Department of Botany, Gujarat University, Ahmedabad-380009
The shoot apex of rice is built up of biseriate tunica up to spiklet primo rdia only. The concentration of the seven metabolites studied viz. RNA.-SH proteins, ascorbic acid (AA), total proteins, polysaccharides, DNA and histone increased uniformly after cell elongation in the three zones of the growing apex and was maximum in secondary branch primordia cells, but decreased to reach a minimum value in spikelet primordia. The extinction vaule runs parallel to concentration during the entire period of transition from vegetative to reproductive condition. The minimal content per cell has been observed in primary and secondary branch primordia as cells diminish in area by rapid cell division. The content per nuclear volume of DNA and histone runs parallel to nuclear volume while the content per cell of RNA, polysaccharides, -SH proteins and total proteins is parallel to cell area during flowering. Maximum concentration of all metabolites and minimum cell area in primary and secondary branch primordia indicate intense mitotic division and also occurrence of more metabolites. This rise in all the metabolites is due to an increase in the mitotic activity and this activity promises for the production of a floret.
