温度对双低两用核不育水稻96-5-2S与培矮64S育性的影响

在自然变温、人工控温及冷水灌溉条件下,比较研究了温度对双低两用核不育水稻96－5－2S与两用核不育水稻培矮64S育性影响的差异。结果表明：（1）当它们在雄性育性转换温敏感期1－12d平均自然日均温23.0-23.8℃的低温时,96－5－2S表现不良,套袋自交结实率为0,而培矮46S可育,套袋自交结实率为0．1％－4．5％;（2）在它们雄性育性转换温敏感期用22℃恒温处理5d,96－5－2S败育彻底,套袋自交结实率为0,而培矮64S可育,套袋自交结实率为10．7％;用17℃恒温处理6d,96－5－2S与培矮64S均可育,但96－5－2S套袋自交结实率（6．8％）显著高于培矮64S（2．5％）;（3）在它们雄性育性转换温和不同温度的冷水串灌15d,水深维持在20cm左右,当水温为22－22．5℃时,96－5－2S不育,结实率为0,而培矮64S可育,结实率为18．5％;当水温为19．5－21．5℃时,96－5－2S与培矮64S均可育,但96－5－2S结实率（2．5％－45．1％）显著或极显著低于培矮64S（50．4％－56．9％）以上结果说明：导致双低两用核不育水稻96－5－2S雄性不育的起点温度与导致其生理不育的下限温度均低,其不育性比培矮64S更稳定,耐寒性比培矮64S更强,即可确保制种安全,又可确保自身繁殖,对加快两系法杂交水稻的发展步伐将起到重要的促进作用。     

增大农垦58s小穗育性对光周期条件响应强度的尝试

光敏核不育水稻农垦５８ｓ在１５ｈ长日照下小穗完全不育,在１０ｈ短日照,日平均气温２８．４℃或２３．５℃下自交结实的小穗只有６％￣１３％,以小穗育性对光周条件响应较强为指标做选择,所得农垦５８ｓ－０１在ＬＤ下小穗仍然完全不育,在ＳＤ的ＬＴ乃至ＨＴ下,平均自交结实率超过３５％,对光周期的响应增大两倍多。     

温室冬繁水稻低温敏核不育系原种方法的初步研究

１９９５年１—５月,在广州利用玻璃温室加温冬繁籼型水稻低温敏核不育系培矮６４ｓ和ＧＤ－２ｓ原种．当不育系进入育性转换敏感期时,温室室温调控至日均温约２３℃,检查花粉育性和自然结实率,结果表明,培矮６４ｓ的结实率为５０．７％,单株产量平均为３．５ｇ．培矮６４ｓ原种温室冬繁的成功,为现有种量少、繁种难、提纯复壮株严格的低温敏核不育系加速世代扩大繁殖系数提供了一种可靠的途径．     

温光条件对水稻安农S—1,衡农S—1的育性及生理的影响

研究了不同温、光条件下安农Ｓ－１和衡农Ｓ－１的育性变化,以及颖花和花药中ＡＴＰ含量和呼吸速率的变化。结果表明,在光照期温度３１℃／２８℃高温条件下,每日以１０－１３．５ｈ等各种光照长度处理,安农Ｓ－１和衡农Ｓ－１都表现为雄性不育,而在２４℃／２２℃的低温条件下,各种光照长度处理均为可育,证明了这类不育系为温敏不育系。并在花粉母细胞形成期和减数分裂期对温度最为敏感。在高温条件下,这两个时期颖花和花药     

高温敏感不育水稻育性敏感期幼穗和叶片中的总RNA含量变化

在育性敏感的两个时期－花粉母细胞形成期和花粉母细胞减数分裂期,１３５６Ｓ和衡农Ｓ－２不育株幼的总ＲＮＡ含量极显著低于可育株,分别是可育株的４２．３％,４６．５％,４１．８％和４０．１％,这必然影响花粉母细胞形成及分裂所必需的蛋白质的合成,以致花粉不能正常发育,最终导致花粉败育。     

新型化学杂交剂GENESIS诱导小麦雄性不育的初步研究

ＧＥＮＥＳＩＳ是美国Ｍｏｎｓａｎｔｏ农业化学公司研制的一种新型小麦化学杂交剂。试验专门对其杀效果进行了初步研究。结果表明：以试的５个品种,在生育期Ｆｅｅｋｅｓ标准８．０－９．０时,用ＧＥＮＥＳＩＳ进行一次叶在喷施,３．０ｋｇ／ｈｍ＾２和５．０ｋｇ／ｈｍ＾２,剂量下,均可达到９９．０％以上的杀雄效果,人工饱和授粉证明ＧＥＮＳＥＳＩＳ对雌蕊的育性没有影响;     

植物生长调节剂对水稻光敏核不育系培矮64S育性恢复的作用…

一定剂量的ＣｏＣｌ２,ＩＡＡ和２,４－Ｄ以及与ＧＡ３配合叶面喷施或根部水施后,水稻培矮６４Ｓ的育性在不育条件下得到部分恢复,其中以浓度各为５０ｍｇ／Ｌ的,２,４－Ｄ和ＧＡ３配合进行根部水施效果最好,自交结实率提高达７．９％。     

甲基乙二醛—双（脒腙）处理对光敏核不育水稻多胺含量的影响及其与育？…

ＭＧＢＧ（ｍｅｔｈｙｌｇｌｙｏｘａｌ－ｂｉｓ（ｇｕａｎｙｌｈｙｄｒａｚｏｎｅ）处理短日可育,处于光敏感时期的农垦５８Ｓ,可显著降低花粉可育度和自交结实率,但并不影响其正常的生长,ＭＧＢＧ处理长日不育株地效果不明显,以１０＾－４ｍｏｌ．Ｌ＾－１处理短日可育株效果最佳,ＭＧＢＧ主要影响穗子中下部枝梗的结实,对上部结实影响较小。ＭＧＢＧ处理引起腐胺增加而使亚胺精胺和精胺减少,推测亚精有胺和减少是育性下降     

核酸代谢抑制剂对水稻光敏核不育性的影响

在稻穗分化的二次枝梗期后,观察比较了叶片喷施核酸代谢抑制剂５ＦＵ对水稻光敏核不育性及幼穗发育的影响,结果表明：长日照下,５ＦＵ在使农垦５８Ｓ穗长缩短、颖花数减少的同时,却使其抽穗提前,可育性得到一定程度的恢复;５ＦＵ处理还使农垦５８的抽穗被完全阻止。在短日照下,５ＦＵ处理则使农垦５８Ｓ与农垦５８在穗长与颖花数减少的同时,其抽穗反被延迟,可育性受到抑制而结实率显著降低,上述效应还可被随后施用的恢复剂乳清酸所弱化。因此可以认为光敏核不育现象与稻穗发育中核酸代谢的改变有关。     

向日葵CMS育性恢复的研究

向日葵细胞质雄性不育（Ｃｙｔｏｐｌａｓｍｉｃｍａｌｅｓｔｅｒｉｌｉｔｙ,ＣＭＳ）育性恢复的机理是非常复杂的。运用遗传学和分子生物学方法,分析了具代表性的４种不同细胞质类型的ＣＭＳ育性被恢复的频率和２０种向日葵自交系对１９种ＣＭＳ的恢复能力及个别ＣＭＳ植株自发恢复的原因。实验结果表明,４种ＣＭＳ品系育性被恢复的频率分别为５８．８％．５６．３％．１１．８％和０％．２０种自交系的恢复力为５．９－７５．０％。部分ＣＭＳ品系和大多数自交系含有恢复基因,恢复基因的数量及类型决定了ＣＭＳ品系被恢复的程度及自交系的恢复能力。同时,提出并证实了线粒体不育基因变异是导致ＡＲＧ１ＣＭＳ植株自发恢复育性的主要原因。     

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.