Chlorophyll Content of New Cotyledon Mutants of Cucumber1

The chlorophyll content ( a, b and total) of cotyledons of ‘Burpless Hybrid’ cucumber ( Cucumis sativus L.), 5 radiation-induced mutants of ‘Burpless Hybrid’ ( yc-2, Is, gc, pi, albino , no symbol assigned), and 1 naturally occurring mutant (yc-1) was determined at 6 different stages of seedling development. Maximum chlorophyll content of ‘Burpless Hybrid’ (control) was reached 4 to 6 days after seedling emergence, but development was slower in the mutants. Average concn of chlorophyll a in yc-1, pl, gc and albino and chlorophyll b in yc-1, yc-2, gc, pl and albino was significantly lower than the control; gc contained only trace amounts of chlorophyll, and albino had none. The mutants pl, gc and albino were lethal. The changes in chlorophyll content of cotyledons generally agreed with visual appearance except Is which were distinctly pale, but had concn of chlorophyll a and b similar to those of the control.