Genotypic Variances And Environmental Effects On Several Mineral Elements In Sweetpotatoes(Ipomoea Batatas Lam.)

Sweetpotato, which contains large quantity of Iron(Fe), Zinc(Zn), Calcium(Ca) and Selenium(Se), is one of the principal food sources to supply the lack of favorable elements in human body. The Fe, Zn, Ca and Se contents in the storage roots of 21 different varieties of sweetpotato were determined by ICP-OES (The IRIS/AP Optical Emission Spectrometer). The contents of four mineral nutritional elements in sweetpotato under different potasium fertilization were also studied. Meanwhile, the distribution of the four mineral nutritional elements in sweetpotato plant and storage roots was identified. The main results were as follows:1. The average contents of Fe, Zn, Ca and Se in sweetpotato storage roots were 38.97, 49.02, 889.70,0.1472mg/kg (dry base) respectively, and their ranges were 1.97-167.86, 11.68-245.40, 37.63-1925.6 and 0.0100-0.5142 mg/kg (dry base).2. There were no significant differences in these four mineral contents among genotypes with different flesh color types. In general, the Fe, Zn and Se contents in orange and yellow type were higher than that of white type. The Ca content of orange type was the highest among all genotypes.3. There were marked differences in the Zn and Ca contents among genotypes with different dry matter content types. The Fe, Zn and Ca contents in low dry matter content types were higher than that of intermediary and high types.4. Significant differences in Fe, Zn and Ca contents of sweetpotato were observed among different growing period types. The Fe content of intermediary maturing types was the highest among all types. The Zn and Ca contents in intermediary and late maturing types are conspicuously higher than that of early maturing types. However, there is no marked difference of Se content between different growing period types.5. The Fe, Zn and Ca contents were influenced by the potassium fertilization.The Fe, Zn and Ca contents of the storage roots with potassium application were higher than that with non-potassium application. Moreover, the Fe, Zn and Ca contents in the storage roots increased with increase in the potassium application.6. Fe, Zn and Ca contents in the leaves and petioles were found to be much higher than that in other parts. Moreover, the Fe, Zn and Ca contents in the cortexes of storage roots were notably higher than that in the piths.7. The results of analysis by AMMI model showed that the genotype effect, environment effect and genotype X environment interaction effect in Zn and Ca contents of the storage roots reached the conspicuous level, and the genotype effect and genotype X environment interaction effect in Fe content reached the significent level. The results of biplot analysis indicated the stability and adaptability of these three elements in different varieties, the discriminability of locations were also exhibited.