Three sites where mother plants grew
Mammillaria carnea Zucc. ex Pfeiff. is a species accepted in Plants of the World Online from southern Mexico, with a natural range from Veracruz to Oaxaca. Matus and coauthors collected seeds in April 2018 near Zapotitlán de las Salinas in Puebla state, at about 1500 m elevation. The site is in the Tehuacán-Cuicatlán valley. The study concerned variation in this population, divided according to shelter of the mother plants. [2-WWW][Matus et al. 2024, POWO, 11 October 2026; Matus et al., pp. 2–3]
One group consisted of plants beneath Neltuma laevigata canopies, another of plants beneath Parkinsonia praecox, and a third of plants in open places. In the last group, plants grew in the open without canopy shelter within a 5 m radius. Ten plants were selected from each microhabitat and one mature fruit was taken from each. The offspring of one mother were termed a family. A family was defined by shared maternal origin, with paternal origin undetermined. [Matus et al. 2024, pp. 2–3]
Before the main experiment, an auxiliary germination test was performed on moist filter paper at 25°C by day and 20°C at night. Each provenance comprised six dishes with fifteen seeds each. Germination occurred in 69 of 90 seeds from open places, 62 of 90 from beneath Neltuma and 60 of 90 from beneath Parkinsonia. Differences were not statistically significant. Viability was assessed indirectly through the ability to germinate under the specified conditions. [Matus et al. 2024, p. 3, Seed viability test]
The lighting treatments differed in two properties
Each of the thirty families was sown in six dishes under each lighting treatment. Each dish contained ten seeds, giving 360 dishes and 3600 seeds. For 45 days, a twelve-hour day at 28°C and night at 25°C were maintained. Dishes were watered every third day. This arrangement allowed comparison of responses of the same families in two light environments. [Matus et al. 2024, p. 3, Experimental design]
The first treatment used white LEDs at 146,07 ± 11,7 µmol photons/m²/s. The second used the same LEDs with red and blue filters, producing a spectrum enriched in far-red light and an intensity of 4,04 ± 0,4 µmol photons/m²/s. Photosynthetically active radiation was therefore much lower, while wavelength proportions also changed. The filters modelled characteristics of light beneath plant shelter. Other conditions were kept the same for both treatments. [Matus et al. 2024, pp. 3–4, Table 1]
The design compared two combined treatments of light quantity and spectrum. The resulting effect covers the joint change in intensity and far-red proportion. Both treatments were illuminated, so the comparison concerns germination under two lights with the stated parameters. [Matus et al. 2024, pp. 3–6, Methods, Results and discussion]
Mean germination and provenance responses
Under white light, a mean of 66,5 ± 2,1% of seeds germinated, compared with 43,9 ± 2,3% in the filtered treatment. These are means from 180 dishes per treatment, with standard errors. The difference was 22,6 percentage points. The means combine three provenances and differing seed families. [Matus et al. 2024, p. 4, Results, Fig. 1]
Seeds from open places germinated at a mean of 71,1% under white light and 64,3% under filters. For offspring of plants beneath Neltuma, the values were 76,0 and 39,6%, and beneath Parkinsonia 52,3 and 27,8%. Each mean covered sixty dishes. The comparison test found no significant difference between lighting treatments for open places. In both canopy provenances, the reduction in germination was significant. [Matus et al. 2024, p. 4, Fig. 1]
In both canopy groups, germination was higher under white light. At the same time, seeds from open places maintained relatively high germination even in the low-light filtered treatment. The result describes germination of seeds of a particular provenance under the dish-experiment conditions. [Matus et al. 2024, pp. 4–6, Fig. 1–2]
Families retained distinct responses
In the analysis of variance, the family factor nested within provenance accounted for 43,98% of the total sum of squares. Lighting accounted for 12,87%, provenance for 12,01%, and the lighting-by-family interaction for 9,55%. There were thus both differences in overall germination between families and differences in the strength of their response to light. Lines connecting each family's results in the two treatments, termed reaction norms, had different slopes. [Matus et al. 2024, pp. 4–5, Table 2, Fig. 2]
The family's share of the sum of squares describes differences in observed germination between offspring of individual mothers. Seeds of a shared mother can share genetic characters and maturation conditions, while their paternal origins may differ. The division adopted includes these influences together. The term “genetic families” in the publication title refers to grouping by maternal origin without DNA analysis. [Matus et al. 2024, pp. 2–3, 5–6]
When comparing sowings from this population, retaining batches by mother plant makes visible variation that mixing all seeds would obscure. Each germination value remains linked to provenance, light treatment and observation period. The study ended with assessment of germination after 45 days in moist dishes. [Matus et al. 2024, pp. 3–6]
Light stress conditions affect variability in the phenotypic expression of germination in Mammillaria carnea from different origins and genetic families
Matus R., Perroni Y., Flores J., Miranda-Jácome A., Light stress conditions affect variability in the phenotypic expression of germination in Mammillaria carnea from different origins and genetic families, Flora, 2024, 315:152522, doi: 10.1016/j.flora.2024.152522
The experiment compares germination in thirty Mammillaria carnea seed families from three microhabitats in the Tehuacán-Cuicatlán valley. It includes 3600 seeds and two treatments differing simultaneously in light intensity and spectrum. The analysis shows differences among origins and families, and differing family responses to changes in lighting.
Plants of the World Online — Royal Botanic Gardens, Kew
Accepted names, synonyms and distribution. A citation beside a taxon leads to its record.
Accessed 2026-10-08.
