Let us make an in-depth study of the definition, objectives and historical background of plant breeding.
Definition:
Plant breeding is a science based on principles of genetics and cytogenetic. It aims at improving the genetic makeup of the crop plants.
Improved varieties are developed through plant breeding. Its objectives are to improve yield, quality, disease-resistance, drought and frost-tolerance and important characteristics of the crops.
Plant breeding has been crucial in increasing production of crops to meet the ever increasing demand for food. Some well known achievements are development of semi-dwarf wheat and rice varieties, noblization of Indian canes (sugarcanes), and production of hybrid and composite varieties of maize, jowar and bajra.
As written above, crop improvement means combining desirable characteristics in one plant and then multiplying it. The job of a plant breeder is to select plants with desired characters, cross them and then identify the offspring that combine the attributes of both parents. He then multiplies the progeny to supply to farmers, growers or planters.
The modern age of plant breeding began in the early part of the twentieth century, after Mendel’s work was rediscovered. Today plant breeding is a specialized technology based on genetics. It is now clearly understood that within a given environment, crop improvement has to be achieved through superior heredity.
Objectives of Plant Breeding:
To develop varieties with better characteristics, such as:
1. Higher yield
2. Disease resistance
3. Flood resistance
4. Early to mature
5. Adaptability to wide range of habitats
6. Resistance to alkaline and saline soil conditions
7. Better quality
8. Drought resistance
9. Response to manuring
10. Insect and pest resistance
Historical Background:
1. R. Camerarius produced the first artificial hybrid plant of maize in 1694.
2. Kolreuter (1733-1806) produced successful hybrids through artificial crosses in many plants.
3. The discipline of plant breeding witnessed great advances with the increased knowledge in the field of genetics.
4. Shull (1908, 1909) while investigating effect of inbreeding and cross-breeding in maize gave the concept of heterosis which has resulted in manifold increase in agricultural production.
5. Male Sterility in plants was reported by Kolreuter in 1763 which led to the economic exploitation of heterosis.
6. Alphonse de Condolle in 1882 was the first to give an account of the history and origin of cultivated plants.
7. N.I. Vavilov in 1925 proposed eight centres of origin of crops. These centres provided the regions of immense genetic resources of cultivated plants which existed there.
Institutes Engaged in Plant Breeding at National and International Level:
1. International Rice Research Institute (IRRI), Philippines.
2. International Maize and Wheat Improvement Centre (CIMMYT), Mexico.
3. International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad.
4. International Potato Centre (CIP), Peru.
5. International Board of Plant Genetic resources (now International Plant Genetic Resources Institute; IBPGR, now IPGRI).
6. Central Potato Research Institute (CPRI), Kufri (Shimla).
7. Indian Agricultural Research Institute (IARI), New Delhi.
8. Sugarcane Breeding Institute (SBI), Coimbatore.
9. Jute Agriculture Research Institute (JARI), Barackpore.
10. Indian Grassland and Fodder Research Institute (IGFRI), Jhansi.
11. Forest Research Institute, Dehradun.
12. Central Arid Zone Research Institute (CAZRI), Jodhpur.