Mammillaria hernandezii

Accepted name

Plants of the World Online accepts Mammillaria hernandezii Glass & R.A.Foster. The name was published in 1983. Its natural range includes Oaxaca in Mexico. The record assigns the plant to the tropical montane biome and lists Bartschella hernandezii as a synonym. [2-WWW]

Seedling material and multiplication

Lázaro-Castellanos and colleagues started the culture from seeds supplied by the UNAM Botanical Garden. Mammillaria hernandezii seedlings reached about 10 mm tall after twelve months, longer than the other two groups in the same experiment. Material was kept on MS medium with 30 g/l sucrose and 0.8% agar, at 25 ± 1°C, with a sixteen-hour day and 55 µmol photons/m²/s. Before the main comparison of regulators, seedlings were initially multiplied with meta-topolin to obtain a stock of shoots. [Lázaro-Castellanos et al. 2018, p. 519–521, Materials and Methods]

The best meta-topolin treatment for lateral stem sections contained 2.2 µM of this regulator. A mean of 7.4 ± 1.1 shoots per explant formed. Callus, proliferating tissue with altered organisation, occurred on 12.5 ± 6.5% of sections. Shoots arose mainly from stimulated axillary meristems retained within the section. No new shoots were obtained from basal stem parts. [Lázaro-Castellanos et al. 2018, p. 521–523, tab. 2]

Roots, acclimatisation and flowering

Separated shoots were rooted on MS without growth regulators. For M. hernandezii, the authors reported 98.4% rooting after eight weeks. Subsequent transfer concerned already rooted plants about 10 mm tall. In the greenhouse, they grew in a 1:1 mixture of garden soil and pumice at about 30°C. For the first month, a cover maintained 80–90% relative humidity, after which 50–60% was gradually reached. Survival after acclimatisation reported for the entire set of species exceeded 95%. [Lázaro-Castellanos et al. 2018, pp. 520–521, 523–525]

After twelve months of greenhouse growth, 80% of the M. hernandezii plants described were flowering. After cross-pollination, the authors obtained fruits and seeds. Time to flowering was counted from the greenhouse stage, following earlier seedling culture and multiplication. Combining these stages shows that the one-year greenhouse period is only part of the plant's overall development. [Lázaro-Castellanos et al. 2018, p. 523–525, ryc. 1]

DNA markers in successive cycles

Over three multiplication cycles within two years, daughter shoots were compared with retained starting material. In M. hernandezii, reproducible results were obtained for seven SSR loci, short DNA repeats analysed using PCR. Shoots showed high similarity in these markers, with little detected variation. Similarity assessment covered the seven genomic loci analysed. [Lázaro-Castellanos et al. 2018, p. 521, 525–528, tab. 6]

Related articles

Materials from the author's archive

The species also appears in Konrad Szychowski's private material archive. [Flores Martínez et al. 2002, file p. 3] [Flores Martínez and Manzanero Medina 2003, file p. 2, 3, 4, 7, 10, 11, 12, 13] [Martínez et al. 2001, file p. 4] [Rodríguez Ortega and Franco 2001, file p. 6]