栽培绿豆V2709抗豆象特性遗传分析

利用原产于印度的抗豆象栽培绿豆品种V2709与农艺性状优良的感豆象推广品种中绿1号(VC1973A)杂交,以杂交种F1、F2为试验材料,通过田间农艺性状调查、室内人工接虫鉴定及多元相关分析等,研究V2709中所包含的抗豆象特性的遗传背景。结果表明V2709的抗豆象特性由一对显性基因控制;通过相关性分析发现其抗虫性与植株高度呈极显著正相关,与主茎节数呈显著正相关,而与其他性状无明显相关性。     

大明绿系选后代遗传多样性与高产特征分析

以内蒙古中东部地区61份绿豆品种大明绿系选后代为研究材料,通过对农艺性状的多样性及通径分析,明确了后代品系遗传类型及高产群体性状特征。结果表明,大明绿后代品系间性状差异显著,单株荚数变异系数最大为31.61%,其次为单株粒重28.05%,遗传多样性较丰富,多样性指数为单株荚数2.02,每荚粒数2.01,百粒重1.89,单株粒重1.96。后代品系主要有6种类型,各性状对单株粒重影响大小依次为:单株荚数>每荚粒数>百粒重>节数>株高。高产类型品系主要特征指标为单株粒重超过15 g,单株荚数超过30荚,每荚粒数8~10粒,株高48~60 cm,节数9~10节,百粒重可根据不同需求制定标准。     

烟草不同基因型耐低氮能力差异评价

以单株叶重及其氮素反应指数作为耐低氮能力的评价指标,分析了烟草种质资源的耐低氮能力以及单株叶重及其氮素反应指数与主要农艺性状间的相关关系。结果表明,不同施氮水平下多数农艺性状基因型间差异较大,在低氮水平下表现最大;和其他农艺性状相比,单株叶重在不同氮素水平间平均差异最大。不同施氮水平下,单株叶重均与最大叶叶面积、单株生物量呈显著或极显著正相关;单株叶重的氮素反应指数与单株叶重、生物量呈显著或极显著正相关,且低氮水平下单株叶重的氮素反应指数与上述性状间的相关性比中氮水平下更为密切。在供试的36个烟草品种中,永定400号、金烟6号、红花大金元、G80、Nc82等烟草种质具有较强的耐低氮能力,可以作为氮高效的烟草品种利用。     

水稻、小麦及高粱改良体细胞无性变异体的田间试验

参与作物组织培养(TCCP)工程的科学家们田间试验鉴定了耐盐水稻、耐盐春小麦、耐酸性春小麦及抗秋粘虫高粱的体细胞无性变异体品系.此外,日本和匈牙利亦田间试验鉴定了具有几种改良农艺性状的组培衍生水稻品系.在菲律宾Pampanga,TCCP研究人员发现,从组织培养物再生的9个水稻品系表现出显著的盐抗性的增强(与非组培物对照相比).其中有8个品系来源于离体筛选的抗盐     

甘蓝型油菜无花瓣矮秆新种质APL03的选育

以正常四瓣双低甘蓝型油菜品系ZH004为母本、无花瓣种质APL01为父本杂交,对无花瓣及矮秆等性状进行多代定向选择,育成APL03新种质。该种质群体无花瓣株率迭100％,单株无花瓣度〉90％,植株高度130—140cm,单株有效角果数〉400个,种子含油率高达43％-47％,兼有抗倒伏、抗耐菌核病等特性,成为培育适于全程机械化作业栽培油菜新品种的基础材料。     

水稻不同基因型耐低氮能力差异评价

以水稻单株谷重及其氮素反应指数作为耐低氮能力指标,分析不同施氮水平下水稻种质资源的耐低氮能力以及单株谷重及其氮素反应指数与其他农艺性状的相关关系。结果表明,水稻种质资源的耐低氮能力在不同施氮水平间均有较大差异,多数农艺性状的表型差异顺序为未施氮〉施低氮〉普通施氮;不同施氮水平间单株谷重、单株草重和穗数的差异大于其他农艺性状。在不同施氮水平下,单株谷重与单株草重均呈极显著正相关;单株谷重的氮素反应指数与单株谷重、单株草重和谷草比均呈极显著正相关。在未施氮水平下,单株谷重与株高、穗数、穗粒数和单株草重的相关性以及单株谷重的氮素反应指数与穗数、单株谷重、单株草重和谷草比的相关性比施低氮或普通施氮水平更为密切。花峰稻、中作9059、旱稻9号、旱稻502和IRAT359等种质资源表现较迟钝的氮素反应,具有较强的耐低氮能力。     

大豆合丰25复合诱变研究

以大豆合丰25为试验材料,经过航天搭载与^60Co-γ辐射的复合诱变处理,对M2代4个株系的主要农艺性状进行研究。结果表明经过复合诱变后大豆群体株高、底荚高度、主茎节数、单株荚数、单株粒数等主要农艺性状发生不同程度的变化,存在着与对照达到显著或极显著的株系;只有1个株系主茎节数存在单株变异率,其它株系主茎节数单株变异不明显;株高、底荚高度、单株荚数、单株粒数等农艺性状均有不同程度的单株变异率,可以为大豆种质创新所利用。     

苦荞种质主要农艺性状的变异及其对单株粒重的贡献研究

对180份苦荞种质资源的8个主要农艺性状进行了评价,并对单株粒重与其他7个农艺性状之间进行了相关性分析和通径分析。结果显示,主要农艺性状的变异系数为8.10%~39.40%;简单相关分析表明,单株粒重与单株粒数、主茎分支数呈极显著正相关;偏相关分析表明,单株粒重与单株粒数、千粒重呈极显著正相关;多元回归和通径分析均表明,单株粒数、千粒重是影响单株粒重的主要因素,其中单株粒数影响最大。系统聚类分析表明,180份苦荞种质资源可划分为5类,其中第Ⅲ类(包括47份供试材料)的综合农艺性状较好,主要表现为主茎分枝能力强、单株粒数多、单株粒重和单株米粒重高,可作为优异基因资源进一步开发利用,也为以增加单株米粒重与出米率为选育目标的苦荞薄壳育种提供依据。     

乌塌菜主要农艺性状的变异、相关性和聚类分析

对63份乌塌菜种质资源的株高、最大展幅、单株叶片数、最大叶片面积、最大叶柄长、最大叶柄宽、单株重、单株叶片重、单株叶柄重、最大叶片长、最大叶片宽等11个主要农艺性状进行了测定、并进行了相关性和聚类分析.结果表明,供试的63份乌塌菜种质资源的11个主要农艺性状具有较丰富的变异潜力,其中单株叶片数、单株叶片重、最大叶片面积、单株叶柄重、最大叶柄长度、单株重、最大叶柄宽度、株高变异较大,最大叶片长、最大叶片宽、最大展幅变异较小.农艺性状间的相关性分析表明,最大叶柄宽度与最大展幅不相关,最大叶柄宽度与最大叶柄长度呈负相关,其余性状间均呈显著或极显著正相关.通过聚类分析,利用类平均法在欧氏距离5.15处,供试材料可分为5个不同的类型,各类型的农艺性状差异明显.     

绿豆抗豆象育种后代F2群体遗传变异分析

选用抗豆象品种(系)VC6089A-6、VC1973A×V2709-2、V2 802,与农艺性状优良的推广品种中绿1号(VC1973A)和中绿2号(VC2917A系选)作亲本, 按照完全双列杂交试验设计,配置杂交组合.对20个杂交组合后代F2群体主要农艺性状及抗虫性分析,发现株高和抗虫性有超亲遗传现象,杂交优势明显;单株荚数普遍低于亲本, 而单荚粒数略高于亲本,百粒重与亲本之间差异不明显.抗虫基因有抗性累加效应,3份抗虫材料的抗虫基因可能不在同一位点上.单株荚数是产量构成的主要因素,且遗传变异程度大与抗虫性相关性不紧密,在后代选择时,应以单株荚数为主攻目标,其次是株高、荚粒数、百粒重和抗虫性.初步认为从P1×P4、P1×P5、P2×P4、P4×P2、P2 ×P5、P5×P2和P5×P3组合后代中选择效果明显.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78?µg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell line.

     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Novel compounds with potent CDK9 inhibitory activity for the treatment of myeloma

Cyclin-dependent kinases (CDKs) and Polo-like kinases (PLKs) play key role in the regulation of the cell cycle. The aim of our study was originally the further development of our recently discovered polo-like kinase 1 (PLK1) inhibitors. A series of new 2,4-disubstituted pyrimidine derivatives were synthesized around the original hit, but their PLK1 inhibitory activity was very poor. However the novel compounds showed nanomolar CDK9 inhibitory activity and very good antiproliferative effect on multiple myeloma cell lines (RPMI-8226).