Hau Bernard.
1997. Cotton breeding for south East Asia.
In : Abstracts. Regional conference and workshop on "cotton research and development in South-East Asia" and the third national cotton conference. Kasetsart University; CIRAD-CA; Ministry of Foreign Affairs
Résumé : Southeast Asia has a very long history of cropping cotton diploid species-mainly G. arboreum-or ancient tetraploid types. Upland cotton varieties have been introduced very recently, i.e. over the last fifty years. Current varieties are derived from relatively old cultivars and a study of their genealogy shows only restricted genetic variability. Certain countries have chosen to promote the cropping of F I hybrids but this option may be discussed. Old varieties (G. arboreum, G. hirsutum Cambodian type G. harhadense vitifolium race) continue to be cropped in a traditional manner and, for the selector, may constitute a reservoir of genes providing resistance to insects and disease. Varietal improvement by selectors has great potential. Because cotton is grown in various geographic zones, several varietal types may be selected corresponding to different climates (plants with low-level vegetative development, short inter-node, restricted canopy for wet areas; more vegetative pyramidal type for the dry areas). Resistance to bacterial disease and to jassids is an essential aspect and is easy to obtain (B2, B3, B9, BIO genes for resistance to bacterial blight, hairinegs developed against jassids). The genetic basis that provides tolerance to leaf roll (blue disease) is known and may be used to improve resistance to this disease. With regards to technological characteristics of the fiber, finenesss, tenacity and Ginning Out Turn should to be improved. A lot of foreign improved recent varieties may be used as genes source for this purpose. New research methods (plant mapping, gene transformation and marker-assisted selection) are now available to assist in selection work. Gene transformation in particular opens up the possibility of developing varieties resistant to Helicoverpa armigera and Pectinophora gossypiella boll worms thanks to the incorporation of Bt (Bacillus thuringiensis) genes. However, researchers should now determine the conditions under which sustained resistance may be conserved before recommending extension of this new type of cotton plant.
Auteurs et affiliations
- Hau Bernard, CIRAD-CA-CAPA (FRA)
Source : Cirad - Agritrop (https://agritrop.cirad.fr/392561/)
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