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Post by pagnr on Nov 23, 2022 7:57:41 GMT -5
The genes for acidity do not in the most part get transferred around by themselves. Firstly they get into a hybrid as the full strand of DNA from each parent ( more strands in the case of triploids , tetraploids ). After that, the genes are on a chromosome with a set of other genes for other characteristics. It is possible in genetic experiments to trace one visibly unseen character, ie acidless, in if it happens to be on the same chromosome as a gene for a visible character ie thornless. In this theoretical example, if a seedling is thornless, it must have received the thornless gene on a particular chromosome, along with the acidless gene. So you can visibly select the thornless as also being acidless as a screening process. If the genes for acidless and thornlessness are somehow genetically / hormonally related, or if the two individual genes are very close together on a chromosome area they will virtually always travel together into progeny. This type of process, called genetic linkage could be used to screen seedlings if you could determine that the trait you want to encourage always appears with another you can easily visibly screen for. Without definite evidence it is a very risky strategy, but worth investigatigating via research. Please realise that I only used Thornless/acidless as a convenient example without evidence.
The genes for acidity do not in the most part get transferred around by themselves. Well to some extent they actually can, by swapping between the other matching chromosome, jumping to other chromosomes, jumping around on a chromosome. These are rarer events, but the can be useful in generating new types of variation. Conventional Plant breeding often aims to join characters together in this way, ie early flowering genes and disease resistance genes grouped together in a parent for F1 hybrids.
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Post by ilya11 on Nov 23, 2022 10:30:50 GMT -5
"This type of process, called genetic linkage could be used to screen seedlings if you could determine that the trait you want to encourage always appears with another you can easily visibly screen for. Without definite evidence it is a very risky strategy, but worth investigatigating via research"
In modern citrus research they use genomic marker assisted breeding that guarantee the presence of desirable genes in screened population.
"The genes for acidity do not in the most part get transferred around by themselves. Well to some extent they actually can, by swapping between the other matching chromosome, jumping to other chromosomes, jumping around on a chromosome. These are rarer events, but the can be useful in generating new types of variation."
Reshuffling between individual chromatides occurs obligatory during each meiosis event.
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Post by mikkel on Nov 23, 2022 16:57:35 GMT -5
pagnr, I understand your point, but in this case it is very difficult for us as amateur breeders to find these linked traits. If there were knowledge about such linked traits with the acid-relevant genes from science, it would be very helpful, but as long as it is not known, it is not practical for hobby breeders, although such an idea is correct, but only theoretically, because in reality there is no way to find such possible linked traits. As long as we don't know how to recognize the acid genes by other visible traits, we have to go another way. And that is breeding with varieties with known genetics, with known inheritance traits and with varieties that have the simplest and most reliable inheritance of absence of acidity. In combination with the known breeding strategies, we can then achieve the highest probability for the desired goal. However, it will not be possible to shorten the selection process. In cold regions one can at least do a cold selection with the seedlings to combine at least a second selection.
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Boris
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Post by Boris on Nov 25, 2022 3:32:01 GMT -5
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Post by mikkel on Nov 25, 2022 13:59:38 GMT -5
Some Ichang Papeda and some of its hybrids show a reddish flush. But as far as I know all I P are more or less sour. Would be nice to find out.
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Post by pagnr on Nov 25, 2022 17:14:41 GMT -5
There are studies showing a relationship between the acidity of citrus fruits and the presence of anthocyanins in young shoots and flowers.
A short list from my experience would be Citrons, Lemons, Limes, Rangpur, Rough Lemon, all with sour fruit.
edit The Australian and PNG Microcitrus ie australis, australasica, my "seedling" of warburgiana, various Hybrids have pigmented growth tips. Not sure if C.inodora has pigmented new growth that I've noticed ?
Some Ichang Papeda and some of its hybrids show a reddish flush.
Another Papeda with red purple growth tips is C.hystrix.
It would be interesting to note if acidity and pigmented new growth are linked or travel together ?
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till
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Post by till on Nov 30, 2022 13:36:30 GMT -5
I think the linkage between protoanthocyanin or anthocyanin and acidless traits brings us back to the beginning of this threat. This linkage only exists in varieties that are homozygot for a deficient NOEMI gen. We shall also keep in mind that varieties can have two functional NOEMI genes but no functional Ruby gen. Best example are sweet oranges. They do not produce anthocyanin (expect for blood oranges) but can accumulate acids in the fruit because the NOEMI genes are functional. So the asence of red coloration can have two reasons and need not be linked to acidless phenotypes. The linkage is restricted to certain varieties (lemons, citrons and limes).
Poncirus does produce anthocyanin. It might be rare in young shots but is is quite common as a autumn color or as a reaction to sun stress. Poncirus and C. ichangensis are homozygot for a functional Ruby gene. Mandarines have two deficient Ruby genes.
I have tried to cross Chandler with Poncirus and other citrus varieties for some years. Chandler always got seedless fruits. But this year I got a fruit full of seeds after I pollinated a flower with African Shadock x Poncirus. It seems to me that Chandler as a mother plant tends to accept only pummelo pollen or pollen of at least half-pummelos. I also pollinated Poncirus with Chandler pollen this year. But it is too early for presenting results. Seeds will germinate in spring.
A friend of mine send me an scientific article that showed that Vaniglia Sanguigno has the same genetic outlook as Vaniglia analized by Cameroon and Soost. That means Vaniglia Sanguigno is acidless because of a deficiency of the NOEMI gene. That means that my four crosses with Vaniglia Sanguigno (two with F. margarita, two with Poncirus) are expected to bear sour fruits. I should have better used Sucrena.
I shall soon post the article here. I also got one that showed that Sucrena has a metabolism different from Vaniglia that is responsible for low acidity.
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till
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Post by till on Nov 30, 2022 13:43:30 GMT -5
Regarding the inheritance of early blooming with regard to Laaz precocious Poncirus, I have to ask you for more patience. I have indeed a Kucle x Poncirus cross that bloomed as a small plant (1m high). Since I used, among other Poncirus pollen, frozen pollen of precocious Poncirus in the cross it is very likely that the early blooming was inherited by it. I pollinated a better tasting Poncirus with the precocious Kucle x Poncirus - cross. Fruits were full of seeds. But that is all I can say at the moment. If early flowering is really inheritable in Laaz precocious Poncirus you will see results in about two years when my second generation (Poncirus x (Kucle x Poncirus)) is big enough to flower. I think though that this is a bit off-topic here where we discuss acidless types.
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till
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Post by till on Nov 30, 2022 14:06:48 GMT -5
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jibro
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Czech Rep. | USDA 6b
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Post by jibro on Dec 3, 2022 5:25:45 GMT -5
I'm not too sure if I remembered it correctly, but I read somewhere that the problem with Pomelo pollination may be due to the large size of the pomelo flower compared to small flowered citrus, their pollen was not able to grow through the stigma, but I haven't found the source, so take it with a grain of salt. My FF trifoliate did not produce single fruit during the last 9 years, looks unhealthy, and grows poorly at this point regular trifoliate will produce fruits sooner... usually around 8-10 years... My first Chandler fruit has just fallen off the tree so I will know soon if there are any seeds inside, it is still rather green, approximately 12cm diameter and weighs 0.5 Kg. I've read about interesting somatic hybrids with Succari + trifoliate and also Changsha + trifoliate, I think these could have good fruits and frost resistance... UFR-5 rootstock [(Nova + Hirado Buntan pummelo seedling) × (Succari sweet orange + Argentine trifoliate orange)] UFR-6 rootstock (Changsha mandarin + Trifoliate orange 50-7)
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till
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Post by till on Dec 3, 2022 13:59:32 GMT -5
A pitty that they do not state the eating quality. Even if it were pour it would be intestering to know for our discussion here.
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Post by ilya11 on Dec 4, 2022 3:58:11 GMT -5
In the past Bernhardt Voss succeeded to produce several ChandlerXPT hybrid seedlings.
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till
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Post by till on Dec 4, 2022 7:22:42 GMT -5
So it is somewhat mysterious how my Chandler behaved.
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till
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Post by till on Jan 17, 2023 11:17:14 GMT -5
It is a little bit off-topic here to speak about crosses of normal sweet citrus with poncirus because we dicuss the inheritance of acidless varieties here and not just sweet citrus. Yet I thought I best write it here. I have been occupied with hardy citrus for a while but had my own harvests only the last few years. So I can only speak from own experience about the sweetness of Dunstan citrumelo, Batumi Citrumelo, Swingle 5 Star, Morton, and now of a dubious citrumelo called "Yuma Gwangne Poncirus x Chansa Citrandarin" by the nursery (Yuma Citrange = Sacaton Citrumelo?). What is interesting for me is that Morton was quite sweet and that now the first fully ripe fruit of the mentioned citrumelo is also quite sweet. By sweet I do not mean sweet like a Clementine. They taste like a sourer sweet orange. Saying that I mean they have a pronouced sweet taste and a definite sourness that, however, is weak enough to allows you eating the fruits out of hand (if there were not the bitter and resinous taste of the citrumelo). So it is not true what I had read earlier that sweetness is always a recessive trait, right? In the case of Morton and the mentioned citrumelo it rather seems to be intermediarily inherited. I would say though that sourness is dominating in Batumi, Dunstan citrumelo and Swinge 5 Star. What are your experiences with other Poncirus hybrids?
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Post by pagnr on Jan 18, 2023 3:56:24 GMT -5
Benton citrange fruit is far more acceptable to taste than Troyer or Carrizo. I grew some Citrangequat seedlings, that fruited. Some were markedly better than the parent fruit. Plants were not strikingly different to the original parent, there are slight differences, but minor.
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