Timing Unbalance at Meiosis in the Pollen-sterile Lathyrus odoratus

Abstract

Pollen sterility in Lathgyrus odoratus is known to behave as a simple Mendelian recessive.
As compared with the normal meiosis, chromosome development in the sterile is delayed in relation to the growth of the anthers. This delay begins to take effect before pachytene.
That the timing is abnormal is shown by the fact that the sterile anthers containing pollen-mother-cells at the first metaphase are equal in size to normals containing binucleate pollen and by the fact that the spindle at metaphase is elongated as it is at a normal anaphase. The development of the chromosomes is delayed relative to that of the spindle. Associated with this delay is a difference of substrate conditions in the nucleus as shown by (i) its reaction to the fixative in prophase (ii) greater spiralisation (iii) greater terminalisation, indicating that these are all a function of rate of development.
After the first division, the timing disharmony apparently becomes so acute that further development ceases.