瓜棉套种棉花黄萎病发生原因及生物防治

棉花黄萎病是棉花生产为害最重的病害之一。在棉花生产上,瓜棉套种棉花由于播种早、前期肥水多,利于棉花黄萎病早发生。棉花生长中期连降暴雨,易造成棉花黄萎病大发生。若用不同药剂组合进行防治,即可控制其为害,促进棉花生长,提高产量。     

Emergence of a new satellite RNA from cucumber mosaic virus isolate P1

INTRODUCTIONCucumbermosaicvirus (CMV) ,thetypespeciesofthegenusCucumovirusoffamilyBro moviridae,isanisometricviruswithatripartitesingle strandedRNAgenomeofpositivepolari ty.CMVhasaparticularlywidehostrange ,in fectingmorethan 80 0speciesinover 70familieso…     

施肥处理对黄瓜营养品质的影响

本试验以露地栽培的黄瓜为试材，探讨了施肥对黄瓜营养品质的影响．结果表明五种施肥处理中最佳施肥处理为半量虫粪(3750Kg／hm2)与50％NPK配施，可显著提高黄瓜中Vc、可溶性糖、可溶性Pr、果胶质含量，降低硝酸盐含量及纤维素含量，从而提高蔬菜营养品质和产量．与单施尿素处理比较，黄瓜中糖酸比增加41．09％，硝酸盐含量降低9％．     

基质栽培荷兰3号黄瓜N、P、K营养特性研究

通过基质栽培试验 ,研究了荷兰 3号黄瓜N、P、K的营养特性。结果表明 :1、在黄瓜的各生长阶段 ,植株中N、P、K的含量范围分别是 4.67～ 6.5 1 %、0 .5 0～ 0 .67%、4.0 1～ 4.91 % ;2、黄瓜自苗期到盛果期 ,植株中N和K的含量逐渐降低 ,P的含量呈倒置的抛物线型变化 ;3、荷兰 3号黄瓜在苗期、挂果期、盛果前期、盛果期 4个生育阶段 ,植株中N、P、K含量比例依次为 :9.7∶1∶7.4、1 1 .2∶1∶8.0、8.4∶1∶7.6、7.7∶1∶6.6;4、荷兰 3号黄瓜果实中N、P、K的含量均要高于其它器官中的含量 ,到生长后期 ,根、叶中的N素向果实中转移 ,叶片中的K则向果实和根系中转移。     

黄瓜青枯病内生拮抗菌株HE-1的初步鉴定及培养优化条件

根据形态和生理生化特征,初步确定了HE-1菌株的分类地位。光学显微镜下观察到菌体为杆状,革兰氏染色阳性,产芽孢。生理生化鉴定结果表明,各项试验均与巨大芽孢杆菌(Bacillus megaterium)的标准菌株结果一致。采用正交试验确定了HE-1菌株的培养基添加成分最优组合为:(NH4)2SO44g/L,K2HPO4 KH2PO4(28 12)g/L,柠檬酸三钠0.5g/L。添加成分最优组合的细菌培养与基础培养基比较,产量增加约68.8%,能极显著地促进HE-1菌株的生长。研究了温度等主要理化因素对HE-1菌株的影响,结果显示,在初始pH7的培养基中,培养温度为35℃、培养时间为36h时,HE-1菌株的生长量和抑菌效果最佳。     

紫色辣椒与黄瓜、芥菜混合泡制中某些品质指标的变化

为了检测紫色辣椒新品种在加工过程中的品质,以绿色辣椒为对照,分别与黄瓜、芥菜等配料进行6个处理组合的泡制试验,测定各处理卤汁的pH值变化及各组份的原花青素、VC、硝酸盐、亚硝酸盐含量.结果表明:各处理卤汁pH先降低后趋向稳定;各组份间原花青素、VC含量达(极)显著差异;硝酸盐含量随泡制时间持续下降,亚硝酸盐先升高,后下降.具有紫色辣椒组份的处理,其pH略大于绿色辣椒;其辣椒、黄瓜及芥菜的原花青素、VC含量都高于绿色辣椒,而硝态氮和亚硝酸盐含量均低于绿色辣椒.具有紫色辣椒组份的处理,其黄瓜或芥菜的营养品质及风味有了一定改善.     

Characterization and RNA2 nucleotide sequence of broad bean wilt virus 2 isolate P158

Broad bean wilt virus 2 (BBWV2) isolate P158 was characterized and the complete nucleotide sequence of viral genomic RNA2 was determined. P158 has 30 nm diameter isometric particles. Double immunodiffusion test suggested that P158 has high antigenicity homology with BBWV2 isolate B935. SDS-PAGE result showed that the coat protein of P158 was comprised of two types of polypeptide with molecular weight of 44.7 kD and 21.9 kD, respectively. The genome of P158 was made up of two RNA molecules with the length of 6.0 kb and 3.6 kb, respectively. cDNA of RNA2 was cloned by RT-PCR and sequenced. RNA2 was composed of 3597 nucleotide (nt) residues excluding the poly(A) tail and contained single long open reading frame extending from nt 230 to nt 3424 in the viral sense RNA, and encoded a polyprotein ofMr 119002 (119K). Comparison of the polyprotein and the counterpart of isolate B935 indicated that the polyprotein was cleaved at Q/G (465/466) and Q/A (867/868), to release three mature proteins: a protein of unknown function, large and small subunit. Sequence comparisons of P158 with fabaviruses showed P158 had very high sequence homology with BBWV2 isolates and patchouli mild mosaic virus, but to a less extent with BBWV1 isolates. Project supported by NSFC (No 39770035; 39900005). The GenBank accession number of the sequence reported in this paper is AF228423.     

设施无公害黄瓜平衡施肥技术方案

通过对黄瓜植物营养特性的分析,结合我们近年来黄瓜平衡施肥试验结果,制订了设施栽培无公害黄瓜平衡施肥技术方案.     

夜温对黄瓜幼苗生长及生理特性的影响

以黄瓜为试验材料,研究了不同夜温对黄瓜幼苗生长及生理特性的影响。结果表明,较高的夜温显著提高黄瓜幼苗的根系活力、叶绿素含量及叶片硝酸还原酶活性,从而促进了黄瓜干物质的积累,有利于黄瓜幼苗的生长发育及壮苗指数增加。     

黄瓜施用沼肥肥效研究

试验结果表明,基施沼渣+化肥可改善黄瓜植物学性状,提高黄瓜的产量,增加瓜农收入,与习惯施肥相比,实现增产7.7%、增值115元/667m2,且可增加土壤有机质含量,提高土壤速效磷、速效钾含量;试验同时表明,黄瓜生长期内喷施沼液能够增强黄瓜抗病虫害能力,不仅可节约农本,而且提高黄瓜的商品率、增强黄瓜食用安全性.