The Gymnosperm Phylogeny

A new genetic resource, the gymnosperm genome, was created to help understand the evolution of gymnosperms. These genomes enable researchers to perform large-scale comparative analyses on the functional divergence between gymnosperms. In addition, they provide a basis for breeding and management of commercially important gymnosperm species.

Conifers are among the most widespread gymnosperm plants, accounting for vast areas of forests around the world. These plants include cedar, pine, cedar, spruce and fir and more than 600 species in 50 genera. These plants have secondary growth, woody roots, and needle- or scale-like foliage.

Gymnosperms can be dioecious, which means that female plants produce seeds. The seeds are fleshy, resembling pale cherries. Butyric acid is present in the seed. To increase their diversity, Gymnosperms developed herbivory and pollination. This increased diversity was the result of a balance between attracting certain insects and repelling others. Through the evolution of reproductive organs, plants have also evolved to seed dispersal.

Fossil records show that the first gymnosperms originated during the middle Devonian period, about 390 million years ago. The appearance of giant fern trees and ferns was followed by a period when dry weather favoured seed plants. Angiosperms were the dominant form of plant life by the middle Cretaceous.

The genetic makeup of Gymnosperm plants is similar. Despite their heterogeneous traits, they share several features. All plants have seed covers, while some have internal fertilization. They also possess flagella. Gymnosperm plants are bisexual.

The emergence of seed plants was the key to the colonization of land by bryophytes. This enabled the plants to reproduce even when they had no water. The polyembryony system, which multiple archegonia fertilize various pollen grains, was developed by Gymnosperms. Each archegonia contains two seeds. The dominant embryo is kept while the others die.

The phylogenetic tree for land plants shows that both gymnosperms as well as angiosperms had sexual reproduction before the transition to land from freshwater environments. Both groups evolved simultaneously from green algae and seedless, vascular plants. The transition was an evolutionary event.