Yes - there are "petite" yeasts. These have had their mitochondria "cured" with antibiotics so are respiratory deficient and are slow growing - produce small colonies.

Hi there,

Sure there is! The fact is that on plate you have to compare isolated clone size after the same time of incubation so the analysis is qualitative only. If you want to go a bit further into it monitoring growth rate to calculate generation time will be much more accurate.

If your data are gaussian, you may try Pearson correlation. cor.test() in R. Run a Shapiro-wilk test first to test for normal distribution and then test if the covariance is linear.

If you are comparing a mixed population of Saccharomyces yeast with different ploidy, that you have previously sincronize to the same point of the cell cycle, colony size will be indicative of ploidy and haploid cells will have smaller colony size than diploids. So the colony size will not be indicative of fitness in this case. The lower ploidy, the smaller will be the cell size and the colony size.

And the most tiny, will be petites which will have worst fitness, since they are respiratory deficient.

If you are comparing a population of the same Saccharomyces strain, it will be hard to compare the cell fitness just by the colony size, but again petite cells will have worst fitness