Clonal Selection
- Clonal selection is used in asexually propagated species.
- In this method progeny of a single best clone is released as a variety.
- Such variety has heterozygous but homogeneous population.
Sources of clonal selection
- Local varieties
- Introduced material
- Hybrids and
- Segregating populations
Steps involved in Clonal Selection
a) First year : From a mixed variable population, few hundred to few thousand desirable plants are selected. Rigid selection can be done for simply inherited characters with high heritability. Plants with obvious weakness are eliminated.
b) Second year : Clones from the selected plants are grown separately, generally without replication. This is because of the limited supply of propagating material for each clone, and because of the large number of the clones involved. Fifty to one hundred clones are selected on the basis of clonal characteristics.
c) Third year : Replicated preliminary yield trial is conducted. A suitable check is included for comparison few superior performing clones with desirable characteristics are selected for multilocation trials.
At this stage, selection for quality in done. If necessary, separate disease nurseries may be planted to evaluate disease resistance of the clones.
d) Fourth to eighth years : Replicated yield trials are conducted at several locations along with suitable check. The yielding ability, quality and disease resistance etc. of the clones are rigidly evaluated. The best clones that are superior to the check in one or more characteristics are identified for release as varieties.
e) Ninth year : The superior clones are multiplied and released as varieties.