Maize Genomics and Genetics 2025, Vol.16, No.3, 149-166 http://cropscipublisher.com/index.php/mgg 151 temperature and high humidity conditions in summer, without serious lodging and stem rot problems. Among them, varieties such as 'Caitiannuo 168' also showed high tolerance to low temperature and cold damage. The seedlings were not frozen during early spring sowing, showing strong resistance to low temperatures (Figure 1). According to the performance of trial planting in coastal saline-alkali land, some sweet and glutinous corn varieties have certain salt tolerance and grow normally on plots with soil salt content of 0.2% to 0.3%, with almost no reduction in yield. Figure 1 Seedlings of 'Caitiannuo 168' In terms of disease and insect pest resistance, there are certain differences between different varieties. From the results of the adaptability identification of this introduction, it can be seen that the resistance evaluation of some varieties to major diseases is not ideal. For example, the results of the adaptability test in Zhejiang Province showed that varieties such as 'Xiantiannuo 88' and 'Ditiannuo 336' were susceptible to small spot disease, sheath blight, and southern rust after artificial inoculation of diseases. This suggests that some introduced varieties may lack the corresponding disease resistance genes locally, and field prevention and control need to be strengthened. Similarly, the study found that the overall disease resistance of fresh corn varieties in my country needs to be improved. In the evaluation of the resistance to head smut and gall smut of 58 fresh corn hybrids, no material showed high resistance, only one material ('Yuanyunuo 999') showed disease resistance (accounting for 1.7%), and another 4 materials were moderately resistant, and most of the remaining varieties were susceptible. Another similar identification of 47 fresh corns also showed that only 8.5% of the materials showed resistance to head smut, and most of the others were susceptible (Zhou et al., 2020). It can be seen that the current new varieties of fresh corn still need to be strengthened in disease resistance breeding. However, there are also differences between different varieties, and some varieties show relatively good resistance to diseases and insects. For example, the sweet corn 'Jingketian 608' bred in Beijing has strong disease resistance and stress resistance, and no epidemics of diseases such as large spot disease and rough dwarf disease have been seen in the field. For example, some glutinous corn varieties resistant to head smut ('Wannuo 2018', 'Jingkenuo 2000', etc.) are recommended as one of the key measures for disease prevention (Zou et al., 2024). In this study, no serious epidemic of pests and diseases occurred through agricultural control (such as crop rotation, clean fields) and necessary chemical control. The resistance of the introduced varieties to adversity can meet the needs of field planting in the coastal area, but it is still necessary to breed more resistant varieties or strengthen comprehensive control measures for susceptible diseases. 2.3 Phenological period and flowering characteristics The growth process of various new fresh corn varieties in Linhai is generally early-middle maturity. The full growth period from sowing to fresh ear harvesting is mostly about 80 days, ranging from about 75 to 90 days, which is comparable to the control or local conventional varieties (Zhang et al., 2023). For example, the growth period of 'Xiantiannuo 88' in the spring sowing test was 84.8 days, which was similar to the control 'Suyunuo 5';
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