The Research On Screening And Identifying Of Low Phosphorus Telorant Genotype Maize And The Mechanism Of Adapting To Low Phosphorus Stress Environment

105 maize inbred lines were planted to get the low phosphorus telorant genotype within seedling and in soil media, which was devided three phosphate supplying levels. The representative materials from the result of seedling screening were identified within total bearing period under pot culture and cropland culture. Seedling was harvested at 28d after emergence. On the base of dry matter accumulation and the symptom of P-deficiency, we got 10 low P sensitive genotypes and 11 low P telorant genotypes. The P accumulation percent individual plant and relative P accumulation of inbred lines 2003-92 and 2003-34 is highest among low P telorant genotypes under P deficiency, so they belong to high phosphorus uptake type; The phosphorus utilization efficiency of 2003-06 and 2003-81 were higher than others' apparently under P deficiency, so they belong to high phosphorus utilization type. The Ca and Mg accumulation of every inbred line had not the direct relation with its P efficiency under low P stress, the Ca and Mg accumulation percent individual plant of some low P telorant genotypes were higher or lower than that of low P sensitive genotypes. The experiment of total bearing period shows that low P stress would make the natural bearing period of plant lag, the days of low P stress influencing the emergence of taking out androecium and spining the silk of the low P sensitive genotypes were longer than that of low P telorant genotypes; The low P sensitive genotypes showed the apparent symptom of P deficiency at seedling, it was mitigated via the periods of drawing knurl and taking out androecium, the phosphorus in old leave of below parts were transported to the new-growed tissue situated in top parts, so the P content of old leave of below parts was lower than that of middle and top parts, the symptom of P deficiency disappeared basically till the period of spining the silk. The shape of root under solution culture showed that low P telorant genotype T01 absorbed more phosphorus through elongating the root and augmenting the ratio of root and shoot to satisfy the need of P in bodies, which was also proved through the experiment of detaching the root, but T02 adapted to low P stress not through this mechanism; and the P content of low P telorant genotypes in shoot was higher than that of low P sensitive genotypes under P deficiency, whereas the P content of root was lower than that of low P sensitive genotypes. Different forms of inorganic phosphate had certain effect, but the effect varied greatly. On the dry matter weigh and P accumulation, the efficiency of different forms of phosphate ranked as follows: NaH2PO4>AlPO4>phosphate mine powder; the difference of absorption and utilization efficiency for different maize inbred lines was large, as a whole, the P utilization efficiency of low P telorant genotypes was higher than that of low P sensitive genotypes. The Apase activity based on leaf discmethod can well indicate the P status of abundance or deficiency in overgroud parts; There is tremendous difference between relative secretory Apase activities of telorant genotype from intact roots and that of sensitive genotype. It is one of response mechanisms to secrete acid phosphatase to external environment when crops suffered P deficiency, there are only differences in quantities of relative secretory acid phosphatase between genotypes of different adaptation ability under P deficiency conditions. Under P stress conditions, among the three sections of root, the root tip is the most active one of secretory acid phosphatase, but root base section contribute relatively little.