Study On Seed Productive Models,Seedling Establishment,and Pollen Flow In Different Positions Of Medical Licorice

Taking Glycyrrhiza glabra Linn.,Glycyrrhiz.inflata Batal.Glycyrrhiza uralensis Fisch.,Glycyrrhiza eurycarpa P.C.Li and Glycyrrhiza glabra var.glandulosa X.Y.Li as researched objects.The inflorescence number,floral abortion rate,single-flower number per inflorescence,ear dry weight,fruit biomass investment rate,fruit setting rate,seed setting rate,seed projected area and 1000-grain weight at different positions of plant body and inflorescence were determined;On this basis,reproductive resource allocation model and seed production strategy of five species in Glycyrrhiza Linn.were analyzed.Then the seed emergence percentage,survival percentage and the charateristics of seedling establishment from different positions of three medical Licorice(G.glabra,G.inflate and G.uralensis)were studied to undersand the seed emergence and seedling establishment strategies.In the end,we studied the pollen flow of the seedling from different positions of G.glabra,G.inflate and G.uralensis collected from different areas.The results have important meaning to seed production model,seedling establishment strategies,and adaptive evolution.They also provide theoretical reference to germplasm resources study and protection of Glycyrrhiza L.The results are as follows:1.The results of reproductive resources allocation models and seed production strategy(G.glabra,G.inflate,G.uralensis,G.eurycarpa and G.glabra var.glandulosa)showed that(1)Within a plant body,inflorescence number,single-flower number per inflorescence and ear dry weight,ear biomass investment rate of G.glabra,G.uralensis,G.eurycarpa and G.glabra var.glandulosa decrease successively from lower to upper part of plant body,while there is no significant difference among these four indexes in different positions of G.inflata.For G.glabra,G.uralensis and G.glabra var.glandulosa,the floral abortion rate has no significant difference,while the floral abortion rate of G.inflate and G.eurycarpa decrease successively from lower to upper part of plant body.(2)Within a inflorescence,biomass investment rate,fruit setting rate and seed setting rate of front four species in all of Glycyrrhiza L.decrease successively from lower to upper part of inflorescence.(3)There are no significant difference in seed projected area and 1000-grain weight of seed among different positions of plant body and inflorescence of five species.Therefore,under the influence of resource competition and structure effect,there are two different resource allocation models and seed production patterns among five species in Glycyrrhiza L.G.glabra,G.uralensis,G.eurycarpa and G.glabra var.glandulosa ensure early-development fruit to earn more resources by reducing resource input in late-development flower or fruit and achieve the aim of successful reproduction,while G.inflata reduces resource competition pressure by abortion.These two allocation models of reproductive resource and seed production models have important effects on enhancing reproductive success of Glycyrrhiza L.2.The characteristics of seed germination strategies and seedling establishment from different positions(upper,middle and lower of plant)of three medicinal licorices(G.glabra,G.inflate,G.uralensis)were measured.The results showed:(1)The seedling emergence rate of upper and middle part of G.glabra is higher than that of lower part,For G.inlate and G.uralensis,the seedling emergence rates of the middle and lower part are higher than that of upper part.(2)The seedlings from upper and middle part of G.glabra,lower and middle part of G.inflate,G.uralensis have correspondingly high seedling emergence rate,higher total biomass,root length and root-shoot ration than other seedlings,and the characteristics of chlorophyll fluorescence(Fv,Fm,Fv/Fm,Fv/F0 and electron transmission speed in light reaction)are also higher than other seedlings.The seedling survival rate is not significantly different among different positions.The seedlings from lower part of G.glabra,upper part of G.inflate,G.uralensis have correspondingly lower seedling emergency,higher plant height,and more leaves.In addition,the result implies that the seeds from different positions have two different germination and seedling growth strategies,the seedlings which have high emergence rate allocated relatively more biomass to the underground part,and they have high light proportion.Their root can enhance seedling resistance and environmental adaptability.Seedlings which have low emergence rate allocated relatively more biomass to the overground part to occupy space and light source.The result has greater ecological significance for seedling establishment and population regeneration of wild medicinal licorices.3.The paternity analysis for open-pollination progenies of different positions of G.glabra,G.inflata and G.uralensis was undertaken by using EST-SSR markers to reveal differences in natural mating patterns of Glycyrrhiza L.The results showed that:(1)For the open-pollination offsprings from middle and upper part of G.uralensis,the PIC and I are higher than the lower part,and their F<0.For the open-pollination offsprings from different positions of G.glabra and G.inflate,the PIC and I have no significant difference,and their F>0.(2)The open-pollination offsprings of G.uralensis were from out-cross and out-crossing rate increase successively from lower part to upper part.The open-pollination offsprings of G.glabra and G.inflate were form self-cross and self-crossing rate is greater than 66.67%.Therefore,the natual mating pattens of G.glabra and G.inflate trend to self-cross while G.uralensis trends to out-cross.In addition,due to the flowering phenology,the middle and upper part of G.uralensis accept more heterologous pollen thus open-polliantion progenies have more genetic differentiation.