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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A cytogenetic study of the effect of backcrossing to common wheat in a hybrid between Triticum vulgare Vill. and Triticum timopheevi Zhuk.

Allard, R. W. January 1946 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1946. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 85-88).
2

Defining the genetic and physiological basis of Triticum sphaerococcum Perc. : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Cellular and Molecular Biology at the University of Canterbury /

Josekutty, Puthiyaparambil Chacko. January 2008 (has links)
Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (leaves 86-109). Also available via the World Wide Web.
3

Characterization of Ae. uniaristata chromosomes and the transfer of aluminium tolerance to wheat by induced recombination

Iqbal, Nayyer January 1998 (has links)
No description available.
4

Effects of modern fungicides on the quality of winter wheat

Dimmock, Jeremy January 2001 (has links)
No description available.
5

Statistical studies on the variation of biologic forms of Puccinia graminis tritici and the effect of ecological factors on the susceptibility of wheat varieties ...

Levine, Moses Naphtali, January 1900 (has links)
Thesis (Ph. D.)--University of Minnesota, 1924. / Cover title. Vita. "Reprinted from Phytopathology, January, 1928, vol. xviii, no. 1." Bibliography: p. 121-123.
6

Evaluating disease reaction of western Canadian spring wheat cultivars (Triticum spp.) to natural and artificial infection with Claviceps purpurea (Fr.) Tul.

2013 June 1900 (has links)
Ergot, caused by the fungal pathogen Claviceps purpurea (Fr.) Tul., attacks the floral organs of many grassy species resulting in sclerotia production rather than grain. Infection causes reduced yields, downgrading, and poisoning if consumed by humans or animals. Few recent studies have been conducted on ergot in wheat (Triticum spp.), and prevention is the only means of control. The objectives of this study were to determine if western Canadian spring wheat differed in reaction to infection with C. purpurea and if levels of inoculum would affect disease intensity in a field setting. Three variables were measured for the field experiments to determine disease reaction, including percent sclerotia by weight, number of sclerotia per spike, and weight per sclerotium. In the first experiment, nine wheat cultivars were tested using three inoculum levels. No significant differences were detected among inoculum levels. In the second and third experiments, ninety-two cultivars were studied in field and controlled conditions. Honeydew production, sclerotial size, and the percent of florets aborted were added as variables in the growth chamber experiment. Pearson correlations were calculated using cultivar means for the field and controlled environments. Results indicate that there are differences in disease reaction among cultivars and market classes, but these differences varied depending on the evaluation method used. In the field, CWAD wheat had the smallest sclerotia, but had more per spike compared to the CWRS and CWES market classes. There were no significant differences among these market classes for percent sclerotia by weight. In the growth chamber, CWAD wheat generally had the lowest ergot infection levels. When comparing the market classes within T. aestivum (CWRS, CPS, and CWES), there were no significant differences except for honeydew production. The correlation between environments was not significant for any of the variables, suggesting alternate resistance mechanism expression. In the field, reduced infection may be due to an escape mechanism, while artificial inoculation in a controlled environment may detect a physiological resistance mechanism. However, a group of cultivars with Grandin parentage showed promising results in both environments, and might confer resistance that could be integrated into disease resistance breeding programs.
7

Porovnání vztahu sink-source a způsobu tvorby výnosu u pšenic s mnohořadým a normálním klasem při různých úrovních výživy

Pokorová, Petra January 2012 (has links)
No description available.
8

Efecto del rastrojo de trigo (Tritricum aestivum L.) sobre la germinación y crecimiento inicial de genotipos de lupino y capacidad alelopática de rastrojo de trigo (Tritricum turgidum L. spp. durum) en descomposición

Becerra Donoso, Marcelo Segundo January 2010 (has links)
Memoria para optar al Título Profesional de Ingeniero Agrónomo / En Chile se ha observado problemas de establecimiento y rendimiento de lupino cuando se cultiva después de trigo en condiciones de cero labranza con rastrojos sobre el suelo. Esta inhibición ha sido descrita como efecto alelopático del rastrojo de trigo sobre lupino. Dado que en el país se cultivan dos especies de lupino (L. albus y L. angustifolius) y que el efecto del rastrojo sobre lupino puede ser modificado por las condiciones ambientales, es que los objetivos de este trabajo fueron determinar la sensibilidad intra e interespecífica de dos especies de lupino al extracto de rastrojo de trigo y determinar la capacidad alelopática del residuo de trigo sometido a diferente grado de descomposición. Se realizaron dos ensayos. El primer ensayo fue para determinar la sensibilidad intra e interespecífico de las dos especies de lupino al extracto de rastrojo de trigo y el segundo ensayo fue para evaluar la capacidad alelopática del residuo de trigo sometido a diferente grado de descomposición. Para el primer ensayo se embebió semillas de siete genotipos de Lupinus albus y nueve genotipos de Lupinus angustifolius con extracto de 0, 23, 47 y 70 g de rastrojo de trigo L-1. Se evaluó la capacidad germinativa (CG), valor máximo de germinación (VM), longitud de radícula e hipocotilo (LR y LH), peso fresco de radícula e hipocotilo (PR y PH), relación LR/LH y longitud de plántula (LP). Para el segundo ensayo se dejó 0, 5 y 10 Mg ha-1 de rastrojo sobre la superficie de un suelo que había tenido trigo la temporada anterior. Estas cantidades de rastrojo fueron sometidas a distintos grados de descomposición aplicando tres niveles hídricos mediante una línea de aspersión. Se evaluó la descomposición del rastrojo y su capacidad alelopática. Se encontraron diferencias entre especies. Lupinus angustifolius mostró una mayor sensibilidad al extracto de rastrojo, observándose reducción en el valor máximo de germinación. Esta variable permitió encontrar diferencias inter e intraespecíficas. Las diferencias intraespecíficas en L. albus fueron consecuencia de las diferencias entre genotipos, mientras que las diferencias entre los genotipos de L. angustifolius se debieron a la interacción genotipo * concentración de extracto, por lo que la selección de genotipos tolerantes al extracto de rastrojos debe ser distinta según la especie de lupino. La aplicación de riego, independiente de la cantidad, aumentó la descomposición del rastrojo, mientras que el establecimiento de lupino aumentó con la mayor cantidad de agua aplicada en el periodo de mayor temperatura. El efecto de la cantidad de rastrojo superficial en el establecimiento de lupino fue secundario. Se evidenció un importante efecto alelopático en el suelo que sólo tenía raíces de trigo de la temporada anterior. El bioensayo con extractos acuosos de rastrojo de trigo afectó la germinación de lupino, pero no identificó diferencias alelopáticas entre los residuos con distinto grado de descomposición. / Problems of lupine establishment and yield have been observed in Chile when this crop is grown following wheat under zero tillage conditions with stubble on the ground. This inhibition has been described as an allelopathic effect of wheat stubble on lupine. Since two species of lupine (L. albus and L. angustifolius) are grown in the country and the effect of stubble on lupine may be modified by environmental conditions, the objectives of this study were to determine the intra- and inter-sensitivity of these lupine species to wheat stubble extract and to determine the allelopathic capacity of wheat residue subjected to varying degrees of decomposition. Two tests were carried out for this purpose. The first one was to determine the intra-and interspecific sensitivity of the two lupine species to wheat stubble extract and the second one was to evaluate the allelopathic capacity of wheat residue subjected to varying degrees of decomposition. For the first trial seeds of seven genotypes of Lupinus albus and nine genotypes of Lupinus angustifolius were imbibed in 0, 23, 47 and 70g of wheat stubble extract L-1. Germinative capacity (CG), maximum germination (VM), radicle and hypocotyl length (RL and HL), fresh weight of radicle and hypocotyl (PR and PH), RL/HL ratio and seedling length (LP) were evaluated. For the second test, 0, 5 and 10 mg ha-1 of stubble were left on the soil surface which had had wheat the previous season. These amounts of stubble were subjected to different degrees of decomposition using three water levels through a spraying line. Stubble decomposition and its allelopathic capacity were evaluated. Differences were found between species. Lupinus angustifolius showed a greater sensitivity to stubble extract, with a decrease in the maximum germination value being observed. This variable allowed to find inter- and intraspecific differences. The instraspecific differences in L. albus resulted from the differences among genotypes, while differences among L. angustifolius genotypes were due to the genotype-extract interaction, for which reason the selection of genotypes tolerant to stubble extract must be different depending on the lupine species. Irrigation application, irrespective of its amount, increased stubble decomposition, whereas lupine establishment increased with the greatest amount of water applied at the time of highest temperature. The effect of surface stubble amount on lupine establishment was secondary. An important allelopathic effect was seen on the soil which only exhibited roots from the previous season’s wheat. The bioassay with aqueous extracts of wheat stubble affected lupine germination, but did not identify allelopathic differences among residues with different levels of decomposition.
9

Efeito residual da aplicação de gesso na eficiência da adubação fosfatada para a sucessão trigo-soja em sistema plantio direto / Residual effect of gypsum application in the efficiency of phosphate fertilization for the succession wheat-soybean no - till system

Salgado, Adliz Ayram de Bastos Budziak 12 December 2017 (has links)
Submitted by Eunice Novais (enovais@uepg.br) on 2018-07-05T17:43:12Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Adlliz Salgado.pdf: 1207262 bytes, checksum: 92b81817140d534259d580cdd9c338ff (MD5) / Made available in DSpace on 2018-07-05T17:43:12Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Adlliz Salgado.pdf: 1207262 bytes, checksum: 92b81817140d534259d580cdd9c338ff (MD5) Previous issue date: 2017-12-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O P é o nutriente que mais limita a produtividade agrícola no Brasil, devido ao material de origem dos solos brasileiros, pela forte interação do P com o solo e pela sua precipitação com compostos de Fe, Al e Ca, por esse motivo os adubos fosfatados tem sido utilizado em maiores quantidades comprometendo as reservas mundiais que vem diminuindo. Com isso, há necessidade de se aprimorar a eficiência do uso de P na agricultura e o uso de gesso pode ser uma alternativa, devido à presença em sua composição de P e ao favorecimento do crescimento radicular. Sendo assim o objetivo deste trabalho foi avaliar o efeito residual da aplicação de gesso na eficiência da adubação fosfatada para a sucessão trigo-soja em sistema plantio direto. O experimento foi instalado em outubro de 2013, no município de Ponta Grossa, em um Latossolo Vermelho distrófico típico, textura argilosa. O delineamento experimental empregado foi o de blocos ao acaso, em parcelas subdivididas, com três repetições. Nas parcelas (180 m2) foram aplicadas, no sulco de semeadura, nas safras de inverno e verão, quatro doses de P (0, 30, 60 e 90 kg P2O5 ha-1) na forma de superfosfato triplo (SFT) e, nas subparcelas (45 m2) foram empregadas quatro doses de gesso agrícola (0, 2, 4, 6 t ha-1), em outubro de 2013. A sucessão de culturas do experimento foi: trigo (2015) e soja (2015/2016), sendo avaliado o efeito residual de gesso agrícola após 33 meses de sua aplicação (outubro de 2013) e os efeitos das doses de P. As avaliações realizadas foram os atributos químicos do solo (pH, Al3+, Ca2+, Mg2+, K+, S-SO42- e P) nas camadas (0-10, 10-20, 20-40 e 40-60 cm de profundidade), e nas culturas do trigo (2015) e soja (2015/2016) foram avaliados: (diagnose foliar, extração, rendimento de grãos e o fator parcial de produtividade). O efeito residual de gesso agrícola na superfície e a adubação fosfatada no sulco de semeadura ocasionaram melhoria nos atributos químicos do solo, sendo que o incremento das doses de P ocasionaram aumento de P (0-20 cm), SO42- (20-40 cm), Ca2+ e K+ (40-60 cm) e diminuição de P (20-40 cm), SO42- (0-10 cm) e Mg2+ (40-60 cm). O efeito residual do gesso agrícola ocasionou aumento de Ca2+ (0-60 cm), P (0-20 cm), SO42- (10-60 cm) e K+ (40-60 cm), e diminuição de Al3+ (10-20 cm). Na cultura do trigo, o incremento das doses de P aumentaram o teor foliar de P, Ca e S e diminuiu a extração de Fe, já com o incremento de gesso ocorreu aumento do teor foliar de Ca e S e diminuição do teor de Mg, e aumento da extração de P, S e Cu. Na cultura da soja o incremento das doses de P e de gesso não ocasionaram diferenças estatísticas na diagnose da cultura, já para a extração da planta, houve aumento da extração de K, Fe, Mn e Zn com o incremento das doses de P, e aumento na extração de P, Ca, S e Fe com o incremento das doses de gesso. Para o rendimento de grãos o aumento das doses de P não foram eficientes para aumentar a produtividade das culturas de trigo e soja, já o incremento das doses de gesso foi eficiente somente para a cultura do trigo aumentando em 21,8% o rendimento de grãos. O incremento nas doses de P aplicadas aumentou o fator parcial de produtividade de P (FPPP) nas culturas de trigo e soja, quando a menor dose de P (30 kg ha-1) foi aplicada. O efeito residual do gesso no aumento da produtividade de trigo não foi ocasionado por melhoria na eficiência de utilização de P pelas plantas. / P is the nutrient, which most limits agricultural productivity in Brazil, due to the material from Brazilian soils, because of the strong interaction of P with soil, and its precipitation with compounds Fe, Al and Ca, for this reason, phosphate fertilization has been utilized in larger quantities, compromising world supplies, which have been diminishing. Therefore, it is necessary to improve the efficiency of the utilization of P in agriculture, and the utilization of gypsum may be an alternative, due to the presence of P in its composition and the favoring of root growth. Thus, this paper is aimed at evaluating residual effect of gypsum application in the efficiency of phosphate fertilization for the succession wheat-soybean in no tillage system. The experiment was installed in October 2013, in the municipality of Ponta Grossa, in a typical dystrophic Red Latosol, clay texture. The experimental delineation applied was the blocks by chance, in subdivided parcels, with three repetitions. In the (180 m2) parcels, four doses of P (0, 30, 60 and 90 kg P2O5 ha-1) were applied, in-furrow, for winter and summer harvests, in the form of Triple SuperPhosphate (TSP) and, in the (45 m2) subparcels, four doses of agricultural gypsum were applied (0, 2, 4, 6 t ha-1), in October of 2013. The succession of crops for the experiment was: wheat (2015) and soybean (2015/2016), residual effect of agricultural gypsum was evaluated 33 months after its application (October of 2013), along with the effects of P doses. The evaluations performed were about the chemical attributes of the soil (pH, Al3+, Ca2+, Mg2+, K+, S-SO42- and P) in layers (0-10, 10-20, 20-40 and 40-60 cm deep) in wheat crops (2015), and in soybean crops (2015/2016); foliar diagnosis, extraction, grain yield, and the partial factor productivity were evaluated. The residual effect of agricultural gypsum in the surface and phosphate fertilization in-furrow caused improvements to the chemical attributes of the soil, where the addition of P doses caused an increase of P (0-20 cm), SO42- (20-40 cm), Ca2+ and K+ (40-60 cm) and a decrease of P (20-40 cm), SO42- (0-10 cm) and Mg2+ (40-60 cm). The residual effect of agricultural gypsum caused an increase of Ca2+ (0-60 cm), P (0-20 cm), SO42- (10-60 cm) and K+ (40-60 cm), and a decrease of Al3+ (10-20 cm). In wheat crops, the addition of P doses increased the foliar content of P, Ca and S, and decreased the extraction of Fe, on the other hand with the addition of gypsum an increase of Ca and S foliar content occurred and a decrease of Mg content, and an increase of P, S and Cu extraction. In soybean crops, the addition of P doses and gypsum caused statistical differences in the crop diagnosis, and then again, for the extraction of the plant, there was an increase of K, Fe, Mn and Zn extraction with the addition of P doses, and an increase of P, Ca, S and Fe extraction with the addition of gypsum doses. For grain yield, the increase of P doses were not efficient to boost productivity in wheat and soybean crops, as for the addition of gypsum doses, it was only efficient for wheat crops with a 21,8% increase of grain yield. The addition in applied P doses increased the partial factor productivity (PFP) of P in wheat and soybean crops, when the lowest dose of P (30 kg ha-1) was applied. The residual effect of gypsum in the increase of wheat productivity did not happen because of improvements in the efficiency of P usage by plants.
10

Characterizing Differentially Expressed Genes from the Thinopyrum elongatum 7EL Chromosome that is Responsible for FHB Resistance, After Introgression in Triticum aestivum

Haldar, Aparna 26 March 2019 (has links)
Triticum aestivum (bread wheat) is an important cereal crop not only in Canada but also worldwide. The pathogen Fusarium graminearum is responsible for causing the disease fusarium head blight and generates yield loses and mycotoxin contaminated grains, including in wheat. A strategy used to mitigate this problem is through the production of FHB resistant wheat varieties by crossing strongly resistant germplasms from closely related wheat species. Thinopyrum elongatum is a wild wheat grass that carries genetic resistance to FHB on the long arm of its chromosome 7E (7EL). Previous work has developed genetic material by crossing Chinese Spring (CS) ph1b line with a CS-7E(7D) substitution line to facilitate introgression of 7E fragments from Thinopyrum into the 7D chromosome of wheat. In the first part of this project a genetic order for previously designed 7EL- and 7D- specific markers was proposed using IWGSC RefSeq v1.0 and was used to characterize the introgressed material from the above cross. Progeny from BC1F7 and BC1F5 families of different lineages were genotyped and phenotyped to characterize regions of introgression which were estimated to be at least 42 and 22 Mbp respectively. Gene expression analysis was also performed for selected 7EL genes. Results showed that the expression of selected 7EL genes present within the introgressed fragments were highly variable between the three families characterized as well as within families. It was also observed that the 7EL introgressed progeny had variable expression when compared to the addition line CS-7EL. Additionally gene expression analyses were also performed using 7D genes. These results showed that there was variation in 7D gene expression between the 7EL introgressed progeny and the controls CS-Fg and addition line CS-7EL-Fg. Possible explanations regarding the variation in gene expression includes differential methylation patterns, silencing of genes in the progeny, alteration of repetitive sequences or activation of transposable elements. Further research will be needed to test these hypotheses.

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