Legume Genomics and Genetics 2025, Vol.16, No.6, 297-312 http://cropscipublisher.com/index.php/lgg 303 fluctuation of shade-tolerant varieties is small. This further proves that variety resistance is one of the decisive factors affecting the magnitude of losses caused by continuous rain disasters. In the future, we should strengthen the evaluation of the resistance of pea varieties to rain, establish a variety resistance database, and provide a scientific basis for variety layout in different regions and climatic conditions. 4.3 Application value of selecting resistant varieties Selecting excellent pea varieties suitable for local climatic conditions is one of the most economical and effective measures to deal with the damage of continuous rain. Promoting shade-tolerant and moisture-tolerant varieties in areas with frequent continuous rain can significantly reduce the risk of yield reduction due to weather reasons. Under rain stress, the yield of pea varieties is closely related to their antioxidant enzyme activity, chlorophyll content and root ventilation capacity. Shade-resistant and moisture-tolerant varieties often have stronger antioxidant systems (such as higher POD and SOD activities), which can slow down the damage of photosynthetic organs, and the roots are more adaptable to low-oxygen environments, thereby maintaining normal water and nutrient absorption functions (Yang et al., 2022a). In the plum rain area in the middle and lower reaches of the Yangtze River, by introducing early-maturing and waterlogging-resistant pea varieties, we can avoid the peak of the plum rain season to complete pod formation and maturity, and reduce the impact of continuous rain. While selecting varieties for stress resistance, we must also take into account market demand and quality. For example, some shade-tolerant varieties are for feeding or processing, and the fresh taste is poor. Therefore, in actual promotion, it is necessary to balance resistance and commerciality. Overall, the screening and application of excellent varieties that are resistant to continuous rain have many values: for farmers, it can reduce losses due to disasters and ensure stable income; for agricultural production as a whole, it can improve the resilience of the system and ensure that grain and bean crops still have a certain level of production under abnormal climatic conditions, which is conducive to food security. At present, scientific research units in various places are strengthening research in this area. For example, the northwest rain-fed areas such as Dingxi, Gansu are evaluating the stress resistance performance of a batch of new pea lines to provide a basis for variety replacement in rainy years; humid areas such as Guizhou are also exploring the introduction of highly disease-resistant varieties for rainy season cultivation. The Yunnan Academy of Agricultural Sciences also screened shade-tolerant and moisture-tolerant pea germplasm through resource gardens to lay the foundation for stress-resistant breeding. It can be expected that with the successful breeding and promotion of more shade-tolerant and moisture-tolerant pea varieties, my country's pea production's adaptability to adverse climates such as continuous rain will be further improved (Chen et al., 2021). 5 Indirect Agronomic Impacts of Continuous Rain 5.1 Facilitation of pest and disease outbreaks Continuous rainy weather not only directly affects the pea pod setting rate, but also induces pest and disease problems by changing the ecological environment, which has an indirect impact on agricultural production. The most obvious of these is the large-scale occurrence of various diseases. High humidity conditions are prone to outbreaks of pea gray mold, sclerotinia and other flowering and pod diseases. In fact, continuous rain also contributes to the spread of other diseases and pests. Long-term humidity will reduce the disease resistance of plants, making it easier for latent pathogens to break through host defenses. Many fungal diseases (such as rust and downy mildew) do not show symptoms immediately in the early stages of bacterial infection, but will quickly expand into disasters in the high humidity environment caused by continuous rain. For example, the pea rust pathogen needs a water film on the leaf surface to germinate and invade. Continuous rain provides continuous leaf surface moisture conditions, allowing rust to spread in a timely and large area. After severe infection of the leaves, the photosynthetic capacity of the plant is weakened, indirectly affecting pod setting and filling. Looking at pests, continuous rain has different effects on different pests. Some moisture-loving pests reproduce more on rainy days, such as slugs, snails and other mollusks that eat pea seedlings and pods in a humid environment. However, most field pests are restricted in their activities during continuous rainfall. For example, aphids will be knocked down in the rain, and continuous rain sometimes has an inhibitory effect on aphids.
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