Department of Agricultural Biochemistry, University of Hawaii, 96822, Honolulu, Hawaii.
J Chem Ecol. 1985 Oct;11(10):1411-25. doi: 10.1007/BF01012141.
The allelopathic effects of root exudates ofBidens pilosa L. on seedling growth ofLactuca sativa L.,Phaseolus vulgaris L.,Zea mays L., andSorghum bicolor (L.) Moench were studied using a root exudate recirculating system that allows continuous exposure of crop plants to allelopathic chemicals. This system maintains an undisturbed rhizosphere and eliminates competition and physical contact between the donor and acceptor plants. Comparison of responses to hydrophobic and hydrophilic root exudates is made possible by removal of hydrophobic compounds using XAD-4. Treatments consisted ofB. pilosa, B. pilosa with an Amberlite XAD-4 resin column attached to the donor pot to remove hydrophobic allelochemicals, and a donor pot without weeds.B. pilosa significantly inhibited seedling growth of all crop species tested. The crop species varied in response to the root exudates, withL. sativa being most sensitive. Larger and olderB. pilosa plants caused greater inhibition of seedling growth ofL. sativa andP. vulgaris than did smaller (younger)B. pilosa plants.B. pilosa with XAD-4 caused significantly less inhibition to all crop species, exceptZ. mays, thanB. pilosa without XAD-4, indicating that the hydrophobic exudates played an important role in the allelopathic growth inhibition. Variability in species response toB. pilosa with and without XAD-4 was probably due to differences in sensitivity to hydophobic and hydrophilic allelochemicals.
采用根分泌物循环再生系统研究了三叶鬼针草（Bidens pilosa L.）根系分泌物对莴苣（Lactuca sativa L.）、菜豆（Phaseolus vulgaris L.）、玉米（Zea mays L.）和高粱（Sorghum bicolor (L.) Moench）幼苗生长的化感作用。该系统保持了未受干扰的根际，并消除了供体和受体植物之间的竞争和物理接触。通过使用 XAD-4 去除疏水性化合物，实现了对疏水性和亲水性根分泌物的响应比较。处理包括三叶鬼针草、与附着在供体罐上的 Amberlite XAD-4 树脂柱相连以去除疏水性化感化合物的三叶鬼针草、以及没有杂草的供体罐。三叶鬼针草显著抑制了所有测试作物物种的幼苗生长。作物物种对根分泌物的反应不同，莴苣最敏感。与较小（较年轻）的三叶鬼针草相比，较大和较老的三叶鬼针草对莴苣和菜豆幼苗生长的抑制作用更大。与没有 XAD-4 的三叶鬼针草相比，用 XAD-4 处理的三叶鬼针草对除玉米以外的所有作物物种的抑制作用显著降低，这表明疏水性分泌物在化感生长抑制中起重要作用。对有和没有 XAD-4 的三叶鬼针草的物种反应的变异性可能是由于对疏水性和亲水性化感化学物质的敏感性不同所致。
