Record Details
Field | Value |
---|---|
Title | Aluminum toxicity in wheat (Triticum aestivum Vill., host) |
Names |
Kerridge, Peter Campbell
(creator) Moore, David P. (advisor) |
Date Issued | 1968-07-10 (iso8601) |
Note | Graduation date: 1969 |
Abstract | Wheat varieties of differential tolerance to Al were used in a series of nutrient solution experiments to study the inhibitory effects of Al on growth and nutrient uptake. The pH and the Al and P concentrations were rigorously maintained to prevent the confounding effects of Al and P precipitation and separate effects of pH. For wheat, the inhibitory effect of Al on root elongation was more detrimental to plant growth than inhibition of nutrient uptake. The factors determining onset of inhibition of root elongation appear to be Al concentration, Al valency state and pH. For a fixed Al concentration, toxicity increased with an increase in pH from 4 to 4.5. This may be a function of both an increased ratio of A1OH²⁺ to A1³⁺ and of an increased ion uptake due to an increase in pH. Aluminum inhibition of Mg uptake into shoots and roots was marked at low effective Mg solution concentrations. Uptake of Ca and Mn were also inhibited to a lesser extent by Al at constant pH and in the absence of inhibition of root elongation. However, Al inhibition of nutrient uptake was generally of less magnitude than that due to an equivalent change in H⁺ concentration. Separate effects of Al on inhibition of root elongation and nutrient uptake are best understood by considering the different sites at which the separate effects take place; inhibition of root elongation results from the entry of Al into the meristematic tissue to inhibit cell division while inhibition of nutrient uptake can be explained as the effect of external Al on the region of vacuolated tissue. A preliminary study was made of the nature of inheritance of Al inhibition of root elongation. The difference in tolerance between moderately tolerant and sensitive varieties appears to be controlled by a single dominant gene. Soil experiments confirmed the varietal differences of tolerance to Al observed in nutrient solution and genetic studies. The use of varieties of differential tolerance to Al facilitated the recognition of a response to liming as due to a lowering of exchangeable Al in the soil. |
Genre | Thesis/Dissertation |
Topic | Wheat -- Diseases and pests |
Identifier | http://hdl.handle.net/1957/46142 |