7. Briefly describe various steps involved in plant breeding.
Plant breeding is the process of crossing two genetically different varieties of plants in order to produce a new hybrid variety that combines selective characteristics of both the parent varieties. Plant breeding is done to induce disease resistance, increased food production, resistance to insect/pest etc in plants, adaptability etc. The process of plant breeding gets completed in certain steps. These steps of plant breeding are as follows:
1. Collection of variability- The first step of plant breeding is to collect all the genetic variability present in wild relatives of cultivated varieties of plants. The collection of diverse alleles of a gene in a crop is called germplasm collection. From this collection, breeders can select desired characters.
2. Evaluation of germplasm and selection of parents- The collected germplasm is then evaluated and desirable genes are selected. The plants having desirable genes are selected to be parents and are allowed to hybridise.
3. Cross-hybridisation of parents- The selected parents are allowed to hybridize. to facilitate hybridisation, bagging, tagging and emasculation like techniques are used. During cross-hybridization, unwanted pollination is always avoided.
4. Selection of superior hybrids- The hybrid progenies are evaluated for the desired combination of characteristics through a scientific process. The selected progenies are self-pollinated to maintain homozygosity.
5. Testing, release and commercialisation of new cultivars- The new cultivars are tested and evaluated for factors like yield, resistance to diseases, adaptability etc. These are grown in different countries in different seasons multiple times and their growth is tested. After the successful testing, new varieties are provided to farmers for growing in fields.