IBA则是影响插穗生根率的主要植物生长调节剂。中矮1号新梢中下部绿枝经过2 500 mg/L IBA+NAA(3∶1)速蘸1 s处理后扦插于蛭石基质中,最高获得了10.0%的插穗生根率。     

梨矮化砧木‘中矮1号’生长素氢转运体基因PcAHS及其启动子的克隆与表达分析

以梨（Pyrus communis L.）紧凑型矮化砧木‘中矮1号’及其母本‘锦香’新梢韧皮部为试材,根据转录组测序结果设计特异性引物,克隆到1个长1 239 bp的基因序列。该序列在两个品种间不存在差异,均编码412个氨基酸,其氨基酸序列与苹果（np_001280772.1）、梅（xp_008242099.1）、毛果杨（xp_002306421.2）、草莓（xp_00428771.1）的生长素氢转运体基因（AHS）编码的氨基酸序列的相似性在67% ~ 99%之间,命名为PcAHS。qRT-PCR分析发现,‘中矮1号’新梢韧皮部中PcAHS的表达量均低于母本‘锦香’,推测其启动子序列存在差异。‘中矮1号’及其母本‘锦香’PcAHS 基因上游启动子长度分别为828 bp和888 bp,二者相似性89.1%。序列分析发现‘中矮1号’PcAHS基因启动子有一段58 bp（–496 bp ~–553 bp）的缺失;利用植物顺式作用元件数据库PLACE和PLANTCARE分析表明,‘中矮1号’启动子含有一个‘锦香’没有的BPBF转录因子结合元件P-box。推测‘中矮1号’PcAHS基因启动子特有的片段缺失和P-box转录因子结合元件可能是导致其表达量低并通过影响生长素的运输最终引起矮化的原因。     

梨矮化砧木新品种‘中矮5号’

‘中矮5号’是从‘锦香’梨实生后代中选育出的梨矮化砧木新品种。树体矮化紧凑,1年生株高相当于乔化型‘早酥’梨的17.3%。作中间砧与嫁接品种和基砧亲和性好,矮化程度、早果性及丰产性明显高于无中间砧对照。较抗梨枝干轮纹病和梨干腐病,抗寒性较强,在辽宁兴城地区无冻害,适于在辽宁中南部梨栽培区应用。     

梨矮化砧木研究进展

该文概述了梨矮化砧木的选育及应用、梨矮化砧木的致矮机理及无性系繁育研究等方面的研究进展。现有报道表明,国外主要以榅桲作为梨的异属矮化砧木,梨的同属矮化砧木有一定研究,但是进展缓慢。我国梨矮化砧木研究起步晚,但也选育了一些梨属矮化砧木。     

梨矮化砧木新品种‘中矮2号’

利用矮化自根砧木或中间砧木是梨树密植栽培的主要途径之一。中矮2号（原代号PDR54）由香水梨x巴梨杂交后代选育而成的梨树矮化砧木，1979年杂交，1983年初选．1990年复选，1995年通过专家验收，决选为梨树矮化砧木。利用中矮2号做中间砧进行了梨树露地高度密植栽培、温室栽培及盆栽．效果良好。该品种2006年通过辽宁省品种审定委员会登记备案并定名。[第一段]     

适于中国梨的梨属矮化砧木--中矮2号

“矮砧短周期栽培”是当今果树发展的总趋势。其优点是品种更新快、品质优、易管理、经济效益高、投资回报早。中国农业科学院果树研究所从 2 0世纪 80年代开始进行了西洋梨与秋子梨品种的种间杂交 ,从 30余个有矮化趋势的单株中筛选出具有矮化潜力的单系 10个 ,并且已决选出梨属矮化砧木S2、S5和PDR5 4。其中S2已通过辽宁省农作物品种审定委员会审定并命名为中矮 1号 (见《中国果树》2 0 0 0年第 3期 )。PDR5 4(1996年定名为中矮 2号 )的矮化程度极高 ,为极矮化砧 ,适合南方生长量大的特点 ,可进行高度密植栽培的试栽。1　选育经过梨属…     

中矮1号梨砧木(S_2)PGIP基因的克隆及序列分析

利用RT-PCR技术,根据GenBank中梨属PGIP基因序列设计1对特异引物,以梨矮化砧木S2叶片总RNA为模板,克隆到1条约1100bp的cDNA片段,将其与pMD18-Tvector连接后转化Escherichia coli JM109,对筛选到的阳性克隆进行序列测定并使用生物信息学方法对所得结果进行综合分析。结果表明,克隆片段为梨PGIP基因,该cDNA编码330个氨基酸,预测分子量为36388ku,第1～24个氨基酸残基是信号肽。与梨属其它种中已获得的PGIP核苷酸序列开放阅读框(Open reading frame,ORF)的同源性为97.5%～99.6%,氨基酸序列的同源性为97.6%～99.1%。     

梨矮化基因pcDw的SSR标记定位

以矮化梨(Pyrus communis L.)与茌梨(P.bretschneideri Rehd.)的F1杂交分离群体共110个单株(3a生,矮化型和正常型各55株)为试材,对来自西洋梨的矮化型突变基因pcDw进行了SSR分子标记研究。用分离群体分组分析法(Bulked Segregant Analysis,BSA),通过对源自梨、苹果和桃基因组的共40对SSR(Simple Sequence Repeat)引物的筛选,获得了一个与pcDw基因连锁距离为9.3cM的SSR标记KA14210,由此将该基因定位到了梨品种Barlett遗传图谱的第16连锁群上。     

山核桃赤霉素氧化酶基因CcGA3ox的克隆和功能分析

[目的]赤霉素3-氧化酶(gibberellin 3-oxidases,GA3ox)是赤霉素(GAs)生物合成途径中关键酶之一,对山核桃(Carya cathayensis)中CcGA3ox基因进行克隆,并进行序列分析和功能验证.[方法]以山核桃体细胞胚为材料,提取RNA,采用PCR扩增技术,克隆山核桃CcGA3ox基...     

Identification of organic acid-related genes and their expression profiles in two pear (Pyrus pyrifolia) cultivars with difference in predominant acid type at fruit ripening stage

‘Yandangxueli’ is a pear cultivar with predominant citric acid in the ripe fruit, different from most of pear cultivars such as ‘Gengtouqing’ in which malic acid is the predominant acid type. It was found that ‘Yandangxueli’ accumulated citric acid for three times against that in ‘Gengtouqing’ at fruit ripening stage. To investigate the mechanism of citric acid accumulation in ‘Yandangxueli’, organic acids content, gene expression and enzyme activity were studied in both cultivars. Five genes, Pp:mtCs, Pp:cyAco, Pp:cyIdh, Pp:mtMdh and Pp:cyMe which encoded citric synthase (CS), cytosolic aconitase (cyACO), NADP-dependent isocitrate dehydrogenase (NADP-IDH), NAD-dependent malate dehydrogenase (NAD-MDH) and NADP-dependent malic enzyme (NADP-ME) respectively, were identified from pear fruit. Their expression profiles and the corresponding enzyme activities were determined throughout fruit development in both cultivars. Results from these enzymes indicated that there were no strict relationship between gene expression, enzyme activity and citric acid accumulation. Expression analysis for two Py:vVAtp genes encoding vacuolar H⁺-ATPase A subunit and one Py:vVpp gene encoding Vacuolar H⁺-pyrophosphatase showed that they were all with up-regulated expression at the later development stage of ‘Yandangxueli’ but with down-regulated expression in ‘Gengtouqing’. Therefore, it is concluded that the different ability in citric acid transportation and storage might be involved in the high citric acid content in ‘Yandangxueli’.     

全基因组基因表达分析技术及其在果树上的应用

基因表达分析对于揭示基因功能、了解基因间相互关系、阐明植物生长发育过程中的生理生化调控机制起着至关重要的作用。综述了mRNA差异显示、cDNA-AFLP、基因芯片、EST数据分析、基因表达系列分析(SAGE)等全基因组基因表达分析技术的原理特点及在果树上的应用情况,并介绍了利用全基因组基因表达分析技术开展果树研究的思路。     

鸭梨多酚氧化酶基因CDS区的克隆及表达

以鸭梨(Pyrus bretschneideri Rehd.)果皮基因组DNA为模板,根据已经发表的多酚氧化酶(polyphenol oxidase,PPO)基因保守序列设计引物,利用PCR技术,克隆得到鸭梨多酚氧化酶编码区序列,将此核酸序列克隆到载体pGEM-T,酶切鉴定后测序,结果表明该段序列含有1782个核苷酸,编码593个氨基酸。对鸭梨多酚氧化酶基因片段的一致性分析和进化树分析表明,该片段与沙梨(Pyrus pyrifolia,AB056680)、苹果(Malus domestica,L29450)、李(Prunuss alicina,AY866432)以及杏(Prunus armeniaca,AF020786)的一致性分别为99%、96.3%、82%和51.4%,绘制的进化树和形态学分类地位相一致。将该片段连接到表达载体pET39b上,获得的重组子命名为pET39b-PPO,热激法转化表达受体大肠杆菌BL21(DE3)菌株,用IPTG进行诱导。SDS-PAGE分析表明,PPO基因在大肠杆菌中被诱导表达蛋白质相对分子质量约66ku,检测表明具有多酚氧化酶的活性。     

杨梅酸性转化酶基因cDNA分离及表达分析

杨梅果实富含蔗糖,酸性转化酶是蔗糖代谢关键酶,根据植物酸性转化酶基因保守区序列设计引物,提取杨梅叶片RNA,逆转录获得cDNA,以此为模板通过PCR技术扩增到长度为516bp的基因片段,克隆入pMD18-T载体中,命名为MrIVR1(GenBank:DQ339699)。测序及同源性检索表明,该基因推导氨基酸序列与君子兰、葡萄、草莓、胡萝卜等酸性转化酶基因氨基酸序列同源性为60%～69%。运用ClustalX软件对植物转化酶基因进行了系统树分析,结果显示,MrIVR1编码的蛋白质属于细胞壁酸性转化酶。半定量RT-PCR表达分析显示,MrIVR1基因在杨梅果实发育早期表达量最高,随着果实的发育表达量下降,在成熟果实中表达水平较低。     

High expression level of TAL1 gene in newly diagnosed acute myeloid leukemia

AIM: To investigate the characteristic of T-cell acute lymphocytic leukemia 1 (TAL1) gene expression in acute myeloid leukemia (AML) cell lines and in primary AML cells from de novo AML patients with different subtypes. METHODS: Real-time PCR was used to determine the expression of TAL1 mRNA in acute leukemia cell lines (Jurkat, CCRF-CEM, HL-60 and NB4 cell lines) and peripheral blood mononuclear cells from 47 newly diagnosed AML patients. Twelve healthy individuals were served as healthy control group. RESULTS: A significantly increased level in TAL1 mRNA was found in AML cell lines (HL-60 and NB4), T-cell acute lymphacytic leukemia (T-ALL) cell lines (Jurkat, CCRF-CEM) and primary AML cells compared with the healthy controls. Over-expression of TAL1 was found in all detected AML subtypes, the highest level of TAL-1 mRNA was found in AML-M1 and AML-M5 subtype (P<0.05). CONCLUSION: High expression of TAL1 in AML might influence the differentiation and proliferation of myeloid cells, further investigation needs to confirm whether it would be as a biomarker for pathogenesis of AML.     

Phylogenetic and expression analysis of the magnesium transporter family in pear,and functional verification of PbrMGT7 in pear pollen

The magnesium ion (Mg²⁺) is the most abundant divalent cation in living cells, and it plays essential roles in various cellular functions. Mg²⁺ homeostasis in plant cells is crucial for plant growth. The MRS2/MGT family of proteins localise to various membranes, and they function during Mg²⁺ transport in plants, but their functions are largely unknown in fruit trees. In this study, we performed a genome-wide analysis to identify the MGT gene family members in the pear Pyrus bretschneideri. Sixteen MGT genes were identified. Analysis of the activity of pear pollen showed that a low-concentration magnesium ion treatment was beneficial for pollen germination and pollen tube growth. None of the 16 MGT genes were expressed in any unique tissue, including pollen, and their expression in magnesium-treated pollen varied greatly, where PbrMGT7 was the most sensitive and it was tested as a representative. PbrMGT7 could functionally complement a bacterial strain deficient in Mg²⁺, thereby indicating a role in magnesium transport. A co-localisation experiment confirmed that PbrMGT7 was localised in the mitochondria, which suggests that PbrMGT7 could mediate Mg-trafficking between the mitochondria and cytosol. Overall, these results suggest that PbrMGT7 is related to Mg²⁺ homeostasis during pear pollen tube growth.??