Screening Germplasm Resources Of Barley With High Phosphorus Efficiency And Study In Physiological Characteristics

Phosphorus is one of the most important mineral nutrients for plants growth, is also one of the important compounds in plants components. It participate for various physiological and metabolic processes of the plant in many ways.It has an irreplaceable role in agricultural production.However, phosphorus is a non-renewable resources, it will not only waste resources, but also bring a lot of environmental problems to increase P fertilizer application rate for high production.Many studies have shown that different plants or different genotypes of the same plant is different in the absorption and utilization of phosphorus. Therefore, it has a important significance to screen and nurture new crop varieties which has high utilization rate of P of soil and activate the P available in soil.To compare with the growth condition of Munkel, Alexis, Ganpi 4 and so on under using P and P deficiency, Using the relative plant biomass, relative root/shoot ratio and relative utilization of phosphorus to screen barley genotypes for high-efficiency utilization of phosphorus,and research the Physiological mechanism and the whole growth period for research.The results showed that:1. The hydroponic experiments showed that, the plant biomass were significantly lower than those of P-sufficient plant. the root/shoot ratio and phosphorus utilization efficiency were sharply increased under low-P stress. According to these indexes of the relative biomass, relative root/shoot ratio and relative P use efficiency, the two high P- efficiency genotypes and five low P-efficiency genotypes were selected. They are Alexis, Munkel and Ganpi 4, g-23, Guangmai7, Ganpi 2, EF (98-2), C-13.2. The sand experiment showed that, the MDA content,the activities of SOD,PODand CAT in leaves of high P-efficiency genotypes in range of less than low P-efficiency genotypes.Results suggest that, A strong ability of scavenging active oxygen which barly cuhivars with high phosphorus efficiency can prevent lipid peroxidation and prevent cell membrane damage, but the low P-efficiency genotypes under phosphorus deficiency stress are vulnerable.3. The study of Hydroponic experiment on root morphological characteristics found that the barley roots will change the root number, root length, root volume to adapt to the environmental stress. Phosphorus efficient genotypes are often greater than the inefficient genotypes greater root length and root volume.4. Through the sand culture experiment on barley chlorophyll a, chlorophyll b and chlorophyll found that,the chlorophyll content of high P-efficiency genotypes decreased lower than low P-efficiency genotypes under the conditions of phosphorus deficiency. The result indicate that high P-efficiency genotypes have a small injury with high phosphorus utilization ability.5. Through pot experiments with different phosphorus efficiency for the whole growth period of barley genotypes identified, the results show that the phosphorus content of high P- efficiency genotypes of barley on the growth and maturity in all the various parts of plants greater than low P-efficiency genotypes. At each growth stage in the process of barley plants under normal phosphorus accumulation showed an increasing trend of phosphorus, phosphorus stress in barley plants under phosphorus accumulation declined sharply, but the decline in P efficiency rate of barley genotypes than P inefficiency. It shows that the phosphorus absorption capacity reduced under phosphorus deficiency stress.