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Genome-wide association analyses of agronomic traits and Striga hermonthica resistance in pearl millet

Hussein Shimelis Chris Ojiewo Abhishek Rathore (2023, [Artículo])

Pearl millet (Pennisetum glaucum [L.] R. Br.) is a nutrient-dense, relatively drought-tolerant cereal crop cultivated in dry regions worldwide. The crop is under-researched, and its grain yield is low (< 0.8 tons ha−1) and stagnant in the major production regions, including Burkina Faso. The low productivity of pearl millet is mainly attributable to a lack of improved varieties, Striga hermonthica [Sh] infestation, downy mildew infection, and recurrent heat and drought stress. Developing high-yielding and Striga-resistant pearl millet varieties that satisfy the farmers’ and market needs requires the identification of yield-promoting genes linked to economic traits to facilitate marker-assisted selection and gene pyramiding. The objective of this study was to undertake genome-wide association analyses of agronomic traits and Sh resistance among 150 pearl millet genotypes to identify genetic markers for marker-assisted breeding and trait introgression. The pearl millet genotypes were phenotyped in Sh hotspot fields and screen house conditions. Twenty-nine million single nucleotide polymorphisms (SNPs) initially generated from 345 pearl millet genotypes were filtered, and 256 K SNPs were selected and used in the present study. Phenotypic data were collected on days to flowering, plant height, number of tillers, panicle length, panicle weight, thousand-grain weight, grain weight, number of emerged Striga and area under the Striga number progress curve (ASNPC). Agronomic and Sh parameters were subjected to combined analysis of variance, while genome-wide association analysis was performed on phenotypic and SNPs data. Significant differences (P < 0.001) were detected among the assessed pearl millet genotypes for Sh parameters and agronomic traits. Further, there were significant genotype by Sh interaction for the number of Sh and ASNPC. Twenty-eight SNPs were significantly associated with a low number of emerged Sh located on chromosomes 1, 2, 3, 4, 6, and 7. Four SNPs were associated with days-to-50%-flowering on chromosomes 3, 5, 6, and 7, while five were associated with panicle length on chromosomes 2, 3, and 4. Seven SNPs were linked to thousand-grain weight on chromosomes 2, 3, and 6. The putative SNP markers associated with a low number of emerged Sh and agronomic traits in the assessed genotypes are valuable genomic resources for accelerated breeding and variety deployment of pearl millet with Sh resistance and farmer- and market-preferred agronomic traits.

High-Yielding Varieties Striga-Resistant Agronomic Parameters CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA GENOME-WIDE ASSOCIATION STUDIES STRIGA HERMONTHICA PEARL MILLET

¿Cómo mejorar la provisión del transporte público?: el ordenamiento de las rutas de colectivos para alimentar las estaciones del Tren Suburbano en el Estado de México

Pablo de los Cobos Alcalá (2020, [Tesis de maestría])

Después de caminar, el transporte público colectivo es la base de la movilidad en la Zona Metropolitana del Valle de México. Sin embargo, los incentivos de la regulación del sector, así como la relación entre transportistas y autoridad, han hecho que este servicio tenga deficiencias que diferentes gobiernos han intentado mejorar. Esta tesina versa sobre uno de esos intentos: el ordenamiento de las rutas alimentadoras hacia las estaciones del Tren Suburbano en el Estado de México. A partir de entrevistas semiestructuradas y análisis documental, este trabajo describe la influencia que tienen las estructuras institucionales de gobernanza en los esfuerzos de mejora del transporte público. Esta tesina hace dialogar a las teorías neoinstitucionalistas y de clientelismo político al analizar la forma en la que los grupos transportistas vetan los intentos de mejora por parte de la autoridad. Asimismo, este trabajo discute la pertinencia de las tipologías de provisión del transporte público para comprender las ventajas de las diferentes modalidades de participación de la autoridad, sector privado y personas usuarias. El estudio de las tipologías permite estimar las posibilidades de éxito de ciertas estrategias al considerar si éstas van en un sentido concordante con las lógicas de estructuración institucional.

Urban transportation -- Mexico -- Mexico (State) -- Case studies. CIENCIAS SOCIALES CIENCIAS SOCIALES