Biotization with <i style="">Piriformospora indica</i> and <i style="">Pseudomonas fluorescens</i> improves survival rate, nutrient acquisition, field performance and saponin content of micropropagated <i style="">Chlorophytum</i><i style=""> </i>sp.

Abstract

Micropropagated plantlets usually exhibit high mortality rate upon their transfer to soil as a result of transplantation shock caused by abiotic and biotic stresses and weak root system in the absence of beneficial microflora. Biotization of micropropagated <i style="">Chlorophytum </i>sp<i style="">. </i>with the fungus,<i style=""> Piriformospora indica</i> and the bacterium, <i style="">Pseudomonas fluorescens,</i> improved plantlet survival rate, growth parameters, field performance, P content and the micronutrient acquisition. Biotized plants showed root colonization of <i>P. indica</i> in cortical cells of roots and exhibited the presence of pear shaped spores and hyphae as well as rhizospheric colonization of <i>P. fluorescens.</i> Microbial biotization enhanced plant survival up to 91.2% by dual inoculation over uninoculated control (78.8%), on transfer from laboratory to green house. Biotized field grown plants exhibited increase in root length, number of lateral roots, shoot dry weight, leaf length, number and dry weight of fleshy roots in dual inoculation at P_F which were significantly better over single as well as uninoculated control. Plants inoculated with<i> P. indica</i> exhibited maximum chlorophyll content (8.76 mg g^-<i>1</i>) while maximum P content (0.26%) was observed in dual inoculated plants, which was at par with <i style="">P. indica </i>alone even at low phosphorus. Higher saponin content was observed with both, <i>P. indica</i> alone as well as dual inoculations. Maximum acquisition of Cu (40 μg<i> </i>g^-1₎ was observed in<i style=""> P. indica</i> inoculated plants at P_F level, which was at par with dual inoculation. In dual inoculated plants, the highest contents of Fe (4405 μg<i> </i>g^-1), Zn (135 μg<i> </i>g^-1) and Mn (160 μg<i> </i>g^-1) were observed. Thus, microbial biotization improved survival and nutrient uptake by micropropagated <i>Chlorophytum </i>plants.