The Effects Of Cadmium And Fertilization On The Growth And Development Of Potato

Potato is produced widely in China.However,the soil has been seriously polluted by heavy metals. A more attention has been paid on the issue of potato safety. Two potato cultivars "Kexin No.1"and "favorite" were pot cultured in the cadmium polluted soil. The effects of cadmium and fertilization on the growth and development of potato were investigated. Science instruction had been offered to development of potato industry.The results indicated:1.Under the cadmium stress with low and medium concentration (10,20mg/kg),the growth of the stem,branch,lamina,flower of two cultivars were increased.Under the cadmium stress with high concentration (50mg/kg,100mg/kg),the growth of two cultivars were inhibited.Plants growed weakly,they were dwarf and easy to lodging. The quantity of flowers were low and they were easy to fall.With the increasement of cadmium concentration,the growth of the roots and tubers of two cultivars were inhibited to different extent.The root tolal length, root surface area, root volume and tuber yield were reduced. Yield of "Favorite"tuber reduced more serious than "Kexin No.1".And with increasement of the cadmium concentration,total biomass of both cultivars were decreased.The resistance of Kexin No.1"to cadmium was better than that of’Favorite".2.With the increasement of cadmium concentration,the content of chlorophy Ⅱ a and chlorophy Ⅱ b of two cultivars were decreased significantly. The Chlorophy Ⅱs of "Kexin No.1"was decreased.At the higher cadmium(20mg/kg),the Chlorophylls of "Favorite"decreased significantly. Under the cadmium stress, leave was chlorosis,Net photosynthetic rate (Pn),stomatal conductance (Cond)and transpiration rate(Tr) were decreased.leading to photosynthesis restrainment.3.Under the cadmium stress with low and medium concentration(10,20mg/kg), the activity of SOD,POD,CAT increased.But under the cadmium stress with high concentration,the activity of SOD,POD,CAT decreased,led to physiological metabolism disorder.The stress of cadmium caused the accumulate of MDA and proline in potato leaves. With the increasement of cadmium concentration,the content of starch,protein,vitamine C and soluble sugar in two cultivars potato tubers had decreased.There were significant differences between the contrast and treatments.The tuber quality reduced.4.Under the cadmium stress,the growth of potatos were promoted by applying organic fertilizer and inorganic fertilizer.Compared with low quantity fertilizer and inorganic fertilizer, the starch and vitamine C of potato tubers were improved by applying high quantity of fertilizer. As compared with inorganic fertilizer, the stress of cadmium could be alleviated by applying organic fertilizer.