ObjectivesPotassium content is one of the most important indexes of tobacco quality. Investigation on the K contents of tobacco cultivars will help screen K-efficient tobacco genotype.

MethodsField experiments were carried out for 2 years (2014–2015) in the main tobacco producing region of Xichang City, Sichuan Province. 93 tobacco germplasm resources were collected and grown under normal and reduced K application rates (K₂O 300 and 150 kg/hm²). The K contents of upper, middle and lower parts of leaves of tobacco were analyzed, and the genotypes were grouped into high, middle and low K-efficiency using clustering analysis method.

ResultsThe K contents of the 93 germplasm resources were significantly different under the two K application rates, and the K contents under the normal K rate were significantly higher than those under the reduced K rate. The average K contents of the upper, middle and lower parts of leaves under the normal K rate were 1.13, 1.14 and 1.15 times of those under the reduced K rate in 2014, respectively, and were 1.10, 1.25 and 1.35 times in 2015. According to the K contents in leaves, the tested 93 genotypes were classified into high, common and low K content genotypes. The leaf K contents in the upper, middle and lower parts of tobacco with high-K efficiency were all higher than those of the other two genotypes. The K contents in the upper, middle and lower part of leaves of the high K content genotypes were respectively 1.50–1.92, 1.54–2.52, 1.31–2.36 (under the normal K application rate) and 1.27–1.93, 1.66–2.24, 1.72–1.73 (under the low K application rate) times of those of the low K content genotypes.

ConclusionsThe high K content genotype materials selected in the two-consecutive-year experiment including Gajihongda, Changyehongda, Dabai 1, Dabai 2, MFZS and 930032-7 could be applied to the tobacco production and provided as parent materials for potassium-enriched tobacco breeding operation.