Abstract:

With the passage of time and the advancement of technology, crop breeding has gone through generations from 1.0 to 4.0 and is now moving towards generation 5.0. Although the 3.0 and 4.0 generations of breeding have received extensive attention, only hybrid breeding of the 2.0 generation can enable the parents to achieve genome-wide recombination, resulting in a large number of complex and unpredictable interactions within and between genes, which may be the basis for the emergence of breakthrough traits. Thus hybrid breeding still holds an important position. However, at present, taking rice as an example, the hybrid breeding operations carried out by the majority of breeders may still have issues that need improvement in terms of scientificity and efficiency. In light of the current situation, in order to select high-yielding, high-quality, and multi-resistant varieties, and to overcome the homogenization of varieties, hybrid rice breeding should pay attention to the following aspects. Firstly, the breeding goals should be combined with the local natural conditions and effectively coordinate the combination of advantageous traits. Only in this way can the high-yield, high-quality and highly-resistant high-level goals be achieved, so as to break through the homogenization of varieties. Secondly, because the F₁ generation combines the superior traits of both parents and has certain hybrid vigor, it may be the best-performing generation of the same combination. If F₁ performs poorly overall, it is difficult for its offspring to produce the expected types that meet the breeding goals. Therefore, this generation should be selected as a key generation, which is conducive to significantly improving the efficiency of breeding. Thirdly, in the early stage of breeding, the main task is to promote generations. To enhance the breeding efficiency, direct seeding should be adopted, which can save land and resources. During the breeding process, the current generation should be combined with the early-generation tests to increase predictability and further eliminate combinations to improve the breeding efficiency. Fourth, during the high-generation selection process, after field selecting, the panicle traits of the combinations should be further compared indoors to select the optimal combination, so as to achieve the best from the best. Finally, the intelligent varieties of the 5.0 generation of breeding are those that can adapt to the ecological and biological factors of the wide range of environments, and can meet the production needs with wide adaptability. Due to the complexity of the environmental conditions for crop growth, it is necessary to conduct extensive and long-term identification of the varieties to achieve the breeding goals. In conclusion, by optimizing the field operations and selection techniques in hybrid breeding, the breeding efficiency will be significantly enhanced, laying the foundation for the selection of breakthrough varieties.

Key words: rice, hybrid, breeding objective, selection technology, generational promotion, eurytopic