INBA   12521
INSTITUTO DE INVESTIGACIONES EN BIOCIENCIAS AGRICOLAS Y AMBIENTALES
Unidad Ejecutora - UE
capítulos de libros
Título:
Mycorrhizal Inoculation Improves the Performance of Soybean Subjected to Biotic and Abiotic Stresses.
Autor/es:
LAVADO, R.S.; SPAGNOLETTI, F.; CHIOCCHIO VM
Libro:
Soybeans: Cultivation, Nutritional Properties and Effects on Health.
Editorial:
Nova Publishers
Referencias:
Lugar: Nueva York; Año: 2016; p. 85 - 117
Resumen:
Soybean (Glycine max L.) is one of the main crops in the world and its production has increased following the worldwide food demand. Soybean cropping is advancing on marginal environments and the crop is thus exposed to several stresses. However, one group of fungi, the arbuscular mycorrhizal fungi, showed beneficial effects when crops are subjected to most of those stresses. Present chapter focus on soybean plants inoculated with the mycorrhizal fungus Rhizophagus intraradices when the crop was subjected to i) a sudden and severe water stress; ii) the effect of increasing levels of As in soil, iii) the effect of a biotic stress, the fungal disease charcoal rot and iv) the biochemical effect those stresses cause on the crop and the interaction among them. Water stress, either permanent or transient, occurs in the whole world, and periods of drought may occur frequently even in regions characterized by high annual rainfall. Water stress is a major abiotic factor that limits crop production. Soybean tolerance to water stress improved in mycorrhiza inoculated plants. The significant higher concentrations of K in inoculated plants plus the adjustment of the osmotic potential and their lower transpiration rate are among the reasons for soybean ability to survive under extreme water stress, in present case soils exceeding the soil Permanent Wilting Point. Besides, groundwater is loaded with arsenic (As) in several countries. The irrigation with such water increases the As concentration in soils. Plants exposed to high As levels undergo decreases in growth and yield. Arsenic also affects mycorrhizal symbiosis, because negatively affects the germination of spores, the hyphal length, and the colonization of plants by R. intraradices. However, the mycorrhizal inoculation of soybean plants improves the crop biomass, height, and number of leaves, and limits the negative effect on root length. Arsenic delayed the phenological advance of plants, while mycorrhiza reversed this partially. The mycorrhizal inoculation decreased the As accumulation in the plants aboveground and underground biomass. The AMF have a dilution effect on soybean As concentration and prevent As intake by roots. Mycorrhizal inoculation also seems to improve As tolerance in soybean plants.A very common biotic stress factors on crops are pathogenic fungi. One of the most important soybean diseases is charcoal rot, caused by the pathogenic fungi Macrophomina phaseolina (Tassi) Goid, a facultative saprophyte which is able to infect roots and the lower tract of the stem. The pathogenic fungus did not affect the symbiotic relationship between soybean and AMF. The mycorrhizal play an effective role in the decrease of the disease attack caused by the pathogen.The symbiosis R. intraradices ? soybean is efficient to decreasing the oxidative damage caused by As. However present result suggests that the soybean inoculation with the mycorrhiza could not revert in most cases the oxidative damage cause by As and the pathogen, when they act together. The effect of mycorryza soybean in grain quality was also assessed.