Fluorescence Studies of the Seeds of the Pumpkin (Cucurbita pepo L.)

A violet diode laser of wavelength 405 nm is used to excite fluorescence of seeds of the pumpkin at raw and ripe stages of growth. Emission bands appear at wavelengths 630 and 670 nm at both the stages. Another band in the region 460–550 appears in the ripe stage only. Fluorescence intensity ratio F630/F670 calculated for the two stages show marked variation—indicating the process of ripening of the fruit. Time–resolved spectra at this excitation wavelength show two decay times at both the stages at emission wavelength 500, 630 and 670 nm.