Effects Of Plant Hormones On Flowering Pattern And Reproductive Fitness In Pseudostellaria Heterophylla

P.heterophylla,a perennial herb of the family Caryophyllaceae,is a dimorphic mixed-mating system plant.The special dimorphic flowers of P.heterophylla determines its special flowering pattern,which is a good material for studying the dimorphic mixedmating system of plants.This article takes wild biennial P.heterophylla in the Eastern Liaoning mountainous area as the research object.On the one hand,the contents of four endogenous hormones in rhizomes of P.heterophylla at different developmental stages are measured,and the correlation was discussed between endogenous hormone levels and flowering patterns in different developmental stages.This method can be used to judge the regulating effect of endogenous hormone levels on the flowering pattern and provide new ideas for revealing the physiological mechanism maintained by the dimorphic mixed-mating system.On the other hand,the whole plant was sprayed with exogenous hormones at different developmental stages of P.heterophylla,and the effects of exogenous hormones on the number of flowering,seeds,fleshy roots and root weight of P.heterophylla were inspected and analyzed in order to obtain the most suitable types,concentrations,treatment periods,and methods of exogenous hormones that regulate the flowering,seed yield,and root yield of P.heterophylla provide a reference for the rational use of exogenous hormones in large-scale planting of P.heterophylla and increase seed and root yield.The results are as follows:1.Changes in the levels of four endogenous hormones in rhizomes of P.heterophylla at different developmental stages.Both higher concentration of endogenous hormone GA and low concentration of IAA can promote flower formation and flower development of the dimorphic flowers,especially the effect on CL flowers is more obvious,that is,the GA content in CL flowering period is 1.4 times of CH flowering period.The lower concentration of ZT content is beneficial to the development of CH flowers,while the higher concentration of ZT content promotes the development of CL flowers more significantly.The ABA content is not significantly different from the flower formation and development of the dimorphic flowers.The higher the value of ABA/ZT,the better the development of CH flowers.The values of GA/IAA and ABA/IAA increase,and the values of IAA/ZT and ABA/ZT decrease,which all promote the development of CL flowers.2.Effects of exogenous hormone treatment on the flowering period of the dimorphic flowers of P.heterophylla.GA treatment prolonged the blooming period and flowering period of CH,except for 50 mg/L,other concentrations shortened the flowering period of CL.ABA had no significant effect on the blooming period and flowering period of the dimorphic flowers.Except for 10 mg/L IAA treatment,other concentrations shortened the flowering period of the dimorphic flowers.All ZT treatments shortened the flowering period of CH,while all other concentrations except 200 mg/L ZT prolonged the flowering period of CL.3.Effect of exogenous hormones treatment on the number of the dimorphic flowers of P.heterophylla.At the germination stage,GA and low-concentration ABA treatments could significantly increase the number of the dimorphic flowers.In the early stage of CH flowering,lowconcentration GA and low-concentration ABA treatments could significantly increase the number of CH flowers without significantly affecting CL flower numbers;After two periods of continuous treatment,all treatment groups had no significant promotion effect on CH flower blossom,while GA,IAA,ZT and low concentration of ABA all promoted flower formation of CL flower.4.Effect of exogenous hormone treatment on fruit set and seed set rate of P.heterophyllaLow-concentration GA improved the fruit set and seed set rate of the CH flowers of P.heterophylla,and the effect was the best when the concentration was 50 mg/L.ABA treatments reduced the fruit set rate and seed set rate of the CH flowers.The more obvious the inhibitory effect of elevation;low concentration of IAA also improved the fruit set and seed set rate of the CH flowers,and the effect was best at a concentration of 50 mg/L,but not as good as GA treatment;Low-concentration ZT increased the fruit set and fruit set rate of CH,but the treatment with exogenous hormone had no significant effect on the fruit set and seed set rate of CL.