PHYLOGENETIC ANALYSIS OF THE MALE ONTOGENETIC PROGRAM IN AQUATIC AND TERRESTRIAL MONOCOTYLEDONS

Area of Science:

• Plant reproductive biology
• Developmental botany
• Evolutionary botany

Background:

• The male program of ontogeny in flowering plants involves critical events from microsporocyte meiosis to fertilization.
• Key developmental sequences include cell wall deposition, cytoplasmic organelle changes, and nuclear divisions forming sperm and vegetative cells within pollen grains.
• Monocotyledons display significant diversity in pollen morphology, wall structure, and pollination strategies, highlighting variations in male ontogeny.

Purpose of the Study:

• To compare the male developmental program across selected terrestrial and aquatic monocotyledons.
• To analyze 26 specific characters of male ontogeny.
• To construct a cladogram based solely on developmental data to infer evolutionary relationships.

Main Methods:

• Comparative analysis of male ontogenetic sequences in Liliaceae, Gramineae, Cymodoceaceae, Najadaceae, and Zannichelliaceae.
• Identification and characterization of 26 developmental traits.
• Phylogenetic reconstruction using cladistics, with polarity determined by direct observation and outgroup analysis.

Main Results:

• Detailed comparison of male developmental pathways in diverse monocotyledonous families.
• Identification of 26 characters informative for phylogenetic analysis.
• Construction of a cladogram based on developmental data, revealing evolutionary patterns.

Conclusions:

• Developmental data provides a valuable framework for understanding plant evolution.
• Variations in male ontogeny, particularly in monocots, offer insights into adaptive strategies.
• The study establishes a phylogenetic hypothesis based on developmental characters.