Effects of low phosphorus availability on root cambial activity, biomass production and root morphological pattern in two clones of Chinese fir

Abstract

Phosphorous (P) is a crucial limiting nutrient for plant growth and development in terrestrial ecosystems. As one of the most important subtropical coniferous tree species, Chinese fir (Cunninghamia lanceolata) plays a major role in timber supply, climate mitigation and forest recreation. In this study, two Chinese fir clones (020 and 061) with a high growth rate were subjected to two levels of P supply in a greenhouse pot experiment: P-deficient P0 (no P supply) and P-replete P1 (1.0 mmol L−1 KH2PO4). Our objectives were to study the differences in morphology and growth patterns, cambial development mechanism and secondary root growth. Root sampling was performed at 40, 80 and 120 days after treatment initiation. Results indicated that the P-replete condition produced more root cambial cells (RCCs) in third class (larger) roots of clone-061 than in those of clone-020; concomitantly, clone-061 showed significantly greater stem height (42.87 ± 1.33 cm), root collar diameter (5.45 ± 0.126 mm), root average diameter (RAD, third class = 1.27 ± 0.04 mm) in different root classes and whole-plant biomass (7.55 ± 0.69 g) compared with clone-020 under the P-replete condition. Root diameter and biomass increase due to higher cambial activity resulted in greater seedling quality. In addition, a significant positive correlation was observed between the number of RCCs and root morphological traits (root length, root surface area, RAD and root volume). Root development was significantly promoted by cambium activity in the P-replete environment, thereby enhancing plant secondary growth. Based on these outcomes, we suggest that clone-061 would be more useful for enhancing production. Regarding commercial purposes, these findings will contribute to the improvement of P fertilization efficiency.

Influence of Cambium Mechanism in Plants in Relation to Different Environmental Stresses

“…This approach represents a competent model for studying cambial activity and wood formation. This review also showed that temperature, water, and phosphorus dynamics indicate past and current functions of different tree species [113]. In particular, this review demonstrates the need to research mechanisms within a classified scheme and how identified stresses vary in relation to the physiological and morphological features of different tree species over specific periods.…”

Effects of Slope Position on Morphological, Anatomical, and Chemical Traits of Cunninghamia lanceolata (Lamb.) Hook. Fine Roots

“…Specific root length, specific root area, and specific root tip density of Chinese fir fine roots in mature forests show a decreasing trend with increasing forest age, and the nutrient foraging ability decreases; however, physiological compensation occurs by increasing the nitrogen concentration of the fine roots [18]. By observing the cross-sectional microstructure of the fine roots of Chinese fir, it was found that the activity of the cambium was significantly increased in an environment with sufficient phosphorus, which promoted an increase in root diameter and biomass and improved the quality of seedlings [19]. With increasing research on the relationship between global environmental change and root systems, fine roots are an important bridge connecting the external morphology, internal physiological activity, and functions of plants.…”

Ecological Stoichiometry of N and P across a Chronosequence of Chinese Fir Plantation Forests

“…Numerous studies have demonstrated the relationship between the N:P ratio in green foliage and soil nutrient availability, highlighting the internal linkages between nutrient demand and supply [1,5,6,[9][10][11][12]. In response to low soil P availability, plants typically reduce foliage P concentration [13][14][15]. The biological characteristics of plant species contribute to the variations in nutrient requirements throughout different growth stages [16].…”