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Author Topic: Jackson grapefruit  (Read 322 times)

Heinrich

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Jackson grapefruit
« on: September 08, 2019, 12:25:12 PM »
Last summer (2018), I found a Jackson grapefruit in the supermarket. The fruit contained one seed and tasted pleasant and sweet. This single seed gave two seedlings. Last year, both plantlets were thornless. However, since this summer, one of the plantlets develops thorns.




« Last Edit: September 08, 2019, 01:29:38 PM by Heinrich »

Millet

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Re: Jackson grapefruit
« Reply #1 on: September 08, 2019, 02:15:14 PM »
Almost all citrus seedlings produce thorns until the tree develops maturity.  Most assuredly both of your seedlings will eventually produce thorns.  You are quite lucky to find a seed in a Jackson Grapefruit.  Jackson grapefruits were developed in South Africa as a limb sport, and are seedless..  I would love to have a Jackson grapefruit tree, mainly because this variety contains a much lower level of naringin, the chemical that gives grapefruits its bitter taste, thus they are a much sweeter and less bitter than the normal white varieties.  Unfortunately it will take approximately 8 to 10 years before the trees will begin fruiting.
« Last Edit: September 08, 2019, 02:37:54 PM by Millet »

SoCal2warm

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Re: Jackson grapefruit
« Reply #2 on: September 09, 2019, 01:55:00 AM »
Unfortunately it will take approximately 8 to 10 years before the trees will begin fruiting.
Maybe 6 if you grow the seedlings out and then graft them on rootstock.

Laaz

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Re: Jackson grapefruit
« Reply #3 on: September 09, 2019, 06:04:39 AM »
Heinrich very nice find & healthy plants.

Millet it may take that long in a container, in the ground you know I have two ruby reds that both set their first fruits at 5 years. They are both over 25 ft tall now & produce 100's of fruit each year.

SoCal once again you show your ignorance... Grafting immature buds will not speed up the process. Lol!

kumin

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Re: Jackson grapefruit
« Reply #4 on: September 09, 2019, 06:15:25 AM »
In addition to the presence of thorns on the one plant, the appearance of the one plant differs slightly. Perhaps it's transitional, or is one of the two zygotic?

Heinrich

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Re: Jackson grapefruit
« Reply #5 on: September 09, 2019, 06:38:13 AM »
A nucellar seedling doesn't necessarily give a plant, exact like the mother plant. There is also a change, it is seedy like the original Triumpf grapefruit, from which the limb sport originated.

I regard the second plantlet as a zygotic seedling, because it is different.

Millet

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Re: Jackson grapefruit
« Reply #6 on: September 09, 2019, 03:10:53 PM »
Nucellar seed does give a plant exactly like the mother plant.  Of course zygotic seed does not but it will develop thorns..

kumin

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Re: Jackson grapefruit
« Reply #7 on: September 09, 2019, 03:56:15 PM »
By looking closely, it's noticeable that most of the leaves on the right plant are cupped and the stem is thorny. The plant on the left has wider leaves with little cupping, no thorns. These small details can be useful in separating mixed zygotic/nucellar populations.

Sometimes the differences can be very subtle, others are very dramatic such as segregating wide hybrid progeny. 
« Last Edit: September 09, 2019, 05:23:22 PM by kumin »

Heinrich

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Re: Jackson grapefruit
« Reply #8 on: September 13, 2019, 03:41:12 PM »
A nucellar seedling doesn't necessarily give a plant, exact like the mother plant.

Howard B. Frost, James W. Cameron, Robert K. Soost,
Diversity among nucellar-seedling lines of Satsuma mandarin and differences from the parental old line.
Hilgardia, Volume 27, October 1957, Number 7.

http://hilgardia.ucanr.edu/Abstract/?a=hilg.v27n07p201

Millet

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Re: Jackson grapefruit
« Reply #9 on: September 13, 2019, 10:15:23 PM »
Heinrich, thank you for your informative post, it is interesting. As the saying goes, the exception proves the rule.  As shown in your  post, >occurred only once among several hundred seedlings<.   I still stand by the accepted thought of the citrus industry, that nucellar seeds come true to the mother plant.

SoCal2warm

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Re: Jackson grapefruit
« Reply #10 on: September 14, 2019, 02:54:13 PM »
Nucellar seed does give a plant exactly like the mother plant.
Usually it does, but not always. Sometimes there is a mutation.

It also depends exactly what we mean by "nucellar seed". In some cases a seed can have multiple sprouts and one of those seedlings can be zygotic, yet we might identify them as "nucellar" because multiple seedlings originated from one seed. This is not as common though.

Millet

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Re: Jackson grapefruit
« Reply #11 on: September 14, 2019, 06:01:39 PM »
SoCal2warm,  you are certainly correct. However, the mistake stated in your post is not a mistake on the citrus's part, but rather is a mistake on the human beings part.

 

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