目的 探究油菜素内酯(Brassinolide, BR)浸根对机插水卷苗栽后本田生长及产量的影响。方法 以宁粳8号为试验材料,分析不同浓度BR(T1、T10、T20,分别表示水培营养液中BR浓度为1 mg/L、10 mg/L、20 mg/L)浸根对水卷苗机插本田后返青活棵及产量的影响,以正常水培营养液处理为对照(CK)。结果 BR浸根(T1、T10、T20)能够促进水稻地上部生长,栽插本田21d后株高较CK分别增加11.68%、8.12%和7.61%;BR浸根对水卷苗栽后根系的促生作用更为明显,不同浓度BR浸根对水卷苗栽后根长、根表面积、根尖数、根体积、根直径、根质量和根冠比均产生了显著影响,其中根尖数以低浓度BR处理效果更优,而其他根系指标均以高浓度BR处理效果更优。与CK相比,不同浓度BR浸根降低了叶片过氧化氢浓度(至移栽后12 d,分别降低12.50%、23.25%和22.25%),增强了叶片抗氧化酶活性;与移栽当天相比,移栽后第2天BR浸根处理叶片中玉米素(ZT)浓度迅速增加(分别为197.27%、153.11%和243.78%),而CK增加缓慢(2.94%),根系表现一致,且根系中生长素(IAA)浓度显著高于CK;同时BR处理在栽后一周内赤霉素(GA₃)浓度均明显高于对照。与CK相比,T10处理显著提高了每穗粒数和结实率(分别为15.04%和6.62%),T20处理显著提高了结实率(6.17%),但BR处理千粒重均显著下降,最终产量T10和T20处理较CK分别提高5.11%和7.99%。结论 适当浓度的BR(T10~T20)浸根能减轻水卷苗机插植伤,提高抗氧化酶活性,降低H₂O₂含量,提高ZT、GA₃和IAA浓度,高效地促进根系生长,提高了每穗粒数和结实率。本研究可为减轻机插植伤,促进机插水稻高产稳产提供理论依据和技术参考。

【Objective】Mechanical transplanting results in serious transplanting shock of rice seedlings and a longer recovery stage, which negatively impacts the growth of rice seedlings in the paddy field and the yield formation of machine-transplanted rice. The objective of the research is to investigate the effects of brassinosteroid (BR) soaking on transplanting shock and grain yield of hydroponically grown long-mat seedlings (HLMS) under mechanical transplanting. 【Method】We analyzed the effects of different concentrations of BR (CK, T1, T10, T20,BR concentrations of 0 mg/L, 1 mg/L, 10 mg/L, 20 mg/L in the nutrient solutions, respectively) soaking on morphological traits, dry matteraccumulation, antioxidant system, endogenous hormone concentrations and grain yield of HLMS under mechanical transplanting. 【Result】Root soaking in BR could promote above-ground part growth of rice, the plant height under T1, T10, T20 was 11.68%, 8.12% and 7.61% higher than CK,respectively;and the effect on the root was more obvious, BR soaking significantly increased the root length, root surface area, root tip number, root volume, root diameter, root weight and root/shoot ratio. At low BR concentration, root tip overnumbered thatathighBRconcentrationwhile other root system indicators were better under high concentration BR treatment. Compared with CK, BR (T1, T10, T20) soaking decreased the H₂O₂ content inleaves by 12.50%, 23.25% and 22.25% 12 days aftertransplanting, respectively, and increased the activities of antioxidantenzymes. Compared with the day of transplanting, thezeatin (ZT) concentration in the leaves under BR soaking treatmentsincreased rapidly (197.27%, 153.11% and 243.78%, respectively), while under CK treatment it increased slowly (2.94%), the rootperformance was consistent with leaves, and the auxin (IAA) concentration in the roots was significantly higher than that of CKon the second day after transplanting. The gibberellin (GA₃) content of roots in BR soakingtreatments was significantly higher than that of CK within one week after transplanting. Compared with CK, T10 significantly increased the number of spikelet per panicle by 15.04%, and the seed-setting rate by 6.62%. T20 obviously increased the seed-setting rate by 6.17%. However, T1, T10, and T20 notably decreased 1000-grain weight. The grain yield underT10 and T20 treatments (the corresponding values were 10.58 t/hm² and 10.84 t/hm²) were 5.11% and 7.99% higher than CK (10.04 t/hm²), while grain yield under T1 (9.68 t/hm²) was 3.58%lower than that of CK,and there was no significant difference among these treatments. 【Conclusion】Briefly, BR （T10, T20）soaking at proper concentrationscould mitigate the transplanting shock, increase antioxidant enzymes activities, decrease H₂O₂ content of leaves, improve the contents of ZT, GA3, and IAA to different extent, efficientlypromote roots growth, increase the number of spikelet number per panicle and seed-setting rate of HLMS under mechanical transplanting. This study willlay a theoretical basis and provide technical reference for reducing machine-transplanting shock and promoting high and stable yield of mechanical transplanted rice.