(Mihai Cartoaje) wrote in message . com...
(David Hershey) wrote in message . com...

Many apple cultivars are self-sterile so cannot self-pollinate. Apple
orchards of these self-sterile cultivars must contain a second
cultivar as a pollenizer. Therefore, seeds of some cultivars will be
hybrids of two cultivars. However, each seedling with two parents will
be slightly different because of the "mixing" of genes that occurs in
sexual reproduction.

A possible explanation of the lower quality of most hybrids is if bad
genes are recessive, so alleles (hope I'm using the word correctly) of
hybrids would contain two recessive bad genes.

Maybe the bad genes shall be weeded out by further selection.

If you propose to do that, you will need much land and many years, as
seedlings will grow full size and will not bear (and cannot be
evaluated) for several years.

It isn't just a matter of deleterious recessive genes showing up in
the offspring of hybrids. While hybridization does seek to block the
expression of these genes, it is not the only or even the most
important objective.

The hybridizer seeks a particular combination of genes that gives
fruit of the desired qualities, and that desired combination of genes
is present only in the F1 hybrid generation; the F2 will be diverse,
and few if any of the seedlings will have the combination selected by
the hybridizer. If the experience of others is a guide, most of the
seedlings will produce either crab apples or no usable fruit at all,
and you may go through many generations and thousands of trees to find
one that not only produces satisfactory fruit but also breeds true.

--
Chris Green

Mihai Cartoaje schreef
A possible explanation of the lower quality of most hybrids is if bad
genes are recessive, so alleles (hope I'm using the word correctly) of
hybrids would contain two recessive bad genes.

Maybe the bad genes shall be weeded out by further selection.

+ + +
The other way about. A gene is a particular area of DNA with a certain
function. An allele is one of several possible variants of the gene, so
selection (natural or artificial) eliminates 'bad' alleles, not 'bad' genes.
You cannot select for genes, and if you manage to do so anyway there is a
fair chance you get a new species (as this would mean altering the scope of
the genome). BTW, it is very anthropocentric to speak of alleles being 'bad'
or 'good'. Mostly alleles just are, and are advantageous or not depending on
circumstance.

Of course, colloquially genes are referred to in the reverse of the true
situation. Hope this clarifies it,
PvR

If this is less than crystal clear, just use a book, any decent book!

Mihai Cartoaje schreef
A possible explanation of the lower quality of most hybrids is if bad
genes are recessive, so alleles (hope I'm using the word correctly) of
hybrids would contain two recessive bad genes.

Maybe the bad genes shall be weeded out by further selection.

+ + +
The other way about. A gene is a particular area of DNA with a certain
function. An allele is one of several possible variants of the gene, so
selection (natural or artificial) eliminates 'bad' alleles, not 'bad' genes.
You cannot select for genes, and if you manage to do so anyway there is a
fair chance you get a new species (as this would mean altering the scope of
the genome). BTW, it is very anthropocentric to speak of alleles being 'bad'
or 'good'. Mostly alleles just are, and are advantageous or not depending on
circumstance.

Of course, colloquially genes are referred to in the reverse of the true
situation. Hope this clarifies it,
PvR

If this is less than crystal clear, just use a book, any decent book!

I was counting on the 10 to 20 Celsius degrees of extra cold resistance
seedlings have. BRBR

Seedlings are not likely to have any more cold resistance than their parents.
Actually, for harsh climates, the usual practice is to graft the desirable
cultivar onto a very hardy rootstock. This is done with a wide variety of fruit
trees and ornamental plants.

Apple trees prefer sexual reproduction.

Did they tell you this? I assure you the apple tree does not care whether it is
a seedling, cutting, or graft, as long as it has enough water, sun, nutrients,
& favorable temperatures. The only difference is that a seedling will take ten
or 20 years to bear fruit, while a cutting or graft will start bearing very
quickly.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

(Christopher Green) wrote in message . com...

If you propose to do that, you will need much land and many years, as
seedlings will grow full size and will not bear (and cannot be
evaluated) for several years.

I have found that honeycrisp grow here, and have ordered one. I shall
also plant seedlings in addition, and be able to inform the newsgroup
of how they turn out.

mihai
47N -40C in winter

"P van Rijckevorsel" wrote in message .. .

The other way about. A gene is a particular area of DNA with a certain
function. An allele is one of several possible variants of the gene, so
selection (natural or artificial) eliminates 'bad' alleles, not 'bad' genes.

I have researched in a biology book. Two genes might be alleles, or
they might not be alleles.

"P van Rijckevorsel" wrote in message .. .

The other way about. A gene is a particular area of DNA with a certain

Those are loci.

Give this dude a cigar!!!
He actually read a book!!!!
Believe it or not, there's a lot more where that one came from.
The place is called a library. Check it out.


"Mihai Cartoaje" wrote in message
m...
"P van Rijckevorsel" wrote in message
.. .

The other way about. A gene is a particular area of DNA with a certain
function. An allele is one of several possible variants of the gene, so
selection (natural or artificial) eliminates 'bad' alleles, not 'bad'
genes.

I have researched in a biology book. Two genes might be alleles, or
they might not be alleles.

Give this dude a cigar!!!
He actually read a book!!!!
Believe it or not, there's a lot more where that one came from.
The place is called a library. Check it out.


"Mihai Cartoaje" wrote in message
m...
"P van Rijckevorsel" wrote in message
.. .

The other way about. A gene is a particular area of DNA with a certain
function. An allele is one of several possible variants of the gene, so
selection (natural or artificial) eliminates 'bad' alleles, not 'bad'
genes.

I have researched in a biology book. Two genes might be alleles, or
they might not be alleles.

"P van Rijckevorsel" wrote
The other way about. A gene is a particular area of DNA with a certain
function. An allele is one of several possible variants of the gene, so
selection (natural or artificial) eliminates 'bad' alleles, not 'bad'
genes.

Mihai Cartoaje schreef
I have researched in a biology book. Two genes might be alleles, or
they might not be alleles.

+ + +
No. You either have a bad book (not sure if they exist) or you read wrong.
Try a new book.
PvR

"P van Rijckevorsel" wrote
The other way about. A gene is a particular area of DNA with a certain
function

Mihai Cartoaje schreef
Those are loci.

+ + +
No, a gene is a functional unit.
A locus is (as the word says) the place (of the gene) on a chromosome.
PvR

"P van Rijckevorsel" wrote
The other way about. A gene is a particular area of DNA with a certain
function. An allele is one of several possible variants of the gene, so
selection (natural or artificial) eliminates 'bad' alleles, not 'bad'
genes.

Mihai Cartoaje schreef
I have researched in a biology book. Two genes might be alleles, or
they might not be alleles.

+ + +
No. You either have a bad book (not sure if they exist) or you read wrong.
Try a new book.
PvR

"P van Rijckevorsel" wrote
The other way about. A gene is a particular area of DNA with a certain
function

Mihai Cartoaje schreef
Those are loci.

+ + +
No, a gene is a functional unit.
A locus is (as the word says) the place (of the gene) on a chromosome.
PvR

"P van Rijckevorsel" wrote in message ...

No. You either have a bad book (not sure if they exist) or you read wrong.
Try a new book.

Solomon, Eldra Pearl, et al. Biology. 3rd edition. Sunders, Forth
Worth, 1993.

Page 233: "If genes occupy the same locus on each of a pair of
chromosomes, they are said to be alleles."

They use the expression "not allelic" otherwise. I understand "allele"
as "sister", except for genes.

"P van Rijckevorsel" wrote in message ...

No. You either have a bad book (not sure if they exist) or you read wrong.
Try a new book.

Solomon, Eldra Pearl, et al. Biology. 3rd edition. Sunders, Forth
Worth, 1993.

Page 233: "If genes occupy the same locus on each of a pair of
chromosomes, they are said to be alleles."

They use the expression "not allelic" otherwise. I understand "allele"
as "sister", except for genes.