Asexual Vegetative Reproduction Flashcards
(18 cards)
The most important advantages of asexual reproduction are:
- Maintaining the genetic makeup which gives homogeneous plants.
- The possibility of obtaining large number of plants in a short period.
- Plants reach fruiting stage and adulthood in a shorter time compared to plants resulted from seed planting.
- This method is the only way for the reproduction of certain plants that are not able to produce fertile seeds, or they produce no seeds, such as banana, Abo-Sorrah oranges, and seedless grapes and certain types of non-flowering ornamental plants.
The most important methods of vegetative propagation are:
- Vegetative seeds
- Cuttings
- Layering
- Bulbs
- Budding/Grafting
- Tissue culture
Propagation by vegetative seeds
Certain plants produce seeds containing sexual embryo and non sexual embryo.
When the non sexual embryos grow, the produce plants similar to their mother plants,
such as citrus seeds.
what is propagation by cuttings?
Cuttings are vegetative parts separated from the mother plant, these parts are encouraged to form roots and/or branches.
what are 4 types of propagation by cuttings?
Root cutting
Stem cutting
Budded leaf cutting
Non-budded leaf cutting
What happens in root cutting?
It requires to induce new branches
What happens in stem cutting?
It requires to induce new roots
What happens in budded leaf cutting?
It requires to induce new roots
What happens in non-budded leaf cutting?
It requires to induce new roots and branches
How do roots form on cuttings?
They form through the anatomical changes:
- Conversion of some adult and specialized cells into meristematic cells
- The growth of these cells, and the formation of the primary root
- The initial growth of roots in addition to connecting the new root with cutting
The ability of rooting is dependent on a number of factors:
- Plant growth regulators (hormones)
- Cofactors
- The presence of buds and leaves on cuttings
What are some plant growth regulators?
Auxins (such as Indole Butyric Acid) are considered the most important plant regulators that help in rooting
Usually an IBA solution is prepared with a certain concentration, then cutting bases are dipped in this solution for various time periods (depending on plant type)
How can cofactors help the ability of rooting?
Chemicals found in plants can help in rooting process
The nature of these materials is unknown, for example catechol
How can the presence of buds and leafs on cuttings help the ability of rooting?
The positive effect of leaves and buds in the rooting process comes from the following facts:
- Buds are the place of producing auxins
- Leaves are the place of producing carbohydrates. (Both auxins and carbohydrates help and encourage root formation)
- Buds and leaves have the ability to produce cofactors
Rooting process is affected by a number of plant factors, which are:
- Growth stage
- Time of year at which the cuttings are taken
- Type and position of the part that is used from the stems
How is the rooting process affect by growth stage?
Researchers found that cuttings from plants that did not reach adulthood (fruiting) have the largest capacity in rooting rather than those of adult plants
Plant age can restore youth to plants affected
By severe pruning process therefore it’s possible to get root cuttings from these plants
How can the rooting process be affected by the type and position of stems?
There are 3 types of stem cuttings :
- Terminal or soft cuttings (which have a greater ability for rooting)
- Immediate or semi-hard cuttings (less ability than first one, but more ability than)
- Basal or hard cuttings (the vegetative branches have a greater ability of rooting compared to flowering branches)
What are the environmental factors affecting the rooting process?
A- humidity
B- temperature
C- light/darkness
D- Rooting media : functions and features
