Meloidogne incognita (nematode) parasitism of Lycopersicon esculentum (tomato) plants : Ethylene action in susceptible and resistant host responses

Involvement of ethylene in the etiology of tomato plants (Lycopersicon esculentum) infected with the root-knot nematode (Meloidogyne incognita) was investigated. Endogenous root concentrations of ethylene were not significantly different in uninfected resistant var. Anahu and susceptible var. Vendor plants. Exposure of resistant plants to high doses of infectious nematode larvae did not affect root ethylene concentrations during the subsequent 30 day period. The possibility that ethylene may be involved in the mechanism of resistance is therefore not supported by these experiments. In no experiments did ethylene concentrations in roots of susceptible plants increase significantly subsequent to ~ incognita infestation. This result is not consistent with the hypothesis in the literature which suggests that increased ethylene production accompanies gall formation. Growth of susceptible tomato plants was affected by ~ incognita infestation such that root weights increased (due to galling), stem heights decreased and top weights increased. The possibility that alterations in stem growth resulted from increased production of 'stress' ethylene is discussed. Growth of resistant plants was unaffected by exposure to high doses of ~ incognita and galls were never detected on the roots of these plants. Root ethane concentrations generally varied in parallel with root ethylene concentrations although ethane concentrations were without exception greater. In 4 of 6 experiments conducted ethane/ethylene ratios increased significantly with time. These results are discussed in the light of published data on the relationship between ethane and ethylene synthesis. The term infested is used throughout this thesis in reference to plants whose root systems had been exposed to nematodes and does not distinguish between the susceptible and resistant response.

Welland Canal Survey of Lands Mill Scibes Grand River Dam, n.d.

Survey map of the land for the Mill Scibes Grand River Dam. Created by The Welland Canal Company. Included is a drawing of the land. Noteable features include; Sulphur Creek, post, bridge, Grand River, lot divisions, inside face of embankment. Surveyor notes are seen in pencil on the map.

Residence and Grist Mill of Peter C. Servos, J.P. - Vignette

A vignette of the residence and grist mill of Peter C. Servos, J.P., Township of Niagara.

Spring Mill Distillery & Brewery - Vignette

A vignette of the Spring Mill Distillery and Brewery, Ravine, Stamford.

Envelope Addressed to Noah Phelps, Lincoln Paper Mill Co.

Envelope addressed to Noah Phelps, Lincoln Paper Mill Co. with no postmarks, Merritton [In about 1877 Noah Phelps, Samuel Woodruff, Partrick Joseph Larkin and John Conlon were involved in the founding of a paper mill with Sylvester Neelon], n.d.

Inducción de organogénesis y embriogénesis somática en Pinus cembroides (Zucc) y Pinus halepenesis Mill

Tesis (Maestría en Ciencias en Producción Agrícola) UANL

Análisis y optimización del control y operación de la máquina de control numérico computarizado EMCO PC MILL 125

Tesis (Maestro en Ciencias de la Ingeniería en Manufactura con Especialidad en Automatización) Universidad Autónoma de Nuevo León. Facultad de Ingeniería Mecánica y Eléctrica.

Parámetros fisicoquímicos para la obtención de modelos de predicción en la calidad poscosecha del tomate (solanum lycopersicum).

Tesis (Maestría en Ciencias Agrícolas) UANL, 2011.

Producción de biomasas y calidad nutrimental de opuntia ficus-indica (L) mill para consumo humano cultivado en forma hidropónica.

Tesis (Maestría en Ciencias Agrícolas) UANL, 2012.

Evaluación de sustratos y enrenados en producción de tomate bola (Solanum lycopersicum L.) en invernadero.

Tesis (Maestro en Ciencias en Producción Agrícola) UANL, 2014.

Absorción y asimilación de nitrato y amonio en Opuntia ficus-indica (L.) Mill. en condiciones de hidroponia

Tesis (Doctorado en Ciencias Agrícolas con Especialidad en Agua-Suelo) UANL

Desarrollo radical y producción de nopalito Opuntia fieus-indica ( L.) Mill en función de la biodegradación del estiércol bovino en diferentes profundidades por Rafael Zúñiga Tarango

Tesis (Doctor en Ciencias Agrícolas con Especialidad en Agua-Suelo) U.A.N.L.

Genetic variation of and environmental effects on inducibility of resistance in tomatoes (Solanum lycopersicum L.) to Phytophthora infestans (Mont) de Bary

Many plant strengtheners are promoted for their supposed effects on nutrient uptake and/or resistance induction (IR). In addition, many organic fertilizers are supposed to enhance plant health and several studies have shown that tomatoes grown organically are more resistant to late blight, caused by Phytophthora infestans to tomatoes grown conventionally. Much is known about the mechanisms underlying IR. In contrast, there is no systematic knowledge about genetic variation for IR. Therefore, the following questions were addressed in the presented dissertation: (i) Is there genetic variation among tomato genotypes for inducibility of resistance to P. infestans? (ii) How do different PS compare with the chemical inducer BABA in their ability to IR? (iii) Does IR interact with the inducer used and different organic fertilizers? A varietal screening showed that contrary to the commonly held belief IR in tomatoes is genotype and isolate specific. These results indicate that it should be possible to select for inducibility of resistance in tomato breeding. However, isolate specificity also suggests that there could be pathogen adaptation. The three tested PS as well as two of the three tested organic fertilisers all induced resistance in the tomatoes. Depending on PS or BABA variety and isolate effects varied. In contrast, there were no variety and isolate specific effects of the fertilisers and no interactions with the PS and fertilisers. This suggests that the different PS should work independent of the soil substrate used. In contrast the results were markedly different when isolate mixtures were used for challenge inoculations. Plants were generally less susceptible to isolate mixtures than to single isolates. In addition, the effectiveness of the PS was greater and more similar to BABA when isolate mixtures were used. The fact that the different PS and BABA differed in their ability to induce resistance in different host genotype -pathogen isolate combinations puts the usefulness of IR as a breeding goal in question. This would result in varieties depending on specific inducers. The results with the isolate mixtures are highly relevant. On the one hand they increase the effectiveness of the resistance inducers. On the other hand, measures that increase the pathogen diversity such as the use of diversified host populations will also increase the overall resistance of the hosts. For organic tomato production the results indicate that it is possible to enhance the tomato growing system with respect to plant health management by using optimal fertilisers, plant strengtheners and any measures that increase system diversity.