Person: Sandoval Islas, J.S.
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Sandoval Islas
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J.S.
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Sandoval Islas, J.S.
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- Los nematodos formadores de quistes en México(Sociedad Mexicana de Fitopatología, 2006) Tovar-Soto, A.; Cid del Prado-Vera, I.; Sandoval Islas, J.S.; Martinez-Garza, A.; Nicol, J.M.; Evans, K.
Publication - Genetica de la resistencia a roya amarilla en plantas adultas de trigo harinero(Sociedad Mexicana de Fitogenética, 2009) Villaseñor-Espin, O.M.; Huerta-Espino, J.; Leyva Mir, S.G; Villaseñor Mir, H.E.; Singh, R.P.; Sandoval Islas, J.S.; Espitia-Rangel, E.La roya lineal amarilla del trigo (Triticum aestivum L.) causada por Puccinia striiformis f. sp. tritici es una enfermedad de creciente importancia en los Valles Altos de México, pues llega a causar perdidas en el rendimiento mayores a 60 % y deteriora la calidad del grano. Las variedades de trigo harinero 'Juchi F2000', 'Nahuatl F2000' y 'Tlaxcala F2000' fueron Iiberadas por el Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias en el año 2000 para siembras de temporal 0 secano, que mostraron diferentes grados de infección por esta enfermedad. Para determinar la genética de la resistencia a roya amarilla de las tres variedades, estas se cruzaron con la variedad susceptible 'AvocetYrA'. Los progenitores y 148 familias F3 por cruza se evaluaron durante el Verano 2002 en Toluca, Estado de México, bajo una incidencia natural de roya amarilla. Con los resultados de las familias F3 se determinó que la resistencia de planta adulta a roya amarilla en 'Juchi F2000' esta regalada por tres genes menores de efectos aditivos, y que en 'Nahuatl F2000' y 'Tlaxcala F2000' está condicionada por tres 0 cuatro genes de la misma naturaleza. Un gen en común en las tres variedades fue Yr18, que confiere resistencia parcial de planta adulta a roya amarilla. La progenie de 'Nahuatl F2000' manifestó mayor nivel de resistencia, 10 que indica fue contiene más genes 0 genes diferentes y más efectivos; por ello, a través de una cruza triple entre las tres variedades podría aumentarse el nivel de resistencia a roya amarilla.
Publication - Cambios anatómicos en raíces de cebada (Hordeum vulgare L.) inducidos por Cactodera Galinsogae(Colegio de Postgraduados, 2007) Tovar-Soto, A.; Cid del Prado-Vera, I.; Nicol, J.M.; Evans, K.; Sandoval Islas, J.S.; Martinez-Garza, A.; Cárdenas Soriano, E.The anatomical changes in barley (Hordeum vulgare L.) cv. Esmeralda roots caused by C. galinsogae, collected at 10, 20, and 40 days after plant emergence at Singuilucan, Hidalgo are described. It is a recently described pathogen, whose lessions induced on the host plant are unknown. The histological exam showed the 10-day-old juveniles (J2, J3) in the cortical tissue, breaking of neighbouring cells being observed. At 20 d, the juveniles (J3, J4) were found close to the vascular cylinder. Furthermore, the induction of lateral primordia near the nematode was observed. The feeding sites, small and irregular, covered less than 50% of the vascular cylinder and the cortical tissue, with dissolution of internal, and thickening of external cell walls and with disorganization, displacement, and breaking of xylem and phloem. At 40 d, in the cross sections, syncytia were larger, covering 50 to 60% of the vascular cylinder. At cell level, the changes were similar to those observed at 20 d, besides starch being present in abundance. Mature females were observed in the cortex, surrounded by a layer of cork cambium, and the males appeared bent in the same tissue.
Publication - Cactodera galinsogae N.Sp (Tylenchida: heteroderinae) on barley (Hordeum vulgare L.) of the high valleys of Mexico(Organization of Nematologists of Tropical America, 2003) Tovar-Soto, A.; Prado Vera, C. I. del; Nicol, J.M.; Evans, K.; Sandoval Islas, J.S.; Martinez-Garza, A.Cactodera galinsogae n. sp. (Heteroderinae) was isolated from dicotyledonous Galinsoga parviflora (Asteraceae) roots. It also reproduced on barley (Hordeum vulgare) and wild oats (Avena fatua) (Poaceae) and on other dicotyledonous weeds, notably Bidens odorata (Asteraceae). The samples were taken from a cultivated field of barley in the town of "La Raya", municipality of Singuilucan, Hidalgo, in the Central Valleys of Mexico. Cactodera galinsogae is characterized by the vulval cone of the females and the cysts are smaller than in most other species of this genus, with a straight neck, and the vulval cone with circumfenestra but without vulval denticles. The cysts are small (average length 523 µm), spherical or sub-spherical and light to dark brown with a straight neck, and with the transverse branching striae of the cuticle surface pattern of the midbody forming an interlaced pattern. The second stage juveniles have six pseudolips, and four lateral lines with incomplete areolation (non-areolated internal lines) on the side of the body. The eggs are retained in the females, although a gelatinous matrix (without eggs) is observed in some. The egg-shells, when observed under the scanning electron microscope, show a specific pattern of punctations. The males are cylindrical and small (average length 830 µm) compared to the other species of Cactodera. They adopt a 'C' shape when killed by heat, with 4-5 lip annuli on the irregular labial region. The excretory pore is located at the level of the esophageal gland lobe (distance from the anterior end to the excretory pore/L = 14.7%). The spicules are slightly curved and bifid.
Publication - Mapping and pyramiding of qualitative and quantitative resistance to stripe rust in barley(Springer, 2003) Castro, A.J.; Capettini, F.; Corey, A.E.; Filichkina, T.; Hayes, P.M.; Kleinhofs, A.; Kudrna, D.; Richardson, K.; Sandoval Islas, J.S.; Rossi, C.; Vivar, H.E.The identification and location of sources of genetic resistance to plant diseases are important contributions to the development of resistant varieties. The combination of different sources and types of resistance in the same genotype should assist in the development of durably resistant varieties. Using a doubled haploid (DH), mapping population of barley, we mapped a qualitative resistance gene (Rpsx) to barley stripe rust in the accession CI10587 (PI 243183) to the long arm of chromosome 1(7H). We combined the Rpsx gene, through a series of crosses, with three mapped and validated barley stripe rust resistance QTL alleles located on chromosomes 4(4H) (QTL4), 5(1H) (QTL5), and 7(5H) (QTL7). Three different barley DH populations were developed from these crosses, two combining Rpsx with QTL4 and QTL7, and the third combining Rpsx with QTL5. Disease severity testing in four environments and QTL mapping analyses confirmed the effects and locations of Rpsx, QTL4, and QTL5, thereby validating the original estimates of QTL location and effect. QTL alleles on chromosomes 4(4H) and 5(1H) were effective in decreasing disease severity in the absence of the resistance allele at Rpsx. Quantitative resistance effects were mainly additive, although magnitude interactions were detected. Our results indicate that combining qualitative and quantitative resistance in the same genotype is feasible. However, the durability of such resistance pyramids will require challenge from virulent isolates, which currently are not reported in North America.
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