【作者】 李晓娟；

【导师】 倪穗； 王强；

【作者基本信息】 宁波大学 ， 生物化学与分子生物学， 2013， 硕士

【摘要】 栗(Castanea molissima)与美国板栗(C. dentata)都是属于壳斗科(Fagaceae)栗属(Castanea)植物，是亚洲中部和北美森林生态系统中具有代表性和重要的生态与经济价值的树种，其果实营养丰富。1904年板栗疫病的爆发，导致美国板栗大量死亡，几乎频临灭绝。然而栗树对此病却有很强的抗性。为恢复美国板栗在森林生态和经济中的地位，科学家将栗与美国板栗进行杂交，得到具有抗性的杂交子代。大量研究发现化感作用在森林群落演替与更新过程中扮演重要角色，所以有必要考虑杂交板栗中引入的栗基因所带来的植物化学生态特性对美国板栗种群恢复、重建与演替的影响。本研究以种子发芽率和发芽势为种子萌发参数，以幼根、幼芽长度和鲜重变化为幼苗生长参数，分析栗叶水提取物对双子叶植物莴苣(Lactuca sativa)、萝卜(Raphanus sativus)、黄瓜(Cucumis sativus)，和单子叶植物洋葱(Allium cepa)、水稻(Oryza sativa)、小麦(Triticum aestivum)种子萌发及幼苗生长的影响；比较栗与美国板栗叶水提取物以及经X-5大孔树脂分离得到的11个分离组分对莴苣、萝卜、洋葱和水稻的化感作用。主要研究结果如下：1、栗叶水提取物浓度0.5mg·mL-1时显著抑制莴苣、萝卜和洋葱种子萌发，10mg·mL-1时显著抑制黄瓜、水稻和小麦种子萌发；0.5mg·mL-1显著抑制莴苣、萝卜、洋葱、水稻和小麦幼根生长，对幼芽生长的抑制作用不显著。表明栗叶具有选择性的化感作用。2、栗与美国板栗叶水提取物对莴苣、萝卜、洋葱和水稻种子萌发以及幼苗生长的抑制作用比较差异不显著。表明栗与美国板栗叶化感作用相似。3、栗与美国板栗叶水提取物分别经X-5大孔树脂分离收集到的11个洗脱组分中，均为7:3、6:4和5:5洗脱组分显著抑制莴苣、萝卜、洋葱和水稻种子萌发及幼根的生长；显著抑制莴苣、萝卜和洋葱幼芽的生长。分别对栗与美国板栗的7:3、6:4和5:5洗脱组分进行超高效液相分析发现这六个洗脱组分共同含有保留时间为3.7min的物质。表明栗与美国板栗叶中的主要化感物质可能为同一物质。更多还原

【Abstract】 Castanea mollissima and C. dentata are typical chestnut species which possess rich nutritive value in Asiaand North America, respectively. They play important roles in the ecology and economy in their existing forestecosystems. Chestnut blight has caused catastrophic losses of C. dentata populations since1904. Scientists havetried to make use of blight resistance of C. dentata to help the recovery of C. mollissima population in NorthAmerica.Some scientists point allelopathy has an effect on succession and regeneration of plant communities. Itbecomes especially important to understand the difference of chemical ecology characteristics between C. dentataand C. mollissima. Using germination vigor and rate as seed germination parameters and radicle, plumuleelongation and fresh weight change of seedling as seedling growth parameters, we studied the effect of waterextract of C. mollissima leaves on dicotyledons lettuce, radish and cucumber and monocotyledons onion, rice andwheat. We compared the allelopathic intensity of water extract and11elution components that were separated byX-5macroporous resins from water extract of C. mollissima and C. dentata. The results were as following:1. When the concentration of water extract of C. mollissima leaves is0.5mg·mL-1, it significantly inhibitedgermination of lettuce, radish and onion; when10mg·mL-1, inhibited germination of cucumber, rice and wheat.When0.5mg·mL-1, inhibited radicles growth of lettuce, radish, onion, rice and wheat seedlings and was notsignificant on plumule growth. This result suggested that C. mollissima leaves possessed selective allelopathy.2. The difference of effect of water extract on lettuce, radish, onion and rice seed germination and seedlinggrowth between C. mollissima and C. dentata leaves was not significant, and suggested the allelopathy of C.mollissima and C. dentata were similar.3.7:3,6:4and5:5elution fractions of C. mollissima and C. dentata significantly inhibited seed germinationand seedling growth of lettuce, radish, onion and rice，suggesting that the allelochemicals of C. mollissima and C.dentata extracts are in7:3,6:4and5:5elution fractions.7:3,6:4and5:5elution fractions of C. mollissima and C.dentata concluded the component of t=3.7min according to liquid chromatography. It could be speculated thatthe allelochemicals of C. mollissima and C. dentata might be same substance.更多还原