水分对白三叶种子产量及产量构成要素的影响

Effects of Water on Seed Yield and Yield Components of White Clover

研究水分对白三叶(T rif olium rep ens L)种子产量及产量构成要素的影响。结果表明:处理间花序小花数和花序荚果数差异不显著;对照与其他处理间单位面积花序数差异显著(P<0.05);对照和轻度水分胁迫区单位面积结荚花序数较多;对照小花胚珠数、荚果种子数和千粒重最小,与其他处理间差异显著(P<0.05);对照潜在种子产量和表现种子产量最高,轻度水分胁迫区实际种子产量最高,达44.97 g/m2,收获系数8.7%;产量构成要素中花序数及花序小花数与种子产量间相关显著(P<0.05);无水分胁迫区主要影响因子是花序小花数及千粒重;轻度水分和重度水分胁迫区及对照区主要影响因子是花序数及花序小花数,中度水分胁迫区则是荚果种子数;种子成熟过程中胁迫越大含水量越低;水分对白三叶种子发芽率无影响,各处理硬实率偏高,均达80%以上,但差异不显著。

The research of water management in white clover seed production was carried out at the Yunnan sheep stud farm from July 2003 to June 2004. Five water treatments were designed to determine the effects of different water supply on white clover seed yield and yield components. The results showed： The five water treatments effected no difference among white clover plants in number of florets and pods per inflorescence, though there was a significant difference in the number of flowering head per unit area between the control and the other treatments （P〈0.05）. The number of ripe flowering heads per unit area in control and in light water stress treatment is more than that of the other treatments. Ovules per floret, seeds per pod, and thousand-seed weight of control are lower than those of the others. Control boasts maximal potential seed yield and expressive seed yield. In all treatments, light water stress gives maximal practical seed yield, reaches 44. 97 g/m^2, a harvest index of 8.7%. There are a significant correlation between seed yield and flowering head per unit area and florets per inflorescence （P〈0. 05）. The florets per inflorescence and the thousand-seed weight are the major factors that affect the seed yield of white clover with no water stress treatment. The number of flowering heads per unit area and florets per inflorescence are the major factors affecting seed yield of white clover under light water stress, heavy water stress, and contro. However the major factor affecting white clover under moderate water stress treatment is per-pod seeds. Higher water stress decreases water content of seed during the process of seed maturation. Seed germination rate is not affected by water stress. All water treatments cause high rate of hard seed which reaches as high as 80%.