Abstract: Male sterility with Aegilops kotschyi cytoplasm has a great application potential in hybrid wheat (Triticum aestivum L.) breeding for its stable sterility and broad-spectrum of restoring gene resources. To further reveal the genetic mechanism of male sterility with Aegilops kotschyi cytoplasm, a male sterile line ms (Kots)-90-110(A) and its near isogenic line BC₄F₁ (fertility restored by rk5451) were employed to construct sterility and fertility cDNA libraries by suppression subtractive hybridization (SSH). Wheat anthers with pollen mother cells at dikaryophase were sampled for RNA extraction via microscopic examination. The two cDNA libraries were evaluated to be of good quality with high efficiency of SSH. Total 120 positive clones were randomly selected and sequenced from the 2 libraries, and 100 high quality sequences were obtained. According to BLAST screening and functional annotation, energy-related genes were identified with high frequencies in fertility cDNA library, while MADS-box transcriptional factor TaAGL7, ubiquitin-conjugating enzyme, and adenosine diphosphate glucose pyrophosphatase were detected in sterility cDNA library. The MADS-box transcription factor TaAGL7 plays important roles in regulating flower development. Immature spike ubiquitin-conjugating enzyme is likely to relate to apoptosis. The expression of adenosine diphosphate glucose pyrophosphatase directely affectes starch synthase and normal supply of energy. The genes detected in our study are probably important in fertility of wheat with Aegilops kotschyi cytoplasm.

Key words: Wheat, Sterility gene, Suppression subtractive hybridization (SSH), Expressed sequence tag (EST)