ICAR-IINRG Annual Report 2016-17

Abstract

More than 26% of lac insect biodiversity of the world has been reported from India. Some of these lac insects exclusively found in India produce superior quality lac and / or different by-products like dye and wax. This genetic diversity is lying scattered and unattended mostly in the forests. Therefore, collection and conservation of lac insects and host plants is an important activity of the Institute. Three new variants of palas (Butea monosperma) having yellow flower colour have been identified. Eight districts of Tripura have been surveyed for collecton of lac insects and host plants. Majority of the farmers in our country hold less than two hectares of land and practice subsistence farming and uncertain mono-cropping. In such situations, integrated farming provides recourse to sustainable and optimum use of resources leading to bio-diversification besides meeting the food and livelihood security. Integration of lac cultivation especially with horticultural crops has promised to be a very promising venture. Lac Integrated Farming System (LIFS) Models developed by the Institute are being evaluated and demonstrated at farmers’ fields and has motivated farmers to integrate lac with agriculture. Lac insects have been found to be very specific in manifestation of their biological attributes not only to the host species, specific varieties and even to individual phenotype of host-plants but also to locality and season of cultivation. Developing package of practices for kusmi lac cultivation on swadi palas (a variant of B. monosperma used for rangeeni strain) and utilizing pigeon pea for rangeeni lac cultivation has given promising results. A new generation insecticide AugustaTM (active ingredient natural lactose 0.6% and natural alkaloid 0.3%) evaluated on lepidopteron pest E. amabilis and P. pulverea through dipping of broodlac has indicated its safety to lac insect. Significant reduction in the population of lepidopteron pests was also recorded. Development of specific molecular markers and establishment of biochemical pathway of lac resin synthesis are important in understanding of genes and proteins involved. The expression profile study of the partial gene of decaprenyl diphosphate synthase, one of the key genes involved in sesquiterpene synthesis cloned from the Indian lac insect, Kerria lacca (Kerr) has revealed that this gene expression got up regulated in settled larvae and adult female lac insects in comparison to crawlers. One Suppression Subtraction Library (SSH) library was constructed to identify the differential gene expression in female lac insects compared to crawlers. Now-a-days, nanotechnologies are being used for developing delivery systems for bioactive compounds. Lyophilized acacia gum-based silver nanoparticles (AgNPs) were characterized by UV-VIS, FT-IR Spectroscopy, Particle Size Analysis, Zeta Potential, Atomic Force Microscopy (AFM) and SEM. Use of hydrogel for application in agriculture is another developing field with huge potentials. Cross-linked guar gum hydrogels have been synthesized and their dye removal efficiency studied. Different modified derivatives of gum karaya, gum arabic and gum ghatti and moringa & guar gum based hydrogel polymers have been synthesized as an adsorbent for the removal of heavy metals from water. Efforts towards value addition of natural resins and gums have led to synthesis of anionic (carboxymethyl), nonionic (Hydroxypropyl) and cationic (Hydroxypropyl triammonium chloride) derivatives of guar gum involving minimum use of organic solvent. Coating formulations based on shellac modified in aqueous and non-aqueous solvent system developed for paper packaging have been found to be smooth, uniform and glossy. All these research efforts would be futile if not taken to the stakeholders for which they are meant. Commendable efforts have been made in transfer of research findings through training, field demonstrations, technical advisory and extension activities. Slowly but steadily, the Institute is moving towards achieving the self set tough targets for betterment of both the society and the natural resins and gums sector.