what is this stock?

[xiaohuage]

who is mother who is father?

[Frank]

I think the cacti on the photo  are "San-ryou chyu" means 3 ribs column.
A famous Japanese cactus grafting expert, Mr Yamamot found it around 10 year ago and named as "san-ryou chyu".
He though it was a Harrisia sp or a Harrisia hybrid but he noticed in his website in August this year it was not a hybrid, a original cactus sp named "hassleri". I have tried to get the generic name from him because he did not mentioned about it.

The San-ryou chyu is self-fertile.
No special father and mother.

The growing speed of San-ryou chyu is better than H. Jusbertii.
More San-ryou chyu are used as grafting stocks than jusbertii in Japan, I think. 

[fanecchissimo]

is it frost resistant?

[Frank]

Yes it is, frost resistant and so is used in stead of Hylocereus.

[Carlo & Daniele]

do you think it is the same?

https://www.cactuscultivars.com/forum/index.php?topic=617.0

[Frank]

Carlo & Daniele

Yes I do.
I think they are San-ryou chyu.

Frank

[Arioandi]

Hi Frank,
I often have troubles wiht this grafting stock. If it is to cold in wintertime in my greenhouse (around 8°) it makes big brown spots. If I cut grafted plants on this stock, I have big problems to reroot this stock.

Do you have any suggestions for rerooting this stock?

[Frank]

G'morning Arioandi

Does 8 degree C mean maximum or minimum temperature in your greenhouse in winter?
This is not my data but a Japanese reports the minimum acceptable temperature of San-ryou chyu is 1.5 degree C and this is same as H. jusbertii.

Do you want to know rooting of San-ryou chyu in winter or any other seasons?

Frank

[fanecchissimo]

in my greenhouse  H jusbertii last winter had no issues  in a -6°C environment for several days. So i guess it is frost resistant.

[Carlo & Daniele]

last winter we make an experiment to see how different was the behaviour of stocks (we are talking about stocks without scions on them).
well here humidity is quite high and temperatures in the gh goes several days below 0°C if unheated.
This was the general behaviour:
harrisia jusbertii, echinopsis and trichocersus: no problem at all
harrisia hybrid: orange spots, some of them died
myrtillocactus: before covered with orange/brown sposts than they rot (about 30%)
hylocereus: almost all of them died

[robinast]

In addition to Carlo's & Daniele's note's I can say that

• no problems with Harrisia jusbertii,  H. bonplandii, Echinopsis and Selenicereus hybrid
• some problems with Pereskiopsis - but I think it's due to too dry soil rather than due to too low temperatures
• some losses in case of Myrtillocactus geometrizans - but I do not have so much plants on this rootstocks
• I have gradually lost all the plants grafted on to Seleniceereus pteranthus due to rotting and dying rootstocks
• no hope for surviving any of the plants grafted onto Hylocereus in my conditions

The temperature in my heated greenhouse is around +10 C in winter time, occasionally dropping lower if the weather is very cold. I do not water my cacti from October till March.

[Arioandi]

Hi Frank,
8°C was the minimum temperature.

I would like to root them in vegetation season, spring and summer.

Kind regards
andi

[Frank]

Since San-ryou chyu is not here, in Australia I have not used it yet but a Japanese nursery said:

He is selling a scion with grafting stock without roots. (cuttings)
Since customers need rooting of the stock by themselves, he tested the rooting to determine the possible season.
It is possible to root in November but the minimum temperature is more than 8 C' in there.
It is possible to root without drying process of the cutting face.

San-ryou chyu needs a wet organic soil. It will shrink if the soil was too dry.
He have made a hybrid, jusbertii x San-ryou chyu.

[cortona]

i wuld ask to Frank to id my rootstock too:
http://i292.photobucket.com/albums/mm4/cortonafoto/100_1597_zps4ee382b0.jpg
this harisia have a strage grow pattern, on a side it show normal spines, on the other side it show spines similar the the plant on the first photo
http://i292.photobucket.com/albums/mm4/cortonafoto/100_1599_zpsd7fac0d9.jpg