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:
SPAGNOLETTI, F.; LAVADO, R.S; CHIOCCHIO, V.
Libro:
Soybeans: Cultivation, Nutritional Properties and Effects on Health
Editorial:
Nova Science Publishers, Inc.
Referencias:
Lugar: Hauppauge, NY 11788 ; Año: 2017; p. 85 - 118
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 towards marginal environments and thus being exposed to several biotic and abiotic stresses. Water stress, a major abiotic factor that limits crop production, occurs either permanently or transiently in the whole world, and periods of drought may occur frequently even in regions characterized by high annual rainfall. However, A inoculation of stressed crops with the group of arbuscular mycorrhizal fungi (AMF) can improve soybean tolerance to water stress. This ability to survive under extreme water stress, even in soils exceeding the soil Permanent Wilting Point (PWP), can be explained by the significantly higher concentrations of potassium in inoculated plants plus the adjustment of the osmotic potential and their lower transpiration rate. On the other hand, in several countries, groundwater is loaded with arsenic (As). The irrigation with such water increases the concentration of As in soils and plants exposed to high As levels undergo decreases in growth and yield. Arsenic also delays the phenological advance of plants. Mycorrhizal inoculation of As-stressed soybean plants improves the crop biomass, the plant height, and the number of leaves, and limits the negative effect of As on root length. Mycorrhizal inoculation also decreases As accumulation in the aboveground and underground biomass, has a dilution effect on soybean As concentration, and prevents As intake by roots. Mycorrhizal inoculation also seems to improve As tolerance in soybean plants. However, As also affects the mycorrhizal symbiosis, because it negatively affects the germination of spores, the hyphal length, and the colonization of plants by Rhizophagus intraradices. Regarding biotic stress factors, pathogenic fungi are very common in crops. Charcoal rot, caused by the pathogenic fungus Macrophomina phaseolina (Tassi) Goid, a facultative saprophyte able to infect roots and the lower tract of the stem, is one of the most important soybean diseases. Mycorrhizal inoculation plays an effective role in decreasing the disease attack, and this pathogenic fungus does not affect the symbiotic relationship between soybean and AMF. As mentioned above, the R. intraradices - soybean symbiosis is efficient to decrease the oxidative damage caused by As. However, when As and the pathogenic fungus M. phaseolina act together, soybean inoculation with the mycorrhiza cannot reverse the oxidative damage caused by As and the pathogen. The present chapter focuses on the behavior of soybean plants inoculated with the mycorrhizal fungus Rhizophagus intraradices, subjected to i) a sudden and severe water stress; ii) increasing levels of arsenic (As) in the soil, and iii) a biotic stress such as the fungal disease charcoal rot. The chapter also focuses on the biochemical effects caused by these stresses on the crop and the interaction between them, as well as on the effect of mycorrhizal inoculation of soybean plants on grain quality.