Studies On The Change Of Nitrogen Compands And Plant Hormone Of Sweet Potato Under The Stress Of Sweet Potato Scab

The Sweet Potato Scab has become one of the major fungus diseases on the sweet potato in my province up to now. In recent years, domestic and international research work about sweet potato was focused on the spread, prevention, anti-disease filtration etc of the sweet potato diseases. But the nitrogen metabolism and plant hormones regulation of sweet potato has not yet been seen after infected with scab fungus. In this article, I studied the influence that the scab fungus had an effect on nucleic acid metabolism, protein metabolism, polyamine metabolism, the IAA metabolism and ABA content, the N, P and K contents etc in the leaves of the different resistant sweet potatoes. The result showed that the IAA content reduced, the ABA content increased, the N and soluble protein content dropped, the NR and PAO activity increased, the total content of PAs and putrescine increased, the ratio of Put/(Spd+Spm) increased in the leaves of both anti-diseased and diseased sweet potato after infected with scab fungus. But the change range of diseased sweet potato was more extensive than anti-diseased one. In addition, the chlorogenic acid content decreased, IAA oxidase and PAO activity increased, the total nucleic acid and RNA content decreased, RNase activity increased, the FAA content increased, proteinase activity increased, the total P and K content reduced in the leaves of diseasedsweet potato after infected with scab fungus, and the change ofanti-diseased sweet potato was contrary. These results could be used as physiological indexes to the choice of germ plasm and resistant breeding in sweet potato.