Aseesh Pandey

In Vitro Propagation of the Important Tasar Oak (Quercus serrata Thunb.) by Casein Hydrolysate Promoted High Frequency Shoot Proliferation

An efficient micropropagation protocol has been developed for tasar oak. Nodal segments from in vitro grown seedling were used for shoot multiplication. Best shoot multiplication response, in terms of number of shoots per explant as well as shoot length, was obtained in woody plant (WP) medium supplemented with 6-benzyladenine and indole-3-acetic acid (8.88 μM BA + 1.43 μM IAA); but the establishment of cultures was difficult due to basal callus formation and necrosis in due course of time. Out of the two used growth adjuvants, casein hydrolysate (CH, 500 mg L−1) promoted shoot multiplication rate significantly in comparison to silver nitrate and also eliminated the basal callus formation problem and necrosis faced during the later stage of shoot proliferation. In vitro rooting on WP medium supplemented with 100 μM indole-3-butyric acid (IBA) when applied for 48 hr gave the best results in comparison to prolonged exposure. Well-acclimatized plantlets were transferred to the field with 80% survival rate. This protocol could be useful not only to propagate and conserve this oak but can also uplift the socioeconomic status of the Himalayan people as its leaves are used to feed the tasar silk worm during rearing period. This method will also be helpful for propagation of high value trees for a reforestation program.

Influence of kinetin on in vitro rooting and survival of banj oak ( Quercus leucotrichophora L.)

A study concerning the influence of cytokinins on shoot regeneration by using different stem segments derived from in vitro raised seedlings and their subsequent rooting was conducted in banj oak (Quercus leucotrichophora L.). Cytokinins play an important role in shoot regeneration and their multiplication. In the present study, cytokinins particularly kinetin (Kn) influenced in vitro rooting and subsequent survival of these in vitro raised plants in addition to shoot multiplication. It was found that the microshoots raised via kinetin treatment rooted very well (94.44%) without any basal callus formation in comparison to microshoots raised via other cytokinin treatments (that is, BA and 2-iP). In addition to this, these in vitro raised plants showed maximum survival rate (90%) during hardening process. On the basis of available literature this is a unique and significant study regarding the comparative effect of different cytokinins on in vitro propagation study of Q. leucotrichophora by using different stem segments, particularly the influence of kinetin in vitro rooting and survival of in vitro raised plants in addition to shoot multiplication. This significant study could be useful for large scale production of successfully hardened plants so that it would be helpful in conservation of this important Himalayan forest tree species.

Assessment of phytochemicals, antioxidant and antimutagenic activity in micropropagated plants of Quercus serrata, a high value tree species of Himalaya

Abstract The major aim of the present study was to: (i) develop an efficient clonal in vitro propagation procedure, and (ii) investigate and compare phytochemicals, antioxidant, and DNA damage protection activity in methanolic extracts of in vitro raised and mother plant leaves of Quercus serrata. The study succeeded in establishing an efficient clonal micropropagation procedure using nodal segments taken from in vivo growing mother plant. The WP medium supplemented with six-benzyleaminopurine (BAP: 8.88 μM) plus indole-3-acetic acid (IAA: 1.43μM) produced the highest number of shoots/explant having maximum average shoot length. In vitro derived shoots exhibited best rooting upon application of 100μM indole-3-butyric acid for 48 h. Among studied phytochemicals, the total phenol content was recorded higher from in vitro raised plants and total flavonoid in the mother plant. Antioxidant activities were recorded higher in case of in vitro raised plants. Also, the methanolic leaf extract of in vitro raised plants exhibited higher antimutagenic activity that of mother plant. These findings indicate Q. serrata as a promising source of natural antioxidants that could be utilized commercially for the prevention of photoaging and oxidative stress-mediated skin diseases.

Efficient micropropagation of Citrus sinensis (L.) Osbeck from cotyledonary explants suitable for the development of commercial variety

In vitro regeneration of sweet orange (Citrus sinensis (L.) Osbeck Family: Rutaceae) has been performed via direct and indirect organogenesis. For indirect organogenesis, callus was induced and proliferated from leaf explants derived from in vitro grown seedlings on Murashige and Skoog (MS) media containing 2,4-dichlorophenoxyacetic acid (2,4-D) alone or in combination with benzyl adenine (BA) and α-naphthalene acetic acid (NAA). For direct organogenesis, explants were placed on MS media containing BA alone or in combination of NAA and gibberellic acid (GA3). Well-developed microshoots were treated with different concentrations of NAA for rhizogenesis (a two-step procedure). Different responses to these treatments were recorded depending upon the procedure used. It appears that 4.53 μM 2,4-D in combination with 5.37 μM NAA induced 93.33% callus and proliferate 86.67% of callus into 6.93 shoots per explant. Exogenous addition of 4.44 μM BA in combination with 1.54 μM GA3 enhanced shoot multiplication rate significantly (17.73±1.69 shoots/explant) in comparison to control (0.00±0.00 shoots/explant). Microshoots were rooted best (75.00±14.43%) under the treatment 100μM NAA for 48 hrs. and rooted plantlets were transferred to soil, following acclimatization were taken to maturity in the polyhouse. Key words: Malta, Himalaya, benzyl adenine (BA), callus.