Open Access

ARTICLE

Physiological and Biochemical Responses of Perennial Ryegrass Mixed Planting with Legumes under Heavy Metal Pollution

Yi Xi, Li Zhang, Yanhong Xu, Wei Cheng, Chao Chen^*

College of Animal Science, Guizhou University, Guiyang, 550025, China

* Corresponding Author: Chao Chen. Email:

(This article belongs to the Special Issue: Abiotic Stress Impacts on Plant Physiology and Their Alleviation)

Phyton-International Journal of Experimental Botany 2024, 93(7), 1749-1765. https://doi.org/10.32604/phyton.2024.051793

Received 15 March 2024; Accepted 17 June 2024; Issue published 30 July 2024

Abstract

In artificially controlled pot experiments, perennial ryegrass was mixed with other leguminous plants (white clover and alfalfa) and treated with lead, zinc and cadmium (337 mg·kg, 648 mg·kg, and 9 mg·kg, respectively) to simulate compound pollution conditions. The results showed that the concentrations of heavy metals, transport factors, and bioconcentration factors in mixed planting of ryegrass decreased compared with those in monoculture. Regardless of whether heavy metal pollution was introduced, mixed planting increased the aboveground and underground biomasses of ryegrass. The different mixed planting treatments had no significant impact on the chlorophyll concentration of ryegrass. The mowing time, mixed planting treatment, and heavy metal treatment had impacts on antioxidant and osmotic adjustment substances, and there were some interactions. The mixed planting treatment did not significantly affect glutathione concentration, cysteine concentration, or nonprotein thiol. Mixed planting generally increased the nitrogen and phosphorus concentrations of ryegrass while reducing the stoichiometric ratio of carbon, nitrogen, and phosphorus. These results suggest that the mixed planting of ryegrass with legumes promotes the growth of ryegrass in the presence of high concentrations of heavy metal pollution. However, it does not enhance the ability of ryegrass to remediate heavy metal pollution in the soil.

---

Keywords

---