A Delayed Albino Mutant in Soybean

A chlorophyll mutant was observed in the M₃ progenies of UPSM-229 soybean irradiated with 20 kr gamma rays. The cotyledons and the unifoliates of mutant plants had normal amount of chlorophyll but the chlorophyll content of the first and subsequent trifoliates was successively reduced by one half so that the 3rd trifolate was almost yellow and the 4th trifoliate did not emerge at all. These seedlings died within 30 days after emergence. Genetic studies indicated monogenic inheritance with the mutant phenotype being the recessive trait. A gene symbol dy¹⁹dy¹⁹ is being proposed for this trait.