Monosomics in Egyptian Henbane, Hyoscyamus muticus L.

I. Meiotic behaviour and fertility

Abstract

The meiotic behaviour and fertility of the six monosomic H. muticus plants with 2n-1=27 chromosomes isolated from populations raised from seeds treated with higher doses (70 kR, 80 kR, 90 kR and 100 kR) of gamma rays were studied. One of the plants mostly showed thirteen bivalents and one univalent at diakinesis/metaphase I as a result of loss of one normal chromosome was identified as primary monosomic. The remaining five plants were tertiary monosomics lacking interchanged chromosome and thus mainly exhibited twelve bivalents and a chain trivalent at diakinesis/metaphase I. All the monosomics showed a wide variations in chromosome distribution at anaphase I and anaphase II. The pollen fertility of monosomics was highly variable, stainable pollen ranged from 16.66% to 48.03%. Hand pollination with normal diploid pollen resulted in low seed set in three tertiary monosomics only.