Inheritance of Resistance to Iron Deficiency in Dry Beans
Dry bean (Phaseolus vulgaris L.) cultivars differ in their response to iron deficiency when grown on calcareous soils. This response is influenced by environmental factors such as soil pH, soil texture, presence of bicarbonates, organic matter, and temperature. The objective of this study was to investigate the genetic basis for resistance to iron deficiency in beans. Crosses between nine resistant and three susceptible cultivars/lines were made in the greenhouse during Spring 1994, and F2 seeds from 12 different crosses were obtained in the summer. Seed of the parental and F2 generations were planted near Temple, Texas, during Fall 1994. The color (greenness) of 1482 F2 plants was measured using a chlorophyll meter (Minolta SPAD-502) 35 days after planting. Chi-square analysis showed a good fit to a 15:1 ratio of resistant: susceptible plants. The F2 segregation suggests that two dominant genes are involved in the response to iron deficiency in dry beans, and when either dominant gene is present, resistance is expressed to some degree.