In vitro propagation and analysis of mixotrophic potential to improve survival rate of Dolichandra unguis-cati under ex vitro conditions

Abstract

An efficient and reproducible protocol for in vitro propagation of Dolichandra unguis-cati has been established for the first time from nodal segments. In order to enhance survival rate under ex vitro conditions, photosynthetic potential of in vitro grown plantlets was also studied through JIP test based analysis of polyphasic OJIP chlorophyll a fluorescence OJIP transients, density of active reaction centers, light harvesting efficiency, electron transfer rate, dissipation energy, maximum quantum yield of primary PSII photochemistry and photosynthetic performance index. The best morphogenetic in term of explants response (92.2 %), shoot number (3.43 AE 0.07) and shoot length (4.7 AE 0.31 cm) was obtained on Murashige and Skoog medium supplemented with 0.5 mg l À1 BAP and 1.0 mg l À1 TDZ. The shoots exhibited high frequency rhizogenesis on half strength medium augmented with 2.0 mg l À1 IAA. In vitro plantlets developed highest rate of photosynthesis on day 18 after the initiation of rhizogenesis. High survival rate (96.16%) under ex vitro conditions was observed when in vitro plantlets having high photosynthetic efficiency (Fv/Fm > 0.75) were subjected to hardening and acclimatization process. Plantlets with reduced photosynthetic performance exhibited low survival rate under natural conditions. The developed in vitro protocol will be useful for genetic improvement and multiplication of D. unguis-cati. The results of this study also show that photosynthetic screening of in vitro developed plantlets is highly essential after the rhizogenesis process to achieve higher survival rate under field conditions.

Effect of different waterlogging periods on biochemistry, growth, and chlorophyll a fluorescence of Arachis hypogaea L.

“…The reaction was started by adding H 2 O 2 to the reaction mixture, which also included 1.0 ml of guaiacol (1.0 %) and 1.7 ml of phosphate buffer (0.05 M, pH 7.0). Unit enzyme activity was used to express the amount of enzyme required to convert the substrate in 1 min (Soni et al, 2021 ).…”

CO2 enrichment alters morphophysiology and improves growth and acclimatization in Etlingera Elatior (Jack) R.M. Smith micropropagated plants

“…Cross sections of the midportion of leaves were subjected to combined double-staining with toluidine blue and Lugol's solution a, b, c, d, e showing positive (purple color) reaction to starch e, Sudan black B showing positive (dark color) reaction to lipids in idioblast cells f, g, h, i, j, xylidine Ponceau showing positive (red color) reaction to protein bodies k, l, m, n, o, and PAS showing negative reaction to carbohydrates p, q, r, s, t. Abbreviations: Ab, abaxial face of the epidermis; Ad, adaxial face of the epidermis; Am, amyloplasts (starch); Id, idioblast; Pp, palisade parenchyma; St, stomata; Sp, spongy parenchyma; Vb, vascular system. Bars: 100 µm of in vitro-grown plantlets is highly required before transferring plants to ex vitro conditions (Soni et al 2021). Specifically, low photosynthetic pigment levels could affect plant performance during ex vitro acclimatization.…”

“…Low photosynthetic pigment levels could, as a result, affect plant performance during the ex vitro acclimatization. That is, in vitro-grown plantlets with reduced photosynthetic potential show declined rate of survival under natural conditions (Soni et al 2021).…”

Ultrastructure, adaptability, and alleviation mechanisms of photosynthetic apparatus in plants under waterlogging: A review

“…The OJIP transient curve obtained from Chl fluorescence experiments is extremely sensitive to environmental stressors (Calatayud and Barreno 2001, Sayed 2003, Van Heerden et al 2003, Govindachary et al 2004, Badr and Brüggemann 2020, Khan et al 2021. The shape of the OJIP transient changed over the first hours of hypoxia resulting in a significant decline in the variable fluorescence of all phases (Kumar et al 2020(Kumar et al , 2021Soni et al 2021, Bhatt et al 2022a. The fast O to J increase is the phase regulated by photochemical mechanisms, whereas J to I is entirely a thermal phase (Neubauer and Schreiber 1987, dos Santos Junior et al 2015, Khan et al 2021.…”

“…Chl fluorescence is an excellent physiological marker for assessing the primary procedures and mechanisms of photosynthesis, such as absorption of photons and energy transfer owing to excitation, numerous photochemical activities in the PSII can be monitored (Langan et al 2022, León-Burgos et al 2022. The stability and functions of PSII are determined by assessing the variations in Chl fluorescence characteristics (Abdeshahian et al 2010Soni et al 2021). Chl fluorescence marker shifts in plants growing under the conditions of waterlogging.…”