Polyploidy and gene dosage effects on chloroplasts of fern gametophytes

Increasing the complement of nuclear genes in fern gametophytes through polyploidy results in an increase in cell volume and dry weight of plants. The concentration of chlorophyll per cell remains constant but as ploidy increases the chloroplasts also increase in size primarily from the accumulation of starch. Studies of ¹⁴CO₂ fixation support the thesis that the increased nuclear gene dosage is without direct effect on photosynthesis.