Question

when does pollen tube develop in a flower?​

Answer 1

Answer:

after pollen grains reaches the stigma

Answer 2

hlo mate

here is your answer

Pollen tube growth in roses displays similarities to that in other Rosaceae and, by extension, other genera. When a rose pollen grain lands on a stigma, it adsorbs water and a rehydration process occurs. Various signals, especially those of pollen–stigma interaction, induce an intense metabolic activity in the pollen grain which start to grow and forms a pollen tube. The pollen tube invades the pistil, growing between the walls of the stigmatic cells, then traveling through an extracellular matrix within the transmitting tissue of the style. The pollen tube finally arrives at the ovary, where it is attracted to an ovule that contains an egg cell. This phase of pollen development, called the progamic phase, corresponds to the phase occurring between pollination and fertilization.

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