Botany also called plant science or plant biology, is the science of plant life and a branch of biology. Botany has included the study of fungi and algae, studied by mycologists, phycologists respectively, with the study of plants and these three groups of organisms remain within the sphere of interest of the International Botanical Congress. In the 19th and 20th centuries, new techniques were developed for the study of plants, including methods of optical microscopy and live cell imaging, electron microscopy, analysis of chromosome number, plant chemistry and the structure and function of enzymes and other proteins. In the last two decades of the 20th century, botanists exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately. Modern botany is a broad, multidisciplinary subject with inputs from most other areas of science and technology. Plants synthesize a number of unique polymers like the polysaccharide molecules cellulose, pectin and xyloglucan. Botanical research has diverse applications in providing staple foods and textiles, in modern horticulture, agriculture and forestry, plant propagation, breeding and genetic modification, in the synthesis of chemicals and raw materials for construction and energy production, in environmental management, and the maintenance of biodiversity.Plants can synthesize useful coloured dyes and pigments such as the anthocyanin’s responsible for the red colour of red wine, yellow weld and blue woad used together to produce Lincoln green, indoxyl, source of the blue dye indigo traditionally used to dye denim and the artist's pigments gamboge and rose madder.