Jagatpati Tah

Mutagenesis—A Potential Approach for Crop Improvement

Global environmental dissociative changes are now in steady state. Its negative impacts were gradually imposed on a wide range of crops and thus crop improvement was hindered as well. Given this challenge, existing and new, appropriate technologies need to be integrated for global crop improvement. Among the different present approaches, mutagenesis and mutation breeding and the isolation of improved or novel phenotypes in conjunction with conventional breeding programmes can result in mutant varieties endowed with new and desirable variation of agrometrical traits. Induced mutations and its related technologies play very well in this ground and this overall strategy helps to trace the crop genetic diversity along with its biodiversity maintenance. Such induced mutagenesis, a crucial step in crop improvement programme, is now successful in application due to the advancement and incorporation of large-scale selection techniques, micropropagation and other in vitro culture methods, molecular biology tools and techniques in modern crop breeding performance. Time to time, different mutation techniques and their application processes are changing significantly; in this perspective, insertional mutagenesis and retrotransposons are taking more supports for mutational tagging and new mutation generation. For details investigation on plant structure and function, mutagenic agents and their precise role are much essential as it can produce mutants with some phenotypic changes. Functional genomics studies make the ultimatum platform on this field of study where few crop plants were used for mutational experimentation on some prime agronomic traits till now. This is a prerequisite step and is applying on diverse crop for further improvement. High throughput DNA technologies for mutation screening such as TILLING (Targeting Induced Limited Lesions IN Genomes), high-resolution melt analysis (HRM) , ECOTILLING etc. are the key techniques and resources in molecular mutation breeding. Molecular mutation breeding will significantly increase both the efficiency and efficacy of mutation techniques in crop breeding. Such modern and classical technologies are using for the development of mutation induction with the objective of using a set of globally important crops to validate identified relevant novel techniques and build these into modular pipelines to serve as technology packages for induced crop mutations. Thus, mutation assisted plant breeding will play a crucial role in the generation of ‘designer crop varieties’ to address the uncertainties of global climate variability and change, and the challenges of global plant-product insecurity.

Study of genotypic variation of cultivars of winged bean [Psophocarpus tetragonolobus (Stickm.) DC.] with the help of n-alkane profile

The leaf cuticle is covered by epicuticular wax consisting mainly of straight-chain aliphatic hydrocarbons with a variety of substituted groups. Studies have been concentrated on n-alkanes in epicuticular wax of Winged bean [Psophocarpus tetragonolobus (Stickm.) DC.]. Hydrocarbon constituents especially n-alkane analyses of seven cultivars of Winged bean [Psophocarpustetragonolobus (Stickm.) DC.] have been undertaken. All the n-alkanes in between C14–C18 and C20–C38 are present in each of the species. Among the species, amount of n-alkanes is maximum in IC112417 and relatively low in EC38825. Scanning electron microscopic views were also taken for epicuticular layers and their hydrocarbons of the leaves of all the genotype species of the plant. Qualitative and quantitative characterization of n-alkanes present in the epicuticular wax extracted from the mature leaves can be used as an effective tool in chemo taxonomical work and also for the study of genotypic variation of the different cultivars.

Comparative Study for Effects of Chemical Mutagenesis on Seed Germination, Survivability and Pollen Sterility in M1 and M2 Generations of Dianthus

Abstract Chemical mutagenesis is an efficient tool used in mutation breeding programme for improving various vital characteristics in floricultural crop, like Dianthus. In this study, ethyl methane sulphonate (EMS), sodium azide (SA) and colchicine (COL) with three different concentrations (0.1%, 0.4% and 0.7%) were used to analyse their effect on seed germination behaviour, survivability and pollen sterility in both first (M1) and second (M2) mutant generations. It was noted that increase in the dose of EMS and SA, germination percentage and survivability were decreased; whereas colchicine doses were proportional to increase germination percentage at seedling stage, but they were not survived till maturity. In M1 and M2, higher lethality over control (44.3 and 32.89, respectively) was shown by 0.7% of SA and EMS, respectively. Pollen sterility was also increased with increasing mutagenic doses. The maximum pollen sterility was 71.8% and 61.1% for 0.7% COL in M1 and M2, respectively. So, the effect of chemical mutagenesis on biological parameters with SA (0.7%) treatment in M1 and EMS (0.7%) treatment in M2 were much more beneficial as compared to colchicine. For each studied parameter, chemical mutagenesis was higher in M1 than M2. Hence, for the first time in Dianthus, we reported that these mutagens can be used for improving the germination behaviour and the metrical traits in Dianthus cultivar.

Growth Variability and Correlation Studies in Dolichos biflorus L. at Two Locations

Thirty accessions of Dolichos biflorus L. were sown in two different locations viz., Crop Research Farm (CRF), under the Department of Botany of the University of Burdwan and Gagnabad, Adra, Purulia following a Randomized Block Design (RBD) layout having four replications. These accessions were collected from National Bureau of Plant Genetic Resource (NBPGR), New-Delhi, during September, 2010. Seeds were sown in the field in the month of November 2010. Uniform agronomic measures were provided in both the locations for the proper growth and development of the crop. Various metrical characters were observed and all the data were recorded properly for further computations. Correlation analysis was performed among measured characters. Out of thirty accessions, seven genotypes proved themselves to be the most adaptive in both the locations of different agro-climatic conditions. Correlation values between plant height vs. pods plant−1, plant height vs. leaf area, plant height vs. days to flowering, plant height vs. pod length, plant height vs. grains pod−1 and plant height vs. yield plant−1 were determined and exhibited in this context. The aims of this experiment were to explore the suitable area and congenial environment for better crop productivity amongst those two locations.