大白菜白化突变的遗传研究初报

选用三个大白菜(Brassica campessrts ssp pekinensis)雄性不育两用系AB_102-12-2,AB_102-18-94,AB_102-18-14中的白化突变嵌合植株和正常绿色植株,以及自交系R,,的正常绿色植株作为亲本材料,配制成16个自交和杂交组合,并对杂种后代嵌合植株具相对表型性状差异的枝条进行了21个组合的杂交配组试验,以探讨大白菜白化突变的遗传规律。初步的试验结果表明,本试验中的白化突变的遗传符合细胞质遗传的基本特征,属细胞质遗传。白化变异是由细胞质基因突变引起的。     

大白菜白化突变的遗传研究初报

选用三个大白菜(Brassica campestris ssp pekinensis)雄性不育两用系AB_(102-12-2),AB_(102-18-94),AB_(102-13-14)中的白化突变嵌合植株和正常绿色植株,以及自交系R_(23)的正常绿色植株作为亲本材料,配制成16个自交和杂交组合,并对杂种后代嵌合植株具相对表型性状差异的枝条进行了21个组合的杂交配组试验,以探讨大白菜白化突变的遗传规律。初步的试验结果表明,本试验中的白化突变的遗传符合细胞质遗传的基本特征,属细胞质遗传。白化变异是由细胞质基因突变引起的。     

大白菜乙烯受体基因家族分子特征、微同线性与进化分析

采用HMMER与BLAST相结合的方法,在大白菜基因组中挖掘了10个大白菜ERT基因,被命名为BraERT1-10.基因结构分析显示,乙烯受体基因的外显子数目变异大,其范围为1-15.微同线性结果表明,白菜与拟南芥间以及白菜基因组内共有5对基因区段具有较高同线性,每对基因区段间至少共享了8个保守序列模块.蛋白保守结构域和亚细胞定位分析表明,BraERT1、BraERT2和BraERT8都具有N端疏水区域、GAF区、HisKA区、反应调节区,分别被定位于质膜、叶绿体和线粒体;BraERT3、BraERT4和BraERT7虽然有N端疏水区域、GAF区和HisKA区,但没有完整的反应调节区,分别被定位于质膜、质膜和胞质外;其余4个蛋白不具有典型区域,主要定位于核和叶绿体内.进化树结果显示,大白菜ERT基因具有3种类型,分别归属于不同3个类群.本研究为大白菜ERT基因功能研究提供线索,为进一步解析大白菜乙烯信号途径奠定基础.     

与大白菜霜霉病抗性主效QTL连锁的分子标记开发

霜霉病是危害大白菜的三大病害之一,该病的发生会严重影响大白菜的产量及品质,因而研究与霜霉病抗性QTL紧密连锁的分子标记对大白菜抗病新品种培育具有重要意义。该研究在前期工作的基础上,选用高感霜霉病株系91-112、高抗霜霉病株系T12-19以及由二者为双亲构建的DH群体为实验材料,针对大白菜霜霉病抗性主效QTL——BrDW所在的标记区间,利用已有的大白菜基因组信息发展与抗性QTL紧密连锁的分子标记,通过Blast和IMap分析,将与BrDW连锁的RAPD标记K14-1030定位于大白菜KBrB058M10上(位于Contig214上),根据KBrB058M10附近的BAC及BAC-end序列设计引物,结合限制性内切酶酶切及HRM分析方法,筛选得到5个与BrDW连锁的分子标记,包括1个Indel标记Brb062-Indel230,3个CAPS标记Brb094-DraⅠ787、Brb094-AatⅡ666和Brb043-BglⅡ715,1个SNP标记Brh019-SNP137;同时,通过筛选与目标区域具有同源性的Unigene序列得到了1个与BrDW紧密连锁的SSR标记bru1209。标记Brb062-Indel230、Brb094-DraⅠ787、Brb094-AatⅡ666、Brb043-BglⅡ715、Brh019-SNP137和bru1209与RAPD标记K14-1030之间的遗传距离分别为4.3 cM、1.7 cM、5.9 cM、5.9 cM、4.6 cM和0.8 cM,在对DH群体中的抗性株系选择上准确率分别为69.7%、70.9%、72.4%、72.4%、58.3%和74.2%,可应用于分子标记辅助选择,为霜霉病抗性分子育种奠定了良好基础。     

Construction of random sheared fosmid library from Chinese cabbage and its use for Brassica rapa genome sequencing project

As a part of the Multinational Genome Sequencing Project of Brassica rapa, linkage group R9 and R3 were sequenced using a bacterial artificial chromosome (BAC) by BAC strategy. The current physical contigs are expected to cover approximately 90% euchromatins of both chromosomes. As the project progresses, BAC selection for sequence extension becomes more limited because BAC libraries are restriction enzyme-specific. To support the project, a random sheared fosmid library was constructed. The library consists of 97536 clones with average insert size of approximately 40 kb corresponding to seven genome equivalents, assuming a Chinese cabbage genome size of 550 Mb. The library was screened with primers designed at the end of sequences of nine points of scaffold gaps where BAC clones cannot be selected to extend the physical contigs. The selected positive clones were end-sequenced to check the overlap between the fosmid clones and the adjacent BAC clones.Nine fosmid clones were selected and fully sequenced. The sequences revealed two completed gap filling and seven sequence extensions, which can be used for further selection of BAC clones confirming that the fosmid library will facilitate the sequence completion of B. rapa.     

大白菜高产栽培及病虫害防治技术

本文简述了大白菜栽培技术及主要病虫害的防治方法。     

大白菜与结球甘蓝异源三倍体小孢子植株的获得与鉴定

以6个不同基因型的大白菜四倍体(AAAA,2n=4x=40)品系9401、9402、9403、9404、9405、9406为母本,结球甘蓝二倍体(CC,2n=2x=18)自交系9501为父本配制杂交组合得到的6个杂种一代为试材,进行了游离小孢子培养研究,成功诱导出胚状体,获得了再生植株,并对部分再生株进行了染色体数鉴定和性状调查。结果表明:不同组合小孢子胚胎发生能力不同,各组合产胚率均较低;小孢子再生植株中,染色体数为18的个体所占比例最大,达46.7%;小孢子植株减数分裂行为复杂,终变期除二价体和单价体外,还有三价体等联会形式;小孢子植株性状表现各异。     

用EST-SSR分子标记技术构建大白菜核心种质及其指纹图谱库

利用EST-SSR分子标记对大白菜种质资源基因库中686份样品所代表的1 900份大白菜种质资源进行分析研究.构建大白菜种质资源的核心种质并且形成核心种质的EST-SSR指纹图谱库.结果表明利用4组鉴定白菜品种的EST-SSR的特异性标记组合,获得近158个EST-SSR多态的标记,对大白菜种质资源基因库中686份样品所代表的1 900份大白菜种质资源进行核心种质的构建提供了分析数据.形成的核心种质包括168份样品,占库存资源的8.8%,它的多态位点百分率保持了原群体的100%.所构建的核心种质涵盖了原资源的绝大部分区域来源的品种,包含了早、中、晚熟品种中所有典型的大白菜类型和其相关的特征特性.并进一步进行了核心种质资源遗传多样性分析.核心种质的EST-SSR指纹图谱库中,每一份样品的指纹都是唯一的,为登记、评价、整理、分发、繁殖等种质资源库的管理和育种者对其材料的利用提供了重要的有价值的信息.EST-SSR标记组合是构建中国大白菜核心种质及其指纹图谱的经济、高效的方法.     

Determination of n-l-1 Gamete Transmission Rate of Trisomics and Location of Gene Controlling 2n Gamete Formation in Chinese Cabbage （Brassica rapa）

A set of trisomics of Chinese cabbage was used for determining the n-I-1 gamete transmission rate and locating the gene controlling 2n gamete formation on the corresponding chromosome. The results showed that the transmission rates of extra chromosomes in different trisomics varied from 0% to 15.38% by male gametes and from 0% to 17.39% by female gametes. Of the nine F2 populations derived from the hybridizations between each trisomic and Bp058 （2n gamete material）, only Tri- 4xBp058 showed that the segregation ratio of plants without 2n gamete formation to plants with 2n gamete formation was 10.38：1, which fitted the expected segregation ratio of the trisomics （AAa） based on the 7.37% of n＋l gamete transmission through female and 5.88% through male. In other populations the segregation ratios varied from 2.48：1 to 3.72：1, which fitted the expected 3：1 segregation ratio of the bisomics （Aa）. These results suggested that the gene controlling 2n gamete formation in Chinese cabbage Bp058 was located on chromosome 4. Further trisomic analysis based on the chromosome segregation and the incomplete stochastic chromatid segregation indicated that the gene locus was tightly linked to the centromere.