In-vitro approach for multiplication of new sugarcane varieties and their molecular characterization using SSR marker

Abstract

Sugarcane is the most important agro-industrial cash crop of tropical and subtropical regions of the world. It is now commercially grown over 108 countries globally. Sugarcane meets about 86% of the total world sugar requirements worldwide. India is the second largest producer of sugar in the world. Traditionally, sugarcane is multiplied vegetatively using setts as seed instead of actual seeds. This method of sugarcane propagation frequently results in low rates of multiplication and disease susceptibility. Techniques for cultivating plant tissues offer a productive and trustworthy solution to this challenge. Tissue culture is playing a prominent role in greatly improving plant quality and producing pathogen-free plants. Water stress is one of the most restricting abiotic elements impacting sugarcane productivity. It is one of several environmental factors that can negatively affect the increase and expansion of sugarcane production. Sugarcane has an extremely large genome (10GB). with small chromosomes, which complicates the understanding of their genetic architecture and taxonomy. Molecular markers Such as SSRs are potentially useful to assess genetic diversity and in crop improvement programmes. The present thesis focus on three research aims that is to establish standard protocol for In-vitro shoot tip culture of two sugarcane genotypes viz., Co0118 and Co1502, morpho-physio-biochemical analysis of sugarcane genotypes under drought stress conditions and genetic diversity analysis using SSR marker. The study showed that the combination of sterilants in sequence of Labolene (2%) for 10 min, Bavistin (0.1%) for 5 min, HgCl2 (0.1%) for 90 seconds and Ethanol (70%) for 1 min was found to be best for surface sterilization. Morpho-physio-biochemical analysis 15 sugarcane genotypes under drought stress conditions for the traits Plant height, Leaf area, Number of tillers, Chlorophyll content, Relative water content, Membrane stability index, Proline content and Peroxidase activity has showed that the genotypes Co98014,Co0118, Co0238 and Co13235 have shown better overall performance under stress when compared to other genotypes and are assumed to be drought tolerant. Diversity studies of 15 genotypes amplified with 12 SSR primers 8 has exhibited polymorphism, the primer named SKM23 have shown highest number of polymorphic alleles and highest PIC value is obtained by SKM SKM02 and SKM01 i. e., 0.499 and 0.497 respectively. The results obtained during the study will be useful in rapid multiplication of new sugarcane genotypes and in crop improvement programmes.