There are numerous characteristics that one can breed for in an ornamental
plant: color, shape, size, substance, hardiness. All of these can be applied
to leaf, plant or flower. Sometimes a plant is too vigourous or spreads
too easily and must be tamed for the garden. This page is devoted to the
techniques to do this.
This is basic. Nearly every plantsperson sooner or later sees a plant with desirable characteristics that they want to conserve or has the urge to create a "new" or "improved" plant.
Keeping out the bees
Catching the seed
Tropicos: gametophytic count: 40; IPCN reference: 90-91 Sidhu, M. K., R. C. Gupta & N. Goyal, 1990.
Title: SOCGI plant chromosome number reports---IX
Publication: Journal of Cytology and Genetics
Collation: 25: 145
Tropicos: gametophytic count:
There are many reasons to double the chromosomes. In general, a tetraploid is sturdier than the mother plant in all its parts: stems, leaves and flowers. Sometimes it is done to improve inter-species fertility for hybridization. Other times it is done to reduce cross fertility with the normal plant in order to "tame" it.
Techniques and Chemicals
Triploid reduction is usually done to "tame" a plant. Some plants' seed is just too vigorous in the garden. These plants are frequently called "weedy" and are considered a pest, even though they may be very desirable in other ways.
Leaf color changes can be obtained through natural mutation and selection or the odds can be improved with certain techniques: irradiation (both x-ray and gamma) and mutagenic chemicals have been used.
Most often the variegated plants are chimeras, with some of the cells
having lost their chloroplasts. Chimeras are useless for breeding...
the trait is not inheritable. Sometimes you can get this with UV light
on the meristem.
It is important to give improved plants a name and to register that name. This process is standardized by by the International Society for Horticultural Science through its Commission for Nomenclature and Registration, who appoint International Registration Authorities.