耐低磷胁迫下玉米自交系幼苗的生长及磷素分配特征

Growth and Phosphorus Distribution Characteristics of Low-Phosphorus Tolerance Maize Inbred Line

选取耐低磷型玉米自交系QXN233和低磷敏感的QXH0121为材料,研究低磷、正常施磷、高磷3个生长条件下两个自交系幼苗的生长及磷素的分配情况。结果表明,在低磷和正常施磷条件下,自交系QXN233的地上部、根系与整株干重均显著高于QXH0121。低磷条件下,两个自交系根部形态差异较大,QXN233的根长、根表面积、根体积、根尖数均大于QXH0121,且QXN233的侧根数有所增加,推测其通过侧根的大量发育,增加根系表面积与根际环境的接触,促进根系对磷素的吸收。低磷条件下QXN233具有较小的根冠比,其地上部的磷素分配比例更高,表明QXN233能够吸收并输送更多的磷到地上部,从而使植株能够在低磷条件下更好地生长。

To investigate the character of growth and phosphorus distribution of low-phosphorus tolerance maize, two different maize inbred lines, the QXN233 of low-phosphorus tolerable and the QXN0121 of normal, were used as the testing materials. Three P levels of high, normal and low were set up under the conditions of sand and nutrient culture. The results showed that, under the low and normal P level condition, the dry weight of shoot, root and pant of QXN233 was higher than QXN0121, under condition of the low P level, the significant difference of the root architecture between these maize inbred lines was exhibited. The root length, surface area, volumes, the number of root tips of QXN233 was relative higher than QXN0121, and QXN233 have more lateral root than QXN0121, suggest that the P uptake of QXN233 was facilitated by their more developed lateral root which increased the contact area of the root surface and the soil. In addition, QXN233 had smaller root-shoot ratio, and had more P distribution ratio between the shoot and root, imply QXN233 could uptake and transport more P to shoot for the better development of plant under the low-phosphorus stress.