INHERITANCE OF THE TYPE OF SOLID STEM IN GOLDEN BALL (TRITICUM DURUM): I. EARLY GENERATIONS OF A HYBRID WITH RESCUE (T. AESTIVUM)

Abstract

In a population of one thousand F2 plants of the hybrid between Rescue, a solid-stemmed variety of Triticum aestivum L. emend. Thell., and Golden Ball, a solid-stemmed variety of T. durum Desf., the more solid top internode of Golden Ball was associated with a dense spike and with durum-like morphology. Rigid selection failed to produce an F1 line with a top internode as solid as that of Golden Ball combined with the morphological characters of T. aestivum. This was probably because the D genome present in Rescue but absent from Golden Ball tends to inhibit pith production in the top internode. Some increase in solidness was attained in two F1 lines, and some lines had pith patterns different from that of either parent. This was probably due to segregation of genes in the A and B genomes.Segregates with stems less solid than those of either parent appeared in the F2 generation and some fairly hollow, dwarf F1 lines were established. Hollowness was probably caused by a combination of aneuploidy for chromosomes of the D genome and segregation of genes in the A and B genomes. These less solid lines varied more in pith content from plant to plant than did Rescue and the more solid F4 lines; Golden Ball varied least.