Molecular Plant Breeding 2025, Vol.16, No.4, 250-260 http://genbreedpublisher.com/index.php/mpb 254 appearance of the MC mode is relatively ordinary. In terms of taste, mixed sowing and transplanting can reduce chalkiness, amylose and protein content, and also improve gum consistency and overall taste score (Gao et al., 2023). However, the influence of different transplanting methods on the taste value is not particularly significant. Soft rice varieties have the best taste, followed by common japonica rice, and hybrid japonica rice has the worst (Bian et al., 2018). When encountering high-temperature weather, the transplanting method has more advantages in maintaining the whole polished rice rate, gum consistency and amylose content, indicating that it is more resistant to adverse conditions (Zang et al., 2022). 5.3 Nutritional traits and market acceptance The transplanting method can also affect the nutritional components of rice. Under mechanical carpet seedling transplanting (MC), the protein content is higher than that by direct seeding. Under the MD method, the protein content is relatively low and the nutritional quality will be poorer (Bian et al., 2018). Mixed seeding and transplanting can further reduce the content of protein and amylose, thereby making the rice softer and more fragrant (Gao et al., 2023). From a market perspective, the MC method has good processing quality and nutritional level, so consumers are more willing to buy this kind of rice (Abou-Khalifa et al., 2021). In addition, different transplanting methods have little effect on the amino acid composition, and the biological nutritional value of rice remains basically unchanged. 6 Evaluating Yield and Quality Adaptability across Methods 6.1 Definition and indicators of adaptability Adaptability generally refers to whether a variety can maintain high yield and good quality under different cultivation methods or transplanting approaches. When evaluating adaptability, several aspects are usually considered: such as yield per unit area, number of effective panicles, number of grains per panicle, seed setting rate and other yield indicators; Quality indicators such as processing quality, appearance, nutritional components, palatability value, amylose and protein content are also considered. Growth conditions such as leaf area index, dry matter accumulation and nitrogen absorption are also taken into account (Wu et al., 2022; Ren et al., 2024). In addition, it is also crucial whether the yield of a variety can be stable and whether the quality will change little (Chen et al., 2025a). 6.2 Multi-location and seasonal performance variability After conducting experiments at multiple sites and in various seasons, it was found that japonica rice varieties respond very differently to the environment under different transplanting methods. Some studies have pointed out that mechanical transplanting methods (such as pot seedlings, blanket seedlings, direct seeding) perform better in terms of yield and some qualities compared with manual transplanting, but there will also be an interactive effect of “genotype ×environment” depending on the variety (Hu et al., 2018; Wu et al., 2022). For instance, under the condition of appropriate density, mechanical pot seedling wide and narrow row transplanting can achieve the maximum yield and also improve processing and nutritional quality (Hu et al., 2020); while mechanical live streaming has a better appearance, its processing and nutritional quality are slightly inferior (Bian et al., 2018). Regional trials also showed that some hybrid japonica rice varieties (such as Zhegengyou2035 and Changyou20-2) performed well in different regions and had stable yields (Chen et al., 2025a). 6.3 Varietal stability under transplanting stress or environmental fluctuations When a variety is confronted with transplanting pressure (such as mechanical operation, density changes) or environmental changes like climate and soil, its stable performance is also an important manifestation of adaptability. Studies have found that the yield and nitrogen absorption capacity of hybrid japonica rice are generally stronger, especially under new technologies such as mechanical pot seedling transplanting, the advantages can be better exerted (Chen et al., 2025a; Chen et al., 2025b). Some conventional japonica rice varieties have relatively stable processing quality, while soft rice varieties are less affected in terms of nutrition and taste (Bian et al., 2018). In addition, reasonable density and nitrogen application strategies can further enhance the yield and quality performance of varieties under different transplanting methods (Hu et al., 2020; Ren et al., 2024).
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