Transmission of extra chromosomes in moss verbena (Verbena tenuisecta)

✍ Scribed by O. P. Arora

• Book ID: 104629214
• Publisher: Springer Netherlands
• Year: 1978
• Tongue: English
• Weight: 634 KB
• Volume: 49
• Category: Article
• ISSN: 0016-6707
• DOI: 10.1007/bf00120553

✦ Synopsis

In three different primary trisomics of moss verbena (V. tenMsecta) there was little difference between pollen and ovule transmission (3-4% and 5-5.8%, respectively'). Total absence of tetrasomics in progeny after selfing may be due to reduced viability and limited sample size. No isochromosomes were recorded, but two plants were scored with a small extra chromosome, which perhaps is the (telocentric) nucleolus carrying short arm of the nucleolar chromosome. Such an extra chromsome in single dose had marked positive effects on plant morphology and chiasma formation. Two had adverse effects. The small euchromatic extra chromosome did not pair with any nom~al chromosome nor with each other when two were present. They generally divided at Anaphase I, and lagged behind, giving rise to micropollen. Their transmission rate was equal for egg and pollen but only 5% of the progeny upon selfing carried one or two.