Biological Response Of Different Maize Inbred Lines To Low Potassium Stress

In order to find out the dynamic change of biology response of maize to low potassiumstress, tolerance to low potassium maize inbred lines90-21-3,099and sensitive to lowpotassium maize inbred lines D937,835were as materials. Hydroponics was as method. Inthis paper, we mainly studied about root morphology and its’ physiological indexes,photosynthetic characteristics and fluorescence parameters, MDA content and antioxidantenzymes activity, plant dry matter accumulation and potassium content under low potassiumstress on different leaf stage. The results were summarized as follows:1Under low potassium stress, compared with sensitive to low potassium maize inbredlines, tolerance to low potassium maize inbred lines’ roots total root length increases to alarger extent, t root surface area, root volume and root average diameter decrease small. Inthis paper, the maize fine roots (0.05-0.20cm) have great influence by potassiumconcentration. Tolerance to low potassium maize inbred lines’ fine root have little influence,especially on6leaf stage and10leaf stage. From the root of physiology perspective,tolerance to low potassium maize inbred lines’ root activity decline was smaller. The resultsshow that, compared with sensitive to low potassium maize inbred lines, the response to lowpotassium stress was tolerance to low potassium maize inbred lines have a developed rootsystem, small change of fine root.2Under low potassium stress, plant height and leaf area of different tolerance maizeinbred lines were decline. Tolerant to low potassium maize inbred lines’ change range wassmall. Under low potassium stress, the maize’s Pn, Gs, Ci, Tr, Ls and WUE were decrease,due to different tolerance to low potassium stress, there were different response of differenttolerance maize inbred lines, tolerance to low potassium maize inbred lines’ photosyntheticindex affected small. Low potassium stress made different tolerance to low potassium maizeinbred lines’ initial fluorescence rise, the biggest photochemical efficiency descend. Tolerantto low potassium maize inbred lines’ change range was small. The photosyntheticcharacteristics and the change of chlorophyll fluorescence parameters that, under lowpotassium stress, tolerance to low potassium maize inbred lines’ light systemⅡhas a lesserlight inhibition, photosynthetic capacity relatively strong, dry matter accumulation relativelymore.3Under low potassium stress, the MDA content in different tolerance to low potassium maize inbred lines was increased, tolerance to low potassium maize inbred lines’ rise bysmaller, it shows that membrane lipid peroxidation was less, SOD and CAT’ activity declinewas smaller, it means active oxygen defending ability was strong.4Correlation analysis of whole plant K content and root traits shows, plant k content andtotal root length, root surface area, root volume, the root average diameter, root injury flowwere very significant positive correlation. It means the developed root system was benefit toK absorption. It also can explain the tolerance to low potassium maize inbred lines have astrong K uptake ability.