Meloidogyne javanica infection of soybean plants: plant response, seed quality and green seeds occurrence

摘要

Some stresses in immature soybean plants, such as nematode infection, can result in premature plant death and produce greenish seeds with low physiological potential. The objective of this study was to evaluate Meloidogyne javanica infection on soybean plants and its relationship to plant growth, green seeds occurrence and their physiological potential. Plants of two soybean cultivars (TMG-115RR and M 7908 RR) were exposed or not to nematodes (0 or 7,000 nematodes per plant) and submitted or not to water stress treatments. The plant characteristics evaluated included phenology, pod and seed production, nematode multiplication in roots, seed moisture content, seed physiological potential (germination test, accelerated ageing, electrical conductivity and seedling emergence in sand), green seeds occurrence (visual method and chlorophyll fluorescence) and cell cycle activity (using flow cytometry). Depending on the cultivar tolerance, the population of 7,000 nematodes reduced the soybean plant cycle due to a shorter senescent stage, thereby causing premature death and the production of more green seeds. Moreover, the infection adversely affected seed production and quality. Meloidogyne javanica on soybean plants roots increased green seeds occurrence and reduceed their physiological potential due to reduction in cell cycle activity which affected aspects of germination and vigour.