ARS | Publication request: CYTOLOGICAL AND MOLECULAR INVESTIGATIONS ON THE CAUSES OF SEEDSET ON SYNTHETIC HAPLOIDS OF DURUM WHEAT.

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 1999
Publication Date: October 15, 1999
Citation: Jauhar, P.P., Altuntepe, M., Peterson, T.S., Almouslem, A.B. 1999. Cytological and molecular investigations on the causes of seedset on synthetic haploids of durum wheat. Agronomy Abstracts p. 83.

Technical Abstract: The usefulness of haploids as cytogenetic and breeding tools is well known. We produced haploids (2n = 2x 14; AB genomes) on a large scale in several commercial cultivars of durum wheat (Crop Science 38: 1080-1087, 1998) and studied both inter- and intra-genomic chromosome pairing relationships (J. Hered. 90:1999). Despite the presence of various meiotic abnormalities, particularly at anaphase I and telophase I, haploids of several cultivars produced viable seed without colchicine treatment. Thus, Durox, Langdon, Medora, and Monroe produced viable seed, with Durox having a mean of 7.6 seeds per haploid. These seeds resulted from viable embryos formed by fusion of unreduced male and female gametes with 14 chromosomes each. The unreduced gametes were generally formed by two mechanisms: a) Anaphasic movement of all chromosomes to one pole, or b) First division restitution. Most seeds gave rise to normal disomic (2n = 4x = 28; AABB) plants. Fluorescent GISH (genomic in situ hybridization) analysis of somatic and meiotic chromosomes showed the precise duplication of both the A- and B-genome chromosomes.