Journal of Heredity Advance Access originally published online on December 11, 2006
Journal of Heredity 2007 98(1):79-83; doi:10.1093/jhered/esl049
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brief Communications |
Genetics of Resistance to Cotton Leaf Curl Disease in Gossypium hirsutum L. under Field Conditions
From the Central Institute for Cotton Research, Regional Station, Sirsa, Haryana 125 055, India
Address correspondence to S. L. Ahuja at the address above, or e-mail: slahuja2002{at}yahoo.com.
One hundred and forty two cotton germplasm lines were screened for cotton leaf curl virus symptoms in field evaluations during 2003, 2004, and 2005. Fifty cross combinations involving 30 of these lines classified resistant or susceptible were used for inheritance study of the disease. All the F1 plants of crosses involving resistant x resistant, resistant x susceptible, and susceptible x resistant parents were resistant, indicating dominant expression of the disease resistance and there were no maternal or cytoplasmic effects detected from reciprocal hybridization. In 22 crosses, 4 types of segregation patterns were obtained in the F2 generations. A good fit for 15 (resistant):1 (susceptible), 13 (resistant):3 (susceptible), 9 (resistant):7 (susceptible) ratios indicated digenic control of the trait with duplicate dominant, dominant inhibitory, and duplicate recessive epistasis, respectively. Three-gene control with triplicate dominant epistasis was obtained in one of the crosses. This segregation pattern, however, needs further confirmation due to smaller population size. The absence of complementary gene action was obtained in 1 susceptible x susceptible and 27 resistant x resistant crosses as their F1s were susceptible and resistant, respectively, and F2 generation lacked segregation.