International Crops Research Institute for the Semi-Arid Tropics
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Comparison of shoot fly resistance qtls in sorghum introgression lines using snp genotyping
Get PDFShoot fly is a major pest in sorghum that causes significant annual yield loss. Use of pesticide to control this pest is an expensive and environmentally unsafe approach. Present study investigated the host plant resistance mechanism to develop shoot fly resistance (SFR) lines through transfer of shoot fly resistance QTLs (glossiness, trichome density, ovipositional non-preference) using SSR marker assisted backcrossing. Genomic regions for SFR showed four QTLs on SBI 01, SBI 07, SBI 05 and SBI 10 contributing up to 11.5%, 18.3%, 14% and 14.7% phenotypic variation. But QTLs on SBI 05 and SBI 10 for glossiness and trichome density are the major QTLs for which 10 SNPs have been designed. In earlier studies, three QTL regions associated with shoot fly resistance were successfully introgressed into elite cultivar SPV 1411 (Parbhani Moti) and a B line ICSB29004 using donors viz. J2658 (SBI01), J2614 (SBI10), and J2714
(SBI07) (which are derivatives of BTx 623). Phenotyping of introgression lines (ILs) led to the identification of resistant lines for each QTL region present on chromosome SBI-01, SBI-07 and SBI-10. Hence, in this study we have analysed the above developed ILs using single-nucleotide polymorphism (SNP) markers tightly linked to shoot fly resistant QTLs. The results showed that introgression lines with QTL present on chromosome SBI-10 were segregating for favorable alleles for leaf glossiness and for trichome density in homozygous condition. Other introgression lines with QTLs on chromosome SBI-01 and SBI-07 for component traits - oviposition non-preference, seedling vigor are segregated for glossiness trait also thus showing the transfer of non-targeted region, which in this case proved beneficial for SFR. This study showed that these SNPs can be used to analyze introgression lines and can be used as genomic markers for early generation selection of shoot fly resistance lines
Access to credit and heterogeneous effects on agricultural technology adoption: Evidence from large rural surveys in Ethiopia
Get PDFModern agricultural technologies hold huge potential for increasing productivity and reducing poverty in developing countries. However, adoption levels of these technologies have remained disappointingly low in Africa. This paper
analyzes the effect of access to credit on the likelihood of adoption and use intensity of chemical fertilizers using data from large rural surveys in Ethiopia. Using a heteroscedasticity-based identification strategy to address the endogenous nature of access to credit, we find that access to credit has significant positive effects on adoption and intensity of use of chemical fertilizers. However, important heterogeneities are observed. Credit obtained from formal sources is more important for the intensity of use than for the decision to adopt chemical
fertilizers. Credit taken with the primary purpose of financing agricultural inputs is more likely to promote adoption of chemical fertilizers than credit taken per
se. Furthermore, reported credit effects are larger when estimated against the sample of credit-constrained non-users as compared with the pool of the whole sample of credit non-users. The results remain robust to several sensitivity analyses. Our results yield useful implications for the design, promotion, and targeting of credit services to leverage their effect on adoption of agricultural technologies
Study of salinity induced oxidative stress and antioxidant responses in callus cultures of sugarcane
No full textSoil salinity adversely affects sugarcane growth and development by inducing impaired plant-water relations and osmotic imbalance. To understand the physio-biochemical response of sugarcane plants to salt (NaCl) stress, antioxidant enzymatic activity was analyzed in callus cultures of tolerant (BO 91) and susceptible (Co 0239) cultivars under in vitro conditions. Shoot tip explants were excised from the tolerant and susceptible plants and exposed to media without (2.2 ECw; control) and with (4.0, 6.0, 8.0, 10.0, 12.0, and 14.0 ECw) levels of salt for 90, 120, and 150 days. Significant effect of different salt concentrations on catalase (CAT), peroxidase (POX), nitrate reductase (NR), and indole-acetic acid (IAA) oxidase activities were evident from experimental observations. Under salinity stress conditions overall increasing trends of CAT and POX activity was found to be higher in callus cultures derived from tolerant cultivar compared to susceptible cultivar, indicates that antioxidant enzymes enhance cell protection against oxidative stress. Gradual decrease in NR and IAA oxidase activity with a corresponding increase in salt stress was less pronounced in callus of salt tolerant sugarcane than that of susceptible cultivar. A significant difference of soluble protein content was evident in callus cultures derived from both cultivars under varying degrees of salinity. Results of the present study showed that salt tolerant cultivar BO 91 has a more efficient defense mechanism and mitigates oxidative stress by maintaining higher anti-oxidant enzyme activity than the susceptible cultivar Co 0239. Based on multiple observations, it can be concluded that various biochemical and physiological mechanisms operated at cellular level in response to environmental stress in sugarcane. A comprehensive study of antioxidant enzymatic activity under in vitro salt stress conditions may prove to be a key breakthrough that has made a significant contribution to the literature and may guide other studies in the future
BIO-FORMULATIONS FOR PLANT GROWTH-PROMOTING STREPTOMYCES SP.
Get PDFA total of 19 strains of Streptomyces sp. viz., CAI-13, CAI-17, CAI-21, CAI-24, CAI-26, CAI-68, CAI-78, CAI-85, CAI93, CAI-121, CAI-127, CAI-140, CAI-155, KAI-26, KAI-27, KAI-32, KAI-90, KAI-180 and MMA-32 were earlier reported by
us as plant growth-promoters in chickpea, pigeonpea, sorghum, rice, pearl millet, tomato and chili. In the present investigation, the 19 strains of Streptomyces sp. were evaluated for development of a long term, eco-friendly and inexpensive formulation using different carrier materials such as peat, lignite, talc and talc + starch. Streptomyces strains were individually grown and
inoculated into the four selected carrier materials and stored in the refrigerator at 4oC. Samples were collected at the end of every month and tested for their viability and shelf life by plate count method for 12 months. All the 19 Streptomyces strains were viable and grown in all the tested carrier materials, however, peat inoculants showed greater viability and maintained stable colony forming units when compared talc, lignite, and talc + starch inoculants. It is concluded that peat formulation is best suited for mass multiplying the selected 19 Streptomyces strains.
Genetic analysis of tolerance to transient waterlogging stress in pigeonpea (Cajanus cajan L. Millspaugh)
Get PDFPigeonpea (Cajanus cajan L. Millspaugh) is mainly grown in the rainfed ecosystem during the monsoon season on deep vertisols, and it often faces transient waterlogging problems due to continuous and heavy downpours during early monsoon seasons. Thus, waterlogging has become a significant issue in most of the pigeonpea growing areas of the semi-arid tropics due to heavy rain during the initial crop growth stage, which causes 30 to 40% economic yield loss in India and around the world. Only a few sources of waterlogging tolerant genotypes are available in pigeonpea but are not in the required duration. Hence, the present investigation was carried out to identify waterlogging tolerant pigeonpea genotypes in different durations suitable for different agroecologies of India and to find ideal selection indices as appropriate strategies to identify waterlogging tolerant genotypes. In this study, 162 genotypes were screened under in vitro conditions for 2, 4, 6, and 8 days by submerging seeds. Of these, 33 genotypes could survive for eight days. Further, following a standard screening protocol; these 33 pigeonpea genotypes were screened under pot culture for two years (2020 and 2021). Based on different morpho-physiological parameters and waterlogging tolerant coefficient, genotypes ICP-10397, ICP-7507, ICP-7869, ICP-7148, ICP-4903 ICP-16309, ICP-7375, ICP-6815, ICP-7507, and ICP-6128 were identified as tolerant to transient waterlogging. In addition, this study reports the existence of substantial genetic variation for waterlogging tolerant traits in pigeonpea. Stress indices, such as stress tolerance index) (STI), mean relative performance (MRP) and relative efficiency index (REI) were identified as the ideal selection index. Therefore, identified genotypes are further validated and can be deployed in waterlogging tolerance pigeonpea breeding programs
SSR and SNP Marker-Based Investigation of Indian Rice Landraces in Relation to Their Genetic Diversity, Population Structure, and Geographical Isolation
Get PDFIndia is blessed with an abundance of diverse rice landraces in its traditional cultivated areas. Two marker systems (simple sequence repeats (SSR) and single nucleotide polymorphism (SNP)) were used to study a set of 298 rice landrace accessions collected from six different regions of
India (Andaman and Nicobar Islands, Chhattisgarh, Jharkhand, Uttar Pradesh, Uttarakhand, and West Bengal). Thirty hyper-variable simple sequence repeats (HvSSRs) and 32,782 single nucleotide polymorphisms (SNPs) were used in inferring genetic structure and geographical isolation. Rice
landraces from Uttar Pradesh were the most diverse, with a gene diversity value of 0.42 and 0.49 with SSR and SNP markers, respectively. Neighbor-joining trees classified the rice landraces into two major groups with SSR and SNP markers, and complete geographical isolation was observed with SSR markers. Fast STRUCTURE analysis revealed four populations for SSR markers and three populations for SNP markers. The population structure with SSR markers showed that few individuals from Uttarakhand and Andaman and Nicobar Islands were grouped in small clusters. Population structure analysis with SNP markers showed not very distinct region-wise clustering among the rice landraces. Discriminant analysis of principal components (DAPC) and minimum spanning network (MSN) using SSR markers showed region-wise grouping of landraces with some intermixing, but DAPC and MSN with SNP markers showed very clear region-wise clustering. Genetic differentiation of rice landraces between the regions was significant with both SSR (Fst 0.094–0.487) and SNP markers (Fst 0.047–0.285). A Mantel test revealed a positive correlation between the genetic and geographic distance of rice landraces. The present study concludes that rice landraces investigated in this study
were very diverse, and unlinked SSR markers show better geographical isolation than a large set of SNP markers
Enabling gender and social inclusion in climate and agriculture policy and planning through foresight processes: assessing challenges and leverage points
Get PDFScenario-guided foresight processes are increasingly used to engage a broad range of stakeholders in sharing knowledge, reflecting, and setting priorities to respond to present and future climate change related dynamics. They are particularly useful to inform agricultural policies and planning in the face of a changing climate. Such participatory approaches are key to integrating multidisciplinary expertise, perspectives, and viewpoints, and ensuring that the multi-faceted vulnerabilities and the development needs of diverse groups are addressed in the design, planning, and implementation of climate adaptation policy. However, in practice, ensuring meaningful participation in the policy process is far from straightforward. In this paper, we examine the integration of gender and social inclusion considerations in 15 scenario-guided foresight use cases across Africa, Latin America, and Southeast Asia to determine the ways in which gender and social inclusion dynamics were considered and integrated at different stages of scenario-guided planning processes. To inform the analysis, we use qualitative data from key informant interviews, interviewing scenario coordinators and a gender and social inclusion expert who was engaged in one of the cases; we also review associated reports and outputs. The results suggest that few scenario-guided planning processes centred gender and social inclusion considerations from an early stage and consistently throughout the interventions, translating often into low diversity of stakeholders and insufficient depth reached in the content produced. A number of common challenges are reported including time, budget, and human resource constraints, as well as existing power and institutional dynamics. The latter includes, for instance, low women’s representation in technical organizations or important hierarchical social norms structuring discussions. While the focus on the future can disrupt established modes of doing, the complexity of foresight methods can also undermine effective participation leading to important trade-offs. Innovations in the modes of engagement and parallel processes with diverse groups can be important leverage points for inclusion within policymaking processes.
Key policy insights
Gender and social inclusion should be prioritized from the onset and integrated at different stages of scenario-guided planning processes, notably by allocating more time, human, and financial resources to ensure inclusiveness.
Parallel consultations among diverse organizations and groups can provide effective spaces for often-sidelined or marginalized groups’ interests and needs to be integrated into policy decision-making given the existing power structures that regulate access to many workshops and related discussions. Multi-scale engagements with different networks also help deepen understanding and reconcile gaps across scales of decision-making (e.g. from local level to national level).
Practitioners should further their use of foresight processes and development of tools and methods for integrating gender and social inclusion in these as part of the policy process, as well as strengthen the capacities, expertise, and role of conveners.
Promotion and dissemination of existing gender and social inclusion research and documentation as well as support for learning and reflection to refine identified leverage points can lead to improved success
Evaluation of genetic diversity using SSR markers and link with drought response of Azerbaijani durum wheat (Triticum durum Desf.) genotypes
No full textGenetic diversity of 45 genotypes were shown in the list of genotypes Azerbaijani durum wheat (Triticum durum Desf.) genotypes were screened using simple sequence repeats (SSRs). These accessions were collected from various bioclimatic regions of Azerbaijan. Out of the used 22 primers, 13 primers showed polymorphism and were selected for the analyses. Among the genotypes under study, 31 alleles were detected. The highest number of alleles was detected in locus gwm 335 (on chromosome 5B) and on locus gwm 445 (on chromosome 2A) with 5 and 4 alleles, respectively. The lowest number of alleles was found in locus gwm 617 with only 1 allele. For A, B, and D genomes, the total number of alleles detected was 14, 15, and 2, respectively. PIC value between studied SSR markers was 0.912 and this result shows high genetic diversity between Azerbaijani durum wheat genotypes. Therefore, these primers can be recommended for studying the genetic diversity of Azerbaijani durum wheat accessions. The genetic structure of the genotypes was analyzed and the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) dendrogram revealed five major clusters using Nei genetic distance index. The results revealed that SSR markers can efficiently evaluate genetic variation in the wheat samples. Based on the previous characterization of the drought response of these genotypes, links could be established between the SSR markers and drought tolerance. If some of the SSR markers are confirmed for their association with drought tolerance, then, they can be used as markers for the identification of drought-tolerant cultivars needed to enhance wheat productivity for farmers dealing with harsh conditions
Integrating Association Mapping, Linkage Mapping, Fine Mapping with RNA Seq Conferring Seedling Vigor Improvement for Successful Crop Establishment in Deep Sown Direct‑Seeded Rice
Get PDFBackground Ongoing large-scale shift towards direct seeded rice (DSR) necessitates a convergence of breeding and genetic approaches for its sustenance and harnessing natural resources and environmental benefits. Improving seedling vigour remains key objective for breeders working with DSR. The present study aims to understand the genetic control of seedling vigour in deep sown DSR. Combined genome-wide association mapping, linkage mapping, fine mapping, RNA-sequencing to identify candidate genes and validation of putative candidate genes were performed in the present study.
Results Significant phenotypic variations were observed among genotypes in both F3:4:5 and BC2F2:3 populations.
The mesocotyl length showed significant positive correlation with %germination, root and shoot length. The 881 kb
region on chromosome 7 reported to be associated with mesocotyl elongation. RNA-seq data and RT-PCR results
identified and validated seven potential candidate genes. The four promising introgression lines free from linkage
drag and with longer mesocotyl length, longer root length, semi-dwarf plant height have been identified.
Conclusion The study will provide rice breeders (1) the pre breeding material in the form of anticipated DSR adapted
introgression lines possessing useful traits and alleles improving germination under deep sown DSR field conditions
(2) the base for the studies involving functional characterization of candidate genes. The development and utilization of improved introgression lines and molecular markers may play an important role in genomics-assisted breeding (GAB) during the pyramiding of valuable genes providing adaptation to rice under DSR. Our results offer a robust and reliable package that can contribute towards enhancing genetic gains in direct seeded rice breeding programs
Key descriptors for foxtail millet
Get PDFFoxtail millet (Setaria italica (L.) P. Beauv.) is one of the oldest cereals, and its domestication in China dates to over 10000 years ago. Foxtail millet grain is used for human consumption and as feed for poultry and cage birds. The husked grain is used as food in Asia, south-eastern Europe and Africa. The Key descriptors for foxtail millet consist of an initial minimum set of characterization and evaluation descriptors for Setaria italica and Setaria pumila of the family Poaceae. This strategic set aims at facilitating access to and utilization of these species, and it does not exclude the addition of other descriptors later. The key set of access and utilization descriptors was defined through an online survey in which 29 experts from 20 organizations and universities from 13 countries participated. Survey results were subsequently validated in consultation with a Core Advisory Group (see “Contributors”) led by ICAR-IIMR, ICAR-NBPGR and ICRISAT. The strategic set of data standards is designed to facilitate access to and utilization of plant genetic resources for food and agriculture. The list is expected to support studies focusing on genetic and morphological diversity of foxtail millet and its wild and weedy relatives, as well those on conservation, domestication and use