Association Between Percent Total Alkaloids and Other Traits in Flue‐cured Tobacco¹

Abstract

The relationships between percent total alkaloids and nine agronomic and chemical traits were studied in isogenic lines derived from 10 cultivars of flue‐cured tobacco (Nicotiana tabacum L.). Isogenic lines with low total alkaloids percentage (approximately 0.20%) were compared with their “normal” recurring parents (total alkaloids 1.85 to 2.70%). The differences in traits other than alkaloid levels between the low alkaloid lines and their recurrent parent should reflect physiological associations (pleiotropism) and/or genetic linkages. Yield, grade index, total N, and reducing sugar content in the low alkaloid lines were lower than in the normal flue‐ cured cultivars. Chlorophyll contents, at time of harvest, were higher in the low alkaloid lines than in their recurrent parent. Alkaloid levels had little or no association with plant height, leaves per plant, or days to flower.

Genetic and Agronomic Analysis of Tobacco Genotypes Exhibiting Reduced Nicotine Accumulation Due to Induced Mutations in Berberine Bridge Like (BBL) Genes

“…A typical objective of metabolic engineering is to achieve a desired chemical change without otherwise affecting other chemical attributes, growing efficiency, or derived product quality. Prior research has revealed great difficulty in using modified plant genetics to reduce nicotine levels without altering metabolic profiles or negatively affecting tobacco cured leaf yields or quality (Chaplin and Weeks, 1976;Kudithipudi et al, 2017). Similar to the nic1/nic2 system of nicotine reduction, the BBL mutant system was also found to reduce cured leaf yields by up to 29%, with associated reductions in cured quality of up to 15%.…”

“…Recessive alleles at the Nic1 and Nic2 (also known as A and B) loci have been found to contribute to major reductions in nicotine and associated alkaloids (nornicotine, anabasine, and anatabine) from between 1.5 and 4.5% to approximately 0.20-0.45% (Legg and Collins, 1971;Lewis, 2018). This allelic variability is well known to be associated with reduced cured leaf yields and quality, however (Chaplin and Weeks, 1976).…”

Shade During Growth—Effects on Chemical Composition and Leaf Color of Air‐Cured Burley Tobacco1

“…Brown pigments and total phenols are known to play a role in the color of cured tobacco leaves (Andersen et al, 1970). It is also possible that total alkaloids influence the color of tobacco leaves based on the report of Chaplin and Weeks (1976) and the visual observations of Gupton et al ( 1972) that indicated an increased wood color of burley tobacco stalk cross sections was associated with higher leaf alkaloid levels for samples from tobaccos of divergent alkaloid genotype. Nitrate-N presumably does not affect color directly, but it is a biochemical precursor of alkaloids.…”

Polyamines delay leaf maturation in low‐alkaloid tobacco varieties

“…LA Burley 21 plants contain only~5.7% of the total alkaloid levels found in the normal-alkaloid (NA) wild-type variety (Legg, Collins, & Littion, 1970). In LA plants, the synergistic effect of the nic1 − and nic2 − deletions also causes an unfavorable leaf phenotype characterized by lower yields, delayed ripening and senescence, higher susceptibility to insect herbivory, and poor end-product quality after curing (Chaplin & Burk, 1983;Chaplin & Weeks, 1976;Legg et al, 1970). A better understanding of the differences between LA and NA plants could facilitate strategies to improve the quality of LA leaf and its resulting tobacco products and allow the development of new tobacco cultivars with lower alkaloid levels combined with comparable or superior product characteristics.…”