Fibrous Root Growth and Partitioning in Smooth Root Sugarbeet Versus Standard Root Types

Abstract

A greenhouse experiment with controlled lighting, temperature, moisture, and nutrients was conducted to compare the development of the fibrous root system for a smooth root (SR) sugarbeet genotype with that of four other diverse variety/ genotypes having standard grooved root architecture. Comparisons also included partition­ ing of photosynthate to leaf blade, petiole, taproot, and fibrous root for the five variety/ genotypes studied, and for their agronomic performance in a replicated field trial. The SR genotype produced the same ratio of taproot to fibrous roots as did the commercial hybrid variety 'Mono­ Hy E4.' There was a trend for fibrous roots of the SR line to develop lower on the taproot, farther from the crown, than in standard root types. The SR type had simHar leaf area, tap root/ leaf blade fresh weight ratio (TLWR), and. partitioning of photosynthate to leaf blades, petioles, taproots and fibrous roots as did the commercial varieties. The SR line was more closely aligned with the commer­ cial varieties in fibrous root growth and partitioning of photosynthate to plant parts than were the two other stan­ dard root type genotypes. From these greenhouse ex­ periments on fibrous root yield and partitioning, supported by agronomic field data, I conclude that the SR root type can produce enough fibrous roots to transport the required nutrients and water to allow yield comparable to standard root type sugarbeets.