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Niamey, Niger

Upadhyaya H.D.,Indian International Crops Research Institute for the Semi Arid Tropics | Dwivedi S.L.,Indian International Crops Research Institute for the Semi Arid Tropics | Vadez V.,Indian International Crops Research Institute for the Semi Arid Tropics | Hamidou F.,Sahelian Center | And 4 more authors.
Crop Science | Year: 2014

Peanut (Arachis hypogaea L.) is extensively grown by resource-poor farmers in the semiarid tropics where many abiotic and biotic stresses limit the crop's productivity and seed quality. Peanut cultivars with enhanced host-plant resistance, adaptation to abiotic stress, input-use efficiency, and yield potential will maximize yield gains and minimize inputs to sustain production. The peanut mini core collection was evaluated for agronomic traits in multienvironment trials at Patancheru, India. The published information on 184 mini core accessions revealed 28 accessions resistant to abiotic stress, 30 resistant to biotic stress, and 18 that were agronomically desirable but susceptible to stresses, while 16 were seed nutrient dense. The mini core is part of the composite collection, which was previously genotyped using SSRs. The agronomic evaluation, stress response, and nutritional information together with genotyping data were used to identify genetically diverse germplasm with agronomically beneficial traits: ICG 12625 (resistance to drought, low temperature, late leaf spot [LLS], Aspergillus flavus Link, bacterial wilt; high oil and good oil quality) and ICG 442 (resistance to drought, salinity, P deficiency); ICG 12625 and ICG 2381 (resistance to rust, A. flavus; good oil quality); ICG 12697 (resistance to LLS, rust, A. flavus) and ICG 6022 (resistance to early leaf spot [ELS], LLS); ICG 14710 (high oil, Fe, Zn) and ICG 7963 (high protein, Fe, Zn); ICG 11426 (resistance to ELS, LLS, rust) and ICG 5221 (high Fe and Zn and good oil quality). Accessions with adaptation to rainy and/or post-rainy environments were ICG# 434, 5745, 8285, 10036, 11088, 11651, 12625, 15042, and 15419. These accessions are ideal genetic resources that may be used to develop agronomically superior and nutritionally enhanced peanut cultivars with multiple resistances to abiotic and biotic stresses. © Crop Science Society of America.

Ramu P.,Indian International Crops Research Institute for the Semi Arid Tropics | Ramu P.,Osmania University | Billot C.,CIRAD - Agricultural Research for Development | Rami J.-F.,CIRAD - Agricultural Research for Development | And 5 more authors.
Theoretical and Applied Genetics | Year: 2013

Selection and use of genetically diverse genotypes are key factors in any crop breeding program to develop cultivars with a broad genetic base. Molecular markers play a major role in selecting diverse genotypes. In the present study, a reference set representing a wide range of sorghum genetic diversity was screened with 40 EST-SSR markers to validate both the use of these markers for genetic structure analyses and the population structure of this set. Grouping of accessions is identical in distance-based and model-based clustering methods. Genotypes were grouped primarily based on race within the geographic origins. Accessions derived from the African continent contributed 88.6 % of alleles confirming the African origin of sorghum. In total, 360 alleles were detected in the reference set with an average of 9 alleles per marker. The average PIC value was 0.5230 with a range of 0.1379-0.9483. Sub-race, guinea margaritiferum (Gma) from West Africa formed a separate cluster in close proximity to wild accessions suggesting that the Gma group represents an independent domestication event. Guineas from India and Western Africa formed two distinct clusters. Accessions belongs to the kafir race formed the most homogeneous group as observed in earlier studies. This analysis suggests that the EST-SSR markers used in the present study have greater discriminating power than the genomic SSRs. Genetic variance within the subpopulations was very high (71.7 %) suggesting that the germplasm lines included in the set are more diverse. Thus, this reference set representing the global germplasm is an ideal material for the breeding community, serving as a community resource for trait-specific allele mining as well as genome-wide association mapping. © 2013 Springer-Verlag Berlin Heidelberg.

Subbarao G.V.,Japan International Research Center for Agricultural science | Sahrawat K.L.,Indian International Crops Research Institute for the Semi Arid Tropics | Nakahara K.,Japan International Research Center for Agricultural science | Rao I.M.,Centro Internacional Of Agricultura Tropical Ciat | And 6 more authors.
Annals of Botany | Year: 2013

BackgroundAgriculture is the single largest geo-engineering initiative that humans have initiated on planet Earth, largely through the introduction of unprecedented amounts of reactive nitrogen (N) into ecosystems. A major portion of this reactive N applied as fertilizer leaks into the environment in massive amounts, with cascading negative effects on ecosystem health and function. Natural ecosystems utilize many of the multiple pathways in the N cycle to regulate N flow. In contrast, the massive amounts of N currently applied to agricultural systems cycle primarily through the nitrification pathway, a single inefficient route that channels much of this reactive N into the environment. This is largely due to the rapid nitrifying soil environment of present-day agricultural systems.ScopeIn this Viewpoint paper, the importance of regulating nitrification as a strategy to minimize N leakage and to improve N-use efficiency (NUE) in agricultural systems is highlighted. The ability to suppress soil nitrification by the release of nitrification inhibitors from plant roots is termed 'biological nitrification inhibition' (BNI), an active plant-mediated natural function that can limit the amount of N cycling via the nitrification pathway. The development of a bioassay using luminescent Nitrosomonas to quantify nitrification inhibitory activity from roots has facilitated the characterization of BNI function. Release of BNIs from roots is a tightly regulated physiological process, with extensive genetic variability found in selected crops and pasture grasses. Here, the current status of understanding of the BNI function is reviewed using Brachiaria forage grasses, wheat and sorghum to illustrate how BNI function can be utilized for achieving low-nitrifying agricultural systems. A fundamental shift towards ammonium (NH4 +)-dominated agricultural systems could be achieved by using crops and pastures with high BNI capacities. When viewed from an agricultural and environmental perspective, the BNI function in plants could potentially have a large influence on biogeochemical cycling and closure of the N loop in crop-livestock systems. © 2012 The Author.

Vadez V.,Indian International Crops Research Institute for the Semi Arid Tropics | Kholova J.,Indian International Crops Research Institute for the Semi Arid Tropics | Hummel G.,Phenospex | Zhokhavets U.,Phenospex | And 2 more authors.
Journal of Experimental Botany | Year: 2015

In this paper, we describe the thought process and initial data behind the development of an imaging platform (LeasyScan) combined with lysimetric capacity, to assess canopy traits affecting water use (leaf area, leaf area index, transpiration). LeasyScan is based on a novel 3D scanning technique to capture leaf area development continuously, a scanner-to-plant concept to increase imaging throughput and analytical scales to combine gravimetric transpiration measurements. The paper presents how the technology functions, how data are visualised via a web-based interface and how data extraction and analysis is interfaced through 'R' libraries. Close agreement between scanned and observed leaf area data of individual plants in different crops was found (R2 between 0.86 and 0.94). Similar agreement was found when comparing scanned and observed area of plants cultivated at densities reflecting field conditions (R2 between 0.80 and 0.96). An example in monitoring plant transpiration by the analytical scales is presented. The last section illustrates some of the early ongoing applications of the platform to target key phenotypes: (i) the comparison of the leaf area development pattern of fine mapping recombinants of pearl millet; (ii) the leaf area development pattern of pearl millet breeding material targeted to different agro-ecological zones; (iii) the assessment of the transpiration response to high VPD in sorghum and pearl millet. This new platform has the potential to phenotype for traits controlling plant water use at a high rate and precision, of critical importance for drought adaptation, and creates an opportunity to harness their genetics for the breeding of improved varieties. © 2015 The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Tesfamariam T.,Crop | Yoshinaga H.,Crop | Deshpande S.P.,Indian International Crops Research Institute for the Semi Arid Tropics | Srinivasa Rao P.,Indian International Crops Research Institute for the Semi Arid Tropics | And 5 more authors.
Plant and Soil | Year: 2014

Background and aims: Nitrification and denitrification are the two most important processes that contribute to greenhouse gas emission and inefficient use of nitrogen. Suppressing soil nitrification through the release of nitrification inhibitors from roots is a plant function, and termed "Biological Nitrification Inhibition (BNI)". We report here the role and contribution of sorgoleone release to sorghum-BNI function. Methods: Three sorghum genotypes (Hybridsorgo, IS41245 and GDLP 34-5-5-3) were evaluated for their capacity to release sorgoleone, which has BNI-activity, in hydroponic and soil culture. Sorgoleone released was measured using HPLC; BNI-activity was determined using a luminescent recombinant Nitrosomonas europaea assay. Results: Sorgoleone production and BNI-activity release by roots are closely associated (1 μg of sorgoleone is equivalent to 1 ATU activity in assay). Purified sorgoleone inhibited Nitrosomonas activity and suppressed soil nitrification. Sorghum genotypes release varying quantity of sorgoleone; GDLP 34-5-5-3 and Hybridsorgo showed higher capacity for both sorgoleone release and BNI-activity than did IS41245. In soil culture, GDLP 34-5-5-3 released higher quantity of sorgoleone into the rhizosphere, which had higher BNI-activity, and suppressed soil nitrification to a greater extent than did by IS41245. Conclusions: These results demonstrate genetic differences for sorgoleone release and its functional link with BNI-capacity; there is potential for genetic improvement of sorghum BNI-capacity and deployment of this in low-nitrifying sorghum production systems. © 2014 Springer International Publishing Switzerland.

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