Genetics of Cell Size and Sucrose Concentration in Sugarbeet1
- Devon L. Doney and
- J. Clair Theurer2
Sugarbeet (Beta vulgaris L.) root cell size has been shown to be negatively correlated with sucrose concentration. This study was initiated to determine the genetics of sugarbeet root cell size and sucrose concentration and their inheritance relationships. Inheritance was studied in 1) inbred parents and hybrids of five males crossed to the same female, 2) a three-by-three males ✕ females crossing system, and 3) a five-by-five diallel cross, which included parent inbreds but not reciprocals. Sucrose concentrations were determined in replicated field trials, whereas cell diameters were measured microscopically from stained root cross sections of 21- and 28-day-old seedlings. Midparent heterosis, general and specific combining ability, and genetic variances were calculated. Cell diameter and sucrose concentration exhibited little midparent heterosis. General combining ability was significant at P = 0.01 for cell diameter and sucrose concentration. Specific combining ability was nonsignificant in one test for both cell diameter and sucrose concentration and significant at P = 0.05 for cell diameter and at P = 0.01 for sucrose concentration in the other test. Of the total genetic variance, additive genetic variance accounted for 80 and 91% for cell diameter and 72 and 90% for sucrose concentration in two respective sets of hybrid crosses. The significant negative correlation between cell diameter and sucrose concentration and their apparently similar inheritance patterns suggest that the additive genes affecting cell diameter (cell size) may be the same genes responsible for the additive genetic variance of sucrose concentration. There are, however, some notable exceptions to the above relationships, and it must be recognized that other genes not related to cell size also affect sucrose concentration.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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