K. V. Bhat

Value addition in sesame: A perspective on bioactive components for enhancing utility and profitability

Sesame seed is a reservoir of nutritional components with numerous beneficial effects along with health promotion in humans. The bioactive components present in the seed include vital minerals, vitamins, phytosterols, polyunsaturated fatty acids, tocopherols and unique class of lignans such as sesamin and sesamolin. The presence of phenylpropanoid compounds namely lignans along with tocopherols and phytosterols provide defense mechanism against reactive oxygen species and increases keeping quality of oil by preventing oxidative rancidity. In this article, we have reviewed the nutraceutical, pharmacological, traditional and industrial value of sesame seeds with respect to bioactive components that hold high antioxidant value. Valuable information on superior functional components of sesame will strongly promote the use of sesame seeds in the daily diet world-wide. In spite of huge repertoire of sesame germplasm collection, limited research efforts on the use of conventional and biotechnological methodologies have resulted in minimal success in developing nutritionally superior cultivars. In consequence, value addition efforts in sesame would enable development of genotypes with high antioxidant activity and subsequently prevention of free radical related diseases. Modification of bioactive components in sesame would enable production of stabilized sesame oil with enhanced shelf life and better market value.

Quantitative dissection of antioxidative bioactive components in cultivated and wild sesame germplasm reveals potentially exploitable wide genetic variability

Sesame (Sesamum indicum L.) is one of the oldest oilseed crops grown in India and worldwide. This oilseed crop has high nutritional value due to the presence of antioxidants such as lignans and tocopherols. Screening of oilseed germplasm for important nutritional attributes is of prime importance in quality breeding programs. In the present study, the content of lignans (sesamin and sesamolin) and tocopherol homologues (α-, γ-, and δ-tocopherol) was determined using reverse phase HPLC (RP-HPLC) in 143 sesame lines collected from diverse agro-ecological zones of India. Exploitable levels of sesamin, sesamolin, γ-, and δ-tocopherol was observed in the studied sesame lines. Sesamum indicum cultivar CO 1, introgressed line MKN 9, and Sesamum malabaricum showed high values for sesamin. Exotic and indigenous accessions of S. indicum (EC 542283 and IC 132176, IC 204681, IC 204773) showed high sesamolin contents. Cultivars, AKT 64, AKT 101, Phule til 1, and Tapi A showed high values for γ- and δ-tocopherol. The average content of sesamin and sesamolin was 0.86 and 0.50 mg g−1 seed, respectively. The average tocopherol content (292 μg g−1 seed) found in this study indicates the presence of a high amount of tocopherol in Indian sesame germplasm. Superior genotypes of sesame reported in this study could be utilized in sesame breeding programs for enhancing oil yield and nutritional attributes.

Genetic Analysis of Indian Lentil ( Lens culinaris Medikus) Cultivars and Landraces Using RAPD and STMS Markers

Molecular analysis of 29 lentil (Lens culinaris) cultivars and landraces of Indian origin was carried out using twenty RAPD and ten cross-species STMS primers. A total of 97 markers (72 RAPD and 25 STMS) were amplified of which 42.3% were polymorphic. Genetic similarity among the cultivars and landraces was 89.7%. The observed results indicated low level of genetic diversity in the studied material. UPGMA cluster analysis for the combined data of RAPD and STMS revealed two broad clusters — Cluster I with three landraces and Cluster II containing all remaining landraces and cultivars except Precoz. Germplasm line Precoz was found to be the most distinct in individual as well as combined analyses. All cultivars and landraces except K-75 and L4076 could be discriminated from one another using combined data for the two techniques. Germplasm lines Precoz, L830 and cultivars L4147 and JL3 were quite distinct and could be potential germplasm resource.

Analysis of spatial distribution of genetic diversity and validation of Indian foxtail millet core collection

Foxtail millet [Setaria italica (L.) P. Beauv.] is an important small millet, grown as a short duration, drought tolerant crop across the world. This crop can be grown on wide ranges of soil conditions and has an immense potential for food and fodder in rainfed and arid regions of the India. In the present study, 31 primer pairs (27 SSR and 4 EST-SSR) were used to analyse the genetic diversity in 223 core collection accessions. Analysis resulted in detection of a total of 136 alleles with an average of 4.38 alleles per locus. Among these 136 alleles, 22 were rare, 70 were common and 44 were frequent. The PIC value ranged from 0.01 to 0.86 with an average of 0.31. The average number of observed alleles ranged from 2.0 (northern hills of India accessions) to 4.06 (exotic) with an average of 2.72. The mean Shannon’s Information Index ranged from 0.44 (northern hills of India) to 0.69 (exotic) with an average of 0.52. Pair-wise Fst values indicated little to moderate genetic differentiation among the group of accessions. UPGMA clustering grouped the accessions into two major groups while analysis for population substructure indicated presence of four subpopulations. However there was no statistically well supported grouping of the accessions based on eco-geographic specificities. The core collection designated here represented substantial genetic diversity at molecular level, hence may be a good source of diversity for use in foxtail improvement programs in the region.

Identification of genes associated with stress tolerance in moth bean [Vigna aconitifolia (Jacq.) Marechal], a stress hardy crop

Moth bean is the most drought and heat tolerant cultigens among Asian Vigna. We performed comparative transcriptome analysis of moth bean cultivar “Marumoth” under control and stress condition. De novo transcriptome assembly was carried out by using Velvet followed by Oases softwares. Differential expression analyses, SSR identification and validation and mapping of pathways and transcription factors were conducted. A total of 179,979 and 201,888 reads were generated on Roche 454 platform and 48,617,205 and 45,449,053 reads were generated on ABI Solid platform for the control and stressed samples. Combined assembly from Roche and ABI Solid platforms generated 16,090 and 15,096 transcripts for control and stressed samples. We found 1287 SSRs and 5606 transcripts involved in 179 pathways. The 55 transcription factor families represented 19.42% of total mothbean transcripts. In expression profiling, ten transcripts were found to be up-regulated and 41 down-regulated while 490 showed no major change under moisture stress condition. Stress inducible genes like Catalase, Cyt P450 monooxygenase, heat shock proteins (HSP 90 and HSP 70), oxidoreductase, protein kinases, dehydration responsive protein (DRP), universal stress protein and ferridoxin NADH oxidoreductase genes were up-regulated in stressed sample. Genes which might be involved in moisture stress tolerance in moth bean were identified and these might be useful for stress tolerance breeding in moth bean and other related crops.

GinMicrosatDb: a genome-wide microsatellite markers database for sesame (Sesamum indicum L.)

Molecular breeding in sesame is still at infancy due to limited number of microsatellite markers available and the low level of polymorphism exhibited by them. Therefore, whole genome sequencing was used for development of microsatellite markers so as to ensure availability of substantial number of polymorphic markers for use in marker assisted breeding programs. Whole genome sequencing of sesame variety ‘Swetha’ was done using Illumina paired-end sequencing and Roche 454 shotgun sequencing technologies (GCA_000975565.1 in GenBank). ‘GinMicrosatDb’, a genome-wide microsatellite marker database has been developed using the whole genome sequence data of sesame variety ‘Swetha’. The database consists of microsatellites localized on both linkage groups and scaffolds with their genomic co-ordinates. It provides five sets of forward and reverse primers for each of the microsatellite loci along with the flanking sequences, primer GC content, product size and melting temperature etc. The distribution of microsatellites can be viewed and selected through a genome browser as well as through a physical map. The newly identified microsatellite markers are expected to help sesame breeders in developing marker tags for traits of economic importance thereby bringing about greater efficiency in marker-assisted selection programs.

Identification of Putative Sources of Tolerance to Aphid in Mustard and Generation of Molecular Marker for Use in Crop Improvement

Indian mustard (Brassica juncea (L.) Czern.) has been an important crop to India for a long time. It is predominantly cultivated in Rajasthan, Uttar Pradesh, Haryana, Madhya Pradesh, and Gujarat (Shekhawatet al., 2012) and stands at the third position in the list of rape-mustard producing countries.However, India’s average yield of mustard is low in comparison to other mustard-growing countries chiefly due to aphid pest causing excessive losses in the yield of the crop (Pandey et al. 2013; Rao et al. 2014).The yield loss in rapeseed mustard also varies with their germplasms and agro-ecological practices (Ansari, et al. 2007).The mustard aphid is considered to be a major limiting factor for successful cultivation of the crop; causing up to 96 per cent yield losses (Singh and Sachan, 1994; Singh and Premchand, 1995; Sharma and Kashyap, 1998; Singh and Sharma, 2002). Though, it can be controlled by the pesticide to some extent but it has International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 06 (2018) Journal homepage: http://www.ijcmas.com