A longer life for pearl millet hybrids
MetadataShow full item record
CTA. 1991. A longer life for pearl millet hybrids. Spore 36. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/45642
Hybrid varieties of crops usually have a short but spectacular life.
Hybrid varieties of crops usually have a short but spectacular life. When they succumb to disease, replacing them requires a lengthy breeding, process. But plant-breeders at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), in India, have developed a strategy that will keep pearl millet hybrids going indefinitely, even when they become susceptible to disease. Normally hybrids are developed by crossing two uniform inbred parents. The new strategy replaces one of the parents with an open pollinated variety. This new cross produces what are called 'Top-cross' hybrids and they are now being tested by the All-India Coordinated Pearl Millet Improvement Project. So far they have yielded as well as the best uniform hybrid, and yet they have a greater resistance to disease because, within the cross, there is a better spread of genetic material. If, however, the 'Top-cross' hybrid does succumb to disease it is very much easier to get resistance back into it through the open pollinated parent. This can be done in one or two generations. It is possible, therefore, to keep a hybrid going indefinitely by performing maintenance breeding on the open-pollinated parent. The ICRISAT plant breeders are taking the strategy a stage further. They are replacing the uniform inbred parent with a hybrid by crossing the hybrid with an open-pollinated variety. This means that the resulting hybrid has even more genetic variability within it. This method helps, too, in reducing the cost of seed production. ICRISAT is also changing another aspect of its pearl millet breeding programme. Instead of developing varieties that can be grown in all locations and situations, they are now breeding varieties to suit very specific areas. For instance, to breed varieties specially for the deserts of Rajasthan in India the plant breeders have taken local varieties of pearl millet and improved them so that they mature in a shorter time. In this way they can escape the onset of droughts that usually begin at the end of the growing season. ICRISAT, Patancheru PO, Andhra Pradesh 502324, INDIA