水曲柳雌雄株吸收根生物量与形态结构的季节动态OA

[Objective]This study aims to clarify the relationship between absorptive root development and reproductive processes in dioecious Fraxinus mandshurica,investigate gender dimorphism in root traits,and provide insights for sex-specific nutrient management strategies.[Method]Using mature female and male F.mandshurica trees,fine root samples(orders 1-3)were collected across the growing season(April-August)via soil coring.Root biomass,morphology,anatomical structure,and mycorrhizal infection rate were analyzed using root scanning and paraffin sectioning techniques.[Result]Absorptive root biomass increased seasonally in both sexes.Before male flowering,root biomass was similar between genders.From male flowering to female flowering,male root biomass increased by 33.14%,while female biomass remained unchanged.During seed development,both sexes exhibited marked increases in root biomass-females by 481.63%and males by 393.90%(P＜0.05).Root length density was consistently higher in males,with the 1st-order root length density being 2.27 times greater in males at seed maturity.Gender-specific seasonal patterns were observed in root diameter,with male 1st-order roots being 21.80%(June)and 15.52%(August)thicker than females(P＜0.05).Anatomical analysis revealed that this was due to greater cortical thickness in males(11.57%and 7.73%higher in June and August,respectively;P＜0.05),while vascular bundle diameter did not differ.Mycorrhizal infection rate was also higher in males(by 4.45%in June and 3.84%in August).[Conclusion]Seasonal dynamics of absorptive root biomass in F.mandshurica are closely linked to reproductive phenology.Males exhibited earlier root development and maintained higher absorptive root biomass throughout the growing season.The observed gender differences in root morphology,anatomy and mycorrhizal association highlight distinct belowground strategies between female and male trees.