Pollen Characteristics and Genetics of Induced and Spontaneous Genetic Male-Sterile Mutants in Rice

Pollen characteristics, inheritance and allelism of 23 genetic male-sterile (ms) mutants of rice (Oryza sativa L.) were investigated. Ten of the mutants were induced by ethyl methane sulfonate, one induced by ethyleneimine, seven induced by gamma rays, one induced by streptomycin, one derived from tissue culture and three were spontaneous mutants found in the field. Four pollen abortion types were observed among these ms mutants: 3 no-pollen (NP) type, 6 complete pollen abortion (CPA) type, 13 partial pollen abortion (PPA) type, and 1 stainable pollen abortion (SPA) type. Progeny tests over two years indicated that each of the mutants was inherited as a monogenic recessive. A partial diallel cross among the 23 ms mutants indicated that mutant E2 was allelic to G4, E5 was allelic to E9, N2 was allelic to N3, and that three other mutants, E3, G6 and T1, shared the same ms locus. Gene symbols ms-46 (t) through ms-63 (t) were assigned to these mutants.     

The transfer of the synaptic gene (sy-2) from 1EBN Solanum commersonii Dun. to 2EBN germplasm

Summary Crosses of a synaptic mutant (sy-2) of 2x(1EBN) S. commersonii Dun. with 2x(2EBN) S. chacoense Bitt. resulted in the production of 3x(2EBN) hybrids. Low levels of 2n egg production in these hybrids allowed subsequent crosses to be made with 4x(4EBN) cultivars, resulting in 5x(4EBN) S. commersonii-S. chacoense-Group Tuberosum hybrids. Seed set in these crosses averaged 0.22 seeds per fruit. Fifty-four unspotted seeds were produced in 1225 crosses of the 5x(4EBN) hybrids with 2x(2EBN) Group Phureja haploid extraction clones carrying dominant seed spot markers. These seeds yielded a total of 15 confirmed haploids having a diploid (2n=2x=24) or near diploid chromosome number. One haploid clone recovered displayed a synaptically abnormal phenotype similar to the original S. commersonii synaptic mutant. Preliminary test crosses of these haploids indicated that all haploids produced were 2EBN.This method for the transfer of alleles across EBN levels holds promise for the recovery of both qualitative and quantitative traits from 1EBN species. In these recovered, cross-compatible forms, clones with desired characteristics may be selected and easily incorporated into breeding programs.     

Mutation breeding of Chrysanthemum morifolium Ram. using in vivo and in vitro adventitious bud techniques

Summary During experiments, which are being carried out to study the factors which control the process of adventitious bud formation in vivo on detached leaves of Chrysanthemum morifolium Ram, adventitious shoots were produced from leaves, irradiated with 500 rad of X-rays. The most important but disadvantageous result was that the majority of the adventitious shoots proved to be of a chimeral nature and obviously developed from more than one cell.An in vitro adventitious bud technique was developed using different types of explants. Pedicel segments regenerated the highest number of adventitious shoots and, moreover, they developed faster as compared to explants of young flower heads or leaves. The mutants produced by irradiating the various explants were almost exclusively of a solid (non-chimeral) nature. In addition, histological observations suggest that single epidermal cells are involved in the initiation of the adventitious shoot apices.The optimum dose for mutant production is approximately 800 rad X-rays. Rather often, more than one phenotypically identical mutant was found, which was always derived from the same explant. They could for instance originate from a multi-apical meristem formed by a single mutated cell.     

Relative efficiency,ureide transport and harvest index in soybeans inoculated with isogenic HUP mutants of Bradyrhizobium japonicum

Summary Differences between isogenic uptake hydrogenase (HUP) mutants of Bradyrhizobium japonicum in terms of nodule efficiency, N₂ fixation and N incorporation into various plant parts were studied in a monoxenic greenhouse experiment in order to confirm previous results with soybeans and beans inoculated with various HUP⁺ and HUP^– strains. The HUP+ revertant PJ17-1 of a HUP^– mutant (PJ17) of strain USDA DES 122 showed a completely restored relative efficiency (100% versus 78±2% for the HUP^– mutant), higher nodule efficiency (N₂ fixed per g nodules), higher ureide-N transport rates, higher N contents in pods and higher N harvest indices. All these observations confirm previous experiments with HUP⁺ and HUP^– strains.     

利用薄层色谱法快速筛选法夫酵母突变株

法夫酵母（Phaffia rhodozyma）是一种极具产业化前景的天然虾青素资源（Johnson,2003）.本实验从溶剂极性、溶剂组成等方面优选法夫酵母类胡萝卜素薄层分析的溶剂,并对薄层色谱在法夫酵母类胡萝卜素突变株筛选中的应用进行了研究.     

水稻诱变糯质基因回复突变的研究

以杂交稻亲本胚乳糯质基因突变体南恢175wxR、湘恢288wxR、II-32wxB、明恢86wxR、蜀恢527wxR、明恢63wxR、龙特浦wxB以及D62wxB为材料,肉眼鉴定其自交后代胚乳性质,结果发现诱变糯质基因wx发生回复突变(即胚乳性质由糯质回复突变为非糯质),回复突变频率为0～6.34×10-5,平均为3.74×10-5.     

彩色棉纤维色泽遗传规律研究

用 3个棕色纤维和 4个绿色纤维的彩色棉品种与 5个常规白色棉品种配制成 11个杂交组合 ,研究彩色棉的遗传规律。试验结果表明 ,陆地棉绿色和棕色有色纤维性状受不完全显性单基因控制。     

利用RAPD—BSA分子标记技术筛选金针菇色泽基因研究

色泽是金针菇的重要性状之一,受一对等位基因的控制。以FL19(黄色)、8801(白色)及其后代(F1代、F2代)菌株和相应单核菌株为材料,采用分离群体分组分析(BulkedSegregantAnalysis,BSA)方法,对金针菇基因组DNA进行RAPD分析,通过对200个引物的筛选,获得了一个与白色性状基因紧密连锁的RAPD标记S3751800,并在亲本及其后代菌株进行了验证,具有较好的重复性和稳定性。可用于白色金针菇新品种的辅助选育。     

彩色大白菜新品种“金冠2号”的选育

在1996年育成彩色大白菜材料的基础上,应用优良自交系92S24等采用杂交、自交,育成了系列彩色大白菜自交系,2002年从20多个杂交组合中筛选“金冠2号”新品种(01S1024×01S915)。该品种叶球叠抱,高头球形,株高41 cm,株幅65 cm;球形指数1.4;外叶绿色,球叶外层2~3片叶为绿色,内层叶色为橙色,在阳光下叶色稍变红;单球净重2.5~3.0 kg,净菜率为75%以上,结球紧实,营养丰富,商品性好;球叶类胡萝卜素含量为优质普通大白菜秦白二号的3.47倍,vC、可溶性糖、粗蛋白分别提高44%、36%和18%,干物质提高11.73%,粗纤维减少26.0%。一般净菜产量为90.0 t/hm2左右,高抗病毒病、霜霉病、干烧心、软腐病和黑斑病,生育期75~80 d。2004年通过陕西省新品种鉴定。     

牛叠朊编码基因缺失突变体的构建及在大肠杆菌中的表达

本实验室已制备出多株针对牛叠朊的单克隆抗体,为充分鉴定这些单克隆抗体针对的抗原表位,通过基因克隆表达的策略获取牛叠朊基因缺失突变体的重组蛋白,以期为单克隆抗体的表位鉴定提供物质材料。经过对牛成熟叠朊编码基因及预测蛋白结构特征的分析,设计表达9个缺失突变体的引物。以PCR扩增出叠朊基因的缺失突变体,与pET-30a（＋）表达载体连接后转入E.coli DH5α中,经双酶切和测序鉴定后将重组质粒转入E.coliJM109和E.coli BL21表达宿主菌中,经IPTG诱导表达后,以SDS-PAGE、Western blot和ELISA检测表达产物的相对分子质量、相对表达量和反应原性。结果表明,成功构建了9个牛叠朊编码基因的缺失突变体,通过IPTG的诱导表达,其中有6个缺失突变体被大肠杆菌高效表达,并且具有较好的反应原性,这为其单克隆抗体表位的进一步鉴定奠定了物质基础。