谷子主要育成品种在新疆的遗传多样性研究

以274份谷子种质资源为材料,利用聚类分析和主成分分析方法,对参试资源16个农艺性状的遗传多样性进行综合评价。结果表明,参试材料的11个数量性状的遗传多样性指数均大于2.000,在新疆表现出广泛的遗传多样性。基于种质资源间形态标记的遗传差异,将274份谷子种质资源聚类并划分为6大类群。第Ⅰ类群(105份材料)生育期较短,属早熟类型,但其他性状表现一般;第Ⅱ类群(19份材料)出苗-抽穗日数最小,全生育期最短,早熟性明显,穗下节间长度相对其他类群较长;第Ⅲ类群(10份材料)生育期较短,主穗长相对较长,其余性状表现均处于较低水平;第Ⅳ类群(58份材料)主穗长、单穗重在各类群中处于较高水平,生育期相对较短;第Ⅴ类群(26份材料)生育期最长,属晚熟类型,除主穗长度最小外其余性状均表现突出;第Ⅵ类群(56份材料)生育期相对较长,属中晚熟类型,株高较低,生物产量处于中等水平。9个数量性状的主成分分析结果表明,前3个主成分因子(单株秆重、株高、主穗直径)累计贡献率达70.41%,各主成分因子性状载荷值反映了育种中各性状的选择方向及潜力。综合评价谷子种质资源农艺性状,为新疆谷子资源收集、评价和利用提供一定的科学依据。     

苦玄参40个株系表型性状遗传多样性分析

植物遗传多样性一直以来是种质资源研究的热点。为揭示苦玄参栽培种质的遗传多样性,该研究从苦玄参常年栽培种中根据形态学性状差异选择40个株系,以产量、药效物质含量及茎、叶、花等形态学性状为指标,进行物种变异和遗传多样性分析,并对其进行聚类分析,获取各株系遗传亲缘关系。结果表明:苦玄参苷IA和IB含量的遗传变异系数较高,分别为24.225%和17.853%;遗传多样性指数高,分别为1.920和2.075。产量遗传变异系数较低,仅为3.637%,但遗传多样性指数较高,达到1.884。其余表型性状指标遗传变异系数均较高,其中花色高达127.794%。数值型性状具有较高的遗传多样性,均大于1,但描述型指标遗传多样性指标较低,均小于1。聚类分析可将供试材料分为4个大的类群:第Ⅰ类群共有7个株系,此类群产量性状及相关指标平均数较高;第Ⅱ类群有8个株系,茎节长度最长,其余指标中等偏下;第Ⅲ类群数量最多,有20个株系,各指标均较低;第Ⅳ类群有5个株系,苦玄参苷含量和产量均较高,综合指标比较优。相关分析结果表明,苦玄参苷IA的含量与叶缘性状具有显著相关,产量性状与茎节长度、一级分枝和末级分枝数具有极显著相关,选择优良种质应注重该4个性状的选择。该研究结果表明目前苦玄参栽培种具有广泛的变异和较高的遗传多样性,为苦玄参资源的利用提供了参考依据。     

江苏省高粱种质资源的收集及多样性分析

2016-2017年"第三次全国农作物种质资源普查与收集行动"江苏调查队收集到江苏41个县市区地方高粱资源104份,并对15个农艺性状进行调查,利用相关系数、聚类分析研究了高粱资源的遗传多样性。结果表明:高粱资源农艺数量性状变异类型丰富。穗粒重与株高、穗长、节数、百粒重、抽穗期、地上部鲜重呈极显著正相关;地上部鲜重与株高、节数、抽穗期呈极显著正相关,与穗柄长呈极显著负相关。聚类分析将该批高粱资源划分为7个类群,第Ⅰ类群为甜高粱品种,是糖用与饲用材料;第Ⅱ类群穗很长,为工艺专用材料;第Ⅲ类群单穗与百粒重较高,是粒用、糖用兼型材料;第Ⅳ类群植株矮,节数少,早熟,是粒用、饲用及工艺用兼型材料;第Ⅴ类群偏野生型材料,可粒用、饲用及工艺用,但产量性状表现较差;第Ⅵ类群株高、穗长、抽穗期、地上部鲜重适中,是粒用、糖用、工艺用及饲用兼型材料;第Ⅶ类群植株矮、百粒重高、裸粒、生育期较早,是粒用材料。综合表型筛选出9份具有优良与特异性状的种质资源。总之,江苏地方高粱资源具有丰富的多样性,蕴藏着较多的可利用遗传变异,在高产、早熟、穗型和籽粒大小等方面存在可供育种和生产利用的优异资源。     

云南红花种质资源主要农艺性状的遗传多样性分析

为加强红花种质资源的研究利用,对筛选出的66份云南红花优异种质资源16个形态性状进行聚类分析与主成分分析。结果表明:云南红花种质资源具有丰富的遗传多样性,多样性指数最高的是果球着粒数,其次是株高、最末分枝高度和千粒重;性状变异系数最大的是分枝总数,其次分别是单株有效果球数和第一分枝高度,最小的为顶果球直径;基于各种质间形态性状的遗传差异,把66份红花种质聚类并划分为6大类群。第Ⅰ类群可作为有增产潜力的亲本材料,第Ⅲ类群可作为高产量目标选育的亲本,第Ⅳ类群可作为大粒型选育亲本,第Ⅴ类群可作为高含油量选育目标亲本,第Ⅵ类群既是大粒型又是高含油量双重选育目标亲本。11个数量性状的主成分分析结果表明,前4个主成分累计贡献率达82.59%,第一主成分反映植株高度,第二主成分反映产量构成因子,第三、第四主成分分别反映千粒重和果球着粒数。研究结果表明云南红花地方种质资源的变异较大,遗传较丰富。     

甘蔗割手密远缘杂交后代产量性状的遗传及分离

利用甘蔗品种Co419与野生种割手密云南75-1-2远缘杂交,ROC25与远缘杂交后代云野02-356进行回交,分别获得F1和BC1群体,利用R软件,分析了两个群体全部真实性后代产量性状的遗传和分离表现.结果表明,杂交后代产量性状的广义遗传力皆较高,BC1群体株高、有效茎和蔗茎产量等性状的广义遗传力较F1群体有增大的趋势;主要性状均表现出明显的正态分布特性,产量因素与甘蔗产量、甘蔗有效茎数与株高表现出明显的正相关;F1株高、有效茎、蔗茎产量和宿根性表现出明显的超亲优势.     

高粱地方种质资源表型多样性分析及综合评价

以“第三次全国农作物种质资源普查与收集行动”为依托,采用遗传多样性分析、相关性分析、聚类分析、主成分分析等方法,对2020-2021年在河北省内普查收集的136份高粱种质资源进行研究及综合评价。结果表明：河北省高粱地方种质资源具有丰富的表型变异,15个表型性状的多样性指数在0.0844～1.9926之间,变异系数在4.69%～68.00%之间,千粒重的遗传多样性最高,穗形的变异系数最大;株高与穗部性状之间存在极显著正相关关系;聚类分析将136份高粱种质资源分为3个类群,3个类群无明显地域聚类特点。第Ⅰ类群在穗部性状方面表现最好,可进行工艺用高粱资源选育;第Ⅱ类群株高较低,可筛选矮秆高粱资源进行种质创新;第Ⅲ类群在产量性状方面表现最好,可作为粒用高粱育种材料加以利用。主成分分析将表型性状简化为5个主成分,累计贡献率为60.182%,株高、穗部与籽粒性状是高粱表型变异的主要因素;136份高粱的综合得分范围在0.107～1.147之间,以综合得分排序,筛选出肃宁高粱、长穗高粱、笤帚高粱、落黍等排名前10的综合性状表现较好的种质资源。本研究从多方面、多角度对新征集的河北省高粱种质资源进行了分析...     

160份外引鹰嘴豆种质主要农艺性状的遗传多样性分析

对引自国际半干旱热带作物研究中心的160份鹰嘴豆种质资源的13个农艺性状进行了评价鉴定,并筛选了特异种质,为我国鹰嘴豆种质资源创新和品种选育提供参考。结果表明,该批鹰嘴豆种质资源具有较为丰富的遗传多样性,7个数量性状的变异系数由大到小分别为主茎分枝数单株荚数百粒重产量株高单荚粒数生育期,6个质量性状的Shannon多样性指数由大到小分别为粒色株型花色种子表面粒形复叶叶型;产量与粒形、单株荚数极显著正相关,与百粒重显著正相关;前4个主成分的累计贡献率为63.417%,其中第1主成分与产量性状和产量有关,第2主成分与生育期有关,第3主成分与形态性状有关,第4主成分与株高和粒形有关;聚类分析在遗传距离为5时将160份资源分为3个类群,其中第Ⅰ类群的株高较高,第Ⅱ类群的产量较高,第Ⅲ类群的籽粒较大;筛选出63份早熟、矮秆、无分枝、多荚、荚粒数多、大粒、高产的特异种质资源。     

陕西太白尾矿区根瘤菌多样性及抗性菌株筛选

以研究陕西太白金矿尾矿区根瘤菌的资源多样性和重金属、苯酚抗逆性菌株的筛选为目的,选取分离自尾矿废弃地及太白河边的8种豆科植物的108株根瘤菌及42株参比菌株,进行了生长温度范围,唯一碳源、氮源利用,生长初始pH,耐盐性,重金属和苯酚的抗性等151项表型性状分析。结果表明,供试根瘤菌的表型特性存在明显差异,在85%的相似水平上供试菌株聚成5个类群,其中类群I有26株菌,主要分离自天蓝苜蓿(Medicago lu-pulina);类群Ⅱ有12株菌,其寄主各不同;类群Ⅲ有3株菌,寄主均为金翼黄芪(Astragalus chrysopterus);类群Ⅳ有40株菌,主要分离自金翼黄芪;类群Ⅴ有4株菌,寄主均为截叶铁扫帚(Lespedeza cuneata)。类群Ⅳ与已知种R.mongolense聚在一起,其这4个类群未与参比菌株聚在一起,可能是新的表观群,其分类地位需进一步确定。一些菌株表现了较强的抗重金属和苯酚毒性的能力,其中1株菌能耐受0.15 mmol/L的Hg2 ,4株菌能耐受0.4mmol/L的Cu2 ,3株菌能耐受1.6 mmol/L的Zn2 ,5株菌能耐受900 mg/L的苯酚。     

玉米种质资源的抗倒伏性评价及鉴定指标筛选

倒伏是影响玉米高产稳产的主要问题之一。本研究以181份玉米自交系为试验材料,对22个与抗倒伏性紧密相关的性状进行测定,采用相关性分析、主成分分析、聚类分析、逐步判别分析和岭回归分析等方法,综合评价玉米自交系的抗倒伏性。相关性分析的结果表明,22个性状间存在不同程度的相关性。主成分分析的结果表明,前7个主成分代表了181份玉米自交系的22个性状74.460%的信息,其贡献率分别为25.700%、12.369%、9.782%、8.159%、7.782%、5.490%和5.177%。聚类分析的结果表明,当遗传距离为3.5时,181份玉米自交系被聚为4大类,第Ⅰ类群有35份自交系、第Ⅱ类群有47份自交系、第Ⅲ类群有49份自交系、第Ⅳ类群有50份自交系。逐步判别分析的结果表明,175份玉米自交系被正确判别,判对概率为96.69%;6份玉米自交系被误判,误判率为3.31%,这说明聚类分析的结果是准确可靠的。进一步利用岭回归方法筛选出半纤维素含量、穿刺强度、第3节间长度、第3节间直径、穗位高和维管束总面积6个性状,建立了可靠的玉米自交系抗倒伏性评价回归模型。在181份玉米自交系中,以AHU24、e220、7026B等35份自交系的抗倒伏能力最强。本研究结果为玉米抗倒伏种质资源的遗传改良和组配抗倒伏杂交种提供借鉴。     

九个甘蔗新品种在桂林地区的适应性观察和评价

为探讨甘蔗新品种在桂林地区的适应性表现,该研究以ROC22为对照,采用大区互比法,对国家甘蔗产业技术体系的9个甘蔗品种进行1年新植2年宿根的区域试验,观察记录出苗率、分蘖率、株高、产量和糖分等14个性状表现,并利用DTOPSIS法进行综合评价。结果表明:桂糖29号、桂糖31号、云蔗03-194、粤糖60号、福农38号和粤糖55号的综合性状表现优于对照ROC22,其中桂糖29号宿根性好、蔗茎产量和产糖量较高,但病虫害有不同程度的发生,田间栽培需加强病虫害防控;桂糖31号有效茎多、蔗糖分高,建议加强肥水管理,提高产量;云蔗03-194出苗率较高,出苗整齐,有效茎数较多,宿根性好,但枯心苗和黑穗病发病程度较其他品种严重,建议加强苗期病虫管理,保障成茎率;粤糖60号蔗糖产量较高、抗倒伏能力强,但新植出苗率较低,建议加大下种量;福农38号蔗糖分较高、抗病性较好,是优异的抗病材料;粤糖55号宿根性较好。上述筛选出的6个甘蔗品种宿根性好、抗逆性强、高产高糖,适宜在桂林地区进行扩大种植,用于指导当地的甘蔗示范推广。     

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.     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.