Study on the Changes of Cotton Heterosis under Reduced Nutrient Conditions

为了了解外界养分条件对棉花有关性状杂种优势的影响，本文设置了三种养分供给条件和十二个杂交一代，结果表明，(1) 同时减少氮磷钾供给时，棉花全株干重、籽皮棉质量及单株成铃数中亲优势显著增大；(2) 减少氮供给时，棉花全株干重中亲优势呈阶段性更为显著的下降趋势；(3) 氮磷钾正常施用时，生育后期全株干重、籽皮棉质量及生物性状中亲优势不同组合间变异性最大。结论：可以在杂种优势与外界养分条件两者变化之间建立对应关系，这将为最终揭示杂种优势机理奠定基础。因此进一步在不同养分条件下的大样本研究，具有极其重要的意义。In order to understand the influence of external nutrient conditions on the heterosis of cotton related traits, three nutrient supply conditions and twelve hybrids were set up in this study. The results indicate that: (1) when nitrogen, phosphorus, and potassium supply were simultaneously reduced, the mid-parent heterosis of cotton whole plant dry weight, seed cotton and lint cotton yield, and number of bolls per plant significantly increased; (2) when nitrogen supply was reduced, the mid-parent heterosis of cotton whole plant dry weight showed a more significant downward trend in the stage; (3) when nitrogen, phosphorus, and potassium were applied normally, the variability of the mid-parent heterosis among different individuals of whole plant dry weight, yield, and biological traits in the later stage of growth was the greatest. Conclusion: This indicates that a corresponding relationship can be established between the change of hybrid vigor and the change of external nutrient conditions, which will lay the foundation for ultimately revealing the mechanism of hybrid vigor. Therefore, further research on large samples in different nutrient conditions may be of great significance for revealing the mechanism of hybrid vigor.