What are "in vitro" techniques in plant biotechnology?

The term "in vitro" refers to techniques performed outside a living organism, specifically in a controlled laboratory environment. In plant biotechnology, in vitro techniques focus on the use of cultured cells or tissues to propagate plants. This allows researchers to manipulate the growth conditions, enabling them to study plant development, genetic modifications, and tissue responses in a controlled setting. This method is crucial for plant breeding programs, development of disease-resistant varieties, and studying plant physiology and biochemistry.

The other options describe methods that do not align with the definition of in vitro. Field methods involve growing crops in their natural habitat, which contrasts with the controlled settings of in vitro practices. Genetic modification techniques applied directly to soil suggest an on-site modification approach rather than the controlled cellular or tissue culture approaches of in vitro. Lastly, soil health analysis focuses on assessing the quality and fertility of soil rather than plant growth techniques, further distinguishing it from the in vitro methodologies employed within plant biotechnology.