National Research Centre for Sorghum, AICSIP, IARI-Regional Station, Rajendranagar, Hyderabad-500 030, AP, India
*This contribution is the XXI part of a series on “Genetic analysis of some Exotic × Indian Crosses in Sorghum”.
The base populations for the study were provided by 10 high yielding F2 populations with marked specific effects. F2 test crosses to male sterile enabled identification of superior F2 families and superior plants within particular F2’s leading to identification of only four crosses viz., R16×512, R24 × R 16, 393 × M 35–1 and 771 × 512, as promising.
Further continuation of test crosses studied during F3 resulted in identification of only two crosses viz., R 24 × R 16 and R 16 × 512 as the most potential ones. Their progenies had the highest mean yields and the differences between test crosses were also significant indicating scope for further selection.
Regression of F2 test cross performance on F2 plant yields also led to the same conclusion as F3 test crosses resulting in identification of R 16 × 512 and R 24 X R 16 as most promising for isolation of superior parents.
Therefore, test crosses based on F2 enable identification of promising crosses which could yield superior parents. F2 and F3 test crosses limit the number of progenies to be selected and lead to isolation of lines that could yield potentially superior hybrids upon crossing with male steriles.
