Manoranjan Dutta

Global Wild Annual Lens Collection: A Potential Resource for Lentil Genetic Base Broadening and Yield Enhancement

Crop wild relatives (CWRs) are invaluable gene sources for various traits of interest, yet these potential resources are themselves increasingly threatened by the impact of climate change as well as other anthropogenic and socio-economic factors. The prime goal of our research was to cover all aspects of wild Lens genetic resource management like species characterization, agro-morphological evaluation, diversity assessment, and development of representative sets for its enhanced utilization in lentil base broadening and yield improvement initiatives. We characterized and evaluated extensively, the global wild annual Lens taxa, originating from twenty seven counties under two agro-climatic conditions of India consecutively for three cropping seasons. Results on various qualitative and quantitative characters including two foliar diseases showed wide variations for almost all yield attributing traits including multiple disease resistance in the wild species, L. nigricans and L. ervoides accessions. The core set developed from the entire Lens taxa had maximum representation from Turkey and Syria, indicating rich diversity in accessions originating from these regions. Diversity analysis also indicated wide geographical variations across genepool as was reflected in the core set. Potential use of core set, as an initial starting material, for genetic base broadening of cultivated lentil was also suggested.

Broadening the Genetic Base of Grain Legumes

Pigeonpea was labeled as an orphan crop but is now a trendy and pacesetter, with ample genetic and genomic information becoming available in recent times. It is now possible to cross wild relatives not only from the Cajanus group placed in the secondary and tertiary gene pool but also the related genera placed in the quaternary gene pool. This is no small achievement for a legume which is an important crop of Asia and Africa and plays a major role in the diet of majority of the people of this region. The need of the hour is further committed research on wide crosses in pigeonpea.

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.

Genetic studies on morpho-phenological traits in lentil (Lens culinaris Medikus) wide crosses

Genetic studies were undertaken in nine intersubspecific and interspecific crosses of lentil to understand the inheritance pattern of morphological characters viz., growth habit, flower colour, cotyledon colour and pod dehiscence. The F1 and F2 generations of these wide crosses were assessed and suggested monogenic inheritance of these traits. The segregation pattern of these qualitative traits will also help in the identification of true to type F1 plants from the interspecific crosses. All nine intersubspecific and interspecific crosses exhibited a wide variability for days to flowering, maturity and duration from flowering to maturity. The results indicated that these characters are governed by independent sets of genes during the growth and development phases. Heritability of both characters has been reported to be high in all wide crosses. In India, cultivated lentil species have an intrinsically narrow genetic base and that situation limits our plant breeder’s progress today (Earskine et al. 1998). To attain further breakthrough in increasing yield and improving stability in future crop cultivars, new sources of variation need to be incorporated into the cultivated gene pool. Therefore, some efforts for broadening the genetic base of lentil cultivars using wild Lens taxa have been initiated by the National Bureau of Plant Genetic Resources, Pusa, New Delhi, India (Singh et al. 2013), and also in some other research organizations (Ahmad et al. 1995; Fratini and Ruiz 2006; Gupta and Sharma 2007). Incorporation of different traits of interest in the background of cultivated varieties has helped in the flow of useful genes with increased allelic frequency from wild Lens taxa in the common gene pool of cultivated varieties (Ladizinsky et al. 1988).

Cacti: notes on their uses and potential for climate change mitigation

The present review attempts to collate information on various uses of cacti and reflect on their potential to be considered as a possible commercial crop in the era of global climate change. The immense values of cacti has been discussed in view of their aesthetic, nutritional, nutraceutical and industrial uses. Cacti have the potential to mitigate the effects of climate change due to their unique morphological and physiological adaptation mechanisms. Vulnerability and conservation status of different cactus species along with the possible impact of climate change on the diversity of cacti have been discussed. The research and development areas where scarce information is available, are highlighted, so that immediate research and development efforts could be initiated for proper utilization of this important group of plants.

Assessment of phenotypic diversity in pearl millet [Pennisetum glaucum (L.) R. Br.] germplasm of Indian origin and identification of trait-specific germplasm

Abstract. Evaluation of genetic diversity within germplasm collections and identification of trait-specific germplasm is a basic requirement for plant breeders. A total of 221 Indian pearl millet collections from the National Genebank were characterised and evaluated for 27 agro-morphological descriptors. Considerable variation was observed for all characters. Frequency distribution analysis showed predominance of cylindrical and compact spike, grey seeds, earliness (less than 40 days to spike emergence). Hierarchical clustering method was used for classifying 221 pearl millet accessions based on agronomic and disease resistance traits, which resulted into three clusters. Clusters 1, 2 and 3 comprised 91, 54 and 76 accessions respectively. There was high correspondence between the geographic collection sites of accessions and their inclusion in particular clusters. In addition, principal component analysis was used for data reduction and generating biplot. First four principal components explained 66.43% of total variability. Among the traits analysed, plant height, nodes/plant, days to spike emergence, number of tillers, leaf width and leaf length are major contributor towards phenotypic diversity. Further the trait-specific germplasm were identified for agronomic traits, disease resistance, popping and antioxidants activity, namely for earliness (IC343664, IC343689, IC343661, IC309064), spike girth (IC283693, IC283842, IC367638), dual purpose with high grain and fodder yield (IC283705, IC283745, IC283885 and IC335901 and so on). Four accessions of pearl millet germplasm viz., IC309064, IC393365, IC306465 and IC283866, were observed as multiple disease resistant. This study suggested that application of appropriate techniques and their interpretations provide more efficient way to identify potential accessions and improve the utilisation of germplasm collections in plant breeding.

Identification of pearl millet (Pennisetum glaucum (L.) R. Br.) germplasm with unique popping quality in the national genebank collections of India

Popping is an important trait that can add to commercial value of pearl millet for utilization as nutrition rich and low cost popped snacks. The purpose of the present study is to evaluate and identify possible donor for this novel trait in Indian pearl millet germplasm conserved in the national genebank. The study revealed sufficient variability for this trait in the landraces as well as improved genotypes. Positive association between expansion ratio and pop size suggested feasibility to develop germplasm combining both the attributes. The identified promising accessions (IC283734, IC283908 and IC283744) for the popping trait may be utilized in future breeding programme for introgression of popping trait into elite cultivars.

Sources of resistance to Fusarium wilt and root-knot nematode in indigenous chickpea germplasm

Fusarium wilt caused by Fusarium oxysporum, Schlecht. emend. Snyd. & Hans. f. sp. ciceri is prevalent in most chickpea-growing countries and is a major devastating disease. Host plant resistance is the most practical method of disease management. Indigenous chickpea germplasm reveals a heterogeneous genetic make-up and the response of resistance to wilt is an unexplored potential source for disease resistance. There are 70 indigenous germplasm lines selected on the basis of their agronomic performance and diverse areas of collections in the country. Of these, four accessions had a highly resistant score of 1 and six had a score of 3 using a 1–9 rating scale, indicating their level of resistance to Fusarium wilt (race 4). Other germplasm accessions of chickpea were found to be moderately resistant to highly susceptible disease reaction. Likewise, the same set of germplasm was also screened for Meloidogyne incognita (race 1) using pot culture under controlled condition. Only one accession was found to be resistant to this pest. These resistant gene sources can be utilised effectively for race-specific chickpea wilt and root-knot resistance breeding programmes.

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.