Study On Reproductive Allocation And Reproductive Characteristics Of Echinochloa Crusglli (L.) Beauv Under Different Single Treatments

Reproductive allocation (RA), also called reproductive configuration, refers to the ratio for plant's reproduction of assimilation resources in one year. Reproductive allocation is one of the hot research topics in plant reproductive ecology. In recent years, it studies concentrated in herbs, especially reproductive allocation of clonal plants become to one of the hot research topics, but it is still rarely reported in weeds. Echinochloa crusglli (L.) beauv. is an annual herb of gramineae of Echinochloa crusglli, a typical clonal plant, is one of the malignant weeds in the paddy field and hard to remove. To control weed is essentially to control reproductive, therefore the study on reproductive allocation and reproductive characteristics of the reproductive tillers with important significance only in theory, but also in practice.With four different single treatments (mowing, weedicide, nitrogen, intraspecific competition) processed Echinochloa crusglli (L.) beauv.. The biomass of its various organs,clump height, tiller number, thousand-grain weight were determinated in 3 periods.Analysed the characteristics of biomass allocation and the dynamic changes of the quantitative characters of reproductive tiller.The results indicated that:(1) With the increase of mowing intensities, the biomass (dry weight) of per plant and organs showed Y1> Y2> CK> Y3 trends, with significant differences among treatments; the biomass allocation ratio of root gradually increase,but diffent in stem, the biomass allocation proportion of reproductive organs reflected Y1> Y2 CK> Y3. From flowering stage to grain filling stage, Echinochloa crusglli (L.) beauv. nutrients elements (N, P, K) transfer from vegetative organs to reproductive organs, it was in favor of nutrients (N, P, K) accumulation in moderate mowing. Tiller number per plant and plant clipping intensity was positively correlated; moderate mowing treatment was a turning point in the reproductive strategy.(2) By weedcide treatments, biomass allocation ratio did not change significantly in vegetative organs; biomass allocation ratio decreased in flower, biomass allocation ratio in fruit was significantly higher than other treatment.under C5 treatment N content showed a downward trend in all organs, while P, K content showed first increased and then decline trend; it was in favor of N accumulation of Echinochloa crusglli (L.) beauv.under high concentration of weedicide With the increase of herbicide concentration, strains of cluster height, inflorescence length and spike weight showed a downward trend; spike length and reproductive allocationⅠ,Ⅱof Echinochloa crusglli (L.) beauv. promoted under Cl treatment;the number of tillers classification features all had a larger coefficient of variation, of which the spike weight of the largest coefficient of variation.(3) Biomass and the biomass (dry weight) for per plant increased with the increase of nitrogen; biomass allocation ratio of root, stem decreased, the proportion of leaf biomass allocation increased, It'sreproductive allocation was significantly higher than other treatments under low nitrogen and high nitrogen conditions,. With the extension of Echinochloa crusglli growth stages, nutrients allocation showed the ratio gradually decreased vegetative in organs root, leaf; nutrients(N, P, K) allocation ratio increases in reproductive organ. With the increase of nitrogen, strains of cluster high at plant height, tillers per plant showed a increasing trend; and the reproductive characteristics of the relevant indicators (inflorescence length, spike weight, RA I, RA II) increased first and then decreased.(4)Under the conditions of intraspecific competition, from flowering to grain filling stage, the biomass of vegetative organs decreased, but increased in the reproductive organs; expressed as the ratio of biomass decreased in roots, stems increased trends in leaves, fruits; Nutrient elements (N,P,K) conents for per plant increased,which N, K elements increased in the root,and reproductive organs, while the stems and leaves decreased, P element content in vegetative organs decline in a significant increase in the reproductive organs. With increased competition of Echinochloa crusglli(L.) beauv, the biomass and plant weight showed a downward trend; the root biomass ratio decreased, stem did not change significantly, leaf showed increased in turn; each element ratio of vegetative organs had no significant changes, reproductive organ had highest allocation in the M2. With the increase in the density of Echinochloa crusglli(L.) beauv, plants show an increase of high cluster, number of tillers showed a decreasing trend, while inflorescence length at first increased and then decreased; reproductive allocationⅠ,Ⅱcoefficient of variation with the increase of planting density of Echinochloa crusglli(L.) beauv in turn showed an increasing trend.(5)Under different treatment conditions, tiller height and inflorescence length of Echinochloa crusglli(L.) beauv. was positively correlated, was not correlatedwith the reproductive growth rates. tiller height and total biomass, nutritional biomass, reproductive biomass were significantly positively correlated with reproductive allocationⅠ,Ⅱ, was no correlation between reproductive allocation, it had a certain correlatiodealing only in Y3, M1, C1, C2 treatment conditions,and showed a positive correlation.