Pollen tube selfing such as stigma and anther mature at different times or are different lengths, which significantly contributes to increasing genetic diversity of the next generation. There is great variation in the rate of growth of pollen tubes and many studies have focused on signaling. The gene expression in the pollen grain has been identified as that of the gametophyte and not of the parental sporophyte, as it expresses its own unique mRNA and own enzymes. In the peach plant, the style environment in which the pollen tube grows through, provides nutrition for the tube's growth to the egg. Pollen tubes
Diaspore (botany) Diaspore (botany) In botany, a diaspore is a plant dispersal unit consisting of a seed or spore plus any additional tissues that assist dispersal. In some seed plants, the diaspore is a seed and fruit together, or a seed and elaiosome. In a few seed plants, the diaspore is most or all of the plant, and is known as a tumbleweed. Diaspores are common in weedy and ruderal species. Collectively, diaspores, seeds, and spores that have been modified for migration are known as "disseminules". A diaspore of seed plus elaiosome is a common adaptation to seed dispersal by ants (myrmecochory).