History of Plant Breeding
It is reasonable to assume that plant breeding howsoever primitive, began when man first chose certain plants for cultivation; this began about 10,000 years ago when man is believed to have started agriculture. The process of bringing a wild species under human management is referred to as domestication. There is bound to be some selection during domestication. This is likely to give rise to better types than the wild ones. Thus domestication may be regarded as a method, in fact the most basic method of plant breeding; all other breeding.
This is likely to give rise to better types than the wild ones. Thus domestication may be regarded as a method, in fact the most basic method of plant breeding; all other breeding methods become applicable to a plant species only after in has been successfully domesticated. Domestication continues till today, and is likely to continue for some time in future. This is particularly true in the case of timber trees, medicinal plants, microbes and plants satisfying some special requirements. A remarkable case of domestication in recent years was that of Penicillium for penicillin and subsequently of several other fungi for various antibiotics. Transfer of specific genes, E. g for disease resistances, from wild species ( or even from unrelated organism) to cultivated ones may be regarded as domestication of those genes. i. e of a part of the genome of the concerned species.
During the long period of prehistoric and historic cultivation, natural selection has definitely acted on the domesticated species. It is likely than man also exerted some selection either knowingly or unknowingly. Movement of man from one area to another brought about the movement of his cultivated plant species. The introduction into an area of new plant species or varieties from other parts of the world is an integral part of plant breeding today.
Babylonians and Assyrians pollinated date palm artificially as early as 700 B.C. In the 17 the centuray, several varieties of ‘heading lettuce’ were developed in France, some of these varieties were still in cultivation during 1990s. In 1717, Thomas Fairchild produced the first artificial hybrid, popularly known as ‘Fairchild’ mule by crossing carnation with sweet William. The first plant breeding company was established in France in 1727 by the Vilmornis, the family of which Louis de Vilmornis was the notable member. Joseph Koelreuter, a German, made extensive crosses in tobacco between 1760 and 1766. Knight (1759-1835) was perhaps the first man to used artificial hybridization to develop several new fruit varieties. Le Couteur and Shireff used individual plant selection and progeny test to develop some useful cereals varieties, the work of Patrick Shireff was first published in 1873. Shireff began his experiment in 1819, when many subscribed to Lamarckism. He concluded that only the variation of heritable nature responded to selection, and that this variation arose through ‘natural sports’ and by natural hybridization. Vilmorin (1856) further developed the progeny test and used this method successfully in the improvement of sugar beets ( Beta vulgaris). The individual plant selection method was developed in detail by Nilsson- Ehle and his associates at Svalof, Sweden around 1900. Johansen proposed the pure line theory that provided the genetic basis for individual plant selection.
The modern plant breeding methods have their bases in the genetic and cytogenetic principles. The science of genetic began with rediscovery of Gregor J. Mendel’s paper in 1900, which was originally published in 1866. Mendel’s laws of inheritance provided the foundation for the vast knowledge that has, since then, accumulated in genetics. Numerous workers who determined the various modes of inheritance have contributed to the development and understanding of plant breeding. Realisation that the chromosomes are the carries of genes has led to the development of specialized plant breeding methods for chromosome engineering. A noteworthy development resulted from the studies of G.H shull on inbreeding in maize (Zea mays). He found that inbreeding produced a considerable loss of varieties, which are common in the case of maize, Jowar (Sorghum bicolar), bajara, cotton, rice, and several other crops.
The totipotancy of plant somatic and gametic cells allows regeneration of complete plants from single cells. This, coupled with development of recombinant DNA technology, has enabled the transfer of desirable genes from any organism into plants. Crop varieties developed in this manner are already in cultivation in several countries, primarily U.S.A. and world acreage under them is increasing at a very rapid rate. These exciting developments are expected to become increasingly important with time.