【摘要】 经嫁接黄瓜接穗的南瓜根系分泌物对黄瓜和南瓜的发芽率和胚根、胚轴的伸长均具有明显的抑制作用。分析表明:嫁接黄瓜根系分泌物可以促进黄瓜和南瓜体内吲哚乙酸氧化酶的活性,抑制淀粉酶的活性,从而降低其吲哚乙酸(IAA)水平,影响子叶中贮藏物质的转化和利用,抑制其萌发和生长。更多还原

【Abstract】 Cucumber (Cucumis statirus L.) is com-monly cultivated by grafting on squash (Cucurbitamoschata) in commercial production. The effectsof root exudates of squash grafted with cucumberon seed germination rate of cucumber and squashwere tested. In this study, the exudates of cucum-ber-grafted squash roots were continuously collectedwith XAD-4 resin, and were further diluted withdistilled water to make 5%, 10%, 20% and 40%concentrations. Cucumber and squash seeds wereused for bioassay. The seeds were germinated inglass petri dishes with 2 filter papers at bottoms andcontaining 5 mL the diluted root exudates. The re-sults showed that the exudates of cucumber-graftedsquash roots significantly inhibit germination rate,radicel and hypocotyl elongation in cucumber andsquash, and the inhibitory rate positively correlatewith the concentration of the grafted cucumber rootexudates(Fig.1). So grafted cucumber still haveallelopathy. The exudates of cucumber-grafted squash roots significantly stimulated IAA oxidaseactivity in cucumber and squash. As a result, theydecrease IAA level in cucumber and squash, andrestrained their growth. The exudates of cucumber-grafted squash roots also decrease significantly theactivities of amylase and α-amylase in cucumberand squash, and this decrease effects were strength-ening with the increasing of the concentration of thegrafted cucumber root exudates. So the exudatesof cucumber-grafted squash roots can inhibit thehydrolysis and utilization of starch in cucumber andsquash, and thereby suppress germination and seed-ling growth.更多还原