The new rice variety, Zhongke Fa No.5, was developed by the team led by Academician Li Jiayang using the concept of molecular design breeding. By combining phenotypic and molecular marker selection, it has integrated the genotype combination of multiple copies of GL7, GS3, and GW5, resulting in slender grains. It also contains high-yield QTLs such as qSB2, qSB8, qSB10, and SCM2, and carries the blast resistance alleles Pib, qBR10, Pi-ta and Ptr. Based on this, this variety demonstrates outstanding agronomic traits including high yield, multi-resistance and excellent quality. In 2014, it ranked among China’s top ten cultivated varieties and has become a signature variety in Northeast China. In the face of this situation, in the future, Northeastern japonica rice should take it as a benchmark and strive to surpass it. Taking into account the supply and demand situation of rice, the overall breeding goal should be a long-grain fragrant variety with high yield. Specifically, the yield target should be above 9500.0 kg·hm^-2, and the trait combination to achieve this target is a plant height of 95.0-105.0 cm, a total of 3.75 million to 4.2 million effective panicle number per hectare, a grain number of 120.0 or more per spike, and a thousand-grain weight of more than 25.0 grams. The quality target is a grain length greater than 6.0 mm, a length-to-width ratio greater than 2.8, an overall polished rice rate meeting the approved standards, excellent appearance, a taste score of over 80 points. And it also has good adaptability and resistance. To achieve this goal, the first step is to enhance dialectical thinking. In practice, we must resolutely eliminate a large number of materials that fail to meet the breeding objectives. At the same time, we should strengthen the practice of combining superior traits and the dialectical thinking of their adaptability to local cultivation conditions. During the breeding process, high-yield resources and long-grain resources should be coordinated and utilized, and multiple cross should be strengthened. At the same time, the breeding process should be optimized, and modern breeding technologies such as molecular breeding should be actively adopted. The key to the breeding strategy lies in expanding the application of hybrid rice restorer lines derived from indica-japonica subtypes, especially those of high-yield indica-japonica three-line hybrids. Since the high-yield three-line hybrids themselves have a relatively high yield, and their gametes have extensive recombination, there is greater expectation for the emergence of breakthrough types. To better achieve the breeding goals of long-grain rice, it seems that using japonica rice restorer lines with wide compatibility and crossing them with long-grain indica hybrid rice is the best strategy. However, further verification is needed.

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.