The Tropical Fruit Forum

If you don't mind me sharing here (I hope you enjoy)

Two weeks ago I had the chance to visit the Royal Greenhouses here in Belgium. It's only open for roughly three weeks a year (and now closed for a few years due to renovations I believe). Tickets always sell out extremely quickly, but if in the future you need an excuse for a trip to Belgium...

The citrus was at the beginning of the walk route, outside and inside the Orangerie (where they also had a pop up shop inside).

Some large trees in large containers. Unfortunately some of them had what looked like large holes rotting at the bottom of the trunks, but most seemed alright.














 

I had asked a question in the Storing pollen thread, and on Facebook, but wanted to continue here.

I'm still new to making hybrids and want to help making it easier for other newbies.

So firstly some helpful sources I've found so far:
(paper) https://journals.ashs.org/hortsci/downloadpdf/view/journals/hortsci/15/1/article-p81.pdf
(pdf guide) http://www.homecitrusgrowers.co.uk/pdfs/Citrus%20flower%20pollination%20methods.pdf
(forum) https://citrusgrowersv2.proboards.com/thread/959/citrus-pollination-methods-create-hybrids
(blog) https://fruitmentor.com/breeding-growing-citrus-from-seed
https://www.youtube.com/watch?v=f-g6bcX88Eg
https://www.youtube.com/watch?v=pM-kNm7tXSI

Some notes:

- It seems that freezing helps store the pollen for longer, but it needs to be fully dried before freezing. For storage in the fridge (ideally around 4°C), it's less critical for the pollen to be completely dry.

- Freezing, thawing and refreezing would decrease the viability, but unsure by how much.

- First I thought the pollen already needed to be released, but I read both from @orangedays and somewhere else that you can collect them when smooth. You can crush them after drying to release the pollen.

- If the flower petals are removed, bees won't visit the flower anymore so you don't need to bag it, which makes the process easier. But I do not know if the petals need to be completely pulled off, or if it also works if you cut them and there is still a white petal "brim" remaining.

- For best chance of fruit set after hand pollination, it helps to remove the flowers that are not pollinated by you.


Tools I've gathered:

- Silicone tip brushes: they seem easier to clean and the pollen sticks to them well enough, I then wipe the follen from the silicone tip onto the flower stigma.

- Ziplock bags: to store pollen

- Silica desiccant bags (the ones that change color when moist): I use 1g packets now, but you can use bigger ones for larger amounts of pollen.

- Glass jars: One to store the silica packets, and one to store the ziplock bags with dried pollen in fridge/freezer, because ziplock bags are not a true moisture barrier (!!)

- Nail scissor: Both to emasculate the flowers when hand pollinating, and to cut the anthers to collect them for drying.

- Shot glass: To crush dried pollen in

- Some yarn or string, multiple colors if needed: I tie a piece of yarn near the hand pollinated flowers. If I pollinate multiple flowers on one plant with different pollen, then I use multiple colors to keep track of what the father variety is.

- A spreadsheet/document: Write down the mother plant, the pollen father, and color of the piece of yarn that you put on the plant and correlates to this cross.

- Pen: To label things

- Plastic mesh teabags: Only if you want to bag the flowers to isolate them.




So in short how I'm storing the pollen:

- Cut the anthers off, collect in ziplock bag
- Add silica desiccant, close the ziplock.
- Let dry for one or two days, and swap out the desiccant at least once to a fresh packet before storing.
- Put the ziplock bags with pollen in a glass jar, can add desiccant bag into the jar as well for good measure.
- Decide to put either in fridge or freezer


How I pollinate:

- Remove flower petals and stamen of the mother flower, before the flower is about to open
- The next day I take some pollen out of ziplock bag, put it in something like a shot glass
- Crush it in the shot glass with the back of the brush or some other blunt object
- Wipe the pollen on the stigma with silicone brush
- Put piece of yarn around the stem of the flower
- Write the cross and color of yarn down in my document


This is what I've made so far this season:

(Mother + Father)   

Shekwasha + N1Tri
Staraji + Changsha
ClemYuz + Changsha
Hana Yuzu + Changsha
Changsha + Hana Yuzu
Yuzumelo + N1Tri
Yuzumelo + Keraji D14


Questions!:

- Maybe dumb question, but if I emasculate the flowers, and there are seeds in the fruit, will all the embryos be hybrids, or can there still be some kind of asexual embroys?

- If you use a nail scissor to cut petals and stamens on mother flowers, can this transfer the Tristeza Virus from one plant to another, just like with pruning? A bit annoying to sanitize the scissor every time while working on multiple plants.

I have a plant (no fruits yet) and would also not think that it's half poncirus. I'd say it's very unlikely for a 1/2 hybrid to result in something monofoliate without any 'thumbs' or other weird quirks.

It's suggested to be 1/4 Poncirus, 1/4 Temple, 1/2 Clementine on this blog here https://hardycitrus.blogspot.com/2013/11/dimicelli.html

The tree needs to be grafted on Poncirus Trifoliata, it's the only suitable rootstock for you.

Lubera says it's on Trifoliata, but Zitronenlust doesnt mention the rootstock so I suspect it's something else. You could ask them to be sure.

Rodebos seems to still be selling some citrus varieties.

I can't edit my previous post, but Bois de rodebos seems to be reselling Adavo's plant for tripple the price and with risk of CTV, so not great.

Does this have the potential to become a chimera? Kumquat Marumi on Poncirus. The sprout looks to be trifoliate.

I haven't looked into the creation of chimeras, I just happened to see this while I was fertilising my plants. I removed suckers when I saw them, but this one is at the edge of the graft union, so I didn't remove it and wanted to ask here about it.

It's a whip and tongue graft, let me know if it's unclear where the graft line is, but it seems fairly clear on the pictures.

smooth skin hana yuzu is described at lenzis site with a falling growth, it seems yours is just growing normal 
regular hana yuzu is described with "spherical shape". the smooth skin h.y. seems to be very juicy. unfortunately they dont show a pic of a cut regular h.y. - is juiciness the same?

Yes, you are right about the weeping habit, but I'm unsure why my plant has been a bit weak and unhealthy. So it will be a good experiment to graft the Smooth Skin to another rootstock.

I've only had fruit of the Hana Yuzu "Sudachi" from Adavo, so I can't compare the juiciness yet. I thought the fruit that I had was pretty juicy, but of course it had seeds.

I might have some seedlings of the Hana Yuzu, but I don't remember if those specific seedlings where of the Hana fruit I harvested, or from some Sudachi fruit I bought in a store. Will have to take a closer look in spring.

But it would be cool if people worked on making a good selection of Hana Yuzu, one that is hardy, healthy, fragrant and juicy. I think it's worth the effort, even though regular Yuzu seems to take most attention.

Since it is an ichangensis, then all the seedlings are of sexual origin. It may turn out that all the male gametes were from the same plant, but this is not necessary. Mathematically, the number of pollinators can be equal to the number of seeds in a fruit. But this is unlikely.
Each egg cell of the mother and the pollen cell of the father are unique and different from each other. They all went through a chromosomal crossover that made them all different.
So the plants won't be identical clones. And pollinators of the same fruit can be different varieties.

Ah interesting, thank you. So each seed is really a different baby. Then it might be worth it to transplant all 35 and let them grow a bit bigger for a year at least.

I have never sprouted Ichang papeda seeds. The absence of wings is typical for citron. This is also typical for ichangensis, does anyone know? Or could it indicate a pollinator?

I was also wondering about the wing, but it's my first time with IP seeds so no idea if it would be pronounced in the first leaves. But I do feel like there is some variety between the seedlings, some have more wide or narrow leaves, a bit early to tell much detail.

The (ripe) ones that I ate weren't that interesting in taste though. I wouldn't grow it for the fruit. 

Has anyone made a hybrid between Yuzu and Hana Yuzu? Or is that not possible for some reason?

I was thinking, that if you selected for the positive traits, you could get a fruit that has the increased juice and reduced seeds from Hana Yuzu, but closer to the size of regular Yuzu.

Thank you for sharing all of this. One variety that caught my eye is Yuzumelo. If I am unable to obtain seed of this variety, I may attempt my own cross. Perhaps 5star x Yuzu. I hope you can get your hands on N°82, it looks like an exceptional citrumelo. The Iva Swingle citrumelo that we have in the US looks similar and tastes quite good.

Here in Europe there is a Yuzumelo (Yuzu x Citrumelo) that has been around for quite some time, and availalble at a fair amount of nurseries. However the reports on it's fruit seem a bit sparse. It gets both negative and positive taste reviews. The hardiness hower always seems to get positive comments, so that's good.

The other interesting one is Staruzu (5Star x Yuzu) from Ilya, which some forum members seem to have grafted now and hopefully we get some reviews from different people soon.

Personally I expect that Ilya's hybrid might have better taste, but the hardiness is less proven at this time. I have both to compare, but my Yuzumelo has dropped it's flowers/fruits so far (also due to wet spring last year), and my Staruzu graft is still quite small (I will see if I'm able to cut a piece and regraft it on larger and more vigorous C4475 this year).

I have 2 older satsuma trees in the family and each tree has about 2,000 fruits each year. Out of those fruits, I might see 1% of the fruits with a seed so it's not that easy to get seeds to grow out.

Recently I was given some Satsumas by a friend, it was about four fruits, five at most. And from memory, at last two had seeds, and I believe more than one seed (but two or three seeds at most).

So it seems it's possible to get Satsumas with more seeds. They came from a variegated Satsuma tree, I don't know if that has anything to do with it.