Chromosomes Involved in Translocations Obtained From Haploids of Common Wheat

Introduction The haploid chron~osome complenlent of common wheat, Triticz~m crestivum L., is made up of three genomes, designated A, 73, and D. Each genome consists of seven chron~osonles and corresponds to the haploid conlplen~ent of a related, inore primitive species from which it was presun~ably acquired. T h e A genome comes from einltorn wheat, the D genome coines from Aegilops squmrosn L. (McFadden and Sears, 1914; Kihara, 1944), and the B genome ome fro111 Ae. speltoides Tausch (Sarltar and Stebbins, Chapman, 1958). among genomes A, B, and D have been studied by obhavior of chromosomes in F, hybrids anlong the parental Lilienfeld, 1932, 1934; Sears, 1941; McFadden and Sears, ) and in haploids of einltorn (Kihara and Katayama, 1932; hara and Yainashita, 1938; Smith, 1946), enlnler (Kihara, wheat (Gaines and Aase, 1926; Yamasalti, 1934, 1936; ars, unpublished; Krishnaswamy, 1939; i\/IcGiilnis and Unrau, 1952; Person, 1955; Riley and Chapman, 1957). These studies, IIO, have not given specific infirmation as to which chron~osomes of the three genomes associate with each other at meiosis o r as to whether chromosonle pairing is intraor intergenomic, because the wheat chroinoso~nes are all metacentric or nearly inetacentric and cannot be distinguished from each other