Effect of subculture number on pineapple in vitro multiplication and somaclonal variation

This research was conducted to study the effect of subculture number on multiplication rate, 
and occurrence of somaclonal variation in pineapple plants (Ananas comosus). Repeating 
subcultures decreased the multiplication rate in subcultures 1 and 2 (20 times and 9 times, 
respectively) as it was 6 times in all next subcultures. Repeating subcultures over 5 subcultures 
decreased the normal plant percentage, it was 95%, 85%, 25% and 8% for subcultures 6, 7, 8 and 
9, respectively, and also decreased surviving percentage to reach 85%, 62%, 43% and 21% for 
subcultures  6, 7, 8 and 9, respectively. SDS protein analysis dendrogram showed two subgroups, 
where first subgroup included subcultures 2, 3, 4 and 5 subcultures and the second subgroup 
included subcultures 6, 7, 8 and 9. This subgroup contained a category of subcultures 8 and 9 
which were closely related together, whereas subculture 7 was further than this irrelativeness.  
Subculture 6 resulted in the highest number of shoots with best uniformity (95%) and surviving rate 
(85%).