Growth and cadmium accumulation in selected switchgrass cultivars

Abstract

Switchgrass (Panicum virgatum L.) has potential as a sustainable biofuel crop. Utilizing alternative sources of fertilizer nutrients could enhance production of switchgrass. However, alternative sources of fertilizer such as sewage sludge sometimes contain heavy metals such as cadmium (Cd) and the response of switchgrass to Cd is not known. Four switchgrass cultivars (Alamo, Blackwell, Cave-in-Rock, and Trailblazer) grown in sand culture were watered twice weekly with a nutrient solution containing Cd. Cadmium levels in solution were 0, 1, 2, 4, 8, and 16 mg Cd L -1 . Plants were harvested 1 Research conducted while employed by Texas 2656 REEDETAL. 63 d after planting and separated into leaf blade, stem (culm + leaf sheath), and root components. Tissue Cd concentrations were determined using atomic absorption spectrophotometry. Cultivars differed (P<0.05) by less than 15% for biomass accumulation and allocation among plant parts. Cadmium levels of 16 mg L -1 reduced biomass yields by 31% for roots, 39% for leaf blades, and 47% for stems as compared to no added Cd. At 16 mg Cd L -1 , Cd concentration in leaf blades was 9.9 mg kg -1 . The highest levels of Cd (329 mg kg -1 ) were found in roots of Blackwell and Trailblazer grown at the highest Cd level. Cadmium at 16 mg Cd L -1 is phytotoxic to switchgrass and accumulates in all plant parts. The cultivars tested in this study did not differ in biomass accumulation in response to Cd; however, Cd accumulation in plant parts differed among cultivars. Consideration of Cd uptake should be a part of switchgrass cultivar selection when grown in the presence of Cd.

Model optimization of cadmium and accumulation in switchgrass (Panicum virgatum L.): potential use for ecological phytoremediation in Cd-contaminated soils

“…Growth and cadmium accumulation in four switchgrass cultivars (Alamo, Blackwell, Cave-in-Rock, and Trailblazer) were reported (Reed et al 1999). Our results showed that the seeds of Kanlow switchgrass were capable of germinating under all treatment conditions, which indicated that switchgrass seeds were moderately tolerant to Cd stress and mildly acidic conditions.…”

“…Previous research (Entry and Watrud 1998) reported that Alamo switchgrass has the ability to accumulate Cs and Sr from contaminated soil. Reed (Reed et al 1999(Reed et al , 2002 studied several switchgrass cultivars and their response to cadmium in sandy soil, with the conclusion that Cd accumulation in switchgrass was greatly dependent upon the type of switchgrass cultivar and the soil pH. Hopkins (Hopkins and Taliaferro 1997) showed that Kanlow and Blackwell switchgrass have substantial tolerance to acidic conditions.…”

Corn Tolerance to Atrazine and Cadmium and Sunflower to Cadmium in Soil and Hydroponic Culture

“…Soilless culture is often used for rapid screening of plant tolerance in pollutants, using a wide range of concentrations and replications, which is the first step to assess the importance of a plant species for remediation (Jettner et al 1999;Reed et al 1999;Vassilev et al 2004). Advantages of the hydroponic technique are the absence of soil, eliminating absorption and degradation, and the fully controlled environment.…”

Using chemical fractionation to evaluate the phytoextraction of cadmium by switchgrass from Cd-contaminated soils

“…Due to the well-known agronomic characteristics of switchgrass (i.e., fertilization, irrigation, soil pH optima, plant density, biomass field-drying, and harvest schedule), it is practicable to use this grass as a candidate crop for phytoextraction in situ. Thus, in early studies (Entry and Watrud 1998;Reed et al 1999;Shahandeh and Hossner 2000), switchgrass has been used for the phytoremediation of heavy-metal contaminated soils.…”