Mitochondrial genome structure of a cytoplasmic hybrid between tomato and wild potato

A physical map of the mitochondrial genome was constructed for a male-sterile tomato, MSA1, which had been generated by an asymmetric cell fusion between tomato (Lycopersicon esculentum) and wild potato (Solanum acaule). The entire genomic sequence of the MSA1 mitochondria (450 kb) was represented by five maps. Even if sequence duplications were taken into consideration, at least two linkage groups (maps 1–4 and map 5) were necessary to show the overall genome. The mitochondrial genome structure of MSA1 was also analyzed by comparing the Southern hybridization patterns of MSA1 and its parents (tomato and wild potato). The mitochondrial genome of MSA1 consists of a complex mixture of the parental genomes with at least 11 molecular recombination events. Received: 23 February 1998 / Revision received: 2 March 1998 / Accepted: 14 March 1998     

湖北光敏核不育水稻农垦58S叶片60 kD蛋白特异性及其功能的讨论

湖北光敏核不育水稻(Hubei photoperiod-sensitive genic male-sterile rice, HPGMR)是在我国发现并开始应用研究的。人们在应用研究中发现的许多问题,如光敏不育特性转育到籼稻上多变成温敏不育等,很难达成共识。加强机理研究已成为光敏水稻研究深入发展的当务之急。除了对不同时期“农垦58”与58S的代谢做各种分析外,寻找特异蛋白与特异基因是光敏水稻机理研究中两个重要方面。在蛋白研究方面,目前已报道发现35kD、45kD、60kD、61kD等与光敏不育材料有关的特异蛋白。这些结果表明,在“农垦58”与58S之间是可以找到特异蛋白的,但还不能确定这些蛋白与光敏不育性状的关系。为了解决已发现的特异蛋白与光敏不育性状的相关性问题,我们采用多对照的方法,对已知在农垦58S中稳定表达而在“农垦58”中不出现的60kD蛋白做了进一步的研究。     

湖北光周期敏感核不育水稻花药能量和活性氧的代谢

湖北光周期敏感核不育水稻,在单核早期、单核晚期、二核及三核期的不育花药的细胞色素氧化酶(COD)、ATPase、过氧化物酶(POD)、过氧化氢酶(CAT)、SOD 在每小穗花药中的总活性普遍低于其可育花药,不育花药在发育的后期缺1—5条 COD、1条超氧物岐化酶(POD)和1—2条 Cu-Zn SOD 同工酶带。不育花药具较低的 ATP 含量和较高的 O(?)产生效率,且有 H_2O_2和丙二醛(MDA)的积累。对光敏雄性不育的发生与不育花药中异常的能量和活性氧代谢之内在联系进行了讨论。     

雄性不育水稻小孢子败育与花药的有机自由基水平

以电子自旋共振(ESR)检测细胞质雄性不育(CMSR)和湖北光敏核不育水稻(HPGMR)花药的有机自由基水平。在小孢子单核期到三核期的花药中有机自由基为无超精细分裂的单峰信号,其特征 g 因子在2.0024—2.0031之间。细胞质雄性不育系 V_(20)A 和珍汕97A 三核期小孢子的花药干样品中有机自由基是二核期的3.2—3.8倍,相应的保持系则只增加15—43%。光敏核不育水稻农垦58s 和 W6154s 在6月份花药转向全不育的自然条件下,花药的有机自由基也随小孢子发育及采样期推延而增加。表明雄性不育过程发生了自由基代谢异常。     

湖北光周期敏感核不育水稻农垦58S幼穗和花药发育期的蛋白酶活性变化

湖北光周期敏感核不育水稻农垦585的可育与不育株在一次枝梗期的幼穗中可溶性蛋白含量相近。雌雄蕊形成期和花粉母细胞分化期的可有株可溶性蛋白较不育株的分别高21％和12．3％;可有株在花粉二核和三核期亦有较高含量。不育株在雌雄蕊形成期后,酪蛋白酶活性迅速增高,而可有株至二核期才增高。不育株除在二次枝梗期的内肽酶活性略低外,其余阶段酶的活性较高。育性转变时内肽酶类型亦发生变化。可有株有较高的氨肽酶活性．     

A triallelic genetic male sterility locus in Brassica napus: an integrative strategy for its physical mapping and possible local chromosome evolution around it

Background and Aims

Spontaneous male sterility is an advantageous trait for both constructing efficient pollination control systems and for understanding the developmental process of the male reproductive unit in many crops. A triallelic genetic male-sterile locus (BnMs5) has been identified in Brassica napus; however, its complicated genome structure has greatly hampered the isolation of this locus. The aim of this study was to physically map BnMs5 through an integrated map-based cloning strategy and analyse the local chromosomal evolution around BnMs5.

Methods

A large F₂ population was used to integrate the existing genetic maps around BnMs5. A map-based cloning strategy in combination with comparative mapping among B. napus, Arabidopsis, Brassica rapa and Brassica oleracea was employed to facilitate the identification of a target bacterial artificial chromosome (BAC) clone covering the BnMs5 locus. The genomic sequences from the Brassica species were analysed to reveal the regional chromosomal evolution around BnMs5.

Key Results

BnMs5 was finally delimited to a 0·3-cM genetic fragment from an integrated local genetic map, and was anchored on the B. napus A8 chromosome. Screening of a B. napus BAC clone library and identification of the positive clones validated that JBnB034L06 was the target BAC clone. The closest flanking markers restrict BnMs5 to a 21-kb region on JBnB034L06 containing six predicted functional genes. Good collinearity relationship around BnMs5 between several Brassica species was observed, while violent chromosomal evolutionary events including insertions/deletions, duplications and single nucleotide mutations were also found to have extensively occurred during their divergence.

Conclusions

This work represents major progress towards the molecular cloning of BnMs5, as well as presenting a powerful, integrative method to mapping loci in plants with complex genomic architecture, such as the amphidiploid B. napus.     

一种紫色水稻的遗传及其在光敏不育系育种中应用的研究

研究表明,本院获得的一种紫色水稻的植株色遗传受控于C、 A、Pl3个独立基因座位上显性基因的互补作用,另有一独立的显性基因对Pl基因的表达起抑制作用。由于该抑制基因在籼稻中的高频率存在,因而,紫稻与一般绿稻品种杂交F1多表现为绿株。紫稻光敏不育(株)系的不育性表达和配合力表现,均可达到与普通光敏不育系相似的水平。本文还讨论了选育籼型紫稻光敏不育系设想的可行性。 Abstract:The inheritance of a purple rice in crosses to green rices was investigated.A group of dominant and interactive genes,C,A and Pl,was found to control the expression of the trait and the other independent inhibitor I-Pl-1 to inhibit the effect of the gene Pl.Because of the wide existence of the gene I-Pl-1 in indica rice,most of F1 plants of the crosses between purple rice and green cultivars were green.The primary study indicated that,for the purple photoperiod-sensitive genic male-sterile lines,the degrees of the sterility and its stability in the sterile stage,and of the fertility in the fertile stage,and the combining ability levels of the purple rice were as high as the degrees and levels for the green rice.A tentative idea on breeding purple photoperiod-sensitive male-sterile lines of indica rice was suggested and its feasibility and advantage was discussed.     

小麦遗传型与生理型雄性不育花药蛋白质双向电泳分析

为了研究小麦雄性不育蛋白表达机制, 以具有异质同核的3个亲本: 即遗传型不育系ms(S)-西农1376、对应的保持系(A)-西农1376和生理型(化学杀雄剂SQ-1诱导)雄性不育系ms(A)-西农1376为材料, 利用IEF/SDS-PAGE凝胶电泳技术, 对发育到单核后期的花药全蛋白特异性进行了比较分析, 得到320~350个清晰的蛋白点。结果表明: 遗传型和SQ-1诱导的生理型不育系蛋白质图谱与正常保持系在蛋白质(多肽)表达量上存在一定的差异, 同时发现有几种蛋白质的表达有明显的特异性, 两个不育材料2D胶上共有几个明显的特异蛋白点, 而在保持系中未发现; 两个不育材料又分别具有自己的特异蛋白表达, 不育机理不同; 比较分析可知, 不育系中某些蛋白的表达受到了抑制, 并开启了与花药败育有关的特定蛋白的表达, 可能使物质能量代谢受阻,导致雄性不育的发生。