D
Drorchid
Guest
Still one of my favorites!
I did count the chromosomes years ago, and counted 48 chromosomes, so that is why we have always called it a tetraploid as it has the same number of chromosomes as a tetraploid besseae. But technically it should be called an aneuploid (in-between a triploid and a tetraploid)
Following is a look at the chromosome count of its ancestry:
Phrag. longifolium (2n =20) x Phrag. schlimii (2n = 36) -> Phrag. Sedenii (2n = 28) (= (20+36)/2)
Phrag. Sedenii (2n = 28) x Phrag. schlimii (2n = 36) -> Phrag. Cardinale (2n = 32) (= (28+36)/2)
Now a diploid Phrag. Cardinale should have 32 chromosomes. Phrag. Cardinale 'Birchwood' is a triploid, so is either 3n = 46 (32 + 14) as it has one extra set of chromosomes from Phrag. Sedenii (28/2 = 14), or it is 3n = 50 (32 + 18) as it has one extra set of chromosomes from Phrag. schlimii . (36/2 = 18). I am guessing the later is the case.
So our April Fool cross was derived by crossing:
Phrag. Cardinale 'Birchwood' (3n = 50) with Phrag. besseae 'Rob's Choice' (4n = 48). The resulting seedling April Fool 'Fool Gold' probably got 24 chromosomes from besseae 'Rob's Choice' and 24 chromosomes from it's parent Cardinale (which means 1 chromosome got lost, as when the 50 chromosomes split into 2, so 25 and 25, one of the chromosomes could not match up and got lost). So even though Phrag. April Fool has 48 chromosomes and the same number as a tetraploid besseae, technically we would call it an Aneuploid (as it has lost 1 chromosome). Some of these aneuploids will breed like true tetraploids, but out of experience we have noted that Phrag. April Fool 'Fool's Gold' is a reluctant breeder. We have only been able to breed with it twice (once by backcrossing it to besseae 'Rob's Choice' to make Phrag. Jimmy Hendrix, and once to Phrag. fischeri, to make Phrag. Foolerisch.
Hope this was not too confusing!
Robert
I did count the chromosomes years ago, and counted 48 chromosomes, so that is why we have always called it a tetraploid as it has the same number of chromosomes as a tetraploid besseae. But technically it should be called an aneuploid (in-between a triploid and a tetraploid)
Following is a look at the chromosome count of its ancestry:
Phrag. longifolium (2n =20) x Phrag. schlimii (2n = 36) -> Phrag. Sedenii (2n = 28) (= (20+36)/2)
Phrag. Sedenii (2n = 28) x Phrag. schlimii (2n = 36) -> Phrag. Cardinale (2n = 32) (= (28+36)/2)
Now a diploid Phrag. Cardinale should have 32 chromosomes. Phrag. Cardinale 'Birchwood' is a triploid, so is either 3n = 46 (32 + 14) as it has one extra set of chromosomes from Phrag. Sedenii (28/2 = 14), or it is 3n = 50 (32 + 18) as it has one extra set of chromosomes from Phrag. schlimii . (36/2 = 18). I am guessing the later is the case.
So our April Fool cross was derived by crossing:
Phrag. Cardinale 'Birchwood' (3n = 50) with Phrag. besseae 'Rob's Choice' (4n = 48). The resulting seedling April Fool 'Fool Gold' probably got 24 chromosomes from besseae 'Rob's Choice' and 24 chromosomes from it's parent Cardinale (which means 1 chromosome got lost, as when the 50 chromosomes split into 2, so 25 and 25, one of the chromosomes could not match up and got lost). So even though Phrag. April Fool has 48 chromosomes and the same number as a tetraploid besseae, technically we would call it an Aneuploid (as it has lost 1 chromosome). Some of these aneuploids will breed like true tetraploids, but out of experience we have noted that Phrag. April Fool 'Fool's Gold' is a reluctant breeder. We have only been able to breed with it twice (once by backcrossing it to besseae 'Rob's Choice' to make Phrag. Jimmy Hendrix, and once to Phrag. fischeri, to make Phrag. Foolerisch.
Hope this was not too confusing!
Robert
