Morphogenetic induction and organogenic differentiation from foliar explants of Strobilanthes flaccidifolious Nees: a natural dye yielding plant

Strobilanthes flaccidifolious is a shrub and its leaf is the source of blue color natural dye used for dying fibers and play important role in handloom industry. During the present investigation, an efficient in vitro regeneration protocol is developed from foliar segments of in vitro sourced plant materials. The first sign of response from the cultured foliar segments was recorded as swelling and curling of leaf segments within 7 days of culture followed by callusing and shoot buds formation within 3-4 wk. Amongst the different plant growth regulators tested, optimum response was recorded on MS medium enriched with 3% sucrose, 6 µM BA while other growth regulators and their concentrations did not support satisfactory morphogenetic response. Under optimum condition ~75% explants responded positively where as many as 9 shoots buds developed per leaf segment. The shoot buds converted into plantlets/micro shoots on MS medium when supplemented with 3 µM Kn where as many as 7.3 shoot buds developed per subculture of 3-4 wk duration. The micro shoots induced roots on MS medium enriched with 3 µM NAA where as many as 14 roots developed per plant within 4 wk times. The well rooted plantlets were transferred in potting mix and maintained in the poly-shed (50% light) for two months before transferring to the field.    ÂÂ

An efficient <i style="mso-bidi-font-style: normal">in vitro </i>regeneration protocol for a natural dye yielding plant, <i style="mso-bidi-font-style:normal">Strobilanthes flaccidifolious</i> Nees., from nodal explants

810-816&amp;nbsp; Adventitious shoot buds formation from axillary buds of nodal segments of S. flaccidifolious was achieved on MS medium containing sucrose (3%, w/v), and α-naphthalene acetic acid (NAA; 3 µM) and benzyl adenine (3 µM) in combination. The nodal segments were primed on ‘Growtak Sieve’ for 48 h on MS medium containing sucrose (2%), polyvinyl pyrollidone (200 mgL-1) as antioxidant. About 80% of primed nodal segments responded positively and formed ~12 adventitious shoot buds per explants from explants collected during October-November months of every year. The shoot buds converted into plantlets on MS medium containing sucrose (3%) and kinetin (3 µM) where ~7 micro shoots developed per subculture after 8 weeks of culture. The regenerated micro shoots induced average 14 roots/ plant on medium containing NAA (3 µM). The regenerates were hardened for 6-7 weeks on medium with ½MS salt solution and sucrose (2%) under normal laboratory condition before transferring to potting mix. About 70% transplants survived after two months of transfer

<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Germination of immature embryos and multiplication of <i style="mso-bidi-font-style:normal">Malaxis acuminata</i> D. Don, an endangered therapeutically important orchid, by asymbiotic culture <i style="mso-bidi-font-style:normal">in vitro</i></span>

464-469The effect of culture conditions and developmental stages of embryos on asymbiotic germination of immature seeds of Malaxis acuminata D. Don, an endangered therapeutically important terrestrial orchid, was investigated. Immature seeds of ~7-8 wk after pollination (WAP) were germinated on MS medium containing sucrose (3%, w/v) and α-naphthalene acetic acid (NAA; 4 µ<i style="mso-bidi-font-style: normal">M) under diffused light condition (20 µmol m-2 s-1), where about 85% seeds germinated after 135 d of culture. The full light condition (40 µmol m-2 s-1) did not support healthy germination. The germinated seeds converted into protocorm-like bodies (PLBs) and further differentiated into young plantlets on the same germination medium. The rooted plantlets with well expanded leaves and distinct pseudobulb were achieved on MS medium containing sucrose (3%), activated charcoal (AC; 0.3%, w/v), and NAA and benzyl adenine (BA) (3 µM each in combination), where as many as 18 shoot buds/PLBs developed per subculture. Amongst the three different organic carbon sources and two basal media tested, only sucrose supported the optimum plant growth and culture proliferation when maintained on MS medium. Incorporation of AC (0.3%) in the regeneration medim accelerated the culture proliferation and distinct pseudobulb formation. The hardened plants transferred to potting mix and maintained in the polyhouse (75% shade) before transferring to the wild, where ~75% transplants survived after 2 months of transfer