Abstract

Key messagePhosphorous (P) deficiency induces root cortical aerenchyma (RCA) formation in Chinese fir seedlings with marked genotypic variation, and the adaptive role of RCA is mainly related to root P reduction.AbstractRoot cortical aerenchyma (RCA) formation in response to phosphorus (P) deficiency and its adaptive role are largely unexplored in trees. We hypothesized that RCA formation in response to P deficiency varies with its severity and genotype, and that P-stressed seedlings maintain similar seedling growth to non-stressed seedlings by reducing the P requirements of roots and metabolic cost of soil exploration. Seedlings of two half-sib families (nos. 25 and 36) of Cunninghamia lanceolata (Chinese fir) were grown in pots with three levels of P supply for 3months. Significant differences in RCA formation in 40-45mm root segments from the root tip were observed between families and P supply levels. Severe P deficiency induced more RCA formation in family no. 36 than in family no. 25, whereas moderate P deficiency induced RCA formation in family no. 36 only. Family no. 36 had significantly higher height increment, needle biomass, and P concentration in stems and needles, but lower root biomass and root P concentration, than family 25. A significantly negative relationship was found between RCA and root P concentration, increments in average root diameter, and root surface area, whereas significantly positive correlations were observed between some root morphological traits and biomass and P concentration in the organs of P-stressed seedlings of family 36. In conclusion, severe P deficiency induces formation of RCA in Chinese fir seedlings with marked genotypic variation, and the adaptive role of RCA formation during P deficiency is mainly related to the reduction of root P concentration.

Keywords

Chinese fir; Phosphorus stress; Root morphology; Root anatomical trait

Published in

Trees - Structure and Function
2018, Volume: 32, number: 6, pages: 1633-1642
Publisher: SPRINGER HEIDELBERG

SLU Authors

• Tigabu, Mulualem

  • Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
    
UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1007/s00468-018-1739-3

Permanent link to this page (URI)

https://res.slu.se/id/publ/97664