不同玉米自交系苗期铁效率差异研究

摘要

Twelve elite maize inbred lines were hydroponically cultured in this study to investigate the genotypic differences of Fe-efficiency at their seedling stage.After supplying different amount of HEDTA-Fe (2 and 100 μmol/L) in nutrient solutions,plant phenotypes were observed and traced,and plant height,leaf number,dry matter,the ratio of root to shoot,SPAD value and micronutrients were measured.Under low iron supply condition,the plant height,SPAD value,shoot weight,root weight and total dry weight decreased significantly,especially on the genotypes of D340,B77 and CI7.The total weight of B77 was significantly lower than that of others.The total weight of DE3 decreased the least.Zinc,manganese and copper concentrations in shoots and roots enhanced significantly.There was significant differences among these 12 maize inbred lines on their iron efficiency,which varied from 5％ to 40％.DE3 displayed the highest iron efficiency,and B77 had the lowest iron efficiency.The correlation analysis showed that the total dry matter,SPAD value and the ratio of root to shoot correlated negatively with iron efficiency.Taken together,these results indicated that there is significant iron efficiency differences among different maize inbred lines,which would provide references for the improvement of maize iron efficiency in the future.%为探究不同基因型玉米苗期铁效率的差异,以12个玉米自交系(M017、KUI3、CI7、Sc55、DE3、K22、8701、Zong3、BY815、Dan340、Zheng58和B77)为供试材料,用不同浓度的HEDTA-Fe3+(低铁为2 μmol/L,对照为100μmol/L)处理;通过对苗期玉米植株株高、叶片数、干重、根冠比、叶绿素和微量元素等指标进行研究分析.结果表明:1)低铁胁迫下,各基因型玉米的株高、SPAD值、地上部生物量、根部生物量、以及总生物量均显著降低,D340、B77和CI7株高下降最多;B77总生物量显著低于其他基因型,DE3总生物量下降最少.2)低铁处理下各基因型对锌、锰和铜的吸收都有不同程度地提高.12个基因型的铁吸收效率变异范围为5％～40％,其中DE3铁吸收效率最高,而B77铁效率最低.3)正常供铁情况下,玉米的总生物量、SPAD值均与铁吸收效率呈现极显著的负相关;而在低铁胁迫下,根冠比与铁吸收效率呈显著的负相关.