BREEDING SYSTEM IN A POPULATION OF THE GLOBOSE CACTUS MAMMILLARIA MAGNIMAMMA AT VALLE DEL MEZQUITAL, MEXICO
Por:
Callejas-Chavero, Alicia, Vargas-Mendoza, Carlos F., Gomez-Hinostrosa, Carlos, Arriola-Padilla, Victor J., Cornejo-Romero, Amelia
Publicada:
1 abr 2021
Categoría:
Plant science
Resumen:
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 nectar chambers (1.856 +/-
0.151 mm) 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 (F-1,F-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.
Filiaciones:
Callejas-Chavero, Alicia:
Inst Politecn Nacl, Lab Ecol Vegetal, Dept Bot, Escuela Nacl Ciencias Biol, Mexico City, DF, Mexico
Vargas-Mendoza, Carlos F.:
Inst Politecn Nacl, Lab Variac Biol & Evoluc, Dept Zool, Escuela Nacl Ciencias Biol, Mexico City, DF, Mexico
Gomez-Hinostrosa, Carlos:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Bot, Mexico City, DF, Mexico
Arriola-Padilla, Victor J.:
Inst Nacl Invest Forestales Agr & Pecuarias, Ctr Nacl Invest Disciplinaria Conservac & Mejoram, Mexico City, DF, Mexico
Cornejo-Romero, Amelia:
Inst Politecn Nacl, Lab Ecol Vegetal, Dept Bot, Escuela Nacl Ciencias Biol, Mexico City, DF, Mexico
Gold
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