Effect of ionic Al in culture solutions on the growth ofArnica montana L. andDeschampsia flexuosa (L.) Trin.

Abstract

The distribution of Arnica montana L., a hemicryptophytic plant of acid peaty heathlands on nutrientpoor humic podzols has declined in the Netherlands since 1950. The decline is significantly correlated with the 95-percentile of the SO2 concentration in the air over the winter period of 1978/1979. The resulting acid rain could have caused increased levels of ionic A1 in low-buffered soils as 'Haar' and 'Veld' (humic) podzols. Ionic AI is generally considered to be an important growth-limiting factor in many acid soils which are often leached causing additionally low levels of Ca and Mg.The toxic effect of AP + on seedlings growth of Arnica and on the Al-tolerant, calcifugous grass Deschampsiaflexuosa (L.) Trin. was investigated. Seedlings of both species were grown on complete nutrient solutions situated in a heated greenhouse. Various concentrations of AI 3 + at high acidity (pH 3.8) were used. Relatively high and low levels of Ca and/or Mg were factorially combined.It appeared that Arnica and Deschampsia are AI tolerant, the former being somewhat less so. At relatively low concentrations (e.g. 5 mg 1 -~) of ionic A1, growth of shoot and roots of both species were stimulated.Tolerance to AI 3+ is possibly due to an internal Al-chelating mechanism. The Ca and Mg supply did show an influence on growth (yield), but both divalent ions did not affect the magnitude of A1 toxicity. These results may indicate that it is not likely that the decline of the regional distribution and abundance of Arnica since 1950 is regulated by ionic A1 in the rooting zone.

An experimental comparison of aluminium and manganese susceptibility inAntennaria dioica, Arnica montana, Viola canina, Filago minimaandDeschampsia flexuosa

“…Roots are, in general, more susceptible to ionic Al than shoots (Foy et al 1978).However, important reductions in growth were not observed in these species in response to rather high concentrations of ionic AI. Growth stimulation by Al of D.flexuosa (Hackett 1962;Pegtel 1987) and A. montana (Pegtel 1987) was not detected in this study. This may possibly be due to different growth conditions: in the first series of experiments (PegteI1987) a heated greenhouse was used.…”

Aluminum-induced growth stimulation in relation to calcium, magnesium, and silicate nutrition inMelastoma malabathricumL.

“…Growth of some plants other than M. malabathricum, is also stimulated by Al (Mullette 1975;Konishi et ai. 1985;Pegtel 1987;Haridasan 1988;Huang and Bachelard 1993;Malkanthi et ai. 1995a).…”

Aluminum effect on starch, soluble sugar, and phytohormone in roots of Quercus serrata Thunb. seedlings

“…and Bechelard 1993), Quercus acutissima (Oda and Yamamoto 2002), and so on. Although less than the reports of trees, there are some reports of growth increment by Al in herbaceous plants, such as Arnica montana, Deschampsia flexuosa (Pegtel 1987), and Zea mays (Lindon et al 1998). Most research on plants showing beneficial effect of Al have been focused on the mechanism of Al torelance, but very few have approached the mechanism of growth enhancement by Al.…”