Effect of the Yellow-Green (yg) Character on Certain Characteristics of Cigar-Wrapper Tobacco
1966
Dean, C. E.
An investigation was conducted into the effects of the yellow-green (yg) gene on certain characteristics of cigar-wrapper tobacco. The recessive monogenic virescent character was transferred into the varieties ‘Florida 15,’ ‘Dixie Shade,’ ‘Rg,’ and ‘No. 63,’ through four generations of backcrossing and self-pollination. The four virescent selections, together with normally pigmented sister selections, were compared with their respective recurrent parent varieties. Virescent segregates, even though shorter during the period of measurements, grew at a rate comparable to their parental varieties. Virescent selections had longer leaves at the tenth node position, more leaves exceeding 16 inches in length, and a higher total leaf count. A pleiotropic action for the yg gene or the effect of linked or modifying genes was postulated to be responsible for the differences observed. Virescent segregates, as a group, had a lower yield than green varieties; however, variation between families existed. Virescent selections had a higher percentage of tobacco in the light wrapper, off-color, and first three grades, and a lower percentage in the dark and number 2 off-color grades. Grade and crop indices substantiated the superiority of virescent segregates over their respective normally pigmented parental varieties. These data indicate that the yellow-green color inherent in virescent plants will result in a lighter and more uniform colored cured leaf, which could be of value to the cigar-wrapper trade. The degree of reconstitution of the recurrent parent genotype was estimated. Four backcrosses were considered to be a minimum number required in a gene transfer program of this nature.
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