中文摘要：

为明确辣椒（Capsicum annuum）根系分泌的潜在化感物质对生菜（Lactuca sativa）幼苗内源激素及碳氮代谢的影响,分别采用5、10、15、20和25μg·m L-1的N-苯基-2-萘胺（P2NA）和邻苯二甲酸（PA）与1/2Hoagland营养液混合胁迫处理生菜幼苗,测定可溶性蛋白质、可溶性糖、内源激素含量以及碳氮代谢关键酶活性,以期丰富辣椒根系分泌物化感机制研究。结果表明：随着化感物质浓度的增加,生菜幼苗根系长度显著降低,根系活力提高;叶片可溶性蛋白质含量逐渐增加,而谷氨酰氨合成酶（GS）活性逐渐降低;蔗糖磷酸合成酶（SPS）活性、蔗糖合酶（SS）活性和可溶性糖含量随着处理浓度的增加呈单峰曲线分布;在015μg·m L-1浓度范围内,随着处理浓度的增加,生长素（IAA）和赤霉素（GA）含量逐渐降低,脱落酸（ABA）含量逐渐增加,超过15μg·m L-1,结果相反。PA处理的ABA含量和碳代谢活性高于P2NA处理,两者的内源激素含量存在显著的互作效应,而碳、氮代谢和鲜重互作不显著。20和25μg·m L-1的PA和P2NA处理增加了生菜鲜重。影响ABA和GA含量可能是P2NA和PA引起生菜幼苗化感效应的一个重要途径。

英文摘要：

The purpose of this paper is to elucidate effects of potential allelochemicals extracted from hot pepper （Capsicum annuum） root on endogenous hormone and carbon-nitrogen metabolism of lettuce （Lactuca sativa）. Lettuce was treated with 5, 10, 15, 20 and 25μg·mL-1 of N-phenyl-2-naphthylamine （P2NA） and phthalic acid （PA） mixed with 1/2Hoagland nutrient solution. Soluble protein, soluble sugar, endogenous hormone contents and carbon-nitrogen metabolism enzymes of lettuce leave were sampled and determined in order to explore allelopathy mechanism of root exudates of hot pepper. The results show that P2NA and PA stimulated activity of roots, and significantly decreased root length. Soluble protein content of lettuce leaves gradually increased, however, glutamine synthetase activity decreased with increasing concentration. Sucrose phosphate synthase and sucrose synthase activities and soluble sugar content showed a single-peak curve. Auxin and gibberellin （GA） contents gradually decreased, and abscisic acid （ABA） content increased with increasing treatment concentration below 15μg·mL-1; the content was contrary to the above results, when the concentration exceeded 15 μg·mL-1. ABA content and carbon-nitrogen metabolism activity of PA treatment were higher than those of P2NA treatment, and endogenous hormone content of PA and P2NA treatment showed significant interaction effect, however, there was no significant interaction between carbon-nitrogen metabolism and fresh weight. The treatment of 20 or 25 μg·mL-1 PA and P2NA promoted lettuce fresh weight. The allelopathic effects of P2NA and PA may be caused by regulation of ABA and GA contents of lettuce seedlings.