Inheritance of Semidwarfness in Several Wheat Crosses1

Abstract

Inheritance of plant height in wheat Triticum aestivum L.) was studied by using single‐plant measurements from parental, F1 and F2 generations of nine crosses between three “normal‐height” (‘Napo 63,’ ‘Crespo 63,’ and ‘Bonza 63’) and three semidwarf (‘Sonora 64,’ ‘Son‐Sk‐A,’ and ‘Wt‐Nar’) pure lines. All crosses showed partial dominance for tallness over semidwarfness, with degrees of dominance varying from 0.12 to 0.90. Correlation of dominance values estimated in F1 and F2 was 0.83**.Segregations in the F2 generation of the nine crosses showed the semidwarf lines Sonora 64, Son‐SK‐A, and Wt‐Nar differed from the normal‐height cultivars in alleles at one, two, and two loci, respectively. Three loci were involved in height inheritance among the 6 cultivars with alleles at the A‐a and C‐c loci each differentiating approximately 26 cm in plant height, and alleles at the B‐b locus differentiating 13 cm in height. Gene effects between loci were cumulative. The suggested genetic constitutions for the cultivars were: normal‐height parents (106 cm) = AABBCC; Sonora 64 (79 cm) = aaBBCC or AABBcc; Son‐Sk‐A (66 cm) = aabbCC or AAbbcc; and Wt‐Nar (53 cm) = aaBBcc.