中国普通小麦主要品种的变种及其演变的分析

中国种植的小麦以普通小麦为绝大多数。目前中国的普通小麦种质资源共39000多份,分属129个变种。其中编入《中国小麦品种志》的主要品种为1461个,它们分属于55个变种,而主要变种有7个即长芒、颖无毛、白壳、红粒,长芒、颖无毛、白壳、白粒,长芒、颖无毛、红壳、红粒,长芒、颖无毛、红壳、白粒,无芒、颖无毛、白壳、红粒,无芒、颖无毛、白壳、白粒,无芒、颖无毛、红壳、白粒,无芒、颖无毛、红壳、红粒,属于这7个变种的品种1271个,占总数的87％。随着年代的推移,主要品种的变种数呈减少的趋势;7个主要变种各自所包括的品种数有增有减,麦区的分布也明显不同。这些变化是自然和人工选择及新品种选育的结果。     

黑粒青稞HvtUF3GT基因的克隆与表达分析

该研究以黑粒青稞品种‘黑老鸦’籽粒为材料,克隆了青稞类黄酮3-O-葡萄糖基转移酶基因(HvtUF3GT),获得1 449 bp序列。HvtUF3GT基因包含一个1 434 bp开放阅读框,编码478个氨基酸,理论等电点为5.45,预测蛋白分子量为52 912.58 Da。蛋白质序列分析表明,HvtUF3GT为亲水性的不稳定酸性蛋白,且在C-末端具有一段典型的44个氨基酸PSPG box,在空间结构中含有β-α-β-α-βRossmann折叠结构,属于UDP糖基转移酶基因GT-B型超家族成员。进化树分析表明,HvtUF3GT与小麦族的大麦、乌拉尔图小麦、山羊草和二穗短柄草的糖基转移酶聚为一个分支,且与大麦的亲缘关系最近,与稻族的籼稻和短花稻的亲缘关系较远。半定量和定量PCR结果表明,在‘INB0N-7’蓝粒青稞和‘昆仑12号’白粒青稞的籽粒灌浆后期HvtUF3GT基因不表达,而在黑粒青稞和紫粒青稞中的表达强弱依次为‘黑老鸦’(黑粒)‘昆仑17号’(黑粒)‘达章紫’(紫粒)‘涅如姆扎’(紫粒)。研究推测,HvtUF3GT基因在青稞灌浆后期籽粒着色过程中发挥着重要作用。     

川东南杂交中稻超稀栽培对稻米整精米率和垩白粒率的影响

以‘II优7号’、‘汕优63’和‘香优2号’为材料,研究了超稀栽培与稻米整精米率和垩白粒率的关系及其作用原因,结果表明：栽秧密度与整精米率呈极显著负相关,与垩白粒率呈极显著正相关。在中高氮施肥水平条件下,当栽秧密度超稀到7.51万穴•hm-2时,在保证比传统高产栽培密度每公顷栽秧21.64万穴的对照不减产前提下,整精米率提高了15.69%～29.92%,垩白粒率降低了16.34%～21.22%。其原因在于,超稀植增加了每穗着粒数,降低了齐穗期的叶粒比,以致稻穗籽粒灌浆速率减慢而改善整精米率和垩白粒率。齐穗后20 d施氮可同时起到提高结实率和整精米率的双重效果。     

冬小麦穗发芽抗性及其遗传研究

1987—1989年在人工模拟降雨室对123个小麦品种进行了成熟期穗发芽抗性鉴定。重点研究了13个品种的穗发芽率、籽粒发芽率、籽粒含水量,籽粒吸水速率和α-淀粉酶活性的动态变化。并通过6个抗性不同品种的双列杂交,初步探讨了穗发芽抗性的遗传特点。结果表明:红粒品种普遍抗穗发芽,但白粒品种中也存在不少抗源;开花后35—40天是鉴定穗发芽抗性的适宜时期;这个对期的仔粒吸水速率阳α-淀汾酶活性是抗性鉴定的可靠指标;穗发芽抗性是遗传性状,存在母、子体抗性因子互作效应。     

不同品种亚麻籽粒中主要脂肪酸含量的变化

不同亚麻品种‘陇亚7号’、‘82（50）’、‘匈牙利3号’和‘范昵’籽粒中亚麻酸含量最高,其次是油酸、亚油酸和硬脂酸,棕榈酸含量最低。棕榈酸和亚油酸在籽粒发育成熟的初期增长速度较快,含量较高,但随着籽粒逐渐发育成熟而下降,硬脂酸也如此,后者下降幅度较小。油酸和亚麻酸含量随着籽粒发育成熟进程而渐增,油酸含量增加幅度较小。不同品种的籽粒完全成熟时,棕榈酸、硬脂酸、亚油酸和亚麻酸含量有异,同一基因型的亚麻籽粒完全成熟时,开花晚的油酸含量较低,而亚麻酸含量较高。     

黑色食品新秀—乌麦

河东乌麦是山西省农业科学院棉花研究所1995年选育而成的冬小麦新品种。该品种粒质有硬质和软质型,长势长相近似普通小麦,有奇特的功能叶片,分染力强,成穗率高,根系发达,适应性广,颖壳白,籽粒呈黑色。河东乌麦的蛋白质和氨基酸含量均高于白粒小麦。据山西省粮油研究所测定结果：乌麦蛋白质高于白粒小麦（晋麦ZI号）193％,18种氨基酸均值高于白粒小麦32,94％,其中8种必需氨基酸均值高于白粒小麦38．2％,5种半必需氨基酸均值高于白粒小麦20．1％,4种非必需氨基酸高于白粒小麦380％O／J‘麦的营养品质主要是指蛋白质含量和氨基…     

宁夏富铁水稻种质资源筛选及籽粒铁的质量分数与粒形相关性分析

测定102份宁夏水稻种质资源（23份宁夏本地品种和79份外引品种）籽粒铁的质量分数,分析不同品种籽粒铁的质量分数间的差异及其与粒形性状的相关性,并对水稻籽粒铁的质量分数进行遗传分析。结果表明,宁夏水稻种质资源籽粒铁的质量分数为7.75～80.93 mg/kg,平均值为15.25 mg/kg,标准差为8.34,变异系数为54.69%。鉴定筛选出矮血糯、宁农黑粳和长粒5号3个富铁水稻种质资源;水稻籽粒铁的质量分数与粒长呈极显著正相关,与粒厚呈极显著负相关,与长宽比呈显著正相关,而与粒宽和千粒质量的相关性不显著。对宁农黑粳/京香1号杂交组合的292个F₂单株籽粒铁的质量分数进行频率分析,发现其籽粒铁的质量分数整体分布呈趋于单峰的偏正态分布,说明水稻籽粒铁的质量分数是受多基因控制的数量性状遗传。     

一种小麦蓝粒标记单体代换系4E（3D）的创制

以中国春3D单体和小麦-长穗偃麦草4E二体异附加系为材料,通过杂交、回交结合染色体鉴定等方法,培育出了一种具有蓝粒标记的小麦4E(3D)单体代换系.该小麦4E(3D)单体代换系籽粒为浅蓝色,能够正常生长,自交结实率为36.1%,其自交后代可分离出深蓝籽粒小麦4E(3D)二体代换系、浅蓝籽粒小麦4E(3D)单体代换系和白粒小麦3D缺体.结果表明,长穗偃麦草4E染色体对小麦3D染色体缺失有一定的补偿功能,对以染色体定向代换方式快速创制蓝粒标记小麦单体系统具有一定的参考价值.     

外源DNA直接导入小麦及其在育种上的应用

本研究选用两个白粒小麦品种作供体,提取其总ＤＮＡ,采用花粉管直接携带法导入７５（１９８）红粒品种受体植株。ＤＮＡ导入的第一代（Ｄ１）,目的性状的转化频率为１．７５％和２．９４％。Ｄ２代变异率显著低于Ｄ１代。对Ｄ１,Ｄ２代所得目的性状变异后代,按照常规育种程序进行Ｄ３代观察与鉴定,得到已稳定遗传的后代,从中选取保持原品种其它优良性状而籽粒为的白色的变异类型混合脱粒,获得７５（１９８）改良新品系。     

遗传学第一、第二规律的新实验材料——紫冠非甜质和非紫冠甜质玉米

遗传学第一、第二规律的实验材料,除经典的豌豆之外还有黄粒非甜质×白粒甜质玉米。而玉米的黄粒和白粒虽属质量性状,由于受基因剂量效应的影响,黄白杂交后黄粒的胚乳颜色较浅,呈现黄白色。黄白色与白粒差异不显著;特别是甜质型籽粒成熟皱缩后更不易区分,这就给统计粒数时造成困难,不利于理解掌握遗传学第一、二规律。     

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.