In planta suppressiveness to nematodes and long term root health stability through biological enhancement - do we need a cocktail?

摘要

It is taken for granted that plants grow in a very complex soil environment harboring diverse microorganisms and are constantly exposed to numerous complex biological interactions that either positively or negatively affect root health and growth. Some scientists believe the soil environment is not complex, and that biological interactions are rare and seldom affect plant growth significantly. Plant pathologists frequently adhere to the low complexity school of thought and therefore often target their research work to a single pest/disease interaction. Similarly biologists studying microbial-based biological control also tend to study one antagonist and one pest, a concept that has been reasonably successful, for example, in biological enhancement of banana planting material with endophytic microorganisms. Good control has been attained regardless of the antagonist involved: mutualistic endophytic fungi or bacteria, arbuscular mycorrhizal fungi, plant health-promoting rhizobacteria or entomopathogenic fungi. There are many practical reasons for a single antagonist approach, but in planta suppressiveness in the field is not an industrial-based phenomenon but is based on unique interrelationships between the microbial community and plants, which result in a healthy root system. Success has been achieved with biological enhancement of plant material for the management of plant-parasitic nematodes in Musa. Practical application is no longer a question of if, but a question of when and where. However, a number of questions still confront those working with the biological enhancement concept: (1) can we increase the levels of control presently attained? (2) can we extend the spectrum of target pests affected? and (3) can in planta suppressiveness be established for long term control? Since in planta suppressiveness is clearly related to the activity of microbial communities and not to a single organism, the question that requires answering is - do we need a cocktail?