Hypogeal germination of broad bean and root growth

October 26, 2009

Here is a time lapse of a Broad bean showing hypogeal germination and root growth.

‘Hypogeal’ means ‘underground’.
This is when the cotyledons of the germinating seed / bean remain below ground.
salts in the soil.

Roots and root hairs
The main functions of root are:
Absorption of water and nutrients,
Fixation of the plant to the soil,
Root bears unicellular root hairs.

Conduction of water and nutrients to aerial parts of plants

Root cap.

It is a cap-like structure at the tip of root. It cover and protects the growing point from injury as it pushes through the soil.

Filmed by Neil Bromhall www.rightplants4me.co.uk

More of my time-lapse sequences can be found on Youtube

I have made an on-line interactive plant finder, identifier and pruning guide web site.  www.rightplants4me.co.uk which I hope you find interesting.

It has over 3,600 garden plants, 10,000 photographs plus time lapse sequences and each plant has in-depth plant care and illustrated pruning advice.

The plant database is continuing to grow.  If you have good quality photographs of garden plants that are not not already on the database I’d like to hear from you with an interest of adding it to the collection.

Contact me on neil.bromhall@gmail.com

Runner bean germinating underground. Time-lapse epigeal germination

August 25, 2009

Here is a time-lapse of a runner bean germinating underground. This is an example of Epigeal germination where the cotyledons expand, throw off the seed shell and become photosynthetic above the ground.

Beans like other seeds need temperature and moisture to stimulate germination.

Stage 1:
Radicle expands and pushes against the testa at the micropyle
Testa spilts open and radicle emerges
Lateral roots develop
Root hairs form behind tip of radicle which helps absorb water and mineral salts in the soil

Stage 2
Stem below cotyledons elongates
Pulling cotyledon through soil and above the ground
Sometimes the is testa remains underground or discarded above ground
Cotyledons are closed together to protect the delicate pumule within

Stage 3
Cotyledons open up above ground
Cotyledons turn green
First foliage leaves start to develop
Foliage expands and turns green carrying out photosynthesis
Runner bean seedling is now a self-supporting plant

This and other of my time-lapses can be found on You tube http://www.youtube.com/user/neilbromhall

Time-lapse copyright Neil Bromhall. filmed for my plant identification website.  www.rightplants4me.co.uk