Whant to see my...

[eteson]

Chromosomes?

I need to improve my technique because I did not got a good chromosome spread but I am in the right way... this is andreettae x pearcei... a 2N plant.

 

[SlipperKing]

Looks good for me.

 

[troy]

Lol.. chromosome of phragmepedium?

 

[rangiku]

Yes, to check if the plant is diploid (2N) or tetraploid (4N).

 

[naoki]

Eliseo, I've spend quite a bit of time trying to do chromosome counting. But it is tough and requires lots of patience. So I gave up (well, I was trying it with Arabidopsis with tiny genome). Are you using the root tip squash?

 

[eteson]

Eliseo, I've spend quite a bit of time trying to do chromosome counting. But it is tough and requires lots of patience. So I gave up (well, I was trying it with Arabidopsis with tiny genome). Are you using the root tip squash?

Yes, the root tip squash... I´ve got good contraction and good pigmentation of the chromosomes but the spread of my first try was not so good... I think that I need to increase the digestion time in hot Chlorhydric acid... this weekend i am going to try to do it better... I think that Arabidopsis is much more hard to work with!

I am not sure if I am going to be able to get the exact number of chromosomes but for sure it is going to be useful to detect polyploid plants.

If you have some advices I am waiting forward to receive it!

 

[PaphMadMan]

I did a fair number of root tip squash chromosome counts 35 years ago, no orchids unfortunately, mostly Narcissus. I really don't remember much about the procedure except that it seemed to be very touchy. Sometimes it would work incredibly well for a while, then suddenly nothing worked, with no discernible change in how the procedure was done.

It takes patience and sometimes a little luck. I wish you an abundance of both. Please, post more photomicrographs when you can.

 

[naoki]

Kirk probably has more experience than I, but the amount of pressure on the cover glass was difficult. Like Kirk said, there seem to be lots of luck involved (to get it in the right time). Do you use colchicine or something (I forgot which chemical) to arrest the mitosis at the correct time?

What happened to your stomata size experiment to screen ploidy? It seems easier and non-destructive (with nail polish) if it works with Phrags.

 

[cnycharles]

Cool

 

[eteson]

I am using 8-hydroxiquinoline to pretreat root tips and get chromosome contraction.

Naoki, I keep using stomata size to screen ploidy but before labelling a plant as 4N I need to be sure. I think that chromosome count is the only one direct method.

 

[naoki]

I wasn't familiar with the chemical, so I looked it up. It has the similar benefit for chromosome counting as colchicine (I'm not sure the linked pdf is reachable).

I see. Yes, it is good to confirm it with chromosome count! You can probably publish the results (correlation between stomata sizes and chromosome numbers) in a scientific journal (it is probably a low priority for you, though).

 

[eteson]

Naoki, thanks for the pdf. Seems to be a very intetesting reading. I am trying to avoid the use of colchicine in my house... so I am working with oryzalin for conversion and 8- hydroxyquinoline for counting.

I am collecting and recording the results but rigth now I have not much time for publishing... but it would be nice to publish it in the future.

 

[NYEric]

I am trying to avoid the use of colchicine in my house...

Why!? It will make your son's leaves thicker and bloom rounder! oke: