Intraspecific seed competition and genetic diversity within the capsule fruits of Aristolochia contorta

1. Genetic diversity and competitive dynamics are crucial in shaping plant
communities. However, these dynamics have not been examined thoroughly in
the context of seed position within a fruit. This study integrated genetic
analysis and seed competition experiments to understand genetic diversity
and competitive dynamics within Aristolochia  contorta. By
combining molecular markers and seed competition trials, we aimed to
deduce the roles of genetic factors and seed position in influencing
seedling success, facilitating a comprehensive assessment of both genetic
and environmental contributions to growth patterns in this species. 2.
Centrally positioned seeds showed superior growth and germination rates
due to their larger size and weight, providing a competitive edge over
peripheral seeds, highlighting the influence of seed position on nutrient
allocation and competition during germination. 3. Regarding fruit
orientation during sowing, vertically upward-sown fruits showed the
highest number of shoots per fruit, suggesting that the physical
orientation of the fruit may influence early seedling growth. This result
emphasizes the importance of environmental factors (such as light exposure
and soil contact) in determining the success of early-stage seedlings. 4.
Genetic diversity was low within and among fruits, with genetic
differentiation also being low among groups. Most genetic variation was
observed within individuals rather than between groups, indicating a
relatively homogeneous genetic structure within the population. The low
genetic diversity may be attributed to the species' reproductive
strategies, particularly the low efficiency of pollinators, which
restricts gene flow and variation. 5. In summary, these results suggest
that non-genetic factors, such as environmental conditions and seed
position, play a significant role in seedling success and competitive
interactions. Our findings provide valuable insights into evolutionary
biology and conservation strategies of A. contorta. The observed low
genetic diversity highlights potential challenges for the species in
adapting to environmental changes. Our findings remain robust despite the
small sampling size and the use of whole seeds for DNA extraction. They
emphasize the importance of considering environmental factors and seed
position in conservation efforts.