| Cytoplasmic male sterility (CMS), the materally inherited failure to produce functional pollen, is a widespread trait in higher plants. It is generally recognized that CMS is controlled by nuclear-cytoplasmic interaction, and many CMS systems also influenced by environment conditions such as temperature and photoperiod. Studies on mechanism of CMS contribute to promoting heterosis utilization and understanding of nuclear-cytoplasmic interaction, pol CMS system is considered as "the first CMS system of rapeseed with practical value" among available several CMS systems such as ogu and nap. Some investigations indicated that transcription of the orf224/atp6 gene region was associated with pol CMS and restorer gene designated Rf modulated the transcription by very highly specific RNA processing events at the post-transcriptional level.In the present study an ecotypical male sterile-fertile line 8-8112AB, which belongs to pol CMS system, is male fertile when it is sown at Wuhan in Autumn, but it becomes sterile when it is sown at Kunming or Xining in Summer. Yang et al (1997) suggested temperature could be the main factor that could influence the fertility of 8-8112AB. Researches on inheritance of temperature-sensitive gene (Ts) from 8-8112AB associated with fertility change and action of Ts would provide the experimental fundament for understanding, utilizing and improving of 8-8112AB. The main results were as follows:1. As to floral morphology of 8-8112AB under the various temperature conditions, 8-8112AB was showed the similar flower shapes to those of normal fertile line 1141B at relative lower temperature, however, it had the same flower shapes to those of pol CMS line 1141A at relative higher temperature.2. Sowing date experiments of 8-8112AB and it's F1 (1141Ax8-8112AB) indicated that fertility of them was affected by temperature, rather than sowing date in the conditions of Autumn sowing in Wuhan, and they were fertile at relative lower temperature and became sterile at relative higher temperature. Moreover, the F1 had the more temperature-sensitive than 8-8112AB. The experiment of different temperature treatment on 8-8112AB and its hybrid indicated that temperature had considerable influence on their male sterility, and they were partially male fertileat 15℃/5℃ and completely male sterile at 25 ℃/15 ℃.3. It can be speculated that temperature-sensitive gene (Ts) from 8-8112AB is incomplete dominant to temperature-insensitive gene (ts) from 1141A on the basis of stable male sterility of 1141 A. According to the fertility segregation of progenies from F1, F2 and BC1 populations when sown in Wuhan, temperature-sensitivity of 8-8112AB may be controlled by several pairs of minor genes.4. RNA gel blots of floral mtRNA from a set of materials including a male fertile cytoplasm line 1141B, the pol CMS line 1141 A, and nuclear restorer lines, were analyzed using 10 probes of mitochondrial gene. The results showed that differences in transcripts patterns were observed with the probes atp6, or/224 and orf222. The atp6 probe detected a single, 1.1kb transcript in a male fertile cytoplasm line 1141B. In the pol CMS line 1141A and nuclear restorer lines with pol cytoplasm, levels of this transcript appeared greatly reduced and two transcripts of 2.2kb and 1.9kb were observed. And in the nuclear restorer lines, levels of the 2.2- and 1.9-kb transcripts appeared to be marked slightly reduced, and two additional transcripts were observed. The transcription of orf224/atp6 gene region was associated with pol CMS and regulated by Rfp, which was in accord with the consequence reported by other researchers such as Singh and Brown (1991).5. Differential transcription of orf224/atp6 in buds from 8-8112AB under various temperature conditions was regulated by temperature-sensitive genes in the nucleus of 8-8112AB. The atp6 probe detected four transcripts of 2.2kb, 1.9kb, 1.4kb and 1.1kb in partially fertile 8-8112AB at relative lower temperature. The same transcripts were observed...
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