EEB440H1 Chapter Notes - Chapter N/A: Pollen Tube, Soil Fertility, Autotroph
27 Apr 2016
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Document Summary
Pollen loads typically contain pollen from multiple donors, including the self. Often more pollen is placed on the stigma than needed; competition results. Growth of the pollen tube occurs in 2 phases: slow growth (autotrophic) and more rapid growth (heterotrophic). The switch between phases is when the stopping of pollen-tube growth occurs if due to selfing. Role of the paternal sporophyte during the autotrophic phase. Pollen"s make-up is affected by soil fertility, soil nutrients, mycorrhizal infection levels, temperature, and herbivory on the father plant. The first pollen spores to reach the stigma will have an advantage in that they will have access to all the resources in the mother plant. The pollen from the more nutritious father plant leads to more offspring than from a plant that is stressed. Competition during the autotrophic growth phase is due to more provisioning in pollen from healthier plants, resulting in faster growth. Behaviour of self-pollen tubes at the autotrophic-heterotrophic transition.
