On Sep 30, 2:21*pm, Space Cowboy > wrote:
> Are you saying the DNA of tea plants wouldnt necesarily lead us back
> to the Yunnan region in general or to a specific variety if it still
> existed. *Even if it didnt exist there should be the closest surviving
> variety. *I guess has any DNA work been done on tea?

A little DNA work has been done on tea (I covet a Chinese paper
published about it this year but haven't been able to justify $32 to
acquire a copy). Genetic marker studies tend to throw up as many
questions as they answer but certainly the Indian/Burmese assamica
type is different to the Chinese sinensis type. I suspect that the
large leaf China type really is different 'origin' to the large leaf
Assamica type - and that there never was one single definable origin.
Tea genetic history is complex. Camellia sinensis is self
incompatible - it can only cross breed. This feature, over millenia,
resulted in a highly heterogenous and variable gene pool.
Geographical separation kept the main groups from too much crossing -
then along came man and hybridization went into overdrive.

Nigel at Teacraft

If one does a Google search for tea +genetic +DNA the results suggest
that quite a lot of research has been done on the DNA of tea, and that
is only seeing the English, while I rather think that the main bulk of
studies will have been published in Japanese, as well as Chinese and
Korean. Some interesting stuff there, including the discovery that
wild tea in Korea has 2 clearly defined origins, one Chinese (ancient)
and one Japanese (recent).

Br Anthony

On Oct 18, 10:58*pm, An Sonjae > wrote:
> If one does a Google search for tea +genetic +DNA the results suggest
> that quite a lot of research has been done on the DNA of tea, and that
> is only seeing the English, while I rather think that the main bulk of
> studies will have been published in Japanese, as well as Chinese and
> Korean. Some interesting stuff there, including the discovery that
> wild tea in Korea has 2 clearly defined origins, one Chinese (ancient)
> and one Japanese (recent).
>
> Br Anthony

Certainly some interesting stuff exists as you say but 'a little' and
'quite a lot' are relative terms. I was comparing DNA taxonomy work
with the wealth of health work in tea. As a crude tool, Google tea
+genetics+DNA scores 308,000 results but tea+genetics+DNA+damage
scores 263,000, netting but 45,000 for botany to some 85% for
medicine.

Having established that, and allowing serendipity her head, I came
across a paper listing variations in the quality components of tea
plants in the China National Germplasm Repository. [The Chinese are
wisely collecting a huge tea gene pool as a resource for future
breeding - commercial tea culture tends to pick winners and propagate
these few, so reducing genetic variation in the field - a short
sighted technique that assumes teh fallacy that tomorrow's problems
will be the same as today's].

The quality component variations the Chinese show will baffle those
who like a simple correlation between tea type and caffeine level, or
tea type with antioxidant potential. For instance, in the CNGTR
collection, which is mainly China type tea varieties:

Polyphenol varies from 13.6 to 47.8% (highest in Yunnan types)
Catechins range from 8.2 to 26.3% (at variance with total polyphenols;
Hunan teas are highest)
Amino acids range from 1.1 to 6.5% (lowest in southern provinces)
Caffeine varies from 1.2 to 5.9% (Yunnan tends to have the highest,
China and Japanese types have similar variation)
Water extractable solids varies from 24.2 (well below ISO minimum of
32%) to an amazing 57.0% (again Yunnan tending to have the highest).

As you say, Brother Anthony, some interesting stuff !

Nigel at Teacraft

Nigel > writes:

> [...variation in Chinese tea cultivar collection...]
> Amino acids range from 1.1 to 6.5% (lowest in southern provinces)

That would be mostly theanine, right?

/Lew
---
Lew Perin /
http://www.panix.com/~perin/babelcarp.html

On Oct 20, 2:40*pm, Lewis Perin > wrote:
> Nigel > writes:
> > [...variation in Chinese tea cultivar collection...]
> > Amino acids range from 1.1 to 6.5% (lowest in southern provinces)
>
> That would be mostly theanine, right?

Yes, on average some 50% of tea amino acid content is in the form of L-
theanine. Not found anywhere else in the plant kingom except for one
species of Boletus mushroom, yet significantly neuro-active.

Nigel at Teacraft