The Tropical Fruit Forum

Today night we got the first  ground frost, so I want to share some pictures showing the degree of ripiness.
All trees are in ground never protected.

Ichangstar60 have already dropped most of its fruits



SunkiXPT citrandarin







Yuzu




5star citrumelo



Dunstan citrumelo






Changsha


Staruzu (5starXYuzu)

Probably succeeded to have it.
It was done with castrated  PTP flowers pollinated by Valentine pummelo. I tried also another way, but failed.
This year was supposed to be the last to try any cross with PTP, previously the seedlings although different in vigor were rather uniform in the shape of leaves and overall look alike.
Now only one third of them (I am germinating 85 seeds) look like those of poncirus, the rest are clearly different.



Putative nucellar seedling to the right. Red arrows point to the tiny unfoliate alternate first leaves typical for pure poncirus seedlings.

This year, after 6 years from crossing two of my Ichangstars (5starcitrumeloXCitrus Ichangensis are abundantly flowering for the first time
1232061:




The first flower has 8 petals, fruity perfume, close to that of ichangensis

Another hybrid- 1232060 had one non complete flower last year, but hundreds of flower buds now




I pollinated the castrated flowers of 5star with C.ichangensis pink flower clone from Baches nursery in the spring of 2012 and around 70 zygotic seedlings were planted in the ground next year.
Around two dozens survived without protection, the two that bloom now had no damage during this period.

Interestingly, that while 1232061 is blooming on most of its branches, the flowers on 1232060 appear on the lower part, on twigs with nod count almost two times less those at the top  of the bush.

Below is a comparison of three poncirus varieties:

From left to right: Poncirus B.Voss-45 gram,  SwampLemon-41 gram  , PoncirusTrifoliata+ -41gram



Poncirus from B.Voss is almost all seeds (45), SwampLemon contains 21 seeds and PT+ 25seeds



After seed extraction:



Very small quantity of juice in classical poncirus, very high quantity of soluble matters (20° Brix), very acid, bitter oil emulsion

Swamp Lemon: 4 ml of juice, 9° Brix, acid, some bitterness, oils are present and stick to dents

PT+:  6 ml of juice, 10° Brix, acid, less bitter than SL, oils are probably there because of astringent taste, but do not stick to dents




I diluted all three juices with water to 5° Brix and kept them overnight in  refrigerator:



Poncirus Voss: acid, some bitterness, sharp taste, but not much revolting to three people who tasted it, sticky oils with typical poncirus taste are in yellow sediment

SwampLemon: taste more diluted, essentially the same appreciation as above, probably less bitterness and acidity, sticky oils are in yellow sediment

PT+ :  taste almost like white grapefruit but less sweet, some lemony note, sediment consists mostly of pulp membrane residues, may be some oils, but drastically less than in two previous cases.

For me these results are still inconclusive, especially in case of SwampLemon versus usual poncirus.

This year at the end of May the first of the hybrids that I made  in 2011 by pollination of 5* citrumelo flowers by Morton Citrange flowered for the first time:


 
Most of the  flowers were defective without pistils, but eventually three fruits were formed



Fruits began to change color at the end of September, one of them looks ripe now









It is approximately of the size of poncirus fruit, has a pleasant outside odor resembling orange with fruity overtone, albedo is thick with some faint bitter taste, juice is sour like a lemon with no bitterness, no internal oils, no perceptible poncirus aftertaste. By taste it is close  to unripe orange.
I measured a sugar content - it had 13.5° Brix (Spanish clementine in parallel showed only 11°)

This  plant (11_03_24) is very resistant, probably more than both of its parents. It is in open ground without any protection since 2012, never was damaged by snow and freezing temperatures under conditions when both 5* and Morton showed some leaf damage. It requires a lot of iron supplement in  spring  to avoid deficiency, otherwise is very healthy 2 m high bush with small largely monofoliate leaves.
Could be an interesting step toward a  hardy citrus with sweet taste.

A very instructive article on the process of mandarin diversification and domestication has been published recently

Genome of Wild Mandarin and Domestication History of Mandarin

They found a center of radiance of Citrus reticulata in Nanling mountains in South China, sequenced the genome of two wild plants in Mangshan region and used this information and previously developed markers of pomelo, C.ichangensis and  citron to identify two groups of domesticated  mandarins North and South of Nanling ridge.



Domesticated mandarins show a dramatic decrease in fruit citric acid content, while their sugar levels are not different from wild plants.

Mangshan mandarin ( different from Citrus mangshanensis also growing in this region) has already 1.7% of its genome introgressed from Ichang papeda, but almost no influence from pomelo or citron, while domesticated mandarins have up to 10% percent of genes from pomelo.

Satsumas are very different from both groups of Chinese mandarins and have 27% of introgressed pomelo, more than clementines with 18% of pomelo genes.
 
Mediterranean mandarin belongs to the South group of Chinese mandarins, while Changsha and  Ponkan are North mandarins.

Anthocyanin containing  pigmented Mexican limes were produced in Florida by transgenic insertion of genes from red grape (Vitis):

 

 and Moro orange:



http://journal.ashspublications.org/content/141/1/54.abstract   

I like  a lot grapefruits from USA, they are much tastier than those coming from Israel or Italy, but today have seen very strange  fruits with a lot of uneven green coloration. Is it possible, that they are affected by greening?