BIOREGULATOR EFFECTS ON THE ROOT ARCHITECTURE OF MALUS HUPEHENSIS UNDER DIFFERENT PHOSPHATE CONDITIONS

Root architecture (RA) is studied using paper-cultivated Malus hupehensis Rehd. seedlings treated with IBA, GA₃, PP₃₃₃ and TIBA under different phosphate conditions.
The results showed that the types of RA can be classified into 8 types.
After 2 μg/g PP₃₃₃ treatment under complete Hogland solution (no P deficiency), the numbers and lengths and densities of lateral roots increased, and most plants exhibited the type of RA classified as “lateral roots well-distributed on the primary root”. But after PP₃₃₃ 20 μg/g or GA₃ 0.5 μg/g treatments, the numbers and lengths of lateral roots decreased and the types of RA became more simple.
After treatment with IBA at concentrations of 0.1 to 5.0 μg/g under complete Hogland solution, M. hupehensis seedlings produced more and longer lateral roots and they had more of the type of RA classified as “lateral roots clustered on the upper part of the primary root”. After treatment with 2 μg/g PP₃₃₃ under P-deficiency solution, M. hupehensis plants produced more and denser lateral roots, the types of RA reduced, and the plants exhibiting the type of “lateral roots clustered on the upper and middle parts of the primary root” increased.
The numbers and lengths of lateral roots decreased and the types of RA became less after treatment with 20 μg/g PP₃₃₃ under the P-deficiency solution.
The numbers and densities of lateral roots increased, and the types of RA become more in the P-deficiency solution with GA₃ 0.5 μg/g treatment.
The numbers and lengths of lateral roots gradually decreased, and the types of RA became more simple as the IBA concentration was increased from 0.1 to 5.0 μg/g and the RA of most plants became “no lateral roots” when the IBA concentration reached 5.0 μg/g under P-deficiency solution.
But the numbers, densities and lengths of lateral roots decreased after treatment with 10 μg/g TIBA (an auxin transport inhibitor). The results suggest that auxin and gibberellins participate in the regulation of root architecture in M. hupehensis under phosphate deficiency conditions.

XXVII International Horticultural Congress – IHC2006: International Symposium on Endogenous and Exogenous Plant Bioregulators

Weiguo Fan, Hongqiang Yang

Malus hupehensis Rehd., paper-cultivate, root architecture (RA), phosphate deficiency, IBA, GA₃

https://doi.org/10.17660/ActaHortic.2008.774.24