BOTANY OF THE BEET PLANT

Authors: Lewellen, Robert; Panella, Leonard; HARVESON, ROBERT - UNIVERSITY OF NEBRASKA

Submitted to: Compendium of the Beet Diseases and Insects
Publication Type: Book / Chapter
Publication Acceptance Date: 4/1/2007
Publication Date: 5/28/2009
Citation: Lewellen, R.T., Panella, L.W., Harveson, R. 2009. Introduction - Botany of the Beet Plant. Pages 2-3 In: Compendium of the Beet Diseases and Insects, edited by R.M. Harveson, L.E. Hanson, and G. O. Hein, eds. APS Press. St. Paul, MN pp.140.

Interpretive Summary: Beet is classified as Beta vulgaris L. Because of the continuous variation that exists between members of B. vulgaris, it has been divided into subspecies. Formerly, and still casually, the ancestral form was classed as Beta maritima, but now is classified as B. vulgaris subsp. maritima, the (wild) sea beet. The genus Beta is divided into four sections. Section Beta is comprised of the cultivated beets and wild maritima forms that are cross compatible. Section Beta was revised recently, and the non-cultivated forms of Beta have become an important germplasm resource for plant breeding, particularly for genes conferring disease resistance. Cultivated beets are separated into four groups based upon morphology and end use – Leaf Beet Group, Garden Beet Group, Fodder Beet Group, and Sugar Beet Group. Sugar beet is a biennial plant, which is vernalized (induced to flower and produce seed) followed by long-day conditions (photo-thermal induction). Sucrose is stored in the taproot. Sucrose is removed from sugar beet by hot water diffusion from sliced (cossetted) roots. The sucrose is refined from the juice by a series of treatments with lime and carbonization, and filtration to precipitate and remove most of the non-sucrose solubles.

Technical Abstract: Beet is classified taxonomically as Dicotyledoneae, Caryophyllidae (Centrospermae), Chenopodiaceae, Beta vulgaris L. There are very few Chenopodiaceous crop plants. These include beet, spinach (Spinacia oleracea), and quinoa (Chenopodium quinoa), but a number of noxious weeds are also important, including fireweed (Kochia scoparia), Russian thistle (Salsola kali), and lambsquarters (Chenopodium alba). Like many of the other members of the Chenopodiacea, beets are halophytes. All of the cultivated beets and their ancestral forms are classified as Beta vulgaris L., and have 2n = 2x = 18 chromosomes. Because of the continuous variation that exists between members of B. vulgaris, it has been divided into subspecies. Formerly, and still casually, the ancestral form was classed as Beta maritima, but now is classified as B. vulgaris subsp. maritima, the (wild) sea beet. The genus Beta is divided into four sections. The four sections of Beta are: Beta (formerly Vulgares), Corollinae, Nanae, and Procumbentes (formerly Patellares). Section Beta is comprised of the cultivated beets and wild maritima forms that are cross compatible. Beta is indigenous to the Mediterranean Basin and extends west to the Canary Islands, east to India, and north to Scandinavia. Section Beta was revised recently, and the non-cultivated forms of Beta have become an important germplasm resource for plant breeding, particularly for genes conferring disease resistance. Cultivated beets are separated into four groups based upon morphology and end use – Leaf Beet Group, Garden Beet Group, Fodder Beet Group, and Sugar Beet Group. Sugar beet is a biennial plant, growing as a rosette and accumulating sucrose until plants become vernalized followed by long-day conditions (photo-thermal induction). It is a C3 plant and fixes carbon dioxide by the Calvin cycle. Sucrose is stored in the taproot. Sucrose is removed from sugar beet by hot water diffusion from sliced (cossetted) roots. The sucrose is refined from the juice by a series of treatments with lime and carbonization, and filtration to precipitate and remove most of the non-sucrose solubles.