Study On Influence Of Silicon On Reproductive Allocation And Physiological Characteristics Of Echinochloa Crusglli (L.)Beauv.var.oryzicola

Weed (Echinochloa crusglli (L.) Beauv.var.oryzicola) is one of annual herb of the gramineous genus Beauv. As a clonal plant, It have developed root system and the most widely distributed weed in the paddy field, many factors can affect its growth, silicon is the fourth nutrient elements following the nitrogen, phosphorus, potassium, it influences the growth, biological characteristics and physiological characteristics of plant, The influence on reproductive allocation and physiological characteristics of weed by silicon is studied in order to provide reference of weed ecological control, weed is adopted as test material, potting is test method, five silicon(SiO2) processing is setted, in the same time, in order to Eliminate the interference of the salt, five sodium sulfate processing is setted. The results show that:(1)Silicon had no significant influence on biomass of weed in tillering stage. In elongation stage, when fertilizing content is 300 kg/hm2, silicon significantly reduced the leaf and whole plant biomass. when fertilizing amount is 240kg/hm2 in flowering period, silicon significantly increased stem, leaf, flower and the whole plant biomass, when fertilizing content is 300kg/hm2, silicon significantly inhibited the weed whole plant biomass, the variation of weed biomass has no obvious regularity in filling stage.(2)Silicon had no significant influence on biomass allocation of weed in tillering stage. In elongation stage, biomass allocation of stem and leaf first increase and then decrease when silicon content increase, biomass allocation of root and leaf sheath first decrease and then increase when silicon content increase. Silicon have no influence on biomass allocation of root, leaf and leaf sheath in full-bloom stage, but biomass allocation of flower first increase and then decrease. In filling stage, silicon have no influence on biomass allocation of root, leaf and leaf sheath, but biomass allocation of fruit first increase and then decrease.(3)In elongation stage, when fertilizing content is 240 kg/hm2, silicon significantly reduced the nitrogen content of stem organ. In flowering period, when fertilizing content 180kg/hm2, silicon significantly increased the nitrogen content of leaf. In filling stage, when the silicon is 120k/hm2, silicon significantly increased the nitrogen content of fruit. In elongation stage,when the silicon content is 180kg/hm2,silicon significantly increased the phosphorus content of the root organs. The effect on potassium of silicon application is not significant.(4)When silicon application is 240kg/hm2, silicon significantly reduced the nitrogen distribution of stem organ in elongation stage, and significantly increased the flowering leaf nitrogen distribution.In elongation stage, when fertilizing content is 120kg/hm2, silicon reduces the distributive of phosphorus on leaf sheath, when fertilizing content is 60 kg/hm2 in flowering stage, silicon increased the phosphorus distribution of leaf, when silicon content is 240/hm2, silicon significantly increased the potassium distribution of weed reproductive organs.(5)The effect of silicon on weed photosynthetic characteristics mainly in growth period, in tillering and elongation stage, when silicon application is 180kg/hm2, silicon significantly increased net photosynthetic rate and stomatal conductance of weed.(6)When silicon content is 240kg/hm2,silicon significantly increased the content of soluble protein in leaves of weed in the reproductive growth stage.(7)Silicon effect on MDA content of weed mainly at growth stage, flowering stage and filling stage, when silicon content is 300kg/hm2, silicon significantly increased the MDA content of the leaves of weed.(8)In flowering stage, when the silicon concentration was 180kg/hm2, silicon significantly promote SOD activity of weed blade. In filling stage, when the silicon concentration was 240 kg/hm2, silicon significantly increased SOD activity of weed blade, when the silicon concentration was 300kg/hm2,silicon was significantly inhibited SOD activity of weed.(9)In the reproductive growth stage,when the silicon concentration was 240kg/hm2, silicon can significantly increase the POD activity in leaves of weed. In fruiting period, when applying silicon content up to 300kg/hm2, silicon significantly inhibited the POD activity of weed.In conclusion, silicon can increase the biomass of weed in a certain range, Beyond a certain range, the biomass of weed will be suppressed. In a certain range of silicon can increase soluble protein content, SOD activity, peroxidase activity. High concentrations of silicon in reproductive growth stage increased MDA content of weed.