The Tropical Fruit Forum

Easy?  How so?

Hardy Orange doesn't flower at the same time as most citrus.  I can check for zygotic seeds by having HO be the mother, and then anything nonstandard must be a cross.  I can check the crosses the same way.  But I can't think of a good way to find a purebreed, zygotic Hardy Orange, other than looking for a plant that always produces crosses and trying to self-pollinate it.

It's very true that we should sometimes try for a cross despite the odds.  However:

1)  I regard nucellar reproduction as like a cancer for a species.  I really want to eliminate it whenever possible.
2)  I don't have enough space or resources to start hundreds, or even dozens, of seedlings in search of a successful cross.
3)  Except for parent plants that have clear and obvious physical traits (like trifoliata's three-lobed leaves), I can't distinguish crosses from non-crosses.

Still, I plan on making some implausible attempts just to see what I get.  ('Moro' Blood orange x 'Nagami' Kumquat = Bloodquat?)

I guess I'll have to wait and see.

"Elephant garlic" was actually derived from leeks.  Leeks are normally propagated from seed, although some varieties also form tiny bulbs.  Artificially causing a natural accidental triploid into hexaploid resulted in "elephant garlic", which produces large edible bulbs.

I also have another C. ichangensis that has petioles almost a big as the main leaves, quite different to the first plant I bought.

May I ask where you got it?  I've had trouble finding any sources, either seedlings or seeds or grafts.

But maybe you should wait a bit. I am not an expert in Ichang Papeda but have seen that Yuzu leaves of young seedlings sometimes have no broad petioles. Could it be the same with Ichang Papeda that they get broader with age?

Yeah, early leaves don't always have the same shape as mature specimens, so I've tried not to leap to any conclusions.  But if this isn't a pure strain, it's best if I knew that as early as possible, given how slowly ichang grows.  Also, a cross with lemon is likely to be less cold-hardy, and I don't want to expose the plant to conditions that ichang can survive but a hybrid couldn't.

That would produce a hexaploid.  Chromosome duplication in plants tends to produce hardy specimens with exaggerated traits - brighter colors, larger leaves - but eventually the burden of maintaining cells with excessive DNA seems to outweigh any potential benefits.  The point at which polyploidy harms the plant seems to vary by species.  'Elephant garlic' is an artificially-made hexaploid derived from the common leek, and it does flower - but it's not propagated by seeds usually, and I'm not sure precisely why.

It might be worth trying with limes, but even if the hexaploid is fertile, any resulting seeds are likely to behave unpredictably.  Having so many copies of every gene makes anticipating the phenotype of crosses an uncertain art.

I recently ordered one from Woodlanders, it arrived yesterday, and I've found myself a bit skeptical.



Here's a closer view of the older leaves, which are rounded instead of lanceolate:



A close-up of the newer leaves, whose petioles are noticeably smaller than the actual leaf:



The images I've found on the Internet of C. cavalereri, and of related plants like the Makrut Lime, suggest that the petioles should be roughly the same size and shape of the actual leaf.  I know this is a young plant, but is it possible that this is a hybrid?   With, perhaps, a lemon?

I don't necessarily mind, if this plant produces zygotic seeds, but the implications for cold-hardiness are vital.

A photo of your off type key lime would be welcome. Interested to see it.

Finally got the phone working this morning!

Here's all four of them lined up:


The first, which is smaller than the others, bushier, has branched multiple times, and has smaller, softer thorns: 


The second plant has gained roughy two inches over the winter.  It's like the third, only a bit larger: 


The fourth had to be repotted because it kept falling over in the breeze.
 

A closer view of #4's half-inch-long thorns.
 

[edit]  That method of adding images didn't work... let's try this one.

Bearss limes (aka Tahiti limes) are triploid.  When they do form viable seeds, it's almost certainly due to an error in chromosome handling - the same sort of genetic mix-up that created the triploid genome in the first place.  Ironically, it has the potential to restore fertility to the organism that it took it away from.

They are monoembryonic in that case, but it's questionable as to whether they are zygotic - they could be, or the genes could entirely derive from the seed parent.  There's no guarantee what you'd get from a fertile seed - it might be easier just to go back to the parents of the line and work with them.  Key lime was one, and is known for producing diploid gametes more frequently than usual.

But that means it's almost certainly nucellar...   

I don't quite understand why Ugli are zygotic, all types have multiple nucellar parents.

There are citron cultivars that are both sweet and have substantial amounts of pulp - I think the 'citron of commerce' is the classic example.  It's even less cold-tolerant than most lemons, though.  Supposedly the presence of red compounds in the petals and sometimes on early stages of the peel are the markers for acid in citrons, and sweet citrons lack that pigment.

But the tall one got that way when I had them all outside in the same place.  It hasn't done much of anything since I brought it indoors, which doesn't surprise me - it's alive and healthy enough, but it hasn't had enough heat and light to do much growing.

The three right next to a windowsill and above a heating vent have put on a little height, but they're distinctly smaller.

Egggh, I've gotta find that cable...

I'll work on that.  Gotta find the charging cable for my flip phone so that I can upload photos to my laptop.

I measured them again this morning.  The 'normal' seedlings have gained a little height over the last six months, but they've been on a windowsil while the potted seedling has necessarily had less light and heat.  It's still twice their size.