| Silicon has the effects of improving plant growth, quality, yield and relievingabiotic stresses, such as rice, sugarcane, wheat, maize, strawberry and cucumber, bymeans of participating metabolism and physiology in plants. It can be helpful tostrengthen tolerance by pests, diseases and saline-alkali stresses, relieve toxicity byions, keep stable structure and function of cell membrane, improve root activity andphotosynthetic rate of plants and decrease the water transpiration of leaves.The effects of silicon on growth and physiology of maize (Zea mays L.) cultivar,Zhengdan958, which was planted under the condition of three kinds of soil ofmollisols, alluvial soil and saline-alkali soil, were studied and analyzed bycombination of laboratory and field experiments. In field experiments, there were fivelevels of Si (SiO2) application,0kg/ha,45kg/ha,90kg/ha,150kg/ha and225kg/hanamed as T1, T2, T3, T4and T5respectively. Under different levels of Si applying inthe three soils, these parameters of maize, such as seeds germination, regulation ofmetabolic materials, protective enzymes, contents of MDA, photosyntheticcharacteristics, morphological factors and yield were studied and analyzed at differentgrowth stages. The main results are as follows:The values of germination potential, germination index and vigor of maize seedscan be significantly increased under SiO2concentration of150kg/ha in these threetypes of soil; under the condition of mollisols and alluvial soil, the germinationpercentage of maize seed can not be affected by silicon application; the germinationpercentage of maize in saline-alkali soil can be significantly increased by certain doseof silicon; there is positive correlation between certain SiO2concentration and theindexes of germination rate, germination index and seed vigor in the three types ofsoil; the germination potential of maize seeds can’t be changed and seed vigor can beincreased by the use of silicon fertilizer in mollisols and alluvial soil. The activities ofdiastase, protease and lipase in seeds can be changed by silicon in mollisols; the activities of these three enzymes in maize seeds of molisols, alluvial soil andsaline-alkali soil can be promoted significantly when SiO2concentration isrespectively equal to or greater than225kg/ha,150kg/ha and225kg/ha.The concentration of soluble sugar, protein and starch in seeds or leaves of maizecan be affected by the use of silicon in different soil. There are maximums of the threekinds of metabolic materials in alluvial soil and saline-alkali soil under the doses ofsilicon application150kg/ha and225kg/ha; in molisols, the soluble protein is notsignificantly affected by silicon application, which can increase the contents ofsoluble sugar and starch greatly and get the maximums at the dose of225kg/ha.Leaves senescence can be prevented effectively by Silicon in mollisols andalluvial soil; the activities of MDA, SOD, POD and CAT are impacted greatly in thethree soil during the whole growth stages. In saline-alkali soil, the effect ofsaline-alkali stress can be alleviated by certain SiO2concentration, which is alsocontribute to slow down the processes of leaves senescence during late growth stages.The contents of chlorophyll of leaves can get the maximums under the doses of225kg/ha,150kg/ha and150kg/ha silicon application respectively in mollisols,alluvial soil and saline-alkali soil; in the three kinds of soil, from bell-mouthed periodto maturation period, the variation trend of the three indexes of Fv/Fm, ΦPSⅡ and qPof maize leaves was increasing at first and decreasing along, and got to maximum insilking stage; the variation trend of MPQ was decreasing at first and increasing then,the maximum of MPQ appeared in filling stage. The maximum values ofphotosynthetic rate (Pn) of maize leave in mollisols, alluvial soil and saline-alkali soilcan be got at the doses of225kg/ha,150kg/ha and150kg/ha silicon applicationrespectively. The transpiration rate (Tr) can be decreased significantly in the threekinds of soil by silicon application. The values of intercellular CO2concentration (Ci)can’t be affected significantly by silicon application in mollisols and alluvial soil; thevalue of Ci increases significantly with the increase of silicon application doses, and get the maximum under the treatment of225kg/ha. The values of stomaticconductance (Gs) can be significantly increased by the treatment of150kg/ha siliconapplication in mollisols, alluvial soil and saline-alkali soil.It’s can got the highest quality of morphological factors of maize under the silicontreatment of150kg/ha in the three types of soil; it can get the best yielding factors andyield of maize for mollisols, alluvial soil and saline-alkali soil respectively under thetreatments of225kg/ha,150kg/ha and225kg/ha. |
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