Srinath Rao

SOMATIC EMBRYOGENESIS AND PLANT REGENERATION FROM COTYLEDONARY EXPLANTS OF GREEN GRAM [VIGNA RADIATA (L.) WILEZEK.] – A RECALCITRANT GRAIN LEGUME

SummaryThis study reports a protocol for plant regeneration from cultured explants of green gram [Vigna radiata (L.) Wilezek] via somatic embryogenesis. Somatic embryos were induced from nature cotyledons of var., TAP-7 and Pusa Baisaki when cultured on Murashige and Skoog (MS) medium fortified with different concentrations of 2,4-dichlorophenoxyacetic acid, α-naphthaleneacetic acid (NAA) and 2,4,5-trichlorophenoxyacetic acid singly or in combination with 2.22–8.88 μM N6-benzylaminopurine (BAP) or 2.32–9.38 μM kinetin. The type and concentration of auxin and plant genotype influenced the frequency of somatic embryogenesis. NAA was the most effective auxin for somatic embryo induction. The well-developed, cotyledonary shaped embryos of var. TAP-7 germinated into plantlets at a frequency of 56.6% on MS medium supplemented with 1.88 μM abscisic acid and 6.66 μM BAP. Regenerated plants were transferred to soil and grown to maturity with 90% survival. The protocol described here offers a good potential for genetic improvement using gene transfer techniques and the production of synthetic seeds of V. radiata.

Mechanistic Approach of Functionalized Noble Metal Nanoparticles Synthesis From Cassia auriculata L.

Biological resources have gained importance in the synthesis and applications of the nanomaterials. Plants reduce the metal ions faster than fungi or bacteria. This paper aims to extend our previous work to find out the biological components involved in the bio-reduction and stabilization of noble metals by using aqueous (dry leaf) extract of Cassia auriculata L. The extracellular synthesized AuNPs and AgNPs were characterized by UV–Vis spectroscopy and transmission electron microscope. The phytochemical analysis revealed phenols, flavonoids, tannins, cardiac glycosides and saponins. Two associated proteins were found capping on nanoparticles. The study proposes thermostable, polar phytochemicals and polar proteins responsible for the reduction and stabilization of AuNPs and AgNPs in solution controlling partly the size and shape of NPs.

Impact of bio-nanogold on seed germination and seedling growth in Pennisetum glaucum

Nanotechnology is leading towards the development of low cost applications to improve the cultivation and growth of plants. The use of nanotechnology in agriculture will leads to a significant effect on food industry along with opening a new area of research in agroecosystem. In this paper gold nanoparticles were biosynthesized with Cassia auriculata leaf extract at room temperature and characterized by UV-vis spectroscopy, X-ray diffraction and transmission electron microscopy. The objective of this study was to investigate effect of synthesized bio-nanogold on an important food and biofuel producing plant Pennisetum glaucum. Positive effects were observed on percentage of seed germination and growth of seedlings. Improved germination and increased plant biomass have high economic importance in production of biofuel or raw materials, agriculture and horticulture. Although the impact of nanoparticles on plants depends on concentration, size and shape. The biological synthesized AuNPs can replace the chemically synthesized AuNPs used in gene transfer method. The study gives brief insight on nanoparticles effects on plants, brings attention on both positive and negative side of nanomaterial which can resolve phytopathological infections by stimulating nutrition and growth.

Synthesis of Silver Nanoparticles from Plants and Their Applications

Nanobiotechnology defines applications of biosystems to produce novel functional materials. Production of metal nanoparticles is increasing to develop innovative technologies. There are various techniques to characterize the synthesized silver nanoparticles. UV-Vis spectroscopy is used for absorbance pattern, X-ray diffraction reveals crystalline nature with FCC geometry with mean particle size, Fourier transform infrared spectroscopy is for chemical compositions associated with NPs, and transmission electron microscopy is used to determine the shape of the NPs. AgNPs are one of the important materials having wide applications in optoelectronic devices, biosensors, and catalysis. Application of silver nanoparticles depends on the different charges, chemical composition, size, and shape. There are various methods to synthesize AgNPs. Keeping in view of synthesis and applications of AgNPs, a brief study of available literature for biosynthesis method and practices of silver nanoparticles has been reviewed.

In Vitro Selection of Disease-Resistant Plants

Worldwide crops are attacked by several diseases, and due to these diseases, heavy loss in the yield of crop plants is a common phenomenon. This is more common in tropical regions. Diseases affect plants during all stages of their life cycle and even during storage stage. Controlling the pathogens through chemical pesticides is a very costly affair and labor intensive (Bezier et al. 2002). In addition, they also pose environmental hazards as they are nonbiodegradable; they accumulate in the soil and reduce the production of crops. They also cause loss of local flora and fauna. Hence, it has become pertinent to find alternative biotechnological methods to develop disease-resistant crop plants. An important step in the breeding of crops is to develop an effective strategy for selection of desirable traits (Roane 1973; Van den Bulk 1991; Novak and Brunner 1992; Lebeda and Savabova 2010). Conventionally, selection of traits of interest is carried out in the field; this involves identifying resistant plants, crossing them with the superior yielding variety, and studying their inheritance pattern, which may require 12–15 years to release a new variety. Compared with the techniques of in vitro selection (Novak and Brunner 1992; Jin 2001; Patade et al. 2008). Genetic engineering is another approach that can be utilized to develop disease-resistant plants, but limitations in the form of transgene silencing (Manners and Casu 2011) reduced gene expression, and frequency of low transformation (Mondal et al. 1997) and tough legislations (Burnquist 2006) hampers the use of this approach (Table 18.1 and Plates 18.1, 18.2, and 18.3).

Structure and optical properties of MoS2 films deposited by different methods on glass and silicon substrates

Dip coating and thermal evaporation in vacuum have used to prepare MoS2 thin film for application in energy conversion. The details of preparing the thin films are given. The films have been characterized by XRD and reflectance spectroscopy to evaluate their quality, the results suggest that that both techniques produce good quality films and dip coating being low cost will be economically advantageous for preparing large area films for energy harvesting.

A tissue culture derived pesticide tolerant line of chickpea (Cicer arietinum L.)

Chickpea seedlings (Cicer arietinum L.) were used to initiate callus on B5 medium supplemented with 2 mg/l 2,4-dichlorophenoxyacetic acid+0·5 mg/l NAA and kinetin. After a months growth the healthy callus was transferred to a similar medium supplemented with different concentrations of the pesticide Rogor (O, O-dimethyl-S-methyl carbamoyl methyl phosphorodithioate). After one month in the pesticide medium most of the cells exposed to higher concentration died, but a few cells remained healthy. In a control medium the cells remained healthy over the same period. The pesticide treatment inhibited the protein content and the activity of the enzyme amylase, whereas an increase in the activity of peroxidase was observed. The surviving pockets of pesticide exposed cells were exercised and transferred to a medium that caused shoot initiation and later to a medium that caused root formation from the base of the shoot. Plants were taken through to maturity in soil. The resistant cell line contained high levels of proteins and peroxidases compared to control. Additional bands of peroxidase isozymes were observed in the resistant line.