Development of high frequency cost-effective micropropagation protocol for Juncus rigidus using liquid culture medium and extraction of cellulose from their in vitro shoots - An important rush

Abstract

Juncus rigidus is important halophyte with high cellulose content, but no studies has been made on micropropagation of the plant and cellulose extraction from in vitro shoots. To optimize an effective system for shoot multiplication, explants were grown in agar medium, liquid static culture, and bioreactor. Best shoot bud induction was obtained in liquid MS medium supplemented with2.27 μM thidiazuron (TDZ) over 0.46–4.65 μM Kinetin (KN) and 2.22–6.66 μM 6-benzyl aminopurine (BAP). Maximum number of shoot bud (36 ± 1.3) were achieved in static liquid MS medium supplemented with 2.22 μM BAP and 0.57 μM indole acetic acid (IAA). Upon subsequent subcultures >80 shoot buds were achieved in static liquid MS medium supplemented with 1.11 μM BAP, 0.57 μM IAA, and 0.46 μMKN within 30 days of culture. Being halophytic plant NaCl did not have any significant effect on shoot proliferation. Elongated shoots cultured in MS medium supplemented with 0.44 μM BAP, and 0.57 μM IAA developed 97% rooting in filter paper boat culture vessel. Sapling production cost in liquid culture medium was 90% less as compared to solid medium. Cellulose was extracted from the in vitro shoots and 17.64% cellulose achieved from liquid medium cultured shoots. For the first time micro-shoots are tested for in vitro cellulose production. • Maximum shoot bud (36 ± 1.2) induction was achieved in static liquid medium. • More than 80 shoot buds generated in static liquid MS medium supplemented with BAP, IAA, and KN. • 33.4 multiplication rate was recorded in static liquid medium. • 17.64 % cellulose extracted form in vitro shoots of J. rigidus. • In vitro plant based cellulose synthesis is important with future industrial application and bioengineering.