Aluminum effects on growth and P, Ca, and Mg uptake efficiency in red clover cult1vars

Abstract

Climatically controlled growth rooms were used to evaluate performance of 23 red clover cultivars in a nutrient culture system at 5 levels of Al (0, 25, 50, 75 and 100 μM). The shoot and root growth of all the cultivars was reduced by Al. Considerable reduction in growth was observed at Al levels beyond 50 μM. The efficiency ratio (ER) (mg shoot dry matter per mg shoot element) for P declined with increasing Al. ER values for Ca and Mg declined slightly with increasing concentration of Al to 50 μM but then increased considerably with increasing Al. In the absence of Al, Redman, K4–184 and Chesapeake showed the highest ER for P, Ca and Mg, respectively. However, in the presence of 50 μM Al, Altaswede had the highest ER for P and Mg, and Redland showed the highest ER for Ca. In the presence of 50 μM Al, Florie, Norlac and Redmor gave the lowest ER values for P, Ca, and Mg. The growth and ER for P, Ca, and Mg in the presence or absence of Al appears to be different among the various red clover cultivars tested. The presence of a Swedish line in its parentage has improved ER for P and Mg in Altaswede. The ILL‐2 as a parental line improved Ca ER in Redland and Redmor. In Florie, the presence of line ILL‐1 and cultivar Lakeland as parents gave the lowest ER for P. Genetic diversity for P, Ca, and Mg uptake efficiency was observed among the cultivars tested.

Key words:

• Elemental concentrations
• shoot and root growth reduction