Temperature and chiasma formation inRhoeo spathaceavar.variegata

✍ Scribed by Y. J. Lin

• Book ID: 104629715
• Publisher: Springer Netherlands
• Year: 1982
• Tongue: English
• Weight: 807 KB
• Volume: 60
• Category: Article
• ISSN: 0016-6707
• DOI: 10.1007/bf00121453

✦ Synopsis

A clone of Rhoeo spathacea var. variegata was exposed to a constant temperature of 37 ° C to examine the effects of high temperature on the chiasma frequency. Rhoeo was chosen for this study for its unusual meiotic chromosome configurations (rings and chains) at diakinesis and the first metaphase which permitted the calculation of terminal-chiasma frequency, and for its genetic homogeneity among plants in a clone. Plants treated for 12 h and 24 h at 37 ° C had similar mean terminal-chiasma frequencies to that of controls (10.93 + 0.1 i, 10.95 ___ 0.09 and 10.64 + 0.07 respectively), while those treated for 36 h, 48 h or 60 h had lower mean terminal-chiasma frequencies than that of controls (8.06 _--_ 0.18, 4.25 _ 0.15, 0.76 _ 0.07 and 10.64 + 0.07 respectively). Analysis of variance was performed to find out whether the mean terminal-chiasma frequencies resulted from different treatments were significantly different from one another. The results of the analysis indicated that prolonged exposures to high temperature significantly reduced the chiasma frequencies.