PLANT SUSCEPTIBILITY AND RESISTANCE

Author: GARCIA LIMONES MARIA DEL CARMEN.
Year: 2003.
University: CÓRDOBA [www.uco.es].
Place of defense: E.T.S.I. AGRONOMOS Y MONTES.
Place of preparation: E.T.S.I. AGRONOMOS Y MONTES.

Summary: The Fusariosis Vascular caused by various special forms of Fusarium oxysporum diseases are of great interest because of its wide distribution globally and the high number of economically important plants that suffer. However, the mechanisms patogeneicidad and resistance opern in these systems are still generally quite unknown and control of many Fusariosis Vascular is still at present a serious problem. In many systems plant has shown the overproduction of reactive oxygen species (EROs), or oxidative outbreak, as an early response to defend the plant against the attack of pathogens. As a result of the outbreak may cause oxidative induction system components antioxidant to offset the adverse effect that could generate such EROs. In this paper we have studied the evolution of various system components antioxidant chickpea and other markers of oxidative stress during interactions compatible and incompatible with race 5 of Fusarium oxysporum f.sp.ciceris, inducing syndrome Marchitez Vascular. Our study shows quite clearly produce significant changes in both components of the antioxidant system of chickpea, and the rest of markers of oxidative stress during the development of Vascular Fusariosis both in the mix as consistent in inconsistent. Most of these changes were common to both interactions, but, typically, a trend was observed pronounced the earliest and localized expression of the common responses in interaction inconsistent that the consistent. Our interpretation of these events is the production of a situation of oxidative stress caused by the generation and accumulation of EROs, which, based on differences kinetics and / or location, may well be indicative of a successful defensive strategy (incompatibility) from a situation of extensive colonization (compatibility).

Author: FONDEVILLA APARICIO SARA.
Year: 2004.
University: CÓRDOBA [www.uco.es].
Place of defense: ETSIAM UNIVERSIDAD DE CÓRDOBA.
Place of preparation: IFARA/CSIC (CÓRDOBA).

Summary: Studies conducted in macroscopic and microscopic lines that contain genes erl or er2 resistance Erysiphe pisi in guidante show that erl gene confers resistance to penetration. The gene er2 brings a resistance increases with temperature and the age of the leaf. We have identified high levels of resistance to oidio in incomplete species P.sativum susp. Sativum var.arvense, P. Stivum subsp.abyssinivum subsp. In these species have been identified mechanisms both pre - and post-wing penetration. It has been found at the entrances Pisum fulvum P651 and P660, a new dominant gene for resistance to Erysiphe pisi we have called Er3. We have identified four RAPD markers linked in phase coupling and two linked under repulsion with the gene Er3. It describes various lines that have submitted incomplete resistance to different isolates Mycospherella pinodes under controlled conditions. The resistance of these lines has also been effective under field conditions in Cordoba. The highest levels of resistance were detected in species P.fulvum followed P.astivum subsp.elatius. It has developed a map of ligament by analyzing molecular markers morfologícos and in 111 famlias RIL from a cross between two subspecies of Pisum sativum. The force of families RILs, was highly correlated with a corresponding number of jopos per plant, so that the plants were more vigorous enough to hold more jopos. In this paper we propose a resistance index O.crenata in group IV linkage and four QTs associated with resistance M.pinodes in groups ligamiento II, III and A.

Author: SHTAYA MUNQEZ.
Year: 2005.
University: CÓRDOBA [www.uco.es].
Place of defense: E.T.S.I. AGRONOMOS Y MONTES.
Place of preparation: E.T.S.I. AGRONOMOS Y MONTES.

Summary: We identified new sources of potentially durable resistance to rust on the leaf (Puccinia hordei) in a collection of 680 entries barley various geographical regions of Spain and the Fertile Crescent. Selected lines more resistant to study the mechanisms of resistance. Its high level of resistance is due to a high percentage of colonies aborted without necrosis. It has been postulated the presence of resistance genes on the leaf rust (Rph) in 14 lines selected barley Fertile Crescent and Spain on the basis of their reaction to 5 isolated Puccinia hordei virulence differential. Three genes for resistance to rust (Rph3, Rph5 And Rph7) appear to be present in 12 of these lines. However, we can not exclude the presence of other genes to cualestodos isolates were used virulent (Rph1, 2,4,6,8,9) or presenciade other nuevosgenes not known. In the campaign 2003/2004 in Cordoba, an infection was found unexpected Puccinia hordei in lines that carry the gene Rph7. The new insulated on all showed virulence genes for rust resistance of the sheet used in the study including the gene Rph7. This is the first time that described virulence on Rph7 in European populations of P. Hordei. It has been assessed a collection of 680 lines of barley for resistance against this new virulent isolated to Rph7. Segregation was observed in 12 lines, in which some plants showed resistance hypersensitive (low infection rate, TI = 6). These resistant plants were selected and I know are mu [tiplicandopara obtenersemillase introducirlesen programasde improvement. It has been assessed a collection of 111 local varieties of barley Fertile Crescent for resistance oidio in climatic chamber. There were two types of resistance. Twelve lines showed low severity with high infection rate (partial resistance). In 19 lines, so segregation was observed that some plants showed low frequency infeccíón associated with necrosis (resistenciahipersensitiva). These plantasresistentes were seleccionadasy are multiplying for future work. It has been studied resistance to leaf rust (Puccinia hordei) and oidio (Blumeria graminis f.sp. hordei) in a collection of 23 lines recombinant (RLs) from the crossbreeding between Hordeum bulbosum and Hordeum vulgare alongside their parents under controlled conditions. The present study clearly indicates that H. Bulbosum is an important and useful source of partial resistance as hipersensitivatanto to oidio as [on the leaf rust. At various RLs reduction was noted TI or an increase of periodode latenciarespectoa its parent H. Vulgare. In a population of 103 lines recombinant (RILs), we identified two QTLs for resistance oidio and four to blanching (Rhynchosporium secalis). All QTLs for resistance to blanching were previously identified in other populations of barley. However, only one of the QTLs for resistance oidio was previously identified while the second has not been identificadoen other populations.

Author: RODRIGUEZ SUAREZ CRISTINA.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: FACULTAD DE BIOLOGIA.
Place of preparation: UNIVERSIDAD DE OVIEDO.

Summary: In this Doctoral Thesis has deepened understanding of the genetics of resistance to anthracnose, a disease of bean (Phaseolus vulgaris L.) produced by the fungus Colletotrichum lindemuthianum. In particular, have been characterized and localized resistance genes anthracnose incorporated into lines improved Faba Asturian by testing alelismo and analyzing its spectrum of resistance. It has been obtained by piramidalización assisted by molecular markers, a new improved line that meets two different loci of resistance to anthracnose. We have identified genes that confer resistance to anthracnose in varieties used internationally as differential (Cornell 49242, Mexico 222 and Widusa) and other varieties of interest (Andecha, Xana and A252). It has been found that genes previously described as independent Co-3 and C-9, are actually the same locus, which is proposed nomenclature C-3 / 9. The resistance genes identified were located in three groups of linkage: B1, B4 and B11, corresponding to the location of genes previously described as Co-1, C-3 / 9 and C-2, respectively. The organization has been shown in clusters of resistance genes anthracnose, ie clusters of genes closely linked with each other, each with specific resistance of pathogenic different races. It has identified a cluster of resistance in the group ligamiento B11 (formerly described as a single locus, Co-2) and two independent clusters within the group ligamiento B4 (which probably correspond to the loci described above as Co-9 and Co. -10). Finally, it suggests that resistance to some races may be mediated by the interaction of two separate genes located each one of the clusters group ligamiento B4.