Daylily Ploidy

Determination of plant ploidy is an essential plant breeding technique. Below are a few examples by knowing correct ploidy one's hybridizing program can make great leaps forward.

I bloomed a Home of the Free x tetra Rose F Kennedy cross in Florida, but it was dormant and did not do well, so I bought it home to Ohio. After separating 3 fans from a single clump of the plant (all fans generate from the same seed) I analyzed the ploidy of each fan. The results were that each of the three fans had different ploidy as follows: one each 3x = Triploid, 4x=Tetraploid, 5x =Pentaploid. We were able to cross the 4x fan with normal tetraploids and were able to cross the 5x with 3.5x and 5x plants. I did not use the pollen from the 5x on 4x flowers. Concern about ploidy caused me to analyze Tet Rose F Kennedy and the results were the conversion I have is a chimera. I verified this by Flow Cytometry, results not shown. The theory is cells at the apical meristem (growing point) of converted flowers can when dividing yield different ploidies. Mixed ploidy is why many of the flowers we buy are hard to use. Ploidy deviation can be caused in making tet conversions, the use of BAP and Pre-Emergents herbicides and, of course, nature. Conclusion: Difficult to use flowers may not be sterile, you just have to cross on plants with matching ploidy.

Just not limited to higher ploidy, here is a diploid, future of mine, which also shows different results. The flower overy base was almost twice as big. Dose it have higher ploidy or addition to chromosomes, like longer pairs. Chromosome karyotyping will answer this question. In the near future we will be able to offer chromosome karyotyping.

Here I tested one pot of my diploid Chasing Your Dreams after using tetraploid pollen on what I thought was a diploid plant. I was planning on producing triploids which later can be converted to hexaploids. Tetraploids can be crossed to triploids to produce tetraploid offspring. These are untreated plants of Chasing Your Dreams. Question? Why is there a ploidy change? I guess it dose make sense, That's why I got pods and the seeds were good. Results show, 2x, 2.5x and 3x. Confirmation of offspring will be confirmed by flow cytometry at a later date.

Here is a treated plant I thought was tetraploid, 95% of pods fell off tetraploid crosses. Why, because Hexaploid . This is more common than normal.