磷对玉米自交系及其杂交种苗期形态的影响

Effects of Phosphorous Concentration on Morphological Characters of Inbred Line and Crossbreeds Seedlings of Maize

以玉米自交系Mo17、B73及其杂交种Mo17×B73和B73×Mo17作为试验材料,设置了5个磷处理水平,对玉米苗期形态指标进行研究。结果表明:磷浓度高于或低于0.5mM时,玉米苗期株高、地上和地下干重及植株含磷量的值均降低,0.5mM的磷适合作为玉米盆栽蛭石培养的正常供磷水平;低磷下玉米苗期地上和地下干重较正常磷下降低,且不同基因型玉米地上和地下干重变化不同,Mo17×B73地上干重降幅较地下干重大,根冠比增加,其他基因型地下干重较地上干重降幅大,根冠比降低;正常磷和低磷下杂交种株高、成活叶数和地下干重大于双亲平均值,且杂交种根冠比和地下干重耐低磷指数均显著高于双亲。正交杂交种Mo17×B73根冠比耐低磷指数显著高于反交杂交种B73×Mo17。

Morphological characters of different maize cultivars,including Mo17,B73and their crossbreeds were investigated when treated with five different phosphorous(P)concentration at seedling stage.The results were as follows:(1)When P concentration was either higher or lower than 0.5mM,the plant height,dry weight of shoot and root,and P content of shoot of maize seedlings were reduced,which indicated that 0.5mM was the proper P concentration for screening P-tolerance maize cultivars in vermiculite cultivating;(2)Dry weights of both under and above ground sections of maize seedlings treated with low P concentration were lower than those with the normal P concentration and the decreased rate of the dry weight of shoot and root were different among different maize cultivars,in which dry weight of shoot of Mo17× B73was reduced greater than its dry weight of root,and its root to shoot ratio was increased,but dry weight of shoot of other maize cultivars were reduced less than that of root,and their root to shoot ratio were reduced.(3)Treated with normal and low P concentration,plant height,the number of survived leaves and dry weight of root of crossbreeds were higher than average value of their parents,and P-tolerance indexes of dry weight of crossbreeds were higher than those of their parents.The P-tolerance index of root to shoot ratio of Mo17× B73was higher than that of B73× Mo17.