滇重楼种子水浸液对三种植物种子萌发和幼苗生长的影响

利用滇重楼(Paris polyphylla Smith var.yunnanensis(Franch.)Hand.-Mazz.)种子外种皮和胚乳的水浸液对白菜(Brassica pekinensis(Lour.)Rupr.)、绿豆(Vigna radiata(Linn.)Wilczak)、小麦(Triticum aestivum L.)种子进行处理,研究滇重楼种子水浸液对3种植物种子萌发、幼苗生长和保护酶活性的影响,并利用GC-MS方法对滇重楼种子内源抑制物的成分进行分析。结果显示,不同浓度滇重楼外种皮、胚乳水浸液对上述3种受体植物的发芽率、苗高、根长及鲜重均产生影响,其作用强度和水浸液的浓度有关,总体上表现出低促高抑的双重浓度效应。滇重楼种子水浸液对白菜的影响作用最强,对绿豆的影响作用最弱,且胚乳水浸液的影响较外种皮强。不同浓度滇重楼种子外种皮和胚乳水浸液均能影响3种植物幼苗体内保护酶的活性,随着水浸液浓度的升高,叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)活性总体增加,与对照相比差异显著。白菜、小麦过氧化氢酶(CAT)活性减少,与对照相比差异显著;绿豆过氧化氢酶(CAT)活性增加,但与对照相比无显著差异。利用GC-MS方法从胚乳和外种皮水浸液中分别检出8种和2种物质。研究结果表明滇重楼种子中存在内源抑制物质,可能是导致种子休眠的原因;种子水浸液可能通过影响植物幼苗保护酶的活性进而影响其正常生长;有机酸类物质可能是滇重楼种子内源抑制物之一。

Effects of aqueous extracts from Paris polyphylla seeds on seed germination and seedling growth of three kinds of plants

Chinese cabbage (Brassica pekinensis), mung bean (Vigna radiata), and wheat (Triticum aestivum) seeds were treated with different concentrations of aqueous extracts from Paris polyphylla episperm and endosperm. We studied the germination rate, seedling growth, and protective enzyme activity of the three plants through exposure to the aqueous extracts, and explored the activity and ingredients of endogenous inhibitors in P. polyphylla seeds. Results showed that different extract concentrations had certain effects on the germination rate, seedling height, seedling root length, and fresh weight of the seeds from the three plants. The strength of these effects increased at relatively low concentrations and decreased at relatively high concentrations. The effect on Chinese cabbage was stronger than that on wheat and mung bean, and the effect of the extract from the endosperm was significantly greater than that from the episperm. The extracts also influenced the protective enzyme activities of Chinese cabbage, mung bean, and wheat. Superoxide dismutase (SOD) and peroxidase (POD) activities significantly increased with increasing concentrations. Catalase (CAT) activity of Chinese cabbage and wheat significantly decreased, whereas that of mung bean showed a non-significant increase. GC-MS was applied to test eight substances from the endosperm aqueous extract and two from the episperm aqueous extract, with benzoic acid demonstrating germination inhibitory activity. Therefore, P. polyphylla seeds contain an endogenous inhibitor, whose activity changes with concentration, and may be the cause of seed dormancy. Aqueous extracts from P. polyphylla seeds may affect the normal growth of recipient seedlings by affecting the protective enzyme activity of recipient seedlings; furthermore, organic acids may be endogenous inhibitors of P. polyphylla seeds.