Origin and Objectives
Objectives in Plant Breeding
|
The origin of plant breeding is as old as human civilization when the man started selecting superior plants and regenerating them for his use. Initially breeding started as an art, as the superior plants were selected based upon the human skill and preference. The scientific selection and development of superior plants was taken up only after the discovery of sex in plants. This process was further refined when Mendel proposed the laws of inheritance. Objectives of breeding in floricultural crops:
- The prime objective of any plant breeding programme is to develop superior plants over the existing ones in relation to their economic use. Like other crops, the breeding objectives of flower crops also differ from crop to crop and depend upon the nature of the plant and the part used for commercial exploitation.
- Flowers have many beneficial components for the consumer that can be created, enhanced, or improved by flower breeding programmes using classical or molecular techniques.
- Although the breeding objectives are specific yet to generalize, major objectives of floriculture breeding are:
1. Improved quality:
- Quality is the most important attribute of the floricultural crops as a single blemish on the petal can is not be tolerable to the consumer.
- The quality parameters again varies from crop to crop. For example in gladiolus the quality parameters would include novel colour, longer spike length, more number of florets /spike, orientation of florets on the spike etc while in case of rose, the breeding objectives will include flower colour, stem length and strength, bud length, bud shape, freeness from blemishes etc. Therefore improvement in quality although differs from crop to crop but is the major objective of a breeding programme.
2. Induction of Variation:
- The major aim of any improvement programme is to induce variation.
- Variation in colour is the most important breeding objective in different floricultural crops as the trends for colour preferences continuously change in the market.
- Variation in flower shape, size and form and foliage charcters etc. are other important considerations in flower crop improvement programme.
3. High flower yield:
- The ultimate aim of plant breeder is to improve the yield of economic produce. In floricultural crops, increasing yield signifies increased number of flowers per plant per unit area. A newly evolved variety with suitable quality characteristics could only be commercialized if it is giving optimum flower yield and could give economic returns to the growers.
4. Biotic Resistance:
- Considerable yield losses are caused by disease and insect pest infestation to various floricultural crops. Therefore, the newly developed commercial varieties could only be accepted if it would be able to resist the biotic influences e.g. reaction to insect pest and disease attacks etc.
- Resistant varieties could be developed which have genetic resistance to insect pest and disease infestation. For example breeding objectives may include development of resistant varieties in carnation against Helicoverpa armigera and red spider mite, in rose, against aphids and red spider mite, in gerbera, against white fly etc.
5. Resistance against abiotic stresses:
- In flower crops and ornamentals plants cultivars are required to be developed against abiotic stresses like temperature (high and low), light (high and poor intensity), varied photoperiod, drought, salinity, alkanity and acidity conditions of soil.
|
Last modified: Monday, 6 August 2012, 10:12 AM