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A search for metribuzin tolerance in fieldbeans (Phaseolus vulgaris)
Abstract
Fieldbean, Phaseolus vulgaris L.; seed from 217 cultivars or lines were obtained from the regional dry bean nursery, Scottsbluff, NE and the Centro Internacional De Agricultura Tropical (CIAT), Cali, Colombia South America. Cultivars were screened in the field for differential tolerance to chlorsulfuron, 2-chloro-N- ( ((4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino) carbonyl) benzenesulfonamide; glyphosate, N-(phosphonomethyl)glycine; and metribuzin, 4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one. Differential cultivar tolerance was greatest in the metribuzin screening, and consequently future studies were limited to fieldbean tolerance to metribuzin. A tolerant (XP-B146) and susceptible (D78157) cultivar were selected following the initial field screening and subsequent testing in nutrient solution. When these two cultivars were grown under field conditions the following year, no differential response to metribuzin was observed. Additional studies cast doubt upon the initial field screening, and the use of nutrient solution to accurately screen for metribuzin tolerance in fieldbeans. Selected cultivars did not grow similarly in soil and nutrient solution and this discrepancy in growth seemed to effect their response to metribuzin. The response of parents, F$\sb1$, and F$\sb2$ progeny, from the reciprocal crosses made between D78157 and XP-B146, to soil applied metribuzin suggest that metribuzin tolerance in fieldbeans may be controlled by multiple genes. Broad sense heritability values, based on fresh weight response, of 0.528 and 0.582 were obtained. If differential tolerance to metribuzin exists between fieldbean cultivars, it did not appear to be large and was often hidden by the widely variable activity of metribuzin. Metribuzin activity is strongly influenced by environmental factors. Heterosis in the F$\sb1$ progeny and possible transgressive segregation in the F$\sb2$ progeny may provide some hope for improving metribuzin tolerance in fieldbeans through selective breeding.
Subject Area
Agronomy
Recommended Citation
Lyon, Drew Jay, "A search for metribuzin tolerance in fieldbeans (Phaseolus vulgaris)" (1988). ETD collection for University of Nebraska-Lincoln. AAI8904498.
https://digitalcommons.unl.edu/dissertations/AAI8904498