水稻资源GXM-001-2对稻瘿蚊的抗性鉴定与遗传分析

稻瘿蚊对南方水稻的危害日趋严重,育种上急需新的抗源。利用广西地方品种GXM-001-2作父本,分别与感虫品种TN1和已知抗性基因载体品系W1236(Gm1)、IET2911(Gm2)、BG404-1(gm3)、OB677(Gm4)、ARC5984(Gm5)、多抗1号(Gm6)杂交、自交和回交,获得F1、F2、BC1F1群体,对亲本和各杂交后代进行稻瘿蚊的抗性评价及遗传分析。结果表明,抗源GXM-001-2高抗稻瘿蚊中国Ⅱ型,抗中国Ⅳ型,且抗性均由1对显性基因控制;等位性测定表明抗源中的抗性基因与已知抗性基因Gm1、Gm2、gm3、Gm4、Gm5、Gm6不等位,推测该基因可能是1个新的抗稻瘿蚊基因。     

水稻抗衰老IPT基因与抗白叶枯病基因Xa23的聚合研究

以转抑制衰老有关的异戊烯基转移酶(IPT)基因株系GC-1、携带抗白叶枯病基因Xa23的“CBB23”和抗稻瘟病水稻品种“合系15号”为供体．采用分子标记辅助选择与生物学鉴定相结合的方法,将IPT基因与Xa23及抗稻瘟病基因进行聚合。在3个复交组合中获得了17株聚合IPT基因与Xa23基因的植株,用这些植株与两系杂交稻亲本9311、E32、培矮64S及W9834S进行杂交和回交,经PCR分子检测和抗白叶枯病、抗稻瘟病鉴定和细胞分裂素含量的测定,最终在4个BC,回交组合“(9311／／／合系15／CBB23／／GC-1)X9311”、“(E32／／／合系15／CBB23／／GC-1)XE32”、“(培矮64S／／／合系15／CBB23／／GC-1)X培矮64S”和“(GC-1／CBB23／／W9834S／合系15)XW9834S”中获得了17株携带IPT基因与Xa23基因的BC1F1植株,这些植株对来自北方稻区21个稻瘟病菌系全部表现为抗。携带IPT基因的抗病植株再与杂交稻亲本进行回交．在2个BC2回交组合“[(9311／／／合系15／CBB23／／GC-1)X9311]X9311’’和“[(E32／／／合系15／CBB23／／GC-1)XE32]XE32”中获得了7株携带IPT基因与Xa23基因的植株,这些植株再经过1—2代回交和自交,即可用于杂交稻育种。     

粳稻特殊广亲和系GC13的遗传分析及利用研究

粳稻品种GCl3对亚种内亲和力弱,而对亚种间亲和力强,因此特称之为特殊广亲和系(Special wide compatibility variety,SWCV)。广亲和基因等住性和遗传规律研究结果表明,GCl3的广亲和性主效基因效应明显,同时受微效基因修饰,与已知的S7、S9、S15三个育性基因住点之一等位。GCl3可与培矮64S等籼型光敏核不育系配组育成亚种间杂交稻;GCl3是粳型恢复基因源,从其杂交后代中选育出的偏粳(K’)型或偏籼(H’)型通用恢复系GR209、GR220和GR238等,对“野败”、“矮败”等多种不育细胞质和培矮64S等光敏核不育系具有强恢复性,配制出的“三系”或“二系”杂交稻具有高产潜力和利用前景。     

科研新成果简介

成果名称:抗稻瘿蚊新基因Gm6在分子标记抗性育种中的应用 主要完成人:黄炳超,张扬,谢振文,张桂权,肖汉祥,李宏,J.Bennett,刘名镇,周少川,S.Katiyar,陈伟洲,黄朝峰,谭玉娟,徐炎康,赵丽霞,等     

超级杂交稻两优培九及其亲本低温强光适应特性

以超级杂交稻两优培九(培矮64S/9311)和母本培矮64S(PA64S)以及父本中籼9311为材料,以叶绿素荧光参数和活性氧代谢等指标研究生育后期亲本和后代对低温强光的适应特性。结果显示:低温强光处理后,与父母本相比,两优培九的叶绿素、PSⅡ原初光化学效率(Fv/Fm)和光化学猝灭系数(qP)和实际PSⅡ光能捕获的效率(φPSⅡ)的降低较少,说明在低温强光下,超级杂交稻两优培九吸收的光能较多地转化为化学能;同时两优培九的内源活性氧清除酶系如超氧化物歧化酶和过氧化物酶诱导的活性高,表现耐低温强光的特性,从而能有效清除叶片内的活性氧,因而膜脂过氧化较轻。试验结果表明:在生育后期超级杂交稻两优培九对低温强光适应的特性具有超双亲偏母本的现象。     

基因聚合改良杂交稻组合的稻飞虱田间抗性表现

褐飞虱Nilaparvata lugens(Stl)是杂交水稻的重要虫害,培育高抗褐飞虱的杂交水稻新组合被认为是目前防治飞虱最有效、经济的方法。本研究以分子标记辅助选择培育的抗褐飞虱杂交水稻为材料,通过苗期和成株期的全生育期田间抗性鉴定,对基因聚合改良杂交稻组合的褐飞虱抗性进行综合评价,结果表明,基因聚合改良杂交稻组合的苗期抗性介于抗和中抗水平,田间虫量在7次调查中均低于800头/百丛,远低于2000头/百丛的防治标准,而对照扬两优6号、两优培九和当地农家品种两优63在8月29日到9月10日飞虱发生高峰期的百丛虫量分别最高达到5400头、2030头和10700头,高于或远高于2000头/百丛的防治标准。改良组合川香29A/华恢1462的产量在通城比对照扬两优6号增产11.8%。上述结果表明抗褐飞虱改良杂交稻新组合能够有效抑制稻田褐飞虱种群数量,节约人工和农药成本,增加水稻产量。     

三基因聚合改良恢复系福恢673的稻瘟病抗性

为了改良水稻优良恢复系福恢673的稻瘟病抗性,以该恢复系为轮回亲本,以携有3个稻瘟病抗性基因(Pi-1、Pi-9和Pi-k~h)的优质恢复系金恢1059为供体亲本,通过回交育种结合分子标记辅助选择,选育出10个导入了这3个抗稻瘟病基因的福恢673近等基因系,其遗传背景恢复率为92.96%–98.59%。抗性鉴定结果表明,这些近等基因系及其与不育系宜香A配制的杂种一代均表现抗稻瘟病,抗性明显强于对照福恢673和宜优673,且半数以上杂种一代基本保留了原组合的主要优点。用近等基因系Line 9配组的杂交稻新组合两优7283和金泰优683在区试中均表现出产量高、稻瘟病抗性强、生育期适中等特点,表明该近等基因系具较好的应用前景。     

水稻光温敏雄性不育系培矮64S的抽穗期基因型分析

利用抽穗期感光性近等基因系EG0—EG7、ER—LR及T65-T65m对培矮64S抽穗期基因型进行分析表明,培矮64S在E1、E、E3位点分别带有E1、e2、E3基因,在Se-1位点带无感光功能的Se-1^e基因,在Ef位点带有显性早熟基因Ef-1。进一步用抽穗期QTL近等基因系NIL(Hd1)和NIL(Hd4)进行的研究证实,培矮64S带有显性感光基因E1和无感光功能的Se-1^e基因。同时,用QTL近等基因系日本晴和NIL(Hd2)-NIL(Hd8)研究表明培矮64S带有能抑制E1基因表达的隐性感光抑制基因i-Se-1。文中对培矮64S广适性的遗传基础也进行了讨论。     

温敏核不育水稻穗颈节间的SSH特异表达

‘长选3S’是由‘培矮64S’通过辐射诱变选育出的长穗颈温敏核不育水稻．以‘K选3s’二核花粉期穗颈节问作为目标群体,‘培矮64S’二核花粉期穗颈节间作为对照群体,进行抑制差减杂交,川经过‘培矮64S’cDNA差减的‘长选3S’cDNA构建了一个含有大约130个独立克隆的差减文库;采用差减前的‘培矮64S’cDNA和‘长选3S’cDNA以及正向／反向差减杂交后的cDNA为模板标记探针,对随机挑取的96个承组质粒进行羞示筛选,获得了20个阳性候选克隆。从这些阳性候选克隆中随机挑取了8个进行Northern blot分析．证实其巾中1个候选克隆代表了在‘长选3S’穗颈节间中特异表达的基因．序列分析和同源性比较表明它与信号传导有关。这一在‘长选3S’穗颈节间特异表达的cDNA片段有助于进一步揭示其穗颈节间伸长的分子机制．并为水稻不育系的遗传改良提供有用的素材。     

水稻不育系稻粒黑粉病抗性QTL的定位

为了定位稻粒黑粉病抗性基因,建立水稻抗稻粒黑粉病分子育种技术体系.以对稻粒黑粉病抗性较强的光温敏不育系W9593S和易感稻粒黑粉病、与W9593S不育基因等位的光温敏不育系培矮64S为亲本,通过杂交和多年自交,构建了由183个高世代稳定不育系组成的重组自交系遗传群体.以这个重组自交系遗传群体为材料,利用200个多态性S...     

Causality, randomness, intelligibility, and the epistemology of the cell

Because the basic unit of biology is the cell, biological knowledge is rooted in the epistemology of the cell, and because life is the salient characteristic of the cell, its epistemology must be centered on its livingness, not its constituent components. The organization and regulation of these components in the pursuit of life constitute the fundamental nature of the cell. Thus, regulation sits at the heart of biological knowledge of the cell and the extraordinary complexity of this regulation conditions the kind of knowledge that can be obtained, in particular, the representation and intelligibility of that knowledge. This paper is essentially split into two parts. The first part discusses the inadequacy of everyday intelligibility and intuition in science and the consequent need for scientific theories to be expressed mathematically without appeal to commonsense categories of understanding, such as causality. Having set the backdrop, the second part addresses biological knowledge. It briefly reviews modern scientific epistemology from a general perspective and then turns to the epistemology of the cell. In analogy with a multi-faceted factory, the cell utilizes a highly parallel distributed control system to maintain its organization and regulate its dynamical operation in the face of both internal and external changes. Hence, scientific knowledge is constituted by the mathematics of stochastic dynamical systems, which model the overall relational structure of the cell and how these structures evolve over time, stochasticity being a consequence of the need to ignore a large number of factors while modeling relatively few in an extremely complex environment.     

The tree, the network, and the species

To enrich the Hennigian internodal conception of species, a new formalization of the definition of the species concept is proposed. This rigorous definition allows for considerable unification of the various, and sometimes conflicting, techniques of species delimitation used in practice. First, the domain of such a definition is set out, namely, the set of all organisms on Earth, past, present, and future. Next, the focus is on the genealogical relationship among organisms, which provides the key to analysing the giant or global genealogical network (GGN) connecting all these organisms. This leads to the construction of an algorithm revealing the topological structure of the GGN, from families to lineages, ending up with a definition of species as equivalence classes of organisms corresponding to branches of the 'tree of life'. Such a theoretical definition of the species concept must be accompanied by various recognition criteria to be operational. These criteria are, for example, the ill-named 'biological species concepts', 'phylogenetic species concepts', etc., usually, but wrongly, presented as definitions of the species concept. Besides clarifying this disputed point, the definition in the present study displays the huge diversity of the scales (time-scale and population size) involved in actual species, thus explaining away the classical problems raised by previous attempts at defining the species concept (uniparental reproduction, temporal depth of species, and hybridization).  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 509–521.     

Formation of pyrophosphate,tripolyphosphate, and phosphorylimidazole with the thioester,N, S-diacetylcysteamine,as the condensing agent

Summary Reaction of 0.20M orthophosphate with 0.20M N,S-diacetylcysteamine in 0.40M imidazole at pH 7.0 or 8.0 under drying conditions at 50°C for 6 days yields pyrophosphate and tripolyphosphate in the presence and absence of 0.10M divalent metal ion. The efficiency of utilization of N,S-diacetylcysteamine in the formation of pyrophosphate linkages ranges from 3 – 8% under the above conditions. The thioester, N,S-diacetylcysteamine, and imidazole are required for phosphoanhydride formation.Reaction of 0.40M orthophosphate with 0.20M N, S-diacetylcysteamine in 0.40M imidazole at ambient temperature for 6 days yields phosphorylimidazole in the absence or presence of 0.05M MgCl₂. Phosphorylimidazole and pyrophosphate are formed in the presence of 0.05M CaCl₂; pyrophosphate and tripolyphosphate are formed with 0.15M CaCl₂. The efficiency of utilization of N,S-diacetylcysteamine in the formation of pyrophosphate linkages is roughly 7% at 6 days of reaction with 0.15M CaCl₂. The thioester, N,S-diacetylcysteamine and imidazole are required for the formation of phosphoanhydrides. The significance of these reactions to molecular evolution is discussed.Abbreviations P₁ orthophosphate - P₂ pyrophosphate - P₃ tripolyphosphate - ImP phosphorylimidazole - Ac-Csa(Ac) N, S-diacetylcysteamine - Im imidazole     

The parasitic chytrid, Zygorhizidium, facilitates the growth of the cladoceran zooplankter, Daphnia, in cultures of the inedible alga, Asterionella

In food-web studies, parasites are often ignored owing to their insignificant biomass. We provide evidence that parasites may affect trophic transfer in aquatic food webs. Many phytoplankton species are susceptible to parasitic fungi (chytrids). Chytrid infections of diatoms in lakes may reach epidemic proportions during diatom spring blooms, so that numerous free-swimming fungal zoospores (2-3 microm in diameter) are produced. Analysis shows that these zoospores are rich in polyunsaturated fatty acids and sterols (particularly cholesterol), which indicates that they provide excellent food for zooplankters such as Daphnia. In life-table experiments using the large diatom Asterionella formosa as food, Daphnia growth increased significantly in treatments where a parasite was present. By grazing on the zoospores, Daphnia acquired important supplementary nutrients and were able to grow. When large inedible algae are infected by parasites, nutrients within the algal cells are consumed by these chytrids, some of which, in turn, are grazed by Daphnia. Thus, chytrids transfer energy and nutrients from their hosts to zooplankton. This study suggests that parasitic fungi alter trophic relationships in freshwater ecosystems and may be the important components in shaping the community and the food-web dynamics of lakes.     

On the Position of the Genera Turdoides, Argya, Illadopsis, Neociehla, Ptyrticus, Maerosphenus and Pseudoaleippe in the Timaliidæ

Although in these five genera the long broad first primary and rounded wing agree with Timalia pileata, as does the profile of the bill of Argya fulvus and Argya rubiginosus, they do not do so in any other respect,. neither in their habits, nest and eggs, nor in the scutation of the tarsus. We therefore propose to remove them all from the Timaliidae and place them in two separate families, but leaving them in their present position in the classification as placed by Sclater in Syst. Av. Æthiop. ii. 1930.