107(4)_str39

ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 107, No. 4 (2020), p. 309–316
DOI  10.13080/z-a.2020.107.039

The response of Medicago sativa to mobile aluminium toxicity at seedling stage

Aurelija LIATUKIENE, Vytautas RUZGAS, Zilvinas LIATUKAS, Regina SKUODIENE

Abstract

Aluminium (Al) toxicity is a major limiting factor of crop production in acidic soils. The objective of the current study was to evaluate the development of lucerne (Medicago sativa L.) cultivars and their response to mobile Al toxicity. Three screening methods: filter paper-based, hydroponic and soil-based, were used to assess 13 M. sativa cultivars for their tolerance of mobile Al. Major biological indicators used to analyse mobile Al tolerance were hypocotyl length, root length and root and hypocotyl tolerance index. Toxic effects of mobile Al manifested themselves on all the biological indicators tested, which was shown by the correlations between the biological indicators and screening methods. Under filter paper-based method, the root and hypocotyl tolerance index ranged from 0.0% to 23.2% and from 0.0% to 37.2%, respectively at 16 mM AlCl₃ (aluminium chloride). Greater differences in M. sativa cultivars’ tolerance to mobile Al toxicity were identified between the hydroponic and soil-based methods. In the hydroponic method, the root and hypocotyl tolerance index ranged from 41.0% to 78.2% and from 62.1% to 90.2%, respectively at 50 μM AlCl₃. Under the soil-based method, hypocotyls were more damaged by Al toxicity compared with roots at soil pH 4.5 and 4.3. The root and hypocotyl tolerance index at pH 4.5 was 73.5% and 39.3%, at pH 4.3 – 35.6% and 26.3%, respectively. The cultivars ‘Mriia odes’ka’, ‘Romagnola’, ‘Kunsmme’ and ‘Juurlu’ were distinguished by the highest root and hypocotyl tolerance index under hydroponic and soil-based methods. ‘Žydrūnė’, ‘Birutė’, ‘Magnat’, ‘Viktoria’ and ‘Magda’ were distinguished by root and hypocotyl tolerance index under hydroponic method. The root tolerance index of these cultivars was the highest under filter paper-based method. These cultivars are considered as tolerant accessions and may be used as donors in breeding for Al toxicity tolerance.

Key words: lucerne, aluminium toxicity, hypocotyl, root, screening method, tolerance index.

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