Abstract
Root-soil contact is an important factor for uptake of a less mobile soil nutrient such as phosphorus (P) by crop plants. Root hairs can substantially increase root-soil contact. Identification of crop cultivars with more and longer root hairs can, therefore, be useful for increasing P uptake in low input agriculture. We studied the root hairs of wheat (Triticum aestivum L. cvs. Kosack, Foreman, Kraka) and barley cultivars (Hordeum vulgare L. cvs. Angora, Hamu, Alexis, Canut) in relation to P depletion from the rhizosphere in three soils of different P levels (0.45, 1.1 and 1.6 mmoles P kg−1 soil; extracted with 0.5 M NaHCO3). Root hairs were measured in solution culture having nutrients and concentration similar to soil solution. Root hairs of Kraka were much longer (1.27 ± 0.26 mm) and denser (38 ± 3) hairs mm−1 root) than those of Kosack which had shorter (0.49 ± 0.2 mm) and fewer (24 ± 3) hairs mm−1 root) root hairs. Root hairs increased root surface area (RSA) of Kraka by 341%. The increase with Foreman was 142% and with Kosack it was 95%. For winter barley, the length (1.1 ± 0.3 mm) and density (30 ± 1 hairs mm−1 root) of root hairs of Hamu differed from root hair length (0.52 ± 0.18 mm) and density (27 ± 1 hairs mm−1 root) of Angora. Root hairs of spring barley cultivars differed in length (Canut 1.0 ± 0.24 mm; Alexis 0.64 ± 0.19 mm) but not in density (Canut 31 ± 1, Alexis 30 ± 2 hairs mm−1 root). Root hair diameter (12 ± 1µm) did not differ among the cultivars. Root hairs increased RSA of Canut by 245%, Hamu by 237%, Alexis by 143% and Angora 112%. The variation in root hair parameters of the cultivars was related to quantity of P depleted from rhizosphere. The correlation (R2) between the root hair lengths of wheat cultivars and the quantity of P depleted from the rhizosphere soil (Q) was (0.99***) in low-P, (0.85***) in medium-P and (0.78**) in high-P soil. The values of (R2) between the root hair surface areas of wheat cultivars and Q were (1.00***) in low-P, (0.74**) in medium-P and (0.66**) in high-P soil. Similar high values of R2 were found for barley. These results show that the variation in root hairs of cereal cultivars can be considerable and it can play a significant role in P acquisition, especially in low-P soils.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Adam F 1974 Soil Solution. ln The Plant Root and its Environment. Ed. EW Carson. pp 441–482. University Press of Virginia, Charloteville.
Baon J B, Smith S E and Alston A M 1994 Growth response and phosphorus uptake of rye with long and short root hairs: Interactions with mycorrhizal infections. Plant Soil 167, 247–254.
Barraclough P B 1986 The growth and activity of winter wheat roots in the field nutrient inflows of high-yielding crops. J Agric. Sci. Camb. 106, 53–59.
Barraclough P B and Tinker P B 1981 The determination of ionic diffusion coefficients in field soils. Diffusion coefficient in sieved soils in relation to water content and bulk density. J Soil Sci. 32, 225–236.
Barber S A and Silberbrush M 1984 Plant root morphology and nutrient uptake. In Roots, Nutrient and Water Influx and Plant growth. ASA Special Publication 49, pp 65–88. ASA, Madison, WI.
Bhat K K S, Nye P H and Baldwin J P 1976 Diffusion of phosphate to plant root in soil. IV. The concentration depletion profiles in rhizosphere of root with root hairs. Plant Soil 44, 63–72.
Cailloux M 1972 Metabolism and the absorption of water by root hairs. Can. J. Bot. 50, 557–573.
Caradus J R 1979 Selection for root hairs length in white clover. Euphytica 28, 489–494.
Caradus J R 1994 Selection for improved adaptation of white clover to low phosphorus and acid soils. Euphytica 77, 243–250.
Care D A 1995 The effect of aluminium concentration on root hairs in white clover (Trifolium repens L.). Plant Soil 171, 159–162.
Claassen N 1990 Nährstoffaufnahme höherer Pflanzen aus dem Boden. Severin Verlag, Göttingen.
Clarkson D T 1991 Root structure and site of ion uptake. In Plant Roots: The Hidden Half. Eds. Y Waisel, A Eshel and U Kafkafi pp 417–453. Marcel Dekker, Inc New York.
Föhse D and Jungk A 1983 Influence of phosphate and nitrate supply on root hairs formation of rape, spinach and tomato plants. Plant Soil 110, 101–109.
Föhse D, Claassen N and Jungk A 1991 Phosphorus efficiency of Plants. II. Significance of root radius, root hairs and cation anion balance for phosplhorus influx in seven plant species. Plant Soil 132, 261–272.
Gahoonia T S and Nielsen N E 1991. A method to study rhizosphere processes in thin soil layers of different proximity to roots. Plant Soil 135, 143–146.
Gahoonia T S and Nielsen N E 1992 Control of pH at soil-root interface. Plant Soil 140, 49–54.
Gahoonia T S and Nielsen N E 1996 Variation in acquisition of soil phosphorus among wheat and barley genotypes. Plant Soil 178, 223–230.
Gahoonia T S, Raza S and Nielsen N E 1994 Phosphorus depletion in the rhizosphere as influenced by soil moisture. Plant Soil 159, 231–218.
Hoffland E, Findenegg G R and Nelemans J A 1989 Solubilization of rock phosphate. Evaluation of the role of uptake pattern. Plant Soil 113, 155–169.
Itoh S and Barber S A 1983a Phosphorus uptake by six plant species as related to root hairs. Agron. J. 75, 457–461.
Itoh S and Barber S A 1983b A numerical solution of whole plant nutrient uptake for soil-root systems with root hairs. Plant Soil 70, 403–413.
Jones D L and Darrah P R 1994 Role of root derived organic acids in mobilization of nutrients from the rhizosphere. Plant Soil 166, 247–257.
Jost W 1952 Diffusion in Soilds, Liquids and Gases. Academic Press Inc. Publishers, New York.
Lewis D G and Quirk J P 1967 Phosphate diffusion in soil and uptake by plants. III. P31 movement and uptake by plants as indicated by autoradiograph. Plant Soil 27, 445–453.
Mackey A and Barber S A 1984 Comparison of root and root hair growth in solution and soil culture. J. Plant Nutr. 7, 1745–1757.
McCully M E 1995 Water efflux from the surface of field-grown grass roots. Observations by cryoscanning electron micrcscopy. Physiol. Plant. 95, 217–224.
Murphy J and Riley J P 1960 A modified single solution method for determination of phosphate in natural waters. Anal. Chim. Acta 27, 31–36.
Nielsen N E 1984 Crop production in recirculating nutrient solution according to the principle of regeneration. In Proc. 6th Int. Congr. of Soilless culture. Int. Soc. of Soilless Culture, Lunteren. pp 7– 26. The Secretariat of ISOSC Wageningen.
Nye P H 1966 The effect of nutrient intensity and buffer power of a soil, and the absorbing power, size of root hairs, on nutrient uptake by diffusion. Plant Soil 25, 81–105.
Olsen S R and Sommers L E 1982 Phosphorus. In Methods of Soil Analysis. Eds. A L Page et al., Part 2. 2nd Ed. Agronomy 9, pp 403–430. American Society of Agronomy, Madison, WI.
SAS Institute Inc. 1989 SAS/STAT. User Guide. Version 5. SAS Institute Inc., Cary, NC.
Schjørring J K and Nielsen N E 1987 Root length and phoslphorus uptake by four barley cultivars grown under moderate deficiency of phosphorus in field experiments. J. Plant Nutr. 10, 1289–1295.
Watt M, McCully M E and Jeffree C E 1993 Plant and bacterial mucilages of the maize rhizosphere: Comparison of their soil binding properties and histochemistry in a model system. Plant Soil. 151, 15l–163.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Singh Gahoonia, T., Care, D. & Nielsen, N.E. Root hairs and phosphorus acquisition of wheat and barley cultivars. Plant and Soil 191, 181–188 (1997). https://doi.org/10.1023/A:1004270201418
Issue Date:
DOI: https://doi.org/10.1023/A:1004270201418