Cytological identification of some trisomics of Russian wildrye (Psathyrostachys juncea)

Abstract

Russian wildrye, Psathyrostachys juncea (Fisch.) Nevski (2n = 2x = 14; NsNs), is an important forage grass and a potential source of germplasm for cereal crop improvement. Because of genetic heterogeneity as a result of its self-incompatibility, it is difficult to identify trisomics of this diploid species based on morphological characters alone. Putative trisomies (2n = 2x + 1 = 15), derived from open pollination of a triploid plant by pollen grains of diploid plants, were characterized by Giemsa C-banding. Based on both karyotypic criteria and C-banding patterns, four of the seven possible primary trisomics, a double-deletion trisomic, and two tertiary trisomics were identified.

Post-zygotic gametic selection due to endosperm balance number explains unusual chromosome numbers of 3� � 2� progeny in Solanum

“…They have been used as a source of primary trisomics in several crop species, including the tomato (Ramulu et al 1977), barley (Thomas and Pickering 1988), corn (Premachandran and Sarkar 1992) and wildrye (Wei et al 1995). In Solanum, 3× × 2× crosses have also been successfully used to generate trisomics and other aneuploids with low numbers of extra chromosomes.…”