在丝瓜和黄瓜发育过程中肌动蛋白基因的表达

对肌动蛋白基因在丝瓜（Ｌｕｆｆａ ｃｙｌｉｎｄｒｉｃａ Ｌ．）和黄瓜（Ｃｕｃｕｍ ｉｓ ｓａｔｉｖｕｍ Ｌ．）各器官的表达进行了研究．Ｎｏｒｔｈｅｒｎ ｂｌｏｔ和Ｄｏｔｂｌｏｔ结果表明,肌动蛋白基因在丝瓜和黄瓜中表现出器官特异性表达． 首先,肌动蛋白基因在丝瓜幼苗发育过程中表现明显的发育阶段特异性． ３０ ｄ 苗茎的ｍ ＲＮＡ 水平为８ ｄ 苗的根、子叶和１５ ｄ 苗的根、下胚轴的４～６ 倍, 同时为开花植株茎和叶片的ｍ ＲＮＡ 水平的１０～１２ 倍． 其次,肌动蛋白基因在黄瓜中表现器官特异性表达,它们倾向于在黄瓜幼嫩果实中（开花后１５ ｄ）特异表达     

应用斑点法检测植物病毒的研究

应用斑点法检测了病叶粗汁液中的芜菁花叶病毒(TuMV)、大豆花叶病毒(sMV)和黄瓜花叶病毒(CMV),病叶粗汁液可被检测的最大稀释度分别为1:5120、1:2560和1:1280。提纯的大豆花叶病毒和黄瓜花叶病毒可检测的最低限量分别为1.7ng和1.2ng。以牛血清白蛋白、吐温和聚乙烯吡咯啉酮作封闭液,均可获得满意的结果。应用斑点法检测芜菁花叶病毒和大豆花叶病毒时,其抗血清稀释1:500倍可获得满意效果,稀释2000倍仍可用于检测。     

黄瓜不同抗病品种与疫霉菌相互作用的超微结构研究

电镜观察发现,黄瓜（ＣｕｃｕｍｉｓｓａｔｉｖｕｓＬ．）的不同抗病品种在与疫霉菌（ＰｈｙｔｏｐｈｔｈｏｒａｍｅｌｏｎｉｓＫａｔｓｕｒａ）的相互作用过程中有不同的表现。感病性品种易被疫霉菌侵染,被侵染的叶肉组织及周围细胞中胶层解离、胞质凝聚、细胞器解体,叶片组织内有大量胞间及胞内生长菌丝。中抗病性品种也被疫霉菌侵染,但表现出胞间连丝断裂、内质网和高尔基体增多等抗病性反应,与菌丝相接触的细胞出现质膜内陷。抗病性品种出现过敏性坏死反应,叶肉细胞与入侵菌丝一同解体死亡,胞间菌丝向细胞内穿透处形成壁附加物。中抗病性品种和抗病性品种在与疫霉菌的相互作用过程中表现出不同的抗性机制。     

Inhibition of the formation of adventitious roots on cucumber hypocotyls by the fractions and methoxybenzylglutamine from xylem sap of squash root

In studies of the functions of roots in the development of aboveground organs, the butanol fraction of xylem sap collected from squash root was found to have inhibitory activity against the formation of adventitious roots on the hypocotyls of cucumber in a culture of shoot cutting. The inhibitory activity was fractionated with reverse phase column chromatographies, and an inhibitory fraction was recovered with a single peak of absorbance at 280 nm, which contained a novel amino acid,N ⁵-(4-methoxyphenyl) methyl-l-glutamine (methoxybenzylglutamine) as a major component (Inouyeet al. 1998). Chemically synthesized methoxybenzylglutamine (5 mM) inhibited the formation of adventitious roots and also inhibited the growth of first leaf and cotyledons in a culture of shoot cuttings. On the basis of the results obtained, discussed is possible regulation of the developmental events on the aboveground organs by the roots through xylem sap.     

营养膜无土栽培技术的研究

试验研究着重于设备、肥料和配方,产量效益、经济成本等。采用控制和调节pH值、电导度、氧气和设备等措施,使黄瓜亩产量达6861.5公斤;番茄因品种不同而有差异,早丰番茄品种达8361.1公斤。番茄每公斤成本0.29元。植物群体高大,根系发达,结果早,个体大,质量好。证明该技术操作容易,管理简单,产量高,有明显的经济效益。     

樱草花叶病毒的分离与鉴定

樱草(Primula obconica),又称报春花,是早春季节人们喜爱的一种花卉。近年来,患病严重,病株的叶片呈现花叶、畸型、翻卷等症状,影响观赏。关于樱草花叶病毒在国内未见报道。本文简要报道樱草花叶病毒的分离与鉴定(以下简称PMV)。     

The distribution of hydroxyproline-rich glycoprotein mRNAs in shoots of cucumber and pea

The distribution of hydroxyproline-rich glycoprotein (HRGP) mRNAs in the shoots of dark-grown and irradiated cucumber ( Cucumis sativus L. cv. Burpee pickler) and pea ( Pisum sativum L. cv. Alaska) was studied. A cloned genomic DNA fragment encoding carrot ( Daucus carota ) root extensin (pDC5A1) was used to measure HRGP mRNAs from cucumber and pea along the length of dark-grown and irradiated shoots. There was a marked difference in the levels of HRGP mRNAs isolated from apical and basal regions of cucumber. Whereas apical, elongating regions had low levels of HRGP mRNAs, basal regions of the shoot had high levels. Levels of HRGP mRNAs were also compared in shoots of dark-grown and irradiated cucumber. Although light inhibits hypocotyl growth, it had no effect on levels of HRGP mRNAs. There was no gradient in the distribution of HRGP mRNAs along the epicotyl of dark-grown pea. As was the case with cucumber, light did not affect the accumulation of HRGP mRNAs in pea shoots. We conclude that light does not affect elongation by regulating the accumulation of HRGP mRNAs. The gradient of accumulation of HRGP mRNAs along the hypocotyl of cucumber probably reflects differences in cellular differentiation along the shoot.     

Resistance to 2-tridecanone in Tetranychus urticae: effects of induced resistance,cross-resistance and heritability

Earlier studies of resistance to the tomato toxin 2-tridecanone revealedsimilar levels of resistance among tomato and cucumber strains ofTetranychus urticae, whereas we anticipated the tomatostrains to have a higher resistance. Between-strain differences, however, maybeconcealed by toxin accumulation and/or cross-resistance. Mites do accumulate2-tridecanone to a considerable extent, but we have shown before that thiscannot explain the lack of difference in resistance. In this paper, we provideevidence against cross-resistance: selection for resistance to a homologouscompound from cucumber, 2-nonanone, did not confer resistance to 2-tridecanone.Observed increases in resistance levels over generations may be due toinductionor selection. To study induction, adult females from a cucumber strain and atomato strain were exposed to a sublethal dose of 2-tridecanone. One day afterexposure, the cucumber strain gained in resistance to 2-tridecanone (c.8-fold),whereas the tomato strain showed a decrease in resistance. These changes inresistance disappeared within three days after exposure, the time the mitesneedto dispose themselves of the toxin. The results support earlier findings thatresistance is induced in the cucumber strain, but not in the tomato strain. Toassess the heritability of resistance to 2-tridecanone, offspring was obtainedfrom individual females, and both the mothers and their offspring were testedfor resistance. For the cucumber strain, offspring from susceptible orresistantmothers did not differ in resistance. For the tomato strain, however, offspringfrom resistant mothers were significantly more resistant to the toxin thanoffspring from susceptible mothers. This result provides unambiguous evidencethat resistance to 2-tridecanone can be selected for.     

Complex formation of quercetin with lanthanum enhances binding to plant viral satellite double stranded RNA

Due to the broad spectrum of biological activities of flavonoids, their target molecules in the cell are intensively studied. We examined the interactions of the flavonoid quercetin (Q) and its lanthanum complex (QLa³⁺) with very recently isolated plant viral satellite (sat) dsRNA. Comparison of the cumulative binding affinity and the estimated intercalative binding constant pointed towards an additional binding mode of quercetin to exclusively viral dsRNA, which is not recorded for synthetic dsRNAs. The QLa³⁺ showed significantly higher affinity toward viral dsRNA than Q and La³⁺ alone, most likely as the consequence of quercetin intercalation accompanied by additional electrostatic interaction of La³⁺ with the negatively charged viral RNA backbone.     

The major‐effect quantitative trait locus Fnl7.1 encodes a late embryogenesis abundant protein associated with fruit neck length in cucumber

Fruit neck length (FNL) is an important quality trait in cucumber because it directly affects its market value. However, its genetic basis remains largely unknown. We identified a candidate gene for FNL in cucumber using a next‐generation sequencing‐based bulked segregant analysis in F₂ populations, derived from a cross between Jin5‐508 (long necked) and YN (short necked). A quantitative trait locus (QTL) on chromosome 7, Fnl7.1, was identified through a genome‐wide comparison of single nucleotide polymorphisms between long and short FNL F₂ pools, and it was confirmed by traditional QTL mapping in multiple environments. Fine genetic mapping, sequences alignment and gene expression analysis revealed that CsFnl7.1 was the most likely candidate Fnl7.1 locus, which encodes a late embryogenesis abundant protein. The increased expression of CsFnl7.1 in long‐necked Jin5‐508 may be attributed to mutations in the promoter region upstream of the gene body. The function of CsFnl7.1 in FNL control was confirmed by its overexpression in transgenic cucumbers. CsFnl7.1 regulates fruit neck development by modulating cell expansion. Probably, this is achieved through the direct protein–protein interactions between CsFnl7.1 and a dynamin‐related protein CsDRP6 and a germin‐like protein CsGLP1. Geographical distribution differences of the FNL phenotype were found among the different cucumber types. The East Asian and Eurasian cucumber accessions were highly enriched with the long‐necked and short‐necked phenotypes, respectively. A further phylogenetic analysis revealed that the Fnl7.1 locus might have originated from India. Thus, these data support that the CsFnl7.1 has an important role in increasing cucumber FNL.