Mammillaria dixanthocentron

Name and distribution

Plants of the World Online accepts Mammillaria dixanthocentron Backeb. ex Mottram. The first publication of the accepted name is Mammillaria Index from 1980. Its natural range includes Puebla and Oaxaca, and the biome is defined as dry shrubland. M. dixanthocentron var. rubrispina was included among its synonyms. The name's full authorship includes Mottram. [2-WWW]

Multiplication from stem sections

In Lázaro-Castellanos and colleagues' study, material came from seeds of the UNAM Botanical Garden. Seedlings reached about 10 mm tall after eight months. After initial multiplication, shoots were divided into apical, basal and lateral sections. In the comparison of regulators, the lateral section, containing retained axillary meristems, had greater shoot-producing capacity than the other types. [Lázaro-Castellanos et al. 2018, p. 519–522]

With meta-topolin at 1.1 µM, lateral sections yielded a mean of 16.7 ± 0.4 shoots per explant. Callus accompanied this on 80.0 ± 3.1% of sections. Without added regulators, lateral sections yielded a mean of 14.2 ± 2.1 shoots. The material's retained capacity for new shoot growth was therefore considerable even in the control treatment. The high-yield treatment also had a high frequency of callus formation. [Lázaro-Castellanos et al. 2018, p. 522–524, tab. 3]

Rooting and later development

Shoots were rooted on MS medium without regulators. The authors reported 94% rooting after twelve weeks. Rooted plants were transferred to a 1:1 mixture of garden soil and pumice, initially under a cover maintaining 80–90% relative humidity. After gradual acclimatisation, survival of the plants examined in three groups exceeded 95%. Propagation and rooting took place at 25 ± 1°C with a sixteen-hour day. The greenhouse stage was described at about 30°C. [Lázaro-Castellanos et al. 2018, p. 520–521, 524–525]

After twenty-four months in the greenhouse, 56% of the M. dixanthocentron plants described were flowering, with a mean height of about 35 mm and diameter of 32 mm. This stage followed seedling development, production of daughter shoots and rooting. The result describes a specific line and procedure, as well as how age was counted after transfer from culture. [Lázaro-Castellanos et al. 2018, p. 524–525, ryc. 2]

Scope of the stability study

Across three successive multiplication cycles, eight reproducibly amplified SSR loci were assessed. Daughter shoots retained high similarity to the starting material, with differences detected in some markers. The mean PIC index was 0.10, 0.15 and 0.13 in successive cycles. PIC is a dimensionless index of allele diversity in the markers examined. [Lázaro-Castellanos et al. 2018, pp. 525–528, Table 6]

Related articles

Materials from the author's archive

The species also appears in Konrad Szychowski's private material archive. [Kaktologia 2009b, file p. 13] [Neciu b.d., file p. 1]