【摘要】 为明确留桩高度对‘甬优4949’水稻再生季产量的影响，设置保留4.5个、3.5个和2.5个伸长节间的留桩高度，测定不同留桩节位处理下的腋芽萌发、内源激素含量及再生季产量。结果表明：不同留桩高度下，高节位腋芽生长速度大于低节位腋芽，减少伸长节间数可促进下部腋芽萌发；内源激素变化显示，不同留桩高度下，腋芽脱落酸(ABA)、赤霉素(GA)、玉米素核苷(Tzr)含量自下而上表现为低节位腋芽>高节位腋芽，水杨酸(SA)含量表现为低节位腋芽<高节位腋芽；生长素(IAA)和异戊烯腺嘌呤(iP)含量变化规律与留桩高度相关，保留2.5个伸长节间，IAA含量表现为低节位腋芽<高节位腋芽，保留3.5及4.5个伸长节间，则表现为低节位腋芽>高节位腋芽；保留2.5及3.5个伸长节间，腋芽iP含量表现为低节位腋芽>高节位腋芽，保留4.5个伸长节间，腋芽iP含量表现为低节位腋芽<高节位腋芽；保留较少的留桩节位数可增加低节位腋芽促发相关激素积累，降低生长抑制类激素含量，保留较多的留桩节位数促进上部腋芽萌发，顶端优势明显；保留2.5及3.5个伸长节间可显著提高再生季稻的每穗粒数和结实率，与保留4.5个伸长节间相比，再生季产量分别提高13.37%和9.61%。不同节位腋芽萌发与头季留桩高度密切相关，‘甬优4949’头季收割保留2.5～3.5个伸长节间，有利于下部大穗型腋芽萌发，提升再生季产量。更多还原

【Abstract】 To investigate effect of the stubble height of the main crop on the yield formation of ratoon season of ‘Yongyou 4949’ rice, the variations in axillary bud germination, endogenous hormone content, and grain yield in ratoon season under different stubble heights(4.5,3.5,and 2.5 elongated internodes) were examined.The results indicated that the growth of axillary buds at the upper node position was greater than that at the lower node position, and the germination of axillary buds at the lower node position was enhanced by reducing elongated internodes. In terms of endogenous hormone content, the concentrations of abscisic acid, gibberellins, and trans-zeatin riboside in the axillary bud located at the lower node position were significantly, higher compared to those at the upper node position. In contrast, salicylic acid exhibited an opposite trend. Additionally, the IAA content in the axillary bud at the lower node position was lower than that at the upper node position when 2.5 elongated internodes remained, whereas the opposite pattern was observed with 3.5-4.5 elongated internodes remaining. Regarding isopentenyl adenine, a higher content was observed in the axillary bud at the lower node position compared to that at the upper node position when the remaining height was 2.5 and 3.5 elongated internodes. The opposite phenomenon was observed with a remaining height of 4.5 elongated internodes. In conclusion, reducing the cutting height of stubble in the main crop increases levels of endogenous hormone associated with the germination of axillary buds at lower node positions, while decreasing levels of hormone related to the inhibition of axillary bud growth. On the other hand, maintaining a higher cutting height promotes apical dominance and enhances ratooning ability at the upper node position. As a result, there is a 13.37% and 9.61% increase in grain yield with remaining heights of 2.5 and 3.5 elongated internodes, respectively, compared to 4.5 elongated internodes. This increase is attributed to the higher average grain number per spike and seed setting rate during the ratoon season. This study suggests that the germination of axillary buds at different node positions is influenced by the stubble height of the main crop. Therefore, it is recommended to maintain 2.5 to 3.5 elongated internodes to increase yield during ratoon season by promoting the growth of axillary buds at lower node positions.更多还原