1. Garlic and Health, P9 report
02/01/2019
Garlic and Health, P9 report
WP3 Cultivation
Munich, 29-3 October 2003
INRA, Avignon, France
V. Chovelon, research scientist
JP Leroux, research technician
E. Clini, temporary agent
Objectives: research on the best conditions for in vitro bulbification of plants from different varieties (Morasol, Printanor, Messidrôme) issued from embryogenic cell suspensions (ECS): effects of different culture media, temperature, day length and light quality.

2. In vitro bulb production
02/01/2019
In vitro bulb production
Important factors for bulb induction
• 2 varieties:
• Morasol and Printanor (plants issued from cell suspensions)
• 2 tested factors:
• cold treatment: 5 or 10 weeks at 5°C
• light: additional far-red light
• saccharose concentration (60g/l)
• photoperiod (16h)
• temperature: °C
According to the results obtained the during last year with the different varieties in vitro cultured, a new experimentation was realised between December 2002 and June 2003 to define important factors involved in garlic bulb induction and enlargement, in order to homogenise, increase and speed up the bulbification rate of different temperate varieties, and to obtained well-formed bulbs.
Materials: P8 and P9 were involved in this essay.
Two varieties were tested (Morasol and Printanor) on plants issued from cell suspensions.
According to the previous results (2001/2002), only two in vitro factors were tested: cold treatment (5 or 10 weeks at 5°C) and quality of light (white light or additional far-red light).
Saccharose concentration in the culture medium (60g/l) and photoperiod (16h) were constant

3. Essay protocol 02/01/2019 Essay protocol:
- two hundred and sixteen (216) Morasol and three hundred and twelve (312) Printanor plants were produced by embryogenesis from cell suspensions by P8.
- rooted plants were transferred in December 02 on culture medium with high saccharose concentration (B medium with sixty g/l).
- cold treatment: in Juanary 03 a part of plants was cold treated during five weeks at five°C, a part of plants was cold treated during ten weeks at five°C, and some ones were kept at twenty four °C as reference.
In February/March 03 plants were transferred in different culture conditions:
- half plants part (cold treated or not) was cultured under industry white light and half plants part was cultured with additional far-red light.
Photoperiod is constant (16hlight).

4. percentage bulbs obtained / variety
02/01/2019
results
percentage bulbs obtained / variety
Notations and results:
Notations were realised each 15 days (plant development, bulb induction and bulb maturation). Bulbs obtained in vitro were harvested at maturity, measured, weighted 3 days after harvest, described (colour, aspect, shape) and then sent to P5 for sulphur analyses.
Matured bulbs percentages and mean weight bulbs obtained are presented here.
Light quality : in absence of cold treatment or after a cold treatment (5 weeks at 5°C), the additional far-red light had a great influence on Morasol bulbification (91.6% instead of 75% without cold treatment; and 83% instead of 76% after cold treatment during 5 weeks).
However no significative difference was observed on Printanor bulbification during this essay.
Temperature : cold treatment at 5°C applied during 10 weeks greatly favoured bulb formation for Morasol with 100% bulbs obtained in vitro, and with more important bulb diameter and weight. Cold treatment during 5 weeks was not sufficient to increased Printanor bulbification, but at 10 weeks cold treatment had also an effect on Printanor bulbification (37% instead of 23%).

5. Mean diameters and weights bulbs in vitro obtained
02/01/2019
results
Mean diameters and weights bulbs in vitro obtained

6. • for varietal group II (Printanor)
02/01/2019
conclusion
best conditions for garlic in vitro bulbification
• photoperiod 16H
• high saccharose concentration (60g/l)
• additional far-red light
• for varietal group I (Morasol)
• cold treatment (>5 weeks at 5°C)
• for varietal group II (Printanor)
• cold treatment (>10 weeks at 5°C)
In conclusion, the best conditions for garlic in vitro bulbification are different following garlic groups:
-for varietal group I (Morasol, witch is a Mediterranean variety) the mean factors for in vitro bulb induction and enlargement are a great photoperiod (16h), a high sucrose concentration (60g/l), an additional far-red light, and a long cold treatment (5 to 10 weeks at 5°C).
- for varietal group II (Printanor, witch is a temperate variety with great dormancy) these three first factors ( photoperiod, sucrose concentration, additional far-red light) are important to increase the % of bulbs formation, but this variety need a longer cold treatment (up to 10 weeks).