1. Data from F1, F2, and F3 generations indicate that asynapsis seen in PMC in a Marglobe plant of tomato was genetically controlled. 2. The segregation for asynapsis in F2 was not monogenic. Asynapsis in a F3 generation raised from selfing an asynaptic F2 plant was variable and did not affect all the plants. Therefore the asynpsis gene(s) had incomplete penetrance and/or modifiers. 3. The presence of aneuploids, primarily trisomics, in F1 indicates that asynpasis was operative in megasporocyte, as well. 4. The map distance between the microsporic lethal genex and the marker genej of linkage group V was estimated from backcross data to be 7·2. 5. One aneuploid contained as many as 9 or 10 extra chromosomes in PMC. This observation extends the known upper limit of the chromosomes in the aneuploid tomato. 6. A perfect association of orange anther colour with tangerine flesh colour and yellow anther colour with red flesh colour was found in this study.