Sherry Rachel Jacob

Indian Plant Germplasm on the Global Platter: An Analysis

Food security is a global concern amongst scientists, researchers and policy makers. No country is self-sufficient to address food security issues independently as almost all countries are inter-dependent for availability of plant genetic resources (PGR) in their national crop improvement programmes. Consultative Group of International Agricultural Research (CGIAR; in short CG) centres play an important role in conserving and distributing PGR through their genebanks. CG genebanks assembled the germplasm through collecting missions and acquisition the same from national genebanks of other countries. Using the Genesys Global Portal on Plant Genetic Resources, the World Information and Early Warning System (WIEWS) on Plant Genetic Resources for Food and Agriculture and other relevant databases, we analysed the conservation status of Indian-origin PGR accessions (both cultivated and wild forms possessed by India) in CG genebanks and other national genebanks, including the United States Department of Agriculture (USDA) genebanks, which can be considered as an indicator of Indian contribution to the global germplasm collection. A total of 28,027,770 accessions are being conserved world-wide by 446 organizations represented in Genesys; of these, 3.78% (100,607) are Indian-origin accessions. Similarly, 62,920 Indian-origin accessions (8.73%) have been conserved in CG genebanks which are accessible to the global research community for utilization in their respective crop improvement programmes. A total of 60 genebanks including 11 CG genebanks have deposited 824,625 accessions of PGR in the Svalbard Global Seed Vault (SGSV) as safety duplicates; the average number of accessions deposited by each genebank is 13,744, and amongst them there are 66,339 Indian-origin accessions. In principle, India has contributed 4.85 times the number of germplasm accessions to SGSV, in comparison to the mean value (13,744) of any individual genebank including CG genebanks. More importantly, about 50% of the Indian-origin accessions deposited in SGSV are traditional varieties or landraces with defined traits which form the backbone of any crop gene pool. This paper is also attempting to correlate the global data on Indian-origin germplasm with the national germplasm export profile. The analysis from this paper is discussed with the perspective of possible implications in the access and benefit sharing regime of both the International Treaty on Plant Genetic Resources for Food and Agriculture and the newly enforced Nagoya Protocol under the Convention on Biological Diversity.

Evaluation of 19,460 Wheat Accessions Conserved in the Indian National Genebank to Identify New Sources of Resistance to Rust and Spot Blotch Diseases

A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat–Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011–14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels.

An analysis of the persistence and potency of film-coated seed protectant as influenced by various storage parameters

BACKGROUND An efficient delivery system for seed-protectant chemicals is needed in light of several disadvantages of conventional seed treatment methods. This study evaluates the efficacy of film-coat application in maintaining the persistence and potency of imidacloprid on Lycopersicon esculentum (L.) Mill. seeds after simultaneous storage under ambient and regulated environment in paper and aluminium packages. RESULTS High-performance liquid chromatography (HPLC) revealed 0.135 mg kg(-1) of herbage material to be the threshold value beyond which absolute control was obtained, and with film coating the latter was achieved even with half-dosage seed treatment, irrespective of the storage condition. The technique provided early protection to the crop and also nullified the deleterious effects of ambient storage on the persistence and potency of the pesticide. CONCLUSION Film coating enabled superior pesticide dosage as well as higher biological efficacy to be achieved. Hence, in addition to being an ecofriendly alternative, the technique would be a more economically viable option for storage of treated seeds.

Identification, analysis and development of salt responsive candidate gene based SSR markers in wheat

BackgroundSalinity severely limits wheat production in many parts of the world. Development of salt tolerant varieties represents the most practical option for enhancing wheat production from these areas. Application of marker assisted selection may assist in fast tracking development of salt tolerant wheat varieties. However, SSR markers available in the public domain are not specifically targeted to functional regions of wheat genome, therefore large numbers of these need to be analysed for identification of markers associated with traits of interest. With the availability of a fully annotated wheat genome assembly, it is possible to develop SSR markers specifically targeted to genic regions. We performed extensive analysis to identify candidate gene based SSRs and assessed their utility in characterizing molecular diversity in a panel of wheat genotypes.ResultsOur analysis revealed, 161 SSR motifs in 94 salt tolerance candidate genes of wheat. These SSR motifs were nearly equally distributed on the three wheat sub-genomes; 29.8% in A, 35.7% in B and 34.4% in D sub-genome. The maximum number of SSR motifs was present in exons (31.1%) followed by promoters (29.8%), 5’UTRs (21.1%), introns (14.3%) and 3’UTRs (3.7%). Out of the 65 candidate gene based SSR markers selected for validation, 30 were found polymorphic based on initial screening and employed for characterizing genetic diversity in a panel of wheat genotypes including salt tolerant and susceptible lines. These markers generated an average of 2.83 alleles/locus. Phylogenetic analysis revealed four clusters. Salt susceptible genotypes were mainly represented in clusters I and III, whereas high and moderate salt tolerant genotypes were distributed in the remaining two clusters. Population structure analysis revealed two sub-populations, sub-population 1 contained the majority of salt tolerant whereas sub-population 2 contained majority of susceptible genotypes. Moreover, we observed reasonably higher transferability of SSR markers to related wheat species.ConclusionWe have developed salt responsive gene based SSRs in wheat for the first time. These were highly useful in unravelling functional diversity among wheat genotypes with varying responses to salt stress. The identified gene based SSR markers will be valuable genomic resources for genetic/association mapping of salinity tolerance in wheat.

SSR markers based DNA fingerprinting and it’s utility in testing purity of eggplant hybrid seeds

Conventionally, the genetic identity and purity of seeds is assessed by field plot test. However, field plot test method is time consuming, requires large area of land and involves skilled personnel often making subjective decisions. These limitations and the environmental dependency of the entire procedure can be overcome effectively by employing DNA fingerprinting technology. Therefore, the present study was undertaken to identify simple sequence repeat (SSR) markers that could be used to test the genetic identity and purity of six brinjal hybrids and their respective parental lines based on generated DNA fingerprint. In the present study, four markers were found to be polymorphic between parental lines of four respective hybrids (viz. PH-5, PH-9, NDBHL-20 and Kashi Komal) and were found to be suitable for ensuring the genetic identity and purity of these hybrids. Among the identified markers, a set of three markers (emg01B17, emd05F05 and CSM31) could be used for ensuring the identity of the hybrids. U...

Morpho-Physiological Attributes of Cultivated Wheat Germplasm for high yield potential under Rain fed condition

Wheat is the most important cereal crop and staple diet for more than one third of the world population and contributes more calories and protein to the world diet than any other cereal crop. In view of global climate change drought stress is becoming major constraints for the productivity of wheat and hence the breeding for drought tolerance is gaining more importance. More accurate and precise phenotyping of genetic resources is the demand of the new generation quantitative geneticists and plant breeders as this is the most critical research area which will lead to identification of trait specific donor germplasm. In the present study, Wheat germplasm accessions (1483 acc.) were evaluated at Issapur farm in Augmented Block Design with four checks based on morpho-physiological parameters. Irrigation was provided at Crown root initiation stage (CRI) and afterwards moisture deficit was maintained throughout the crop duration. There was wide variability in wheat germplasm for the phonological, agronomical and physiological traits. This experiment identified correlated traits responsible for high grain yield under rainfed conditionsuch as biological yield, harvest index, days to maturity, spike length, spikelets per spike, grains per spike, cholorophyll content, grain weight and 1000 grain weight. Based on stepwise multiple regression analysis, major role of prediction on yield was found through biological yield, including harvest index, grain weight spikelets per spike and chlorophyll content. Based on predictor variables, accessions were selected and will be further validated under controlled condition and will be used for introgression purpose in the background of elite varieties to enhance yield and its stability under moisture stress environments.

Development of Core Set of Wheat ( Triticum spp. ) Germplasm Conserved in the National Genebank in India

Plant genetic resources, the source of genetic diversity provides a broad genetic foundation for plant breeding and genetic research, however, large germplasm resources are difficult to preserve, evaluate and use. Construction of core and mini core collections is an efficient method for managing genetic resources and undertaking intensive surveys of natural variation, including the phenotyping of complex traits and genotyping of DNA polymorphisms allowing more efficient utilization of genetic resources. A mega characterization and evaluation programme of the entire cultivated gene pool of wheat conserved in the National Genebank, India was undertaken. Wheat accessions with limited seed quantity, were multiplied in the off-season nursery at IARI Regional Station, Wellington during rainy season 2011 and the entire set of 22,469 wheat accessions were characterized and evaluated at CCS HAU, Hisar, Haryana during winter season 2011–12 for 34 characters including 22 highly heritable qualitative, and 12 quantitative parameters. The core sets were developed using PowerCore Software with stepwise approach and grouping method and validated using Shannon-Diversity Index and summary statistics. Based on Shannon-Diversity index, PowerCore with stepwise approach was found better than PowerCore with grouping. The core set included 2,208 accessions comprising 1,770 T. aestivum, 386 T. durum, and 52 T. dicoccum accessions as a representative of the total diversity recorded in the wheat germplasm. The core set developed will be further validated at different agro-climatic conditions and will be utilized for development of mini core set to enhance the utilization by wheat researchers and development of climate resilient improved varieties.

Spatial Distribution of Trait-specific Diversity in Indian Wheat Collections

A total of 5,930 accessions of wheat were collected in collaboration with crop-based institutes of Indian Council of Agricultural Research (ICAR) and State Agricultural Universities (SAUs) from diverse areas of the country during the period 1976–2013. Of these, 3,973 accessions were short-listed with details on state, district, village, collector number, latitude (N) and longitude (E) of the collection sites to understand the diversity distribution pattern. The geo-referenced map of collected diversity depicted that Himachal Pradesh and Uttarakhand states were extensively explored for Triticum aestivum and Karnataka, Gujarat and Madhya Pradesh for T. turgidum subsp. durum. Among the local landraces, drought tolerant Jautri local type from Madhya Pradesh; awnless types Lakh, Dhavati and Hansy from Uttarakhand; and non-shattering types Kankoo and Dharmauri from Himachal Pradesh were some notable collections. Besides, the priority areas for collection of cultivated species of wheat distributed in different agro-ecological regions were identified and discussed in the present communication.