Effects of soil amendments on leaf anatomical characteristics of marigolds cultivated in cadmium-spiked soils

Alapha Thongchai,Puntaree Taeprayoon,Isma-Ae Chelong,Weeradej Meeinkuirt

doi:10.1038/s41598-021-95467-9

Alapha Thongchai, Puntaree Taeprayoon + Show 2 more

Open Access

https://doi.org/10.1038/s41598-021-95467-9

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Journal: Scientific Reports	Publication Date: Aug 5, 2021
Citations: 4	License type: open-access

Affiliation: Yala Rajabhat University, Mahidol University

Abstract

The marigolds (Tagetes spp.) in this study were classified as excluders for cadmium (Cd); however, their leaves also accumulated substantial Cd content. Among the experimental treatments (i.e., control, cattle manure, pig manure, and leonardite which served as soil amendments), pig manure resulted in significantly increased growth performance for all marigold cultivars as seen by relative growth rates (119–132.3%) and showed positive effects on leaf anatomy modifications, e.g., thickness of spongy and palisade mesophyll, size of vein area and diameter of xylem cells. This may be due to substantially higher essential nutrient content, e.g., total nitrogen (N) and extractable phosphorus (P), in pig manure that aided all marigold cultivars, particularly the French cultivar which exhibited the highest relative growth rate (132.3%). In the Cd-only treatment, cell disorganization was observed in vascular bundles as well as in palisade and spongy mesophyll, which may have been responsible for the lowest plant growth performance recorded in this study, particularly among the American and Honey cultivars (RGR = 73% and 77.3%, respectively).

Highlights

The marigolds (Tagetes spp.) in this study were classified as excluders for cadmium (Cd); their leaves accumulated substantial Cd content
Soil properties affecting the availability of cadmium (Cd) include: Cd adsorption and desorption on iron (Fe) and manganese (Mn) oxides; redox potential (Eh); presence of both calcium carbonate and oxyhydroxides; pH; organic matter (OM); ionic strength; ligand anions; cation exchange capacity (CEC); phosphorus (P); and the proportion of clay minerals and percentage of charged sites occupied by Cd
Many reports indicate that the presence of certain essential nutrients in plant media can affect the modification of leaf anatomical characteristics

Summary

Introduction

The marigolds (Tagetes spp.) in this study were classified as excluders for cadmium (Cd); their leaves accumulated substantial Cd content. The nutrient content of organic amendments such as pig and cattle manure enhance soil N concentrations considerably, which helps induce both plant growth and yield.

Results

Conclusion