Soybean and Bees

Once confirmed, agricultural practices that might affect pollination should be adapted to
result in higher soybean yields, while protecting the natural service of pollination.
Fertilization: sequence of events
Once a viable pollen grain lands on a receptive stigma, a series of sequential and concatenated
events are deflagrated, starting with the germination of the pollen grain, inducing the
formation of the pollen tube, which emerges and grows. The growing pollen grain moves
inside the pollen tube, towards the ovary.
The formation of the pollen tube make it necessary to digest the female tissue, by way of hydrolytic
enzymes, as the tube moves down towards the stigma and style. The digested tissue
becomes a source of nutrients for the pollen tube.
Should be noticed that two types of nucleus are present in the pollen, and both the vegetative
tube and generative nuclei of the pollen grain pass into the pollen tube, which is stimulated
by a sugary substance secreted by the stigma.
The pollen tube does not reach the ovary in a straight line, instead grows near the style and
curls to the bottom of the ovary and then near the receptacle. At the end, the pollen tube
enters the ovary through a tiny pore called micropyle. Finally, the micropyle bursts into the
embryo sac, when the male nucleus fuses with the nucleus of the egg and forms a diploid zygote,
known as true fertilization or syngamy.
In the sequence, the other male nucleus enters the embryo sac and fuses with secondary nucleus,
generating a triploid nucleus called the primary endosperm nucleus. This process is
called triple fission.
After fertilization, the resulting embryo undergoes a sequence of mitotic divisions, forming
the seed, as well as the endosperm nucleus also divides itself forming the endosperm cells,
providing nutrients for the developing embryo. At the end, a fruit is formed and, in case of
fruits with multiple seeds, multiple pollen grains are necessary to fertilize each ovule.
Sometimes a double fertilization is present, a variant complex mechanism of fertilization
in angiosperms, represented by the conjunction of two male gametes with a single
female gametophyte. While one sperm nucleus fertilizes the egg cell, the second joins
36 SoybeAn and bees