Hybridizing Blue Poppies - about chromosome numbers
Sept 22, 2018 19:39:42 GMT -5
keen101 (Biolumo / Andrew B.) likes this
Post by socal2warm on Sept 22, 2018 19:39:42 GMT -5
Some of you may be familiar with the blue Meconopsis poppy. This is one of the few types of flowers in nature that has a true blue color, so it is somewhat rare and sought after. They also need cool moist climates to grow in, so the flowers typically only grow with ease in places like near the Himalaya mountains or Alaska. (Meconopsis are also perennial, if they don't die from warm dry conditions during the Summer)
There are actually two types of blue Meconopsis in the wild.
Meconopsis baileyi (formerly and still commonly known as Meconopsis betonicifolia)
Meconopsis grandis
baileyi has lighter true blue color flowers, while grandis has darker violet-blue color flowers (there's also another variation of M. grandis that has more burgundy-purple color flowers)
baileyi has 2 sets of chromosomes, while grandis has 4 sets of chromosomes.
In fact it's quite possible that M. grandis originated from M. baileyi after having spontaneously doubled its chromosome number and then begun to evolutionarily diverge (which is not uncommon in the plant world).
Many crosses between M. baileyi and M. grandis have been made, all of them are generally referred to as Meconopsis wilsonii. These crosses are sterile, so these various hybrid cultivars have to be propagated asexually, by division of clumps.
This is because when you cross a diploid (2n) with a tetraploid (4n) you get a triploid (3n), and triploids are generally sterile. (The odd chromosome set number creates problems during meosis)
However, there is one cultivar of Meconopsis wilsonii which does produce fertile seed. It is named 'Lingholm', and is a popular variety under cultivation.
It is believed that at some point, one of the hybrid garden varieties that were in circulation spontaneously doubled its chromosome set number from 3 to 6. This can happen in rare cases.
At some point someone discovered one of the Meconopsis wilsonii plants in a nursery was producing fertile seed.
Lingholm has a similar coloration to baileyi but the plants are a bit larger and has a bigger flower size. They are said to have slightly more tolerance to heat.
Lingholm is generally regarded as a superior cultivar.
The problem is, in some ways Lingholm is an evolutionary dead end. This cultivar can't really be bred much further because it has 6 chromosomes, or so that's what some people may have thought.
I think that it should be possible to cross Lingholm with baileyi. 2n x 6n should give 4n offspring, which would be fertile. The 4n offspring could then be freely bred with M. grandis.
There is one ambiguous complication and that is that sometimes Lingholm is sold as "M. grandis". However, the particular cultivars of true M. grandis sold in commerce often do not produce the light blue color hue that Lingholm and baileyi do, so in that case it would be easy to tell them apart. Even the light blue versions of M. grandis usually have at least some slight tinge of purple near the very tips of the petals.
(One more little note just for complete accuracy, actually M. betonicifolia has been identified as a true separate species with some subtle differences from M. baileyi, but they are so similar that you would have great difficulty telling them apart, and the true M. betonicifolia [the one which is distinct from M. baileyi] is extremely rarely ever encountered in cultivation or commerce.)
There are actually two types of blue Meconopsis in the wild.
Meconopsis baileyi (formerly and still commonly known as Meconopsis betonicifolia)
Meconopsis grandis
baileyi has lighter true blue color flowers, while grandis has darker violet-blue color flowers (there's also another variation of M. grandis that has more burgundy-purple color flowers)
baileyi has 2 sets of chromosomes, while grandis has 4 sets of chromosomes.
In fact it's quite possible that M. grandis originated from M. baileyi after having spontaneously doubled its chromosome number and then begun to evolutionarily diverge (which is not uncommon in the plant world).
Many crosses between M. baileyi and M. grandis have been made, all of them are generally referred to as Meconopsis wilsonii. These crosses are sterile, so these various hybrid cultivars have to be propagated asexually, by division of clumps.
This is because when you cross a diploid (2n) with a tetraploid (4n) you get a triploid (3n), and triploids are generally sterile. (The odd chromosome set number creates problems during meosis)
However, there is one cultivar of Meconopsis wilsonii which does produce fertile seed. It is named 'Lingholm', and is a popular variety under cultivation.
It is believed that at some point, one of the hybrid garden varieties that were in circulation spontaneously doubled its chromosome set number from 3 to 6. This can happen in rare cases.
At some point someone discovered one of the Meconopsis wilsonii plants in a nursery was producing fertile seed.
Lingholm has a similar coloration to baileyi but the plants are a bit larger and has a bigger flower size. They are said to have slightly more tolerance to heat.
Lingholm is generally regarded as a superior cultivar.
The problem is, in some ways Lingholm is an evolutionary dead end. This cultivar can't really be bred much further because it has 6 chromosomes, or so that's what some people may have thought.
I think that it should be possible to cross Lingholm with baileyi. 2n x 6n should give 4n offspring, which would be fertile. The 4n offspring could then be freely bred with M. grandis.
There is one ambiguous complication and that is that sometimes Lingholm is sold as "M. grandis". However, the particular cultivars of true M. grandis sold in commerce often do not produce the light blue color hue that Lingholm and baileyi do, so in that case it would be easy to tell them apart. Even the light blue versions of M. grandis usually have at least some slight tinge of purple near the very tips of the petals.
(One more little note just for complete accuracy, actually M. betonicifolia has been identified as a true separate species with some subtle differences from M. baileyi, but they are so similar that you would have great difficulty telling them apart, and the true M. betonicifolia [the one which is distinct from M. baileyi] is extremely rarely ever encountered in cultivation or commerce.)
