Abstract: To investigate the germination physiological mechanism of Paris polyphylla seeds, different stages of the germination process were divided based on the seed embryo morphology and the changing rules in endogenous hormone content and related enzyme activities were analyzed at different stages. The results were as follows:(1)The germination process of the seeds could be divided into eight stages based on seed embryo morphology: non-germinating embryo stage(S1), heart-shaped embryo stage(S2), embryo swelling stage(S3), radicle not breaking through seed coat stage(S4), cotyledon petiole elongation and radicle breaking through seed coat stages(S5), lower hypocotyl breaking through seed coat stage(S6), upper hypocotyl elongation stage(S7), and radicle elongation stage(S8).(2)The α-amylase activity in the seeds was significantly higher than β-amylase activity at all germination stages.(3)Superoxide dismutase(SOD)activity was the highest at stage S5 and the lowest at stage S1; peroxidase(POD)and catalase(CAT)activities generally increased with seed germination progress; soluble protein content initially decreased and then increased with seed germination progress.(4)The contents of hormones such as indoleacetic acid(IAA), gibberellin(GA₃), abscisic acid(ABA), and salicylic acid(SA)decreased overall, while 1-aminocyclopropane-1-carboxylic acid(ACC), jasmonic acid(JA), brassinolides(BRs)increased overall during seed germination. Cytokinins(CTKs)content showed no significant change. The ratios of IAA/ABA and GA₃/ABA decreased initially and then increased, while CTKs/ABA continuously increased with seed germination progress.(5)The contents of ABA, IAA, GA₃ were negatively correlated with embryo rate, while ACC, JA, BRs, POD, CAT, and β-amylase activity were positively correlated with embryo rate. In conclusion, the germination process of the seeds can be subdivided into eight stages based on seed embryo morphology, with varying endogenous hormone content and related enzyme activities at different stages. The activities of α-amylase and POD may be related to radicle elongation, while GA₃ may affect the embryo formation, and ABA may inhibit the growth and development of the embryo.

Key words: Paris polyphylla, germination stage, endogenous hormone, antioxidant enzymes, amylase

摘要： 为探究七叶一枝花的种子萌发生理机,该文从种胚形态上对七叶一枝花种子萌发过程的时期进行了划分,并分析了不同时期种子内源激素含量及相关酶活性的变化规律。结果表明:(1)根据种胚形态可将种子萌发过程细分为8个时期,即种胚未萌动时期(S1期)、心形胚时期(S2期)、种胚膨大时期(S3期)、胚根未突破种皮时期(S4期)、子叶柄伸长和胚根突破种皮时期(S5期)、下胚轴突破种皮时期(S6期)、上胚轴伸长时期(S7期)、胚根伸长时期(S8期)。(2)不同萌发时期种子的α-淀粉酶活性均明显高于β-淀粉酶。(3)超氧化物歧化酶(SOD)活性在S5期最高,S1期最低; 过氧化物酶(POD)和过氧化氢酶(CAT)活性随种子萌发进程总体呈上升趋势,可溶性蛋白含量随种子萌发进程先下降后升高。(4)吲哚乙酸(IAA)、赤霉素(GA₃)、脱落酸(ABA)和水杨酸(SA)含量随种子萌发进程整体呈下降趋势; 1-氨基环丙烷羧酸(ACC)、茉莉酸(JA)、油菜素内酯(BRs)随种子萌发进程整体呈上升趋势; 细胞分裂素类(CTKs)含量无显著变化; IAA/ABA和GA₃/ABA随种子萌发进程呈先下降后上升趋势,而CTKs/ABA则不断升高。(5)ABA、IAA、GA₃含量与胚率呈负相关,而ACC、JA、BRs、POD、CAT、β-淀粉酶活性与胚率呈正相关。综上认为,七叶一枝花在不同时期种子内源激素含量及相关酶活性各不相同,其中α-淀粉酶活性、POD活性可能与种胚胚根伸长有关,GA₃可能影响种胚形成,而ABA则可能抑种胚的生长发育。

关键词: 七叶一枝花, 萌发阶段, 内源激素, 抗氧化酶, 淀粉酶