Exploration and utilization of maize male sterility resources.

Male sterility refers to the defective development of male reproductive organs, which led to plants incapable of producing normal and functional pollens. Maize (Zea mays L.) is one of the most important food crops, as well as one of the earliest crops to utilize heterosis in breeding.

[Genetics of fertility restoration in the isocytoplasm allonuclear C-group of cytoplasmic male sterility in maize].

Maize is one of the first crops to produce hybrids using cytoplasmic male sterile lines. The C-type cytoplasmic male sterile (CMS-C) line is vital for hybrid seed production, and the fertility-restoration reaction along with its stability has a direct bearing on its applications. However, fertility restoration mechanism of CMS-C is complex and is still not clear so far.

Research progress on mechanisms of male sterility in plants based on high-throughput RNA sequencing.

Male sterility is defined as failing to produce functional pollen during stamen development in plants, and it plays a crucial role in plant reproductive research and hybrid seed production in utilization of crop heterosis. High throughput RNA sequencing (RNA-seq) has been used widely in the study of different fields of life science, as it readily detects all the mRNA and non-coding RNA in cells. Recently, RNA-seq has been reported to be applied in different species and kinds of pollen abortion types in plants, which has contributed to the understanding of the molecular mechanism and metabolic networks of male sterility at the transcription level.

[Research progress of the bHLH transcription factors involved in genic male sterility in plants].

Male sterility exists widely in the spermatophytes. It contributes to the study of plant reproductive development and can be used as an effective tool for hybrid seed production in heterosis utilization. Therefore, the study on male sterility is of great value in both theory and application.

[Combining ability analysis for SP4 lines of maize from space flight].

Three maize (Zea mays L.) inbred lines 08-641, RP125, and 18-599 were carried into cosmic space by recoverable satellite "Shijian 8". Some mutant lines were selected from SP4 and combinations were made according to the NC II genetic design.

[Genetic analysis of maize cytoplasmic male sterile mutants obtained by space flight].

Three maize male sterile mutants were obtained from the offsprings of two maize inbred lines 18-599 and 08-641, which were carried into space by the Shijian 8 Satellite. The stability of male sterile expression was observed in different locations, years, and seasons. In order to analyze the genetic characteristic of male sterility, testcross, backcross and reciprocal cross were made with these male sterile plants.

RNA editing of mitochondrial functional genes atp6 and cox2 in maize (Zea mays L.).

RNA editing of two mitochondrial or organs genes, atp6 and cox2, in different tissues were analyzed using homonucleic but alloplasmic, and homoplasmic but heteronucleic maize (zea mays L.) as experimental materials. A total of 18 and 26 editing sites for atp6 conservative region transcript were identified by direct and clone sequencing, respectively.

[Cytological observation on pollen abortion of genetic male sterile mutant induced by space flight in maize].

In order to understand the cytological mechanism of pollen abortion of genetic male sterile mutant induced by space flight in maize, the sister cross population were used for sterility analysis and cytological observation. Intact anther observation, isolated cells observation and paraffin section were adopted in this research. The results showed that pollen abortion occured mostly in dyad stage of meiosis in genetic male sterile mutant.

[The editing sites in the transcripts of mitochondrial atp6 gene of maize sterile lines and maintainer line].

Using maize (Zea mays L.) cytoplasmic male-sterile lines T Huang Zao Si, C Huang Zao Si, S Huang Zao Si and maintainer line N Huang Zao Si as the plant materials, editing sites in the conservative area of mitochondrial atp6 gene transcripts of the 4 experimental materials' tassels, of which microspores had developed to uni-nucleate stage, were analyzed. The results showed that DNA sequences of the T, C and S male-sterile cytoplasms were completely unanimous, while being compared with the N-cytoplasm, all the sequences were similar except for the 27th and 28th nucleotides.

[The discovery of a specific DNA fragment associated with maize cytoplasmic male sterility and its differential display].

Three pairs of PCR primers were designed according to the mitochondrial DNA sequence. PCR amplification was applied to 3 sets of isonuclear alloplasm materials and 3 sets of isoplasm allonuclear materials. Multiplex PCR and general PCR protocol were adopted with total genomic DNA.

[Locating maize male sterility gene induced by space flight using microsatellite markers].

Two F2 populations with different kinds of spike derived from maize male sterility materials RP(3)195 (A) x S37 (inbred line) ,which had been sib-bred for many generations,were used for sterility analysis and gene location. There were 138 and 247 plants in the two F2 populations respectively. Among the 326 pairs of microsatellite primers selected,56 were found polymorphic.

[The production and multi-color genomic in situ hybridization identification of maize-Z. perennis substituted material].

Genus Zea. L was composed of two sections: sect. Luxuriantes Doebley & Iltis including Z.

[Genetic analysis about maize male sterile mutant obtained by space flight].

The seeds of maize single hybrid Chuandan No. 9 were carried into space in 1996 by satellite. After the seeds were planted in field in comparison with travel in space seeds which was not carried into space.

[A study of genetic stability of male sterile mutant of maize obtained from space flighted seeds].

Objective: To select a male sterile mutant of maize through space flight for production application.

Method: Air dried seeds of maize (Chuan Dan No. 9) were carried to space for 15 d.