不同玉米杂交种亲本磷营养特征及对低磷胁迫的响应

为比较不同玉米杂交种亲本在不同磷水平下植株生长和养分吸收特性,以及养分在体内的循环和分配的差异,选取我国在生产中大面积推广且抗逆性较强的玉米杂交种亲本:郑58/昌7-2(郑单958),PH6WC/PH4CV(先玉335),利用营养液培养的方法进行了这些玉米磷营养特征的研究,通过供磷和缺磷营养液培养研究缺磷对不同基因型玉米生长发育,根系形态、活性和生理特性的影响,玉米苗期光合速率变化,并比较基因型间差异。结果表明,与供磷相比,缺磷亲本的干质量降低,磷增长量降低,根干质量增加,根冠比增加;根长增长,根半径降低,根表面积增加,总吸收面积和比表面积均降低;pH值降低;吸收H2PO4-和耐低磷能力提高,叶面积和光合速率下降。不同亲本间存在显著差异,其中,PH4CV具有相对较大的根长和根表面积,较活跃的根系吸收活性,干重增长较大,吸收速率大,叶面积和光合速率下降幅度较低,耐低磷能力强。

Phosphorus Characteristics of Different Maize Hybrid Varieties and Response to Low Phosphorus Stress

In order to compare the growths and nutrient absorptions of different maize hybrid parents at different levels of phosphorus, as well as the differences of nutrient cycling and distribution in vivo, Zheng 58 / Chang 7-2 （ Zhengdan 958）, and PH6WC/PH4CV （Xianyu335）, which are with strong resistances and largely planted in China, were selected to study maize phosphorus characteristics. The study on phosphorus was implemented by the method of nutrient solution culture. Through the ways of phosphorus sufficiency in one side and phosphorus deficiency in the other side, between genotypes, the influences and differences of phosphorus-deficiency to the growth, root morphology, activity, physiological characteristics and photosynthetic rate changes came out. The results showed that the phosphorus deficiency ,compared with the phosphorus sufficiency, the dry weight reduced, the increments of phosphorus reduced, the root-shoot ratio increased; root length increased, root radius reduced, root surface increased, the total absorption area and specific surface area reduced; pH decreased; the capacity of anti-phosphorus-deficiency and absorbing H2PO4^-strengthened, leaf area and photosynthetic rate decreased. Significant differences existed among the parents, in which, PH4CV had a relatively larger root length and root surface area, better root absorption activity, larger increase of dry weight, higher absorbing rate, lower decrease in the leaf area and photosynthetic rate, as well as better capacity of anti-phosphorus-deficiency.