|RAZA, HASNAIN - University Of Agriculture - Pakistan|
|RANA, IQRAR - University Of Agriculture - Pakistan|
|SHAKEEL, AMIR - University Of Agriculture - Pakistan|
|Frelichowski, James - Jim|
|AZHAR, MUHAMMAD - University Of Agriculture - Pakistan|
Submitted to: Pakistan Journal of Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2017
Publication Date: 7/1/2017
Citation: Raza, H., Rana, I.A., Shakeel, A., Hinze, L.L., Frelichowski, J.E., Azhar, M.T. 2017. Genetic diversity in Gossypium hirsutum L. for cotton leaf curl disease in association with agronomic and fiber traits. Pakistan Journal of Phytopathology. 29(1):47-56.
Interpretive Summary: Cotton leaf curl disease (CLCuD) is an emerging threat to cotton growing regions throughout the world. Pakistan has experienced two epidemics of CLCuD in the last 25 years that have caused extensive losses for farmers. The recent epidemic led to the collapse of genetic resistance in Pakistani cultivars; therefore, new sources of host plant resistance are needed. In the present study, 17 genotypes were screened for resistance to CLCuD under field conditions in Pakistan. Two genotypes were identified as moderately tolerant to the disease, but no genotypes were completely resistant. The results of this screening are immediately relevant to the cotton industry in Pakistan as researchers endeavor to develop cultivars with genetic resistance/tolerance to CLCuD. Unfortunately, this disease has recently appeared in China, prompting the concern that it may spread to other cotton-growing regions in the world which have suitable environments for CLCuD development. Pakistani cultivars tolerant to CLCuD would be valuable sources of germplasm for researchers in other cotton growing regions if the disease continues to spread.
Technical Abstract: Information of genetic diversity in germplasm for cotton leaf curl disease (CLCuD) resistance/susceptibility and economic characters is essential before starting a breeding program to development germplasm with disease resistance. In this study, 17 conventional cotton (Gossypium hirsutum L.) genotypes were screened under field conditions for resistance to CLCuD in addition to yield and fiber related traits. These genotypes were separated into several groups by metroglyph analysis. Disease scores revealed that CIM-615 and CIM-616 were tolerant to moderately tolerant, but none of the varieties was resistant to CLCuD. The S-12 genotype was highly susceptible to the disease. The separation of these genotypes into groups indicated the presence of genetic diversity, and superior parents from different groups could be utilized for pyramiding genes governing yield and fiber related traits in addition to disease tolerance in a single cotton genotype.