茉莉酸介导的番茄韧皮部表达谱对根结线虫侵染的响应

为了研究茉莉酸介导的基因对根结线虫侵染的响应,以番茄野生型和茉莉酸缺失突变体为试材,采用数字表达谱技术检测分析根结线虫侵染后主茎韧皮部中的差异表达基因。结果表明,茉莉酸缺失突变体中有2 427个基因差异表达,其中1 390个差异基因可富集到112个KEGG(Kyoto Encyclopedia of Genes and Genomes)通路。18个差异基因涉及茉莉酸合成前体α-亚麻酸代谢,100个差异基因参与植物和病原体的相互作用。     

南方根结线虫在不同茉莉酸含量番茄株系中发育状态观察

【目的】探究内源茉莉酸对番茄中南方根结线虫生长发育的影响。【方法】以番茄野生型株系CM、过量表达前系统素转基因番茄35S∷PS(35S∷prosystemin)和茉莉酸合成缺失突变体spr2为试验材料,采用石蜡切片的方法,观察接种南方根结线虫二龄幼虫(J2)后不同时间各株系内线虫的发育。【结果】接种南方根结线虫J2 5d和7d,CM、35S∷PS和spr2根系中线虫发育无显著差异;接种J2 14d,21d和28d,35S∷PS根系中线虫发育较CM根系中线虫和spr2根系中线虫缓慢。【结论】茉莉酸在一定程度上可以抑制南方根结线虫在番茄中的发育。     

冬暖式大棚黄瓜根结线虫综合防治技术

通过近几年对黄瓜根结线虫病研究分析表明,黄瓜根结线虫病以病苗、病土、浇水、农作器具传播为主,防治可采用嫁接、高温闷棚、轮作换茬等农艺方式和用氰胺化钙,噻唑磷、10%克线磷等化学药剂防治.     

水杨酸和茉莉酸甲酯对试管马铃薯形成的影响

选用马铃薯Mira和N552继代脱毒苗为材料,在人工诱导条件下研究水杨酸 (SA)、茉莉酸甲酯 (MJ)对试管马铃薯形成的作用,结果表明:适宜浓度的SA和JA均能提高微薯的结薯率,其中SA的最佳浓度为10. 0×10-1mol/L,MJ的最佳浓度为 10×10-6 mol/L,但Mira和N552对SA和MJ诱导反应的敏感程度有差异。SA对Mira和N552的单株结薯数影响较小,但对提高两品种的单株结薯重有明显作用。MJ对Mira的单株结薯数和单薯重有显著促进效应,但对N552的作用不显著。与对照比较, SA和MJ处理均导致茎叶和微薯的可溶性糖含量的降低,但对淀粉含量表现为茎叶中的下降,微薯中的上升。     

7种药剂对黄瓜根结线虫的防治效果

7种药剂对黄瓜根结线虫的防治效果试验表明,10％噻唑膦颗粒剂30．0kg／hm^2对黄瓜根结线虫病的防效最好,为83．80％,其余药剂的防效为59．38％～78．33％。供试的7种药剂在试验剂量范围内对黄瓜安全。考虑到10％噻唑膦颗粒剂、15％毒死蜱颗粒剂、1．8％阿维菌素乳油及15％阿维·毒乳油属中低毒产品,在蔬菜上使用较为安全,建议在生产中推广应用。     

枯萎病菌和根结线虫对黄瓜复合侵染研究

黄瓜枯萎病和根结线虫病是三明地区黄瓜的2种重要病害，经鉴定黄瓜枯萎病的病原为尖镰孢（Fusarium axysporum)，黄瓜根结线虫的种类有南6方根结线虫（Meloiddogyne indcoginta)、爪哇根结线虫（M.jauanica)、花生根结线虫（M.arenaria)，接种试验证实尖镰孢和南方根结线虫在黄瓜上能复合侵染，引起重大损失。     

根结线虫对日光温室黄瓜微量元素含量的影响

对感染根结线虫的黄瓜根、茎、叶各器官中微量元素含量进行了测定。结果表明,叶片中铁、锌含量降低,而锰、铜含量先降低后升高,茎中4种元素含量基本都下降,从而造成了叶片黄化、植株生长缓慢和早衰;根系中锰、铜含量升高阻碍了根系的生长,锌在前期的升高有利于根结线虫的侵入,后期降低则限制了根系的伸长,铁的含量在根结线虫密度低时有一定程度的升高,在线虫密度高时降低。     

杨凌地区黄瓜根结线虫种类鉴定

明确杨凌地区黄瓜根结线虫的种类,为有效防治奠定基础,本试验采用传统形态学鉴定方法,对采自杨凌地区东魏店、西魏店、南庄村以及殿背湾露天与大棚黄瓜地的根结线虫样本进行了分离鉴定。结果表明,杨凌地区危害黄瓜的根结线虫为南方根结线虫(Meloidogyne incognita Chitwood)。     

黄瓜品种资源商品性的评价

试验选用28份黄瓜品种资源,严格按黄瓜无公害生产技术规程生产,研究不同的黄瓜品种资源商品性的差异。结合联合国/欧洲经济委员会品质标准、中华人民共和国国家标准及黄瓜育种指标,确定了不同类型黄瓜品种资源商品性标准,并以此标准对黄瓜品种资源的商品性进行评价。确定评价华北型黄瓜等级的主要指标为:果实的弯度、果实长度的标准差、单瓜重的标准差、瓜把与瓜长的比值;评价华南型黄瓜等级的主要指标为:果实的弯度、果实长度的标准差、单瓜重的标准差、果实顶部粗与中部粗的比值。确定不同类型黄瓜等级评价标准。不同黄瓜品种商品率、商品产量存在显著差异。筛选出商品率、商品产量较高的材料8份,即Z9(拉迪特)、Z6(C03-74)、Z8(649)、Z27(631)、Z26(C03-75)、Z28(京乐5号)、Z16(C03-77)、Z12(D2002-1),其中Z9(拉迪特)商品性最好,标准瓜率91%,特级和一级瓜占标准瓜99%,公顷产量26 668 kg。     

黄瓜T-DNA插入突变体库的构建

[目的]为了进一步研究黄瓜基因的功能,本文构建了黄瓜T-DNA插入突变体库。[方法]以黄瓜栽培品种‘长春密刺’子叶节为转化外植体,通过农杆菌介导的遗传转化方法,将T-DNA插入突变载体pROK2后转化黄瓜;通过筛选压力梯度试验,确定遗传转化体系最适合的卡那霉素(Kan)筛选浓度;使用PCR检测和斑点杂交方法鉴定T0和T1代转化植株;以‘长春密刺’植株为对照,统计T1代植株表型。[结果]确定100 mg·L-1为最适合的Kan抗性芽筛选浓度。T0代植株PCR检测结果初步证明,pROK2成功整合到14S1和14S2两个T0代株系基因组中。14S1自交后获得55个T1代单株,对其进行PCR检测,发现其中12个单株均扩增出了35S和NPT-Ⅱ片段。以Dig标记的35S和NPT-Ⅱ为探针,对这12个单株及随机从剩余T1代中选取的11个单株进行斑点杂交检测,得到了2个含有35S和NPT-Ⅱ杂交信号的单株:14S1-27和14S1-34。性状调查统计显示:T1代植株在生长各阶段相对于野生型无明显突变表型。[结论]pROK2重组质粒成功整合到了14S1株系的基因组中。对14S1自交后代的PCR检测和斑点杂交检测结果进一步证明了14S1为转化植株,确定14S1为插入突变体。结合T-DNA插入位点鉴定技术可进一步开展相关基因分离及功能研究工作。     

Allelochemical p-hydroxybenzoic acid inhibits root growth via regulating ROS accumulation in cucumber(Cucumis sativus L.)

Allelopathy is prevalent in agricultural ecosystems and mediated by plant-derived secondary metabolites(allelochemicals). Allelochemicals are released by donor plants and affect the root growth and development of receptor plants. Allelopathy is responsible for the continuous cropping obstacles in cucumber(Cucumis sativus L.). p-Hydroxybenzoic acid(pHBA), an autotoxin from root exudates of cucumber, has been proposed to be an important allelopathic chemical. However, the molecular mechanism by which pHBA affect root growth and development in cucumber is unknown. Here, we found that pHBA treatment suppressed root growth of cucumber by reducing the meristem activity and cell length. This root growth defect is caused by reduced reactive oxygen species(ROS) accumulation in root tips. After pHBA treatment, the expression levels of several ROS-scavenging-related genes were increased, including peroxidase(POD), catalase(CAT) and metallothionein(MT). Moreover, exogenously application of salicylhydroxamate(SHAM), a peroxidase inhibitor, can partially restore the pHBA treatment induced root growth inhibition. Furthermore, we found that there is natural variation for the inhibitory effect of pHBA on root growth. We also showed that pHBA treatment could maintain higher level of ROS accumulated in the pHBA less sensitive cucumber than that in the pHBA-sensitive cucumber. These results suggest that pHBA inhibits root growth by reducing root tip ROS level in cucumber.     

Current status of genetic transformation technology developed in cucumber(Cucumis sativus L.)

Genetic transformation is an important technique for functional genomics study and genetic improvement of plants. Until now, Agrobacterium-mediated transformation methods using cotyledon as explants has been the major approach for cucumber, and its frequency has been up to 23%. For example, significantly enhancement of the transformation efficiency of this plant species was achieved from the cotyledon explants of the cultivar Poinsett 76 infected by Agrobacterium strains EHA105 with efficient positive selection system in lots of experiments. This review is to summarize some key factors influencing cucumber regeneration and genetic transformation, including target genes, selection systems and the ways of transgene introduction, and then to put forward some strategies for the increasing of cucumber transformation efficiency. In the future, it is high possible for cucumber to be potential bioreactor to produce vaccine and biomaterials for human beings.     

Current status of genetic transformation technology developed in cucumber (Cucumis sativus L.)

Genetic transformation is an important technique for functional genomics study and genetic improvement of plants. Until now, Agrobacterium-mediated transformation methods using cotyledon as explants has been the major approach for cucumber, and its frequency has been up to 23%. For example, significantly enhancement of the transformation efficiency of this plant species was achieved from the cotyledon explants of the cultivar Poinsett 76 infected by Agrobacterium strains EHA105 with efficient positive selection system in lots of experiments. This review is to summarize some key factors influencing cucumber regeneration and genetic transformation, including target genes, selection systems and the ways of transgene introduction, and then to put forward some strategies for the increasing of cucumber transformation efficiency. In the future, it is high possible for cucumber to be potential bioreactor to produce vaccine and biomaterials for human beings.     

利用胚培养诱导单性结实黄瓜果实形成单倍体植株的研究

以强单性结实黄瓜EC1(全雌)、L8(雌雄同株)以及L8与强非单性结实黄瓜6429(自交系)的F2为材料,取其单性结实果实中的种胚进行胚培养.在EC1、L8以及F2(L8×6429)中共产生了34株再生植株,经倍性鉴定是单倍体.研究发现:果实生长时间、植株单性结实座果率对果实形成种子及诱导胚成苗均有影响,并且培养基中高浓度的6-苄基腺嘌呤(6-BA)对诱导胚产生单倍体植株具有较好的效果.     

农杆菌介导黄瓜Tril基因转化及体系优化

采用农杆菌介导法将黄瓜表皮毛基因Tril转入黄瓜‘新泰密刺’品种,并研究了6-苄氨基腺嘌呤(6-BA)和卡那霉素(Kan)分别对再生和转化苗筛选效果的影响。结果表明,在黄瓜‘新泰密刺’转化中,Kan抗性苗出芽率为9.67%,生根率为3.67%,转化株阳性率为0.33%;分化培养基中6-BA适宜浓度为0.5 mg/L,出芽率最高(76.33%),平均出芽天数最短(19.66 d);生根培养基中Kan浓度为60 mg/L时筛选效果最好。3种筛选方式的研究表明,仅在生根培养基中添加Kan(60 mg/L)筛选,其转化周期最短(45 d),阳性率最高(达4.0%)。     

植物激素和多胺与黄瓜性别逆转的关系

用硝酸银和乙烯利分别处理黄瓜雌性系和强雄性系幼苗,可在一定节位上发生性别逆转.在雌性转雄过程中,茎尖赤霉素(GA3)、腐胺(Put)和可溶性蛋白质(SP)含量升高,而生长素(IAA)、细胞分裂素(ZT)和亚精胺(Spd)含量则下降.与此相反,在雄性转雌过程中,茎尖赤霉素、腐胺和可溶性蛋白质含量下降,而生长素、细胞分裂素和亚精胺含量升高.脱落酸、精胺和尸胺在黄瓜雌雄性别逆转过程中则表现为无规律的变化.     

盐胁迫对不同基因型黄瓜幼苗生长的影响

采用营养液水培,以黄瓜品种长春密刺和津春2号为试验材料,研究了不同浓度(0 mmol/L、25mmol/L、50 mmol/L、75 mmol/L、100 mmol/L)NaC l处理对黄瓜幼苗植株生长、叶片萎蔫指数、盐害指数和幼苗存活株率的影响。结果表明,在盐胁迫下,两品种株高、茎粗、叶片数和功能叶面积均明显低于对照;高浓度(75mmol/L、100 mmol/L)NaC l处理下,两品种叶片的盐害指数和萎蔫指数均升高,幼苗存活率下降,在同等盐胁迫条件下,津春2号各项指标的变化幅度明显大于长春密刺,植株受到的伤害更明显,表明津春2号对盐胁迫更敏感,长春密刺耐盐性相对较强。25 mmol/L NaC l处理下,植株生物量变化不显著,而NaC l浓度继续升高时,生物量急剧下降,表明25 mmol/L是本试验条件下黄瓜盐伤害的参考临界点,而100 mmol/L则达到了黄瓜幼苗生长的极限盐浓度。     

甜瓜属野生种及其与黄瓜种间杂交后代抗根结线虫初步研究

为了鉴定甜瓜属野生种酸黄瓜 (CucumishystrixChakr.)对南方根结线虫 [Meloidogyneincognit(Kofoid&White)Chit wood]的抗性 ,进而评估抗性向酸黄瓜与栽培黄瓜种间杂种的转移 ,选用了酸黄瓜、 4个栽培黄瓜材料、两种倍性水平的 3个正反交杂种F1和 1个回交后代作为试材 ,在温室中进行抗性鉴定和筛选。结果表明 ,酸黄瓜对南方根结线虫具有高度抗性 ,而 4个栽培黄瓜材料均为高度敏感。酸黄瓜平均每株根系形成约 3个根结 ,栽培黄瓜材料每株根系的根结数超过 10 0个。酸黄瓜通过与栽培黄瓜的正反交 ,其抗性已被部分转移到杂种之中。当杂种作为供体亲本与栽培黄瓜进行回交时 ,抗性又被进一步转移到回交一代 (BCF1)中