Development of Sugar Beet Salt Tolerant Triploid Hybrids

Abstract

Salinity is a major constraint on crop productivity in arid regions of Iran which decreases sugar beet yield. In order to identify and select salt tolerant triploid hybrids, 20 sugar beet three-way hybrids produced by crosses between 10 salinity improved pollinators and two cytoplasmic male sterile monogerm (231 × 261) and multigerm (MSC2 × A1) lines as seed parents. In 2007–2008 growing seasons, the 20 resulting hybrids along with five check varieties were evaluated in field study using a lattice square (5 × 5) design with three replications, and irrigated with 12 dS m−1 irrigation water. The combined analyses showed that the genotypes differed significantly (P < 0.01) for the most studied traits such as root yield; sugar yield; white sugar yield; sugar content; white sugar content; Na+ content; K+ content; extraction coefficient of sugar and molasses sugar indicating the presence of genetic variation and possibility of selection for sugar beet salinity tolerant lines under saline condition. The mean comparison for yield traits showed that monogerm triploid hybrids (261 × 231) × 19669-T and (261 × 231) × 13030 and multigerm triploid hybrids (MSC2 × A1) × JIT13, (MSC2 × A1) × C3.3, (MSC2 × A1) × 13030 and (MSC2 × A1) × 13022 produced 5.52 t/ha root yield and 1.38 t/ha sugar yield more than the mean of the checks under salinity stress across 2 years. Also, the means of five top hybrids showed 1.52 % sugar content, 1.77 % white sugar content and 3.19 % extraction coefficient of sugar more than the mean of the checks. These hybrids had 0.93 meq/100 gr K+ and 0.81 meq/100 gr Na+ less than the mean of the checks. These promising hybrids are currently being tested in Roudasht Agricultural Research Station as an important step towards development of sugar beet salt tolerant triploid hybrids.