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Author Topic: A new publication on mandarin domestication  (Read 606 times)

Ilya11

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A new publication on mandarin domestication
« on: August 11, 2018, 10:17:54 AM »
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.
Best regards,
                       Ilya

Walt

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Re: A new publication on mandarin domestication
« Reply #1 on: August 11, 2018, 02:46:52 PM »
Very interesting.  Thanks for the link.

Millet

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Re: A new publication on mandarin domestication
« Reply #2 on: August 11, 2018, 04:37:03 PM »
Ilya11, your a treasure.

SoCal2warm

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Re: A new publication on mandarin domestication
« Reply #3 on: August 13, 2018, 03:03:42 AM »
This may raise more questions than it answers but another study done in China suggested that the genetic background of Changsha mandarin may have some introgression from C. maxima (up to 15%).
Genomics of the origin and evolution of Citrus, Guohong Albert Wu, Javier Terol

If this is actually true, it strongly suggests Changsha did not result from purely natural origins. Or at least there has been some substantial introgression into the Changsha genepool from domesticated mandarins.

Presumably, the study only examined the domesticated cultivar of Changsha, and it might be possible the results could be different for other Changsha cultivars in the wild. That there are multiple different types of Changsha adapted to different climatic conditions in different growing conditions suggests that Changsha is native, or at least has been growing in the wild for a long time and has become naturalized.

The study did not show any shared connection to C. ichangensis.

Ilya11

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Re: A new publication on mandarin domestication
« Reply #4 on: August 13, 2018, 05:26:37 AM »
Changsha is a domesticated land race of mandarins belonging to the Northern group.There is no such thing as wild Changsha.

According to the present study Changsha does contain 3.5% introgression from pomelo. This  is almost identical to 4.05% of pomelo admixture from the study you cited (8.1% of heterozygous Mandarin/Pomelo fragments). Also, in this previous paper authors have not studied intogression of C.ichangensis into mandarins. 

Wild Mangshan mandarins that were sequenced in a new study are from Mangshan mountains, they do not have pomelo admixture and are progenitors of both South and  North domesticated mandarins. Other than different patterns of pomelo introgression these two groups contain different signatures of selective evolution in mandarin genes during domestication.
Best regards,
                       Ilya

SoCal2warm

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Re: A new publication on mandarin domestication
« Reply #5 on: August 14, 2018, 10:16:21 PM »
There is no such thing as wild Changsha.
Unless I am misremembering, there are multiple varieties of wild Changsha in a certain region of China. I saw it in a very old publication (before 1920) in Google books, and it had a few black & white pictures. I believe the spelling was also different, and the book might have had something to do with botanical observations from missionaries. I'm not able to find it now.
If it wasn't changsha it had to have been some other cold hardy orange citrus fruit. But I specifically remember it mentioned some of the varieties having more drought tolerance or deeper roots, better adaption to clay soil or flooding, if located near river plains.

The differences didn't relate to fruits but adaptations to growing in different environments in that area. It was a drier area in the North, without much tree cover.
« Last Edit: August 14, 2018, 10:19:36 PM by SoCal2warm »

 

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