Page 130 - 《广西植物》2024年第11期
P. 130

2 1 1 4                                广  西  植  物                                         44 卷
                 seeds of A. paniculata were used as materials to explore the effects of potato root exudates on seed germinationꎬ root
                 border cell morphologyꎬ and root tip antioxidant enzyme activity of A. paniculata under cinnamic acid stress. The results
                 were as follows: (1) Cinnamic acid of 0.4 mmolL significantly inhibited the germination and growth of A. paniculata
                                                        ̄1
                 seeds. Adding different concentrations of potato root exudates had a certain mitigation effect on all gerimation
                                                                 ̄1
                 indexes. When the concentration of root exudate was 25 mgmL ꎬ the allelopathic effect index of each index reached its
                 maximum valueꎬ indicating that the mitigation effect was the strongest at this time. Each germination index showed
                 significant differences compared to the cinnamic acid group (P<0.05). (2) Cinnamic acid strongly damaged the root
                 border cells of A. paniculata seedlings and significantly reduced the number and viability of root border cells. Adding
                 potato root exudates could effectively alleviate this damage. After root exudates treatmentꎬ the number and viability of
                 cells at the root border of A. paniculata increased significantlyꎬ and the apoptosis rate and thickness of the mucilage layer
                 decreased significantly (P<0.05). (3) Cinnamic acid caused strong stress damage to the root tip of A. paniculataꎬ which
                 led to an imbalance of the antioxidant enzyme system and decreased root activity. After the treatment of potato root
                 exudatesꎬ the activities of superoxide dismutaseꎬ peroxidaseꎬ catalaseꎬ and malondialdehyde content in the root tip of
                 A. paniculata decreased significantlyꎬ and the root activity increased significantly (P<0.05)ꎬ indicating that the degree
                 of damage to the root tip decreased. In conclusionꎬ potato root exudates can reduce the degree of oxidative damage to the
                 root tip of seedlings by reducing the allelopathic stress of root marginal cellsꎬ improve the tolerance of A. paniculata to
                 cinnamic acid during germination and the seedling stageꎬ and alleviate the allelopathic inhibition of cinnamic acid on the
                 growth characteristics of A. paniculata seedlings. The results provide a theoretical reference for the rationality of the
                 potato ̄A. paniculata rotation mode.
                 Key words: Andrographis paniculataꎬ potato root exudatesꎬ allelopathic effectsꎬ root border cellsꎬ cinnamic acid
                 (CA)ꎬ crop rotation



                穿 心 莲 ( Andrographis paniculata) 为 爵 床 科       (Mathilde et al.ꎬ 2022)ꎮ 作物轮作时ꎬ通过根系分
            (Acanthaceae)一年生草本植物ꎬ别名一见喜、苦胆                      泌物的调控作用ꎬ能够有效降低化感自毒物质对
            草等ꎮ 其干燥地上部分为中药材穿心莲ꎮ 具有清                            后茬 作 物 的 危 害 程 度 ( 郭 巧 生ꎬ 2004 )ꎮ 人 参
            热解毒、消肿止痛的功效ꎬ常用于感冒发热ꎬ咽喉                             (Panax ginseng)与细辛(Asarum siebddii) 轮作系统
            肿痛ꎬ口舌生疮等症(国家药典委员会ꎬ2020)ꎮ 连                         中ꎬ细辛根系的辛辣分泌物对人参残体分泌物及
            作障碍是指同一作物或近缘植物在相同土地上连                              有害微生物有拮抗、减少及杀灭作用ꎬ从而有助于

            续种植ꎬ导致植株出现生长状况变差、产量降低、                             减轻人参根系分泌物的自毒作用( 刘莹等ꎬ2023)ꎮ
            品质下降等现象( 郭兰萍等ꎬ2006)ꎮ 随着市场需                         姜智英等(2023)发现ꎬ粮草轮作系统中前茬作物
            求的逐年增长ꎬ穿心莲的栽培面积也不断扩大ꎬ穿                             玉米的根系分泌物ꎬ对后茬作物燕麦、豌豆的根长
            心莲在实际生产中普遍认为存在连作障碍( 徐鸿                             和根系活力均具有正向的化感效应ꎮ 李庆凯等

            华和陈蔚文ꎬ2007)ꎮ 连作导致穿心莲长势变差、                          (2020)发现玉米根系分泌物显著降低了连作花生
            产量下降、 药 材 活 性 成 分 含 量 降 低 ( 李 俊 仁 等ꎬ               土壤中酚酸类物质对土壤微生态环境的化感抑制
            2017)ꎬ严重影响了穿心莲产业的可持续发展ꎮ 师                          作用ꎮ
            小平等(2020)研究表明ꎬ化感自毒作用是导致连                               前期调研发现ꎬ在穿心莲主产区之一的粤西
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            的化感效应ꎬ对降低其连作障碍具有重要意义ꎮ                              缓解穿心莲的连作障碍ꎬ效果显著ꎮ 因此ꎬ推测马
                 轮作是充分利用化感促进作用ꎬ减少化感抑                           铃薯根系分泌物在缓解化感自毒物质积累对穿心
            制作用的一项生态农业技术ꎬ对于缓解作物的连                              莲造成的化感损伤方面可能同样具备潜力ꎮ 目
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            根系分泌物是根系在植物生长过程中向外界释放                              物质对穿心莲种子萌发和幼苗生长的影响( 李俊
            的一 类 化 合 物 的 总 称ꎬ 具 有 广 泛 的 生 物 活 性                仁等ꎬ2016ꎻ朱艳霞和黄燕芬ꎬ2019)ꎬ缺乏化感效
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