Triallel analysis for number of bolls per plant in upland tetrapolid cotton (Gossypium hirsutum L.)

Abstract

Triallel analysis provides information on all types of gene actions viz., additive, dominance and epistatic components besides giving information on order of parents in three-way cross combinations for obtaining superior trasgressive segregants [1 J. A. three-way cross symbolised by (AB)C has been defined as a cross between line C and the unrelated F1 hybrid (AB), lines A and B being called grand parental lines and line C as full or immediet parental line [2J. But studies on three way cross hybrids are very scarce in cotton [3]. In the present study an attempt was made to obtain information on gene actions controlling the most important trait of number of bolls per plant in tetraploid cotton (Gossypium hirsutum L.) by using triallel analysis. 60 three-way cross hybrids were developed by crossing six diverse varieties of upland cotton viz., 1. Narasimha 2. Renuka 3. DHY 286 4. MCU 5 5. LRA 5166 and 6. ADB 39 in a triallel mating design [2J and were evaluated under rainfed conditions during kharif, 1999 in a randomised block design with three replications at Agricultural Research Station. Mudhol of Acharya N.G. Ranga Agricultural University, A.P. Fifteen competitive plants were randomly selected from each plot for recording boll number. The mean data was subjected to triallel analysis [4].