Breeding system in a population of the globose cactus Mammillaria magnimamma at Valle del Mezquital, Mexico

Abstract

Background: The breeding system of Mammillaria magnimamma was initially described as hermaphroditic. However, some individuals in a natural population at Valle del Mezquital exhibited a seemingly non-functional androecium.
 Objectives: To determine the breeding system of M. magnimamma through morphological characterization of floral types.
 Study site and years: The study was conducted at Valle del Mezquital, Mexico, during the 2019 reproductive season.
 Methods: We characterized floral polymorphism by means of scanning electron microscopy and morphometric analysis of 18 floral traits. Pollinator frequency, size and number of seeds, and germination rate were compared between flower types.
 Results: 87.85 % of the plants were hermaphrodites, and 12.15 % were females with non-functional androecium, with significantly smaller stamens, indehiscent anthers, and malformed pollen. Female flowers were shorter (14.007 ± 0.742 mm) and had smaller (1.856 ± 0.151 mm) nectar chambers than hermaphroditic flowers (15.821 ± 0.450 and 2.194 ± 0.090 mm, respectively). Although pollinators visited hermaphrodites (124 visits) about twice as often as pistillate flowers (60 visits), the latter produced more numerous (F1,26 = 8.320, P = 0.003) and larger (Hc = 4.637, P = 0.031) seeds that also germinated faster (Hc = 70.59, P < 0.0001).
 Conclusions: This M. magnimamma population exhibits a gynodioecious breeding system with both hermaphroditic and male sterile female plants. Females produce more, higher quality seeds, which favour their maintenance in the population.

Phenotypic Diversity of Morphological Characteristics of Pitahaya (Selenicereus Megalanthus Haw.) Germplasm in Colombia

“…This study demonstrated that the natural populations of pitahaya from the five departments showed high variation in the morphological characteristics that were evaluated in situ. Although the five studied sites have similar climatic conditions, the same variables should be evaluated in accessions established in a single environment, thereby confirming whether the variation might have been affected by uncontrolled environmental factors in this observational study, such as different soil types [29]. Studies in other countries have found high variation in characteristics of agronomic importance, even within the same species of Hylocereus spp.…”

“…[6,8,20], which is favorable for future breeding studies. The availability of this information would be of great assistance in developing an appropriate method for the cultivation of a particular species [29,30]. Several studies related to the diversity of dragon fruit have been reported.…”

Variability in mating strategies in a widespread cactus in the Chihuahuan Desert

“…Recent works focused on widespread cactus species have revealed mating and breeding system variations as a result of eco‐geographic heterogeneity (e.g. Pachycereus pringlei (Gutiérrez‐Flores et al 2017), Mammillaria magnimamma (Callejas‐Chavero et al 2021)), but the link between pollinator availability and among‐population variation in mating systems has not been explored. The closest approximation is a study between two sympatric Opuntia species that differ in their mating systems, which found that the self‐incompatible O. polyacantha attracts twice as many species of visitors as does the self‐compatible O. phaeacantha , probably due to its longer flowering time, larger flowers and the greater nutritional value of its nectar (Osborn et al 1988).…”

Morphoagronomic Evaluation of Yellow Pitahaya (Selenicereus megalanthus Haw.) in Miraflores, Colombia

“…In Colombia, morphological, molecular, and biochemical characterization studies are scarce [3]; most studies have been focused on the physiological component of seeds for in vitro propagation and on the identification of limiting pathogens in production, among others [12][13][14][15]. Morphological and molecular characterization studies carried out on the germplasm at the Department of Boyacá have shown that there is genetic diversity in the province of Lengupá, which is the basis for the establishment of any selection process that would identify elite materials that respond to the needs of the farmer, producers, and consumers.…”