仁果类果树资源育种研究进展Ⅰ:我国梨种质资源、品质发育及遗传育种研究进展

梨是我国落叶果树的第二大树种。近几年来,在梨种质资源评价挖掘、性状遗传发育机理以及特色多样化品种培育等方面取得了诸多重要进展,主要研究结果如下:(1)中国原产的东方梨有13个种,其中基本种只有中国豆梨、台湾豆梨、川梨、砂梨和秋子梨等5个种,而白梨、麻梨和褐梨等3个种系杂种起源,不属于基本种;(2)我国优质早熟梨新品种选育研究取得了突破性进展,成就斐然,早、中、晚熟梨的比例已由1994年的7∶23∶70调整到2006年的20∶28∶52,近10年育成的早熟品种比例接近50%;(3)新疆库尔勒香梨优质、耐贮的特性遗传能力很强,是梨品质育种不可或缺的珍贵种质,而复杂的遗传背景和丰富的遗传多样性是亲本选择进行梨品质育种的关键;(4)优质耐贮极晚熟梨品种的选育与推广,是满足优质大梨市场周年供应、提振消费者消费信心、撬动我国梨产业高效发展的关键。针对目前的研究现状,今后应在如下两个研究领域下功夫,一是进一步加强优质耐贮极晚熟梨新品种的选育,构建以优质耐贮极晚熟梨新品种为主,优质早、中晚熟品种配套的品种结构,以满足市场的多样化及周年供应需求;二是利用现代分子生物学技术,从转录、翻译及修饰等多个层面进一步探讨品质性状发育机理,为梨品质育种提供理论支撑。     

关于小麦早熟育种的几个问题

在毛主席的无产阶级革命路线指引下,我所职工坚持科研为无产阶级政治服务、为社会主义农业生产服务的方向,积极开展小麦早熟育种工作。建国以来,先后育成了华东6号、矮秆早等早熟小麦品种,在淮南稻麦地区种植推广,在生产上起了一定的作用。     

梨种质对梨火疫病的抗性研究

针对未来梨火疫病侵入我国的风险,采用幼果人工接种鉴定技术,对保存的54份梨种质资源进行梨火疫病抗性评价。通过接种后的症状鉴别、再分离细菌的分子检测,证明有16份种质对梨火疫病表现感病,其中9份为中国种质,7份为引进种质。中国的37份（80．4％）梨种质表现抗梨火疫病,而引进种质中表现抗病的仅有1份（12．5％）。结果初步表明,在中国梨种质中可能存在较丰富的抗梨火疫病资源;东方梨的抗性较西方梨更强;而在梨的地方品种中蕴藏着良好的抗病性。     

台湾早熟蜜桃优良芽变新种质'五月红'的鉴定

桃是我国重要的果树种类,分布十分广泛,在水果生产中排第四位,但适合南方栽培的品种却稀少。该研究通过资源调查在广西大学标本园内的一棵台湾早熟蜜桃大枝上发现一个芽变新种质,命名为‘五月红'',并进一步对其主要生物学特性、植物学性状以及果实经济性状等进行观测分析,同时还通过SRAP分子标记检测与母株台湾早熟蜜桃的差异性。结果表明:‘五月红''芽变新种质成熟期比台湾早熟蜜桃提前20 d左右,5月上中旬成熟,果变大,核变小,可食率提高,且颜色均匀,可溶性固形物含量显著提高,保持了台湾早熟蜜桃需冷量低、品质优良和风味极佳的优点,属于特早熟优质种质资源; 通过琼脂糖电泳检测SRAP扩增组合引物me9/em5在‘五月红''DNA样品中能够扩增到1 200 bp大小的特异性条带,表明‘五月红''在DNA遗传水平上与母株台湾早熟蜜桃发生了变异,属于新的特早熟种质资源。‘五月红''芽变新种质的发现将为选育适合南方栽培的特早熟桃品种提供重要材料,有助于优化不同熟期品种的栽培结构,进而促进南方桃种植产业经济效益的提高。     

早熟甘蓝型油菜研究进展及其应用北大核心CSCD

随着油-稻-稻三熟制种植模式的推进和油菜机械化生产的要求,早熟性状已经成为油菜理论研究和品种选育的关键性状。本文从油菜早熟性状的理论研究、品种选育以及生产应用的层面开展了综合论述。首先介绍了早熟油菜的界定标准及其生长特性和选择依据。随后从早熟性状的遗传特性、早熟基因的定位等层面介绍了早熟性状的理论研究现状。在品种选育和应用层面,从早熟品种选育的必要性、早熟品种的选育途径、育种现状以及早熟油菜品种生产应用现状和前景等方面开展了论述。最后针对油菜早熟性方面存在的问题和对策作了简要概述。本文将为我国早熟油菜种质创新和品种选育提供参考。     

豇豆优异种质综合评价

摘要 以60份具有早熟、矮秆、多荚、大粒、抗逆、抗病虫、高蛋白性状的优异种质为材料,在河北、河南与安徽进行多点农艺性状综合评价,评选出48份优异种质,其中34个品种达到一级优异种质标准.这些优异种质已结合鉴定繁种入国家中期库,以备科研与生产利用.     

早熟甘蓝型油菜研究进展及其应用

随着油-稻-稻三熟制种植模式的推进和油菜机械化生产的要求,早熟性状已经成为油菜理论研究和品种选育的关键性状。本文从油菜早熟性状的理论研究、品种选育以及生产应用的层面开展了综合论述。首先介绍了早熟油菜的界定标准及其生长特性和选择依据。随后从早熟性状的遗传特性、早熟基因的定位等层面介绍了早熟性状的理论研究现状。在品种选育和应用层面,从早熟品种选育的必要性、早熟品种的选育途径、育种现状以及早熟油菜品种生产应用现状和前景等方面开展了论述。最后针对油菜早熟性方面存在的问题和对策作了简要概述。本文将为我国早熟油菜种质创新和品种选育提供参考。     

早熟桃最佳采收期的多目标决策模型研究

本文在拟合出早熟桃品种早花露品质诸项指标变化曲线的基础上，结合市场价格变化，以经济效益作为目标函数，建立了适时采收的多目标决策模型，并由此求出该品种在合肥地区最佳采收期是5月24日，为早熟桃生产取得最佳经济效益提供理论指导.     

豇豆优异种质综合评价

以60份具有早熟、矮秆、多荚、大粒、抗逆、抗病虫、高蛋白性状的优异种质为材料,在河北、河南与安徽进行多点农艺性状综合评价,评选出48份优异种质,其中34个品种达到一级优异种质标准。这些优异种质已结合鉴定繁种入国家中期库,以备科研与生产利用。     

贵州地方梨种质果实品质性状多样性分析

为探讨贵州地方梨(Pyrus spp.)资源的遗传多样性,对贵州34份梨典型资源的12个果实品质性状指标进行分析。结果表明:除可食率外,地方梨种质资源间的果实品质性状指标均存在极显著差异,表明贵州的梨种质资源具有丰富的遗传多样性。主成分分析结果表明,前5个主成分的累积贡献率可达到85.52%,表明各性状的贡献率较分散,累积贡献率增长不明显,同时也表明贵州梨资源果实的品质性状变异存在多向性。Q型聚类分析结果表明,海子梨-3和葫芦梨各自聚为一类,显示出它们果实品质上的独特性。这些为贵州梨种质资源的开发利用和品种选育奠定了基础。     

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.