Cytological Studies of Hybrids Involving <i>Triticum durum</i> and <i>Secale cereale</i>

Abstract

The allopolyploid of T. durum var. Carleton and Secale celeale (spring rye) was crossed to the T. durum varieties Iumillo, Stewart, F.P.I. 94587 and Golden.A single hybrid each was obtained from the crosses involving Stewart and F.P.I. 94587. Fourteen bivalents and seven univalents were the most frequently observed configuration in the pollen mother cells. A quadrivalent in the form of a ring of four chromosomes was observed in some of the pollen mother cells. Genome constitution of these hybrids is believed to be AABBS.Five hybrids between Triticale and lumillo were obtained. Four hybrids had 32 and one hybrid had 31 somatic chromosomes. All hybrids lacked the hairy neck character. A quadrivalent in the form of a ring of four chromosomes was observed in the pollen mother cells of the hybrids. The genome constitution of the 32 and 31 chromosome hybrids is postulated to be AABBS-3 and AABBS-4 respectively.Two BC1 plants with 28 wheat chromosomes plus 1 rye chromosome were obtained by backcrossing hybrids 35-1 to Khapli. The presence of the rye chromosome resulted in plants with thin culms and narrow leaves.An individual with 28 wheat chromosomes plus chromosome I of rye was obtained by backcrossing hybrid 37-1 to Khapli. The presence of the rye chromosome adversely affected plant height and increased the frequency of asynapsis of one or two pairs of wheat chromosomes.Quadrivalents observed in the hybrids involving durum varieties are believed to be due to a reciprocal translocation present in the Triticale parent.