The Characterization and Geographical Distribution of the Genes Responsible for Vernalization Requirement in Chinese Bread Wheat

The frequency and distribution of the major vernalization requirement genes and their effects on growth habits were studied.Of the 551 bread wheat genotypes tested,seven allelic combinations of the three Vrn.1 genes were found to be responsible for the spring habit,three for the facultative habit and one for the winter habit.The three Vrn-1 genes behaved additively with the dominant allele of Vrn-A1 exerting the strongest effect.The allele combinations of the facultative genotypes and the discovery of spring genotypes with "winter" allele of Vrn-1 implied the presence of as yet unidentified alleles/genes for vernalization response.The dominant alleles of the three Vrn-1 genes were found in all ten ecological regions where wheat Is cultivated in China,with Vrn-D1 as the most common allele in nine and Vrn-A1 in one.The combination of vrn-A 1vrnB 1Vrn-D1 was the predominant genotype in seven of the regions.Compared with landraces,improved varieties contain a higher proportion of the spring type.This was attributed by a higher frequency of the dominant Vrn-A1 and Vrn-B1 alleles in the latter.Correlations between Vrn-1 allelic constitutions and heading date,spike length,plant type as well as cold tolerance were established.     

小麦春化发育的分子调控机理研究进展

春化发育特性是小麦品种的重要性状,直接影响着小麦品种的种植范围和利用效率.本文就小麦春化相关基因的发现,以及对春化相关基因VRN1、VRN2和VRN3的克隆、表达特性以及春化发育分子调控机理方面的研究进展进行了综述.     

冬小麦春化过程中低温诱导的与花芽分化相关的mRNA和蛋白质的合成

应用SDS电泳及高分辨双向电泳技术,分析了冬小麦经春化、脱春化及超期春化处理后茎类蛋白质组分的变化。发现52.5,38kD和16.2kD蛋白质与冬小麦开花诱导密切相关。mRNA体外翻译结果表明,春化作用中低温诱导与开花紧密相关的mRNA的出现有一定的顺序性。因此推测:春化诱导开花是低温导致某些特定基因表达的结果,而表达的调节主要发生在转录水平上。     

黄淮南片冬麦区主导品种春化基因及冬春性分析

以1950～2007年黄淮南片冬麦区的127个主导小麦品种为材料,利用第5同源群的春化基因分子标记对其进行了春化基因检测,并分析了小麦品种的春化基因与其冬春性的对应关系及黄淮南片冬麦区8次品种更换中春化基因与品种冬春性的演变规律.结果表明,参试品种中没有品种携带显性Vrn-A1基因,7个品种含有Vrn-B1基因(5.5%),2个品种含有Vrn-B1+Vrn-D1基因(1.6%),56个品种含有Vrn-D1基因(44.1%).春化基因类型与品种冬春特性基本相符,春化基因控制着小麦品种的冬春特性.主导品种含春化显性基因频率的变化趋势与冬春性变化规律存在较大差异,与传统方法相比,仅用春化基因来确定品种冬春性存在一定的不完善之处.采用春化基因分子标记与传统的冬春性鉴定方法相结合来认识品种冬春性、预测品种的抗寒性对黄淮南片冬麦区的小麦品种利用更具有指导意义.     

Effect of Photoperiod on the Regulation of Wheat Vernalization Genes VRN1 and VRN2

Wheat is usually classified as a long day (LD) plant because most varieties flower earlier when exposed to longer days. In addition to LD, winter wheats require a long exposure to low temperatures (vernalization) to become competent for flowering. Here we show that in some genotypes this vernalization requirement can be replaced by interrupting the LD treatment by 6 weeks of short day (SD), and that this replacement is associated with the SD down-regulation of the VRN2 flowering repressor. In addition, we found that SD down-regulation of VRN2 at room temperature is not followed by the up-regulation of the meristem identity gene VRN1 until plants are transferred to LD. This result contrasts with the VRN1 up-regulation observed after the VRN2 down-regulation by vernalization, suggesting the existence of a second VRN1 repressor. Analysis of natural VRN1 mutants indicated that a CArG-box located in the VRN1 promoter is the most likely regulatory site for the interaction with this second repressor. Up-regulation of VRN1 under SD in accessions carrying mutations in the CArG-box resulted in an earlier initiation of spike development, compared to other genotypes. However, even the genotypes with CArG box mutations required LD for a normal and timely spike development. The SD acceleration of flowering was observed in photoperiod sensitive winter varieties. Since vernalization requirement and photoperiod sensitivity are ancestral traits in Triticeae species we suggest that wheat was initially a SD–LD plant and that strong selection pressures during domestication and breeding resulted in the modification of this dual regulation. The down-regulation of the VRN2 repressor by SD is likely part of the mechanism associated with the SD–LD regulation of flowering in photoperiod sensitive winter wheat. These authors contributed equally to this work     

河南小麦新品种的春化基因型鉴定

为了了解河南省最新培育小麦品种春化基因的等位变异状况,本研究利用分子标记技术对河南省新培育的50份冬小麦新品系(种)的春化基因Vrn-A1、Vrn-B1、Vrn-D1和Vrn-B3位点的等位变异组成进行了鉴定和分析。结果表明,所有参试小麦品种的Vrn-B3位点基因型均表现为隐性,48份小麦品种的Vrn-A1和Vrn-B1位点基因为隐性,42份小麦品种的Vrn-D1位点基因为隐性,说明隐性基因在河南小麦中占据主导地位。其中,豫农2019、豫农2020、豫农2071、国麦301、平安08-8、百农69、囤麦3698、08漯33共8个小麦品种的Vrn-D1位点基因均为显性的Vrn-D1a类型。小麦品系豫农2053和豫农3052的Vrn-A1和Vrn-B1位点的春化基因均表现为缺失,进一步研究表明,这2份小麦新品系仍能正常开花,但开花期比对照周麦18分别晚1d和2d,因此Vrn-A1和Vrn-B1并非小麦开花的必需基因。本研究将为黄淮麦区广适、高产小麦新品种的选育和推广提供参考。     

玉米赤霉烯酮在冬小麦短日春化中的作用

应用酶联免疫技术,研究了冬小麦品种燕大１８１７ 在不同光周期条件下,体内内源玉米赤霉烯酮（ＺＥＮ） 和ＡＢＡ 含量的变化。结果表明,冬小麦品种燕大１８１７ 具有短日春化性,苗期经４ 周ＳＤ 处理后转到ＬＤ 下能正常抽穗。ＳＤ 诱导春化的幼苗茎尖和叶片中ＺＥＮ 含量高于未经诱导的ＬＤ 幼苗,而在两种光周期条件下生长的幼苗中ＡＢＡ 含量变化趋势并无明显差异。马拉硫磷（ ＭＡＬ） 抑制ＳＤ 幼苗体内ＺＥＮ 含量高峰的出现,也部分抑制抽穗;外源ＺＥＮ 可部分抵消ＭＡＬ对植株的影响,降低茎尖内源ＡＢＡ 含量,并有促进小麦拔节的作用。说明在冬小麦短日春化过程中,ＺＥＮ 具有促进作用,而ＡＢＡ 没有直接影响。     

春化处理控制冬小麦的小穗发育

春化作用是决定冬性及二年草本植物成花和穗化的一个关键生理过程,通过用不同时间的前期低温处理,观察对冬小麦（Triticum aestivum L.)后期形态建成中穗分化启动,小花发育及结实率的影响,发现前期低温处理对穗启动分化的早晚具有决定作用,春化时间越长,穗分化启动越早,较长时间低温有利于促进穗分化,在实验室低温处理条件下,促进小花分化和提高结实率的最佳春化处理时间是45d左右,实验观察表明,春化处理促进小麦生长锥分化启动时间和分化速率,减少小穗退化,这一结果表明了春化处理不仅是冬小麦开花启动过程所必需的,而且是花序正常发育过程和顶部与基部小穗完全结实所不可缺少的。     

Vernalization,a Switch in Initiation of Flowering,Promotes Differentiation and Development of Spikelet in Winter Wheat

Vernalization is a decisive physiological process for heading, flowering and graining of biennial plants. Variable duration of low-temperature treatment has effects on lateral morphogenesis, such as spike initiation, floral development and graining rate in winter wheat ( Triticum aestivum L.). The investigation data showed that the duration of vernalization treatment was a decisive factor for the initiation of spike relevant to the time of initiation; the longer the duration at low temperature, the earlier the spike initiation in winter wheat. In the process of the spike differentiation, relatively lower temperature and longer differential time benefited for spike differentiation. Under laboratory condition, a low-temperature treatment for 45 d was optial for flower differentiation and graining in winter wheat. It is novelly recognized that vernalization treatment is essential for development of both spikes and spikelets, besides for promoting initiation of differentiation in winter wheat.     

Molecular and Structural Characterization of Barley Vernalization Genes

Vernalization, the requirement of a period of low temperature to induce transition from the vegetative to reproductive state, is an evolutionarily and economically important trait in the Triticeae. The genetic basis of vernalization in cultivated barley (Hordeum vulgare subsp. vulgare) can be defined using the two-locus VRN-H1/VRN-H2 model. We analyzed the allelic characteristics of HvBM5A, the candidate gene for VRN-H1, from ten cultivated barley accessions and one wild progenitor accession (subsp. spontaneum), representing the three barley growth habits – winter, facultative, and spring. We present multiple lines of evidence, including sequence, linkage map location, and expression, that support HvBM5A being VRN-H1. While the predicted polypeptides from different growth habits are identical, spring accessions contain a deletion in the first intron of HvBM5A that may be important for regulation. While spring HvBM5A alleles are typified by the intron-localized deletion, in some cases, the promoter may also determine the allele type. The presence/absence of the tightly linked ZCCT-H gene family members on chromosome 4H perfectly correlates with growth habit and we conclude that one of the three ZCCT-H genes is VRN-H2. The VRN-H2 locus is present in winter genotypes and deleted from the facultative and spring genotypes analyzed in this study, suggesting the facultative growth habit (cold tolerant, vernalization unresponsive) is a result of deletion of the VRN-H2 locus and presence of a winter HvBM5A allele. All reported barley vernalization QTLs can be explained by the two-locus VRN-H1/VRN-H2 model based on the presence/absence of VRN-H2 and a winter vs. spring HvBM5A allele. Electronic Supplementary Material Electronic Supplementary material is available for this article at and accessible for authorised users.     

粘类小麦细胞质雄性不育系育性基因的地区分布

以具4种细胞质、2种核类型的粘类小麦雄性不育系为测验种,对309份来自国内外不同地区普通小麦品种对应粘类小麦不育系的育性恢复和保持关系进行调查,研究粘类小麦雄性不育系育性基因的地理分布.结果表明:(1)普通小麦品种中广泛存在着粘类雄性不育系的恢复基因,所配组合中,高恢复度以上的组合占到45.24%;(2)所配组合F1小穗结实率范围在0~91.35%之间,其中0和60%~80%的分布范围较多;(3)具有恢复能力的品种在供试6个地区均有分布,但比例不同,中国南方、新疆内陆、青藏高原等春麦地区高,可育品种的分布比例均超过50%;具有育性保持作用的品种在中国黄淮海暖温带冬麦气候生态区和加拿大地区分布较多,在新疆麦区分布最少;(4)恢复度80%以上的品种在6个地区均有分布,但在各地区供试材料中的比例都不高.     

广东两栖动物地理分布的聚类分析

对广东省49种两栖动物的地理分布进行了聚类研究.将各种两栖动物在各动物地理省分布的有或无作为二元状态,用结合系数来表征每两个动物地理省同两栖动物组成的相似程度,以类平均法进行聚类.聚类结果表明两栖类在广东各动物地理省的分布受地形明显影响.论述了广东省两辆动物地理分布的特点,并对聚类结果与动物地理区划进行了比较.     

木兰属(Magnolia)的地理分布及起源

分析了现代木兰属（Ｍａｇｎｏｌｉａ）植物的地理分布及其散布途径,认为华夏植物区系区域不仅是现代木兰属的分布中心,同时也是木兰属的分化中心及原始类群保存中心,并结合地史资料,推断全球木兰属植物应共同起源于华夏植物区系。     

小麦穗发芽基因等位变异及其区域分布研究

为了解中国不同麦区小麦种质资源抗穗发芽基因的等位变异与分布特征,利用小麦抗穗发芽相关的Vp1B3和Dorm-1标记对7个不同麦区的446份小麦种质资源的等位变异和分布差异进行了检测。结果表明:(1)利用标记Vp1B3检测出Vp1的等位基因共有3种类型,分别为Vp1Bc(与抗穗发芽相关)、Vp1Ba(与感穗发芽相关)、Vp1Bb(与抗穗发芽相关),其频率分别为62.8%、32.9%和4.3%。(2)标记Dorm-1在供试材料中共检测出2种特异性条带,分别为468bp(DormB1a,与感穗发芽相关)和606bp(DormB1b,与抗穗发芽相关),所占比例分别为98.6%和1.4%。(3)具有DormB1b基因型的种质主要分布在黄淮冬麦区和长江中下游冬麦区,比例分别为5.1%和1.9%;具有(Vp1Bc+Vp1Bb)基因型(组合)的种质在长江中下游冬麦区和西南冬麦区分布最多,比例分别为75.0%和74.1%。(4)通过标记Vp1B3和Dorm-1的综合鉴定,共筛选出同时携带Vp1与Dorm-B1位点种质6份,分别是‘陕麦611’、‘郑农19’、‘豫49-198’、‘信阳0913’、‘咸阳大穗’与‘徐州8066’,可以作为抗穗发芽育种的参考亲本。     

青海育成小麦5个主效矮秆基因的分子检测

为系统了解青海小麦矮秆基因的分布特点,并进一步为青海高原小麦的株高育种提供优异种质资源。本研究利用5个矮秆基因的特异性分子标记对82份青海小麦品种资源中的矮秆基因进行了检测,并对不同矮秆基因的降秆效应进行了分析。结果表明:82份青海育成小麦品种中有49份材料至少含有一个矮秆基因,其中Rht-B1b的分布频率最高,约占参试材料的28.0%,其次是分布频率为23.2%的Rht8基因,而矮秆基因Rht-D1b、Rht5以及Rht12的分布频率分别为9.8%、13.4%、9.8%。在49份含有不同种类矮秆基因的材料中,其中16份材料同时含有2种及以上的矮秆基因,即RhtB1b和Rht8、Rht-D1b和Rht8、Rht-B1b和Rht5、Rht-D1b和Rht5、Rht8和Rht5、Rht-B1b和Rht12、Rht5和Rht12,并未发现同时含有矮秆基因Rht-B1b和Rht-D1b的品种;2份材料分别含有3种矮秆基因,即Rht-B1b、Rht8、Rht12和Rht-B1b、Rht5、Rht8;其余31份材料仅含有1种矮秆基因。82份青海育成小麦材料中仅含有Rht-B1b的材料11份,平均株高为86.2 cm,其降秆效应为5.7%;只含有Rht-D1b的材料有5份,平均株高为84.9 cm,其降秆效应为7.1%;仅含有Rht8的材料有9份,平均株高为88.6 cm,其降秆效应为3.1%。因此,在青海育成小麦品种中,矮秆基因的降秆效应为Rht-D1bRht-B1bRht8。     

中国蜘蛛地理区划和东洋界区系特点

根据业已系统研究过的园蛛科、狼蛛科和跳蛛科 5 5 0种中国蜘蛛的地理分布 ,讨论了在我国境内古北界和东洋界东段分界线的划分问题并提出了作者的主张 ;阐明了中国东洋界蜘蛛区系的特点 ,认为该界的西南区 (包括云、贵、川、湘西和鄂西 )是中国蜘蛛起源演化的中心     

The Influence of Genes for Vernalization Response on Development and Growth in Wheat

Studies were made of the influence of genes for vernalizationresponse on the growth and development of four near-isogeniclines of bread wheat (Triticum aestivum L.). The duration from sowing of flower initiation, terminal spikeletformation and ear emergence all increased with increasing vernalizationresponse. There was a close positive relationship between thedays from sowing to flower initiation and from sowing to earemergence, indicating that the duration of either phase of developmentis a useful measure of relative vernalization when daylengthdoes not limit the rate of development. Total spikelet number per ear and the duration of spikelet initationincreased with increasing vernalization response and there wasa correspondingly higher rate of spikelet initiation in thetwo lines with stronger vernalization response. Most of the differences in growth between the lines were associatedwith diferences in development caused by the vrn genes. Maximumtotal above-ground dry matter and total leaf area per plantincreased with increasing vernalization repsonse but relativegrowth rate and leaf area per plant were not significantly differentbetween the lines. There were no differences in net assimilationrate between the four lines until 40 d from sowing; thereafterit decreased, with the greatest decrease in the line with thestrongest vernalization response. Flower initiation, terminal spikelet formation, spikelet initiation, ear emergence, growth rate     

The Floristic Characteristics and Geographical Distribution of the Rosaceae in Xizang

The Rosaceae is one of the five largest families of Xizang flora, consisting of 30 genera with 242 species, the total number of species is slightly less than those of Compositae, Graminae, Leguminosae and Ericaceae in Xizang, amounting to 62.5% of the total number of genera and 28% of the total number of species of the rosaceous flora in China. The four subfamilies of Rosaceae including primitive, intermediate and advanced groups have been found in Xizang. These groups consist of 11 types of floristic elements, i.e. 4 genera belong to cosmopolitan, 9 genera belong to North Temperate, 3, E. Asian-N. American, 3 Sino-Himalayan, 3 Sino-Japanesa, 2 Old World Temperate, 1 Temperate Asian, 2 Mediterranean-W. and O. Asian, 1 C. Asian, I Tropical Asian and 1 endemic to China. It is obvious that Rosaceae in Xizang comprises holarctic, Ancient Mediterranean and paleotropical elements, among which the temperate components are the most dominant. The characteristics of the floristic composition of Rosaceae in Xizang may be summarized as follows: (1) Xizang abounds in both genera and species of the family which are diverse in forms, including the primitive, intermediate and advanced groups, (2) The geographical elements are rather complex, mostly belonging to the temperate, among which the Sino- Himalayan components and the elements endemic to China are dominant, (3) The proportion of plants endemic to China and distributed in Xizang is much higher than those endemic to Xizang itself, but there exist newly arisen species and infraspecific forms or varieties which show that the speciation is apparently still active in Xizang. The rosaceous flora of Xizang is a combination of old and new floristic elements, based on the old floristic components, affected by the upheaval of the Himalayas, the differentiation and speciation have been taking place in the long history. The geographical distribution of Rosaceae in Xizang may be divided into 5 regions, i.e. the northeastern, southeastern, southern, northwestern and northern. The rosaceous plants are most abundant in the southeastern area, next in southern area, fewer in the northeastern and very rare in the northwestern and northern regions. The general tendency of the distribution of Rosaceae in Xizang is that the number of species gradually decreases from the southeast to the northwest and the habit gradually changes from trees, shrubs and herbaceous plants in the southeast to cushion-like scrubs and dwarf perennial herbs in the northwest. These facts clearly show that the uplift of the Himalayas has deeply affected the phytogeographical distribution of Xizang Rosaceae. The rosaceous flora of Xizang has close relationships with those of the adjoring regions, i.e. Yunnan and Sichuan. Besides, it is connected with floras of Nepal, Sikkim, Bhutan nothern Buram and nothern India, but silghtly influenced by the Ancient Mediterranean flora.     

石松类卷柏科地史时期和现代地理分布格局的形成

卷柏科仅含一属,全球分布,具有宽幅生态适应性,属于维管植物基部类群石松类植物,现生约700种。卷柏科起源于泥盆纪,化石记录遍布自石炭纪至今的各地质时期。目前,现代卷柏属亚属的分类方案基本稳定,但对于化石卷柏的亚属分类、以及地质历史时期的时空分布问题还缺乏相关研究。本文全面总结了卷柏科化石记录的时代和地理分布,并结合分子系统学探讨其地理分布格局的演化,为该科植物的分类与进化研究提供参考。根据现有研究基础,结合最新的卷柏科系统分类研究成果和化石记录,本文对该类群化石的系统分类进行归纳和厘定,并对化石类群的卷柏亚属Selaginella、Hexaphyllum亚属及rhizophoric clade物种的分化和地理分布格局的形成进行了讨论。本文认为,卷柏科起源于古生代的欧美植物区,不晚于二叠纪,其后伴随着泛大陆解体扩散至华夏植物区及冈瓦纳植物区。化石亚属Hexaphyllum是rhizophoric clade的基部类群,在石炭纪末灭绝。化石证据表明,从古生代末期起,rhizophoric clade已成为卷柏科的优势类群,并在中生代形成了全球分布的格局。     

河北省大鸨的分布与保护

报道并探讨了河北省在大鸨迁徙途径中的重要性,河北省大鸨的地理分布与居留期变化,大鸨的保护工作及其保护与研究展望,指出河北省是大鸨重要的越冬地.