| This experiment studied the allelopathic effect of different soybean cultivars onOrobanche cumana Wallr. and O. aegyptiaca Pers. through water culture experiment, potexperiment and field experiment. Soybean tissues which can produce high level ofgermination stimulants were detected by LC-MS/MS.Three soybean cultivars were planted under water culture and the roots exudates weregathered and extracted. Roots exudates concentrates, extractions of roots exudates andsoybean plant organs were detected for their effect on O. cumana Wallr. and O. aegyptiacaPers.. The results showed that soybean roots could exudate germination stimulants for O.cumana Wallr. and O. aegyptiaca Pers.. Different soybean tissues have different effects onstimulating germination of Orobanche spp., and the effect of root was better than stem andleaf.Fourteen commercial soybean cultivars were used for pot experiment and the sampleswere collected at V1, V3, V5, R2and R4stages. Rhizosphere soil, root, stem and leaf werecollected at each stage. The results showed that different soybean cultivars inducedsignificantly different germination rates of O. cumana Wallr. and O. aegyptiaca Pers.,respectively. Soybean rhizosphere soils could induce the germination of O. cumana Wallr. andO. aegyptiaca Pers. and Zhonghuang13showed higher germination effects on O. cumanaWallr. than the other cultivars. So the germination stimulants could exist in the soils steadily.Soybeans collected at V3showed higher germination effects than the other growth stages.Root showed higher germination ability than stem, and stem showed higher germinationability than leaf. The germination rates of O. cumana Wallr. induced by10%of root extractswere linear positively correlated with germination rates induced by10%of stem and10%ofleaf extracts. The germination rates of O. cumana Wallr. induced by root extracts were alsopositively correlated with soybean nodule diameter and dry weight in the form of power. Thisshowed that there were connections between the production of germination stimulants androot nodules.Three soybean cultivars of high, medium and low germination effects were selected frompot experiment for field experiment. The samples were collected at V3, V5and R4stages.The plant organs were extracted by water and methanol. The results showed that distilled water extracts of soybean organs induced lower germination rates than methanolic extracts.So methanol is a kind of solvent that could better verify the different allelopathic potential ofdifferent soybean cultivars. Rhizosphere soils of soybean from field experiment could inducethe germination of O. cumana Wallr. and O. aegyptiaca Pers., so soybean could be used as atrap crop of O. cumana Wallr. and O. aegyptiaca Pers.. The soybean samples collected at V3induced higher germination rates of O. cumana Wallr. and O. aegyptiaca than those collectedat V5and R4. Different soybean organs induced different germination rates of O. cumanaWallr. and O. aegyptiaca Pers.. Root extracts induced higer germination rates than stem, andstem extracts induced higer germination rates than leaf. The results are in consistent with thepot experiment.The root sample collected at V3from pot experiment was analysed using LC-MS/MS.And the result showed that the soybean root contained a kind of strigolactone, orobanchylacetate.To sum up, this experiment studied the stimulative effect of different soybean cultivarson O. cumana Wallr. and O. aegyptiaca Pers. and concluded that the soybean (rhizospheresoils and plant tissues) could induce the germination of O. cumana Wallr. and O. aegyptiacaPers.. Based on this result, further experiment could be done on rotating soybean with thehosts of Orobanche spp. in the Orobanche spp. infested field in order to confirm the ability ofusing soybean as the trap crop of O. cumana Wallr. and O. aegyptiaca Pers.. |
PDF Full Text Request