Some natural extracts from plants as low-cost alternatives for synthetic PGRs in rose micropropagation

Abstract: Effect of various plant extracts during in vitro culture of rose (Rosa hybrida L. cv. bush rose), with the objective of replacing synthetic Plant Growth regulators (PGRs) to reduce the production cost, was studied. Test extracts included sweet lime juice, orange juice, sweet corn extract, tomato fruit extract and coconut water. Significant increase in shoot multiplication (15.41±1.12 shoots/explant), shoot length (3.66±0.08 cm), fresh weight (7.48±0.71 g) and dry weight (1.68±0.075 g) was observed when coconut water (@10 % v/v) was used in the standard MS medium. Addition of tomato fruit extract in the MS medium did not show any noteworthy effect on growth in rose micropropagules. Total chlorophyll and other biomolecules varied with the change in the type and concentration of plant extract. Highest accumulation of biomolecules was recorded on coconut water (@ 10 % v/v) supplemented MS medium followed by sweet corn extract and orange juice. Although tomato fruit extract (@10 % v/v) enhanced the total chlorophyll biosynthesis but at the same time depressed the accumulation of other biomolecules. Treatment of plant extract was given in two different ways; a) incorporation in the medium prior to autoclaving (PrA) and b) post-autoclaving addition of filter sterilized extract (PoA). No significant changes were noted in growth when mode of application was changed. To know the physiological pandemonium in the cells, peroxidase and IAA-oxidase activity was noted. No abnormal changes in the activity of these enzymes were recorded in the propagules grown on different plant extracts. The total cost of synthetic 6-benzylaminopurine (BA) can be reduced upto 98 % by replacing it with natural plant extract.