An in vitro screening system to assess aluminum toxicity in sugarcane (Saccharum spp.) cultivars

Autor: R. S. Rutherford, S. J. Snyman, M. Naidoo, M.P. Watt
Rok vydání: 2019
Předmět:
Zdroj: In Vitro Cellular & Developmental Biology - Plant. 55:403-408
ISSN: 1475-2689
1054-5476
Popis: Mutagenic breeding is an approach being developed especially for those characteristics that are not inherited through conventional genetic hybridization. Soil acidity and aluminum (Al3+) toxicity limit sugarcane production, particularly in leached soils in the coastal cultivation regions in South Africa. An in vitro screening procedure was developed based on plantlet re-rooting in Al3+-containing medium to select putative Al3+ tolerant variants produced by induced mutagenesis. A preliminary test did not show any difference among three cultivars in their ability to re-root in the presence of Al3+. Subsequent work focused on Saccharum sp. ‘NCo376’ and two Al3+ concentrations (15 and 45 mM), representing LC50 and LC90 re-rooting inhibition. In an attempt to increase the stringency of the selection conditions, the possible effects of inorganic nitrogen (N) forms in the culture media on Al3+ toxicity were investigated. The form of N affected root regrowth and citrate exudation. Sugarcane plantlets showed an uptake preference for ammonium (NH4+) over nitrate (NO3−), and 10 and 20 mM NH4+ appeared to alleviate Al3+ toxicity compared with NO3−. Although in agricultural soils NO3− is the dominant form of N, it can readily leach into the sub-soil, in which deep roots encounter Al3+ toxicity in the presence of NO3−. Therefore, the ability to withstand the toxic effects of Al3+ in the presence of NO3− could be beneficial for N use efficiency and access to water at depths during drought.
Databáze: OpenAIRE
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