Influence of bean yellow mosaic and tomato ringspot viruses on elemental content of bean, Phaseolus vulgaris L. Thesis (Ph.D.)

Greenhouse nutrient solution culture expt. were conducted to study the influence of isolates of BYMV and tomato ringspot virus on elemental content of kidney bean plant parts. A modified Hoagland solution at 1x and 2x levels was used. Primary leaves were inoculated 11-12 days after sowing; root, stem and leaf samples were harvested approx. 2 and 3 wk. after inculation. Fresh and dry wt. of samples were recorded. Concn. and total amounts of N, P, K, Ca, Mg, Mn, Fe, Cu, B, Zn, Al, and Na were determined. Measurements of changes in nutrient solution pH, conductivity, vol. and P, K, Ca, Mg, Mn, and B were made. All isolates examined reduced both fresh and dry wt. of plants. Quantitative and qualitative differences in root system growth and development were observed. Ptants grown in 2x solution tended to be somewhat smaller than comparably treated 1x solution grown plants. Solution measurements showed that the overall affects of all treatments were an increase in solution pH and conductivity but a decrease in solution vol. Control solution vol. decreased more while pH's and conductivities increased more than was observed for solutions containing virus infected plants. Control plants absorbed more total P, K, Ca, Mg, Mn, and B from the solutions than inoculated ones. Data on elemental composition clearly indicated that important changes in the nutrient content of bean plants occurred as a result of virus infection. The higher concn. and total amounts of Mn in virus- infected plant parts than in tissues from control plants and the possible association between plant K levels and the amounts of water absorbed by roots were of special interest. However, findings were difficult to interpret or generalize. Observed interactions included: virus and/or isolate x plant part sampled x time of sampling x nutrient solution concn. x element. (AS) eng