ISSN:
1573-5036
Keywords:
Barley
;
Kinetic parameters
;
Phosphorus
;
Varietal effects
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Barley cultivars grown under field conditions of moderate deficiency of phosphorus (P) had great differences in P uptake and grain yields. As the rate determining step in P uptake under these conditions is located in the root net influx of P (ĪnL*) per g of dry matter of the plant can be expressed by $$\bar I_n L^* = \bar I_{max} L^* \frac{{c - c_{min} }}{{c - c_{min} + K_m }}$$ where Īn, L*, Īmax, c, cmin and Km denote mean net influx per unit length of the root, root length per unit weight of the plant, maximal mean net influx per unit length of the root, P concentration at the root surface, minimum concentration in solution of which net influx appears to be zero and Michaelis-Menten factor of P uptake, respectively. Studies of P uptake kinetics in water culture showed that the values of L*, Īmax, Km and cmin of P uptake varied considerably between barley cultivars. Furthermore, agreement was found between P uptake in the field and P uptake predicted from Īmax-, Km-, cmin- and L*-values observed in water culture experiments. The data thus indicate that it should be possible to improve the efficiency by which plants utilize soil as a source of P by selecting and/or developing genotypes of barley with a smaller cmin and/or Km and a greater Īmax and/or L* during the main period of growth. The results suggest therefore that it should be feasible to adapt plants to a considerably lower soil P level.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02181961
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