**10. Individual selection for breeding Mexican garlic cultivars**

492 Genetic Diversity in Plants

The treatment supplemented with 2,4-D showed the highest number of protocorm formation (Table 4); when the treatment included IAA and adenine, 'Chino' and 'Coreano' doubled to genotypes 'C-3-1/8' 'C-37-1/25'. Other treatments induced root formation. This different varietal response was found by Capote et al., (2000) and Quintana-Sierra et al., (2005) for *Allium cepa* and would be related to differences in sensibility to growth regulators (Fehér et al., 2003). Microbulbils placed, during three weeks, on basal MS (no regulators) increased their size (Fig. 7d), but after 30 weeks they developed into bulbils 1 cm diameter

Table 4. Effect of growth regulators on protocorm and microbulbil formation of four garlic

Fig. 7. *In vitro* regeneration of garlic plants (*A. sativum* L.). A) Protocorms regenerated from root tips, B) 'Chino' protocorms, C) 'Perla' protocorms, D) Microbulbil, E) and F) 'Chino'

12 genotypes. IAA: Indole acetic acid, NAA: Naphthalene acetic acid, Kin: Kinetin, 2,4-D: 2,4-13 Dichlorophenoxyacetic acid, Pic: Pichloram, 2iP: 2-isopentenyl adenine.

**9.2 Microbulbil formation** 

whole plant.

(Fig. 7e and 7f) and finally grew into whole plants.

Garlic in some cases may produce inflorescences but infertile seed; hence, crosses are not possible. Sometimes, bulbs o bulbils develop onto inflorescences (Brewster, 1994). Individual selection on best plants (yield or quality) has been used for breeding (Heredia and Heredia, 2000; González, 2006; Con, 1997). The CAEPAB group worked with individual selection from 'Perla' clones and 'Chileno' having heads with fewer cloves than the average for the original cultivar taking into account also: head size, vigor (hardiness) and plant healthiness. This initial work led to obtain two garlic cultivars: 'San Marqueño' from line 'C-37-1/8' (Macías et al., 2009) and 'Diamante' from line 'CAL-RN-11-1-1-2-4' derived from an Aguascalientes-Zacatecas collection (Macías & Maciel, 2003). In brief methodology for garlic breeding:


Clones obtained through this kind of breeding are grown by farmers from Aguascalientes and Zacatecas (Macías et al., 2009). Nowadays, 'San Marqueño' and 'Diamante' garlic are demanded in Europe because of their high quality that makes them suitable to be exported (Fig. 8). These clones have their optimal conditions at 2000 meters over the sea level, on loamy soils, well drained, without salinity or pedregosity. Lab test are encouraged to check for soil pathogens that may reduce yield.


Table 6. Evaluation of 'San Marqueño' and 'Diamante' garlic cultivars.

Fig. 8. Garlic cultivars from the Mexican breeding program (CAEPAB): A) 'San Marqueño' ('Perla type'), B) 'Diamante' ('California' type) and C) Packaging box for exportation.
