Shoot pruning affect micropropagation of P. guajava L. and P. friedrichsthalianum (O.Berg) Nied.

Abstract

The present experiment has been designed in order to see the effect of pruning on explants collection and it’s in vitro performance on shoot initiation, shoot multiplication and root initiation. For this purpose, two species of guava namely, Psidium guajava L. and P. friedrichsthalianum (O.Berg) Nied. (Chinese guava) were selected. Healthy shoots were pruned at 50% and 75% level along with the unpruned shoots (control). Nodal segments of new growth were used as explants. Best MS media along with plant growth hormones obtained in our previous work were used for culturing explants. Explants collected from pruned shoots (50% and 75%) gave better shoot regeneration and shoot multiplication over the unpruned (control) shoots in case of P. guajava L cv. L-49. The highest numbers of shoot regeneration (64.2%) were recorded in explants obtained from 50% pruned shoots of P. friedrichsthalianum. Lowest shoot regeneration was recorded in explants collected from unpruned (39.3%) shoots in highest number of days (21.3). The highest number of root formation was obtained in explants obtained from 75% pruned shoots in both guava species over 50% pruned shoots with 66.3% in cv. L-49 and 64.3% in P. friedrichsthalianum. Hence, the explants when collected after pruning gave better results for in vitro shoot initiation, shoot multiplication and root formation over the explants collected from unpruned shoots (control).