Answer:
30
Step-by-step explanation:
According to the given information, the diploid chromosome number of tomato is 12. And the diploid chromosome number of potato is 48. Gametes are haploid and contain only one complete set of chromosomes. Therefore, the haploid gametes of tomato would have 6 chromosomes while that of the potato plant would have 24 chromosomes. The fusion of these gametes from tomato and potato would obtain the zygote carrying 6 chromosomes from tomato and 24 chromosomes from potato. Therefore, before doubling, the hybrid would have 6 + 24= 30 chromosomes.