International Crops Research Institute for the Semi-Arid Tropics
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Multi-Population Analysis for Leaf and Neck Blast Reveals Novel Source of Neck Blast Resistance in Rice
Get PDFRice blast is one of the most devastating biotic stresses that limits rice productivity. The North Eastern Hill (NEH) region of India is considered to be one of the primary centres of diversity for both rice and pathotypes of Magnaporthe grisea. Therefore, the present study was carried out to elucidate the genetic basis of leaf and neck blast resistance under Meghalaya conditions. A set of 80 diverse genotypes (natural population) and 2 F2 populations involving resistant parent, a wildtype landrace, LR 5 (Lal Jangali) and susceptible genotypes Sambha Mahsuri SUB 1 (SMS) and LR 26 (Chakhao Poireiton) were used for association analysis of reported major gene-linked markers with leaf and neck blast resistance to identify major effective genes under local conditions. Genotyping using twenty-five gene-specific markers across diverse genotypes and F2 progenies revealed genes Pi5 and Pi54 to be associated with leaf blast resistance in all three populations. Genes Pib and qPbm showed an association with neck blast resistance in both natural and LR 5 × SMS populations. Additionally, a set of 184 genome-wide polymorphic markers (SSRs and SNPs), when applied to F2-resistant and F2-susceptible DNA bulks derived from LR 5 × LR 26, suggested that Pi20(t) on chromosome 12 is one of the major genes imparting disease resistance. Markers snpOS318, RM1337 and RM7102 and RM247 and snpOS316 were associated with leaf blast and neck blast resistance, respectively. The genotypes, markers and genes will help in marker-assisted selection and development of varieties with durable resistance
Selective InDel Marker Identification Across the Peanut (Arachis hypogaea L.) Genome Using ddRADSeq
Get PDFThe advent of next-generation sequencing technologies, mainly double digest restriction site-associated DNA sequencing (ddRADSeq), has significantly advanced the development of molecular markers for crop genetics. This study used ddRADSeq to identify and develop insertion-deletion (InDel) markers in 25 peanut genotypes from diverse geographic regions. The bioinformatic analysis unveiled 62728 InDels across the peanut genome, predominantly between 1-5 bp, which constituted 96% of the total, while InDels of ≥ 6 bp accounted for 3.96%. We focused on 1013 InDels of at least 10 bp for further analysis, representing 1.61% of the total reads, with a distribution of 832 insertions and 181 deletions. Of those, 21 InDels were selected for primer design and successfully amplified to produce markers within a 150-400 bp range. Approximately 14% of InDels were located in coding sequences enhancing their potential utility in genomics-led breeding. These markers' polymorphic information content (PIC) varied from 0 to 0.371, demonstrating substantial genetic diversity with an average of 0.163. These findings confirm the effectiveness of ddRADSeq for InDel marker development in peanuts, illustrating its potential to enhance marker-assisted breeding programs by providing robust tools for assessing genetic diversity
How has the COVID-19 pandemic impacted undocumented migrants' children?
No full textThe COVID-19 pandemic has brought to the forefront issues of economic, political, and social marginalisation faced by migrant populations globally. In India, the issue of undocumented migration has been at the centre of political debates for the past few decades and has been manifested in recurrent legislation around the discourse of citizenship. As documentation becomes a precondition for the statist recognition of citizenship, the conditions of vulnerable groups such as undocumented migrants entail precarity. For undocumented migrant children whose existence is located around questions of citizenship, their rights and welfare become increasingly precarious amidst the twin burdens imposed by their undocumentedness and restrictions during the COVID-19 pandemic.
This chapter explores the issues faced by undocumented migrant children in India who are enmeshed in a precarious tangle between undocumentedness and soaring vulnerabilities amidst political and health crises. It also brings to light the lack of a social justice framework to cater to children of undocumented migrants. It takes into account how the intersectional location of these children in caste, class, gender, ethnicity, and religious positionings shape their ability to access welfare and rights across sectors such as health, education, nutrition, and security at the destinations
Linking of Genebank to Breeding and Food Security
Get PDFGenebanks have the responsibility of collecting, maintaining, characterizing, evaluating, documenting and distributing plant genetic resources for research, education and breeding purposes globally. About 7.4 million germplasm accessions are conserved ex situ in the genebanks globally. Efficient use of germplasm in crop improvement is depending on the availability of accession-level information on the traits of interest. For the majority of accessions, only basic passport and characterization data are available, while data on unique traits is generally lacking that limits their utilization in crop improvement. Development of germplasm diversity and trait-specific subsets enhanced availability of accessions-level information. Researchers can search in the global plant genetic resources database called Genesys PGR which contains passport data, characterization and evaluation data sets and trait-specific subsets developed on various crops (https://www.genesys-pgr.org/). The impact of germplasm for contributing to increased yield, adaptation, nutrition and improved health and sustainable agriculture has been demonstrated in many crops. There are many instances where a single plant genetic resource has proved to have large commercial value by conferring a specific trait. With the availability of new technologies such as high-throughput large-scale phenotypic assessment for key traits and use of multi-omic tools could accelerate rapid identification of traits and genes for breeding improved cultivars. This chapter details about ex situ germplasm conservation, discovering climate resilient germplasm following different approaches such as diversity and trait-specific subsets, focused germplasm identification strategy, molecular characterization of germplasm and trait discovery, access to germplasm and the impact of genebank contributing to the global agriculture sustainability
Harnessing the potential of pigeonpea and maize feedstock biochar for carbon sequestration, energy generation, and environmental sustainability
Get PDFCrop residues in agriculture pose disposal challenges and contribute to air pollution when burned. This study aims
to use pigeonpea and maize stalks to produce biochar at different pyrolysis temperatures. Biochar can serve in carbon sequestration, as a soil amendment, and as an alternative fuel source. Pyrolysis was conducted at 400, 500, and 600 °C to examine the effects on physicochemical properties, fuel, and energy related properties. Increase in temperatures resulted in decrease of biochar yield, volatile matter, and O/C and H/C atomic ratios, while ash content and essential nutrients increased. Yield was observed to be higher in pigeonpea stalks derived biochar compared to maize stalks derived biochar at same pyrolysis temperatures. The yields of pigeonpea stalks derived biochar at 400 °C, 500 °C, and 600 °C are 34, 33 and 29%, respectively, and the yields of maize biomass-derived biochar at 400 °C, 500 °C,
and 600 °C are 29, 28, and 26%, respectively. The organic carbon content is found to be higher in the biochar samples
prepared at 600 °C, i.e., 10.44%, and 10.39% for pigeonpea and maize-derived biochar, respectively. The essential
elements of biochar were increased with an increase in pyrolysis temperature except nitrogen which is conversely
related to temperature. The biochar obtained through pyrolysis at 400 °C demonstrated superior characteristics
compared to biochar produced at other temperatures. It exhibited a higher biochar yield, with approximately 84.60%
for pigeonpea and 64.85% for maize fixed carbon content. Additionally, the energy retention efficiency was higher,
reaching 67.33% for pigeonpea and 42.70% for maize-derived biochar at a pyrolysis temperature of 400 °C. The fixed
carbon recovery efficiency was also notable at around 200.44% for PPS and 142.37% for maize biochar which is higher compared to biochar produced at other temperatures. Furthermore, the higher heating value (HHV) was approximately 30.75 MJ kg−1 for both the biochars, indicating their suitability as alternative solid fuels. A significant CO2 reduction potential of 84 CO2 eq kg−1 and 55 CO2 eq kg−1 was observed for pigeonpea and maize biochar, respectively. Hence, biochar is a promising and effective option for carbon sequestration, offering environmental benefits
Optimizing speed breeding and seed/pod chip based genotyping techniques in pigeonpea: A way forward for high throughput line development
Get PDFBackground
The challenge of pigeonpea breeding lies in its photosensitivity and seasonal specificity. This poses a problem to the breeder, as it restricts to single generation advancement in a year. Currently, the cross to cultivar gap is twelve to thirteen years resulting in a limited number of varietal releases over the past six decades. Shortening the breeding cycle was need of the hour, unlikely achieved by conventional breeding. To overcome these hindrances speed breeding was a necessary leap. An experiment was planned to optimize the speed breeding coupled with single seed descent and seed or pod chip-based genotyping to shorten the breeding cycle in pigeonpea at ICRISAT, Hyderabad. Monitored photoperiod, light wavelength, temperature and crop management regime were the indicators attributing to the success of speed breeding.
Result
A photoperiod of 13 h: 8 h: 13 h at vegetative: flowering and pod filling stages is ideal for shortening the breeding cycle. Broad spectrum light (5700 K LED) hastened early vegetative growth and pod formation. Whereas far-red (735 nm) light favoured early flowering. A significant difference between the photoperiods, genotypes as well as photoperiod x genotype interaction for both days to flowering and plant height was noted.
Conclusion
The optimized protocol serves as a road map for rapid generation advancement in pigeonpea. Deploying this protocol, it is possible to advance 2–4 generations per year. The breeding cycle can be reduced to 2–4 years which otherwise takes 7 years under conventional breeding. Single Seed Descent and seed or pod chip-based genotyping for early generation marker assisted selection, strengthened the precision of this technique aiding in high throughput line development
Identification of disease resistant bmr sorghum recombinant inbred lines derived from diverse donor and recurrent parents
No full textBrown midrib mutants discovered in maize, sorghum and pearl millet through mutagenesis constitute an important genetic resource. Studies indicated that the discovered bmr mutants not only have lower lignin content than their wild-type counterparts, but they are also associated with an improved fodder digestibility and improved process yield in biofuel production. There is need to combine this novel trait with disease resistance to enhance the commercial utilisation of sorghum cultivars by end users. We have assessed reaction of a random set of F2:4 generations that represented progenies from 46 unique cross combinations involving 12 recurrent parents and 5 donor parents against anthracnose, leaf blight, and charcoal rot diseases. The genotypes were artificially inoculated with the pure cultures of the disease-causing organisms in separate experiments. There were significant genotypic differences for the disease severity and area under disease progress curve (AUDPC) in leaf blight and anthracnose, and number of nodes crossed and lesion length in charcoal rot disease. Progeny expressing bmr12 and bmr6bmr12 were generally superior in resistance to foliar diseases and charcoal rot than bmr6. The reaction of most of the bmr lines against the diseases was similar to their corresponding wild-type parents. Principle component and hierarchical cluster analysis identified sets of genotypes with bmr6, bmr12, and bmr6bmr12 loci that combine desirable levels of resistance to two or all the three diseases. These sets of bmr derived lines could be the potential sources to develop disease resistant bmr hybrids and pure line varieties, and improved breeding populations in sorghum
Genome‑wide association study and expression of candidate genes for Fe and Zn concentration in sorghum grains
Get PDFSorghum germplasm showed grain Fe and Zn genetic variability, but a few varieties were biofortified with these minerals. This work contributes to narrowing this gap. Fe and Zn concentrations along with 55,068 high-quality GBS SNP data from 140 sorghum accessions were used in this study. Both micronutrients exhibited good variability with respective ranges of 22.09–52.55 ppm and 17.92–43.16 ppm. Significant marker-trait associations were identified on chromosomes 1, 3, and 5. Two major effect SNPs (S01_72265728 and S05_58213541) explained 35% and 32% of Fe and Zn phenotypic variance, respectively. The SNP S01_72265728 was identified in the cytochrome P450 gene and showed a positive effect on Fe accumulation in the kernel, while S05_58213541 was intergenic near Sobic.005G134800 (zinc-binding ribosomal protein) and showed negative effect on Zn. Tissue-specific in silico expression analysis resulted in higher levels of Sobic.003G350800 gene product in several tissues such as leaf, root, flower, panicle, and stem. Sobic.005G188300 and Sobic.001G463800 were expressed moderately at grain maturity and anthesis in leaf, root, panicle, and seed tissues. The candidate genes expressed in leaves, stems, and grains will be targeted to improve grain and stover quality. The haplotypes identified will be useful in forward genetics breeding
Agricultural innovation platforms for scaling innovations – insights from the Transforming Irrigation in Southern Africa project
Get PDFA major challenge in agricultural research for development is understanding how agricultural innovation platforms (AIPs) scale innovations to maximize environmental and socioeconomic benefits. Multilevel perspective and anchoring frameworks were used to assess the effectiveness of AIPs in anchoring innovations to go to scale under the Transforming Irrigation in Southern Africa project. Resultant scaling approaches, and whether and how scaling impacts were sustained are assessed at the sociotechnical regime. AIP collective capabilities ensured anchoring strategies and scaling approaches utilized by AIPs led to the embedding of innovations within the agricultural sociotechnical system. This resulted in changes in policy, behaviour and practices