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Registration of IG KY 171 and IG KY 160 Tobacco Germplasm Lines
Author(s) -
Legg Paul D.
Publication year - 1995
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1995.0011183x003500020072x
Subject(s) - germplasm , citation , biology , library science , horticulture , computer science
IG KY 171 (Reg. no. GP-48, P1 578863) and IG KY 160 (Reg. no. GP-49, P1578862) dark tobacco (Nicotiana tabacum L.) germplasm lines were released by the Kentucky Agricultural Experiment Station in 1992 for their indeterminate growth habit. Plants of IG KY 171 and IG KY 160 continue vegetative growth until shorter day lengths in late summer. Other terms often used to describe tobacco with an indeterminate growth habit are mammoth, gigantism, and nonflowering. Indeterminate growth is inherited as a simple homozygous recessive trait (1,2). IG KY 171 and IG KY 160 were developed by transferring this trait from a mammoth flue-cured line, Mammoth C187, into fire-cured 'KY 171' (3) and air-cured 'KY 160'. The backcross method was used, and IG KY 171 and IG KY 160 were identified as homozygous lines in the second self generation following five backcrosses (BC5S2). Agronomic performance of IG KY 171 and IG KY 160 depends on topping time and height. Three-year performance trials have been conducted in which the two lines were topped on the same date as KY 171 and KY 160 and at a similar point, which was directly above the smallest leaf exceeding 15.25 cm (6 inches) in length. Compared with KY 171, IG KY 171 had six more leaves, was 19 cm taller, had leaves that were about 3 cm longer and 3 cm narrower, yielded 44% more cured leaf, and had about the same level of nicotine in cured leaves. Compared with KY 160, IG KY 160 had three more leaves, was 25 cm taller, had leaves that were 6.7 cm longer and 1.6 cm wider, yielded 64% more cured leaf, and had about the same level of cured-leaf nicotine. The tall plants and big stalk sizes of IG KY 171 and IG KY 160 make them undesirable for commercial production; however, they can be used as sources of germplasm for development of breeding populations such as segregating generations from crosses with short-internode lines. Small quantities of seed of the two germplasm lines are available upon written request to the author.