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Cytogenetics of Interspecific Hybrids in the Bromopsis Section of Bromus . II. Triploid Hybrids and their Amphiploid Derivatives 1
Author(s) -
Barnett F. L.
Publication year - 1957
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1957.00021962004900020007x
Subject(s) - hybrid , bivalent (engine) , biology , ploidy , cytogenetics , botany , interspecific hybridization , bromus , interspecific hybrids , chromosome , poaceae , genetics , chemistry , organic chemistry , metal , gene
Synopsis Hybrids between diploid and tetraploid Bromopsis species of Bromus were generally more vigorous than their parents. In most morphological aspects, however, they were intermediate. At MI they exhibited mean frequencies of 6.66 to 9.63 univalents and 4.78 to 5.48 bivalents per cell. Trivalents were moderately common at MI, and high frequencies of irregularity occurred in AI and quartet stages. All triploid hybrids were highly sterile. Artificial amphiploids obtained through chromosome doubling from the triploid hybrids showed bivalent frequencies of 18.93 to 20.10 per MI cell. Univalents, trivalents, and quadrivalents were moderately common in these forms. The amphiploids varied considerably in fertility.