Resistance to boron toxicity amongst several barley and wheat cultivars: A preliminary examination of the resistance mechanism
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The mechanism of resistance toB toxicity in barley and wheat was studied in a solution culture experiment using several cultivars displaying a large range of sensitivity to excessB supply. Plants were cultured for 35 d atB concentrations ranging from normal to excessive (15 to 5000 μM, respectively) then examined for dry matter production and theB distribution between roots and shoots.
In both species, increasedB supply was accompanied by increased tissueB concentrations, development ofB toxicity symptoms and depressed growth. At each level ofB supply, however, resistant cultivars accumulated considerably lessB than did sensitive cultivars, in both roots and shoots. Even at the lowestB supply, at which noB toxicity symptoms developed and growth was not affected, resistant cultivars maintained relatively low tissueB concentrations. No cultivar displayed an ability to tolerate high tissueB concentrations.
These results indicate that sensitivity toB toxicity in barley and wheat is governed by the ability of cultivars to excludeB. If theB concentrations of tissues is used to indicate resistance toB toxicity, then cultivars have the same ranking whether cultured at a normal or excessB supply.
Key wordsbarley boron toxicity genotypic variation mineral nutrition wheat
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- Bowen J E and Nissen P 1976 Boron uptake by excised barley roots I. Uptake into the free space. Plant Physiol. 57, 353–357.Google Scholar
- Cartwright B and Hirsch M 1986 Boron toxicity in barley and wheat — a disorder resembling foliar disease. Dept. Agric., South Aust. Fact Sheet No. FS 8/86.Google Scholar
- Cartwright B, Rathjen A J, Sparrow D H B, Paull J G and Zarcinas B A 1987 Boron tolerance in Australian varieties of wheat and barley.In Genetic Specificity of Mineral Nutritin in Plants. Eds. B C Loughman, L H Gabelman. pp 139–151. Martinus Nijhoff Publishers, Dordrecht, The Netherlands.Google Scholar
- Cartwright B and Zarcinas B A 1987 Toxic concentrations of boron in South Australian barley crops. CSIRO Aus., Div. Soils Div. Rep. No. 86.Google Scholar
- Eaton F M 1944 Deficiency, toxicity, and accumulation of boron in plants. J. Agric. Res. 69, 237–277.Google Scholar
- Kluge R and Podlesak W 1985 Plant critical levels for the evaluation of boron toxicity in spring barley (Hordeum vulgare L.). Plant and Soil 83, 381–388.Google Scholar
- Mehrotra O N, Srivastava R D L and Mishra P H 1980 Some observations on the relative tolerance of wheat genotypes to boron. Indian Agric. 24, 223–238.Google Scholar
- Nable R O 1988 Effects of boron toxicity upon the mineral nutrient composition of barley and wheat cultivars. CSIRO Aust., Div. Soils Div. Rep. No. 105.Google Scholar
- Passioura J B 1977 Grain yield, harvest index, and water use of wheat. J. Aust. Inst. Agric. Sci. 43, 117–120.Google Scholar
- Paull J G, Cartwright B and Rathjen A J 1987 Responses of wheat and barley genotypes to toxic concentrations of soil boron. Euphytica (in press).Google Scholar
- Rathjen A J, Cartwright B, Paull J G, Moody D B and Lewis J 1987 Breeding for tolerance of mineral toxicities with special reference to boron.In Perspectives and Priorities in Plant Production Research. Eds. P G E Searle and B G Davey. Sydney University Press. Australia.Google Scholar
- Raven J A 1980 Short-and long-distance transport of boric acid in plants. New Phytol. 84, 231–249.Google Scholar
- Ryan T A, Joiner B L and Ryan B F 1982 Minitab reference manual. Statistics Dept., Pennsylvania State Univ., USA 16802.Google Scholar
- Zarcinas B A and Cartwright B 1983 Analysis of soil and plant material by inductively coupled plasma-optical emission spectrometry. CSIRO Aust., Div. Soils. Tech. Paper No. 45.Google Scholar