The reporter learned from Shandong Agricultural University on the 26th that the scientific research team led by Professor Duan Qiaohong of the university has recently successfully revealed the molecular mechanism of maintaining interspecific reproductive isolation by regulating the level of reactive oxygen species in the stigma of Chinese cabbage and other cruciferous vegetables, and developed a breeding technology to break the reproductive isolation of distant hybridization. Relevant scientific research achievements were published online in the international academic journal Nature on the 25th. The vegetable reproductive mechanism and breeding application team of Shandong Agricultural University, which has made relevant achievements, said that while revealing the molecular mechanism and developing the breeding technology, the team has successfully obtained the interspecific and intergeneric distant hybrid embryos of Chinese cabbage. The interlocking scientific research achievements have realized the renewal and expansion of the ideas and approaches of distant hybridization breeding. The reporter learned that most cruciferous vegetables such as Chinese cabbage have self-incompatibility and are typical cross-pollination crops. In the breeding process, self-incompatibility breeding and distant hybridization breeding are the main breeding techniques for cruciferous vegetables. However, the actual situation is that it is laborious and inefficient to carry out traditional distant hybridization breeding for related vegetable varieties. It is imperative to analyze the control mechanism of crop self-pollination and efficiently utilize the germplasm resources of distant species. "Based on the one-way incompatibility phenomenon of distant hybridization, we have built the corresponding theoretical basis in the early stage." Duan Qiaohong said that the team further verified the theoretical presupposition that "self-flowering pollen within the species will activate the production of living oxygen in the stigma of Chinese cabbage to inhibit self-flowering pollen" in the experiment. Subsequently, the team broke through the barrier of distant hybridization of cruciferous vegetables by removing active oxygen from stigma, and successfully obtained interspecific and intergeneric hybrid embryos of Chinese cabbage. Zou Xuexue, an academician of the CAE Member and professor of Hunan Agricultural University, believed that this research systematically analyzed the formation mechanism of reproductive isolation in distant hybridization and developed distant breeding technology to break reproductive isolation. It has both theoretical innovation and breeding application value, and is a landmark achievement in the field of plant reproductive biology and hybrid breeding. Relevant theories and technologies will have a profound impact on vegetable breeding. (Xinhua News Agency)