The Tropical Fruit Forum

Citrus => Citrus General Discussion => Topic started by: Millet on September 05, 2021, 02:23:27 PM

Title: For Those In HLB Areas That Want A New Citrus Tree
Post by: Millet on September 05, 2021, 02:23:27 PM
 Cultivars that appear to have commercially useful levels of HLB tolerance. The two most noteworthy cultivars are Sugar Belle and SunDragon.
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: roblack on September 05, 2021, 03:07:25 PM
Growing Sugar Belle, a few finger limes, finger lime hybrid, kumquats, amongst others.

FL's seem unaffected by anything except too much sunlight.

Caterpillars and something else have hit Sugar Belle, but seems okay.
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Millet on September 05, 2021, 05:08:33 PM
SunDragon
 1. Released by  USDA/ARS primarily for dooryard use.   
 2. Scored highly for sweetness.
 3. Is 1/8 percent Poncirus
 4. Fruit is the size of a Navel Orange
 5. Peelable
 6. Flavor is like a mild orange with zesty notes.
 7. Matures October through January (Florida)
 
 It took decades to produce the first citrus scion variety (Sun Dragon) from crossing trifoliate orange followed by transferring some of its genes across multiple generations into sweet orange.
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Citradia on September 06, 2021, 01:44:52 PM
Is poncirus supposed to be tolerant of HLB?
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Laaz on September 06, 2021, 02:41:26 PM
Lol! Why would anyone want a xponcirus hybrid except for those in a cold climate? There are way to many good citrus you can grow, even into 8a.
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: pagnr on September 06, 2021, 06:02:17 PM
Why would anyone want a xponcirus hybrid except for those in a cold climate?

These ones rates high on juice taste tests. I read there are further siblings that are pretty close to "Orange" juice, and suitable for blending with other varieties. The HLB tolerance is the main factor. As you say, why otherwise choose an alternative to many other excellent varieties ??
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Millet on September 06, 2021, 09:58:09 PM
The SunDragon's development took almost 20 years.  It is no longer a case of just pollinating a cultivar with Poncirus pollen to get a cross cultivar tree.  Much of the Poncirus parentage within the SunDragon that was finally released was done by selecting individual poncirus genes to give the tree the qualities  wanted, and was done by gene transfer.  The taste of the SunDragon is quite good without the PT off flavor.  If one lives in a high HLB areas such as Florida, having a citrus tree in your front yard that will give good tasting fruit and will not be affected by HLB is a big deal. I would like to grow one here in my greenhouse.
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Galatians522 on September 06, 2021, 10:01:40 PM
The SunDragon's development took almost 20 years.  It is no longer a case of just pollinating a cultivar with Poncirus pollen to get a cross cultivar tree.  Much of the Poncirus parentage within the SunDragon that was finally released was done by selecting individual poncirus genes to give the tree the qualities  wanted, and was done by gene transfer.  The taste of the SunDragon is quite good without the PT off flavor.  If one lives in a high HLB areas such as Florida, having a citrus tree in your front yard that will give good tasting fruit and will not be affected by HLB is a big deal. I would like to grow one here in my greenhouse.

Well said. Unfortunately, I have not seen the tree for sale anywhere.
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Citradia on September 07, 2021, 07:55:46 AM
Again, are we implying that the poncirus genes in Sundragon are what gives it HLB protection?
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Ilya11 on September 07, 2021, 09:45:02 AM
Yes, poncirus and some of its hybrids show a tolerance to the HLB infection.
link (https://www.researchgate.net/profile/Anoop-Srivastava/post/Is_there_any_rootstock_in_citrus_which_resist_citrus_greening_disease/attachment/59d651e879197b80779aa4d4/AS%3A509750690238464%401498545443390/download/00003019.pdf)
This tolerance is polygenic , that is requires a presence of several resistance genes, some of them diminish attack by psylids, while other are controlling the infection.
 In SunDragon only some of these genes are present, so its resistance is lower than for the pure poncirus.
Still, this is quite remarkable achievement and probably a proof that  cold hardiness  trait can also be introduced to  conventional citruses without a loss of fruit quality.
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Millet on September 07, 2021, 11:55:34 AM
llya11, thanks for the link, most informational.  Appreciate it.
Title: Re: For Those In HLB Areas That Want A New Citrus Tree
Post by: Citradia on September 07, 2021, 08:59:17 PM
Thanks, Ilya11