CTH8 flue-cured tobacco hybrid

Amankwa, G. A., Mishra, S., Shearer, A. D., Brammall, R. and Van Hooren, D. L. 2014. CTH8 flue-cured tobacco hybrid. Can. J. Plant Sci. 94: 461–463. CTH8 is a new flue-cured tobacco (Nicotiana tabacum L.) hybrid recommended for commercial release in Canada. It has superior grade index compared to the check varieties Delgold and CT157, and its yield potential is intermediate between the two checks.

CTH14 flue-cured tobacco F1 hybrid

CTH14 is the second flue-cured tobacco (Nicotiana tabacum L.) hybrid recommended for commercial release in Canada. The yield of CTH14 is significantly superior to that of CT157, one of two check varieties, while the grade index is superior to the other check variety Delgold. As a result, the economic return of CTH14 is significantly superior to both check varieties. CTH14 has uniform growth both in the greenhouse and in the field. Leaf quality traits of CTH14 are far superior to Delgold, as well as most other commercial varieties in Ontario.Key words: Nicotiana tabacum L., tobacco, hybrid, male sterility, black root rot, cultivar description

Organogenesis from cultured floral meristems of a male sterile tobacco hybrid

Very young floral meristems of a male-sterile tobacco hybrid were excised and cultured on Linsmaier and Skoog medium in continuous light. Basal medium was supplemented with kinetin and gibberellic acid, singly and in combinations. On medium with kinetin, all four types of floral organs arose in the normal sequence and pattern and the male sterile phenotype was expressed, GA3 suppressed the formation of these organs. The data show that male sterile organs may form and begin differentiation in vitro without direct influence from the plant.

A developmental study of the stamens in a male-sterile tobacco hybrid

The ontogeny of the feminized stamens in a male-sterile tobacco hybrid has been studied. Plant material 1A was derived from an initial cross between Nicotiana debneyi as female and N. tabacum cv. Kupchunos as male. All 1A flowers exhibit stigmatoid anthers at anthesis and are sterile. This teratism is cytoplasmically inherited. In a developmental series of 1A floral buds, it was found that 1A stamen primordia diverge relatively early from the normal stamen shape and appear as spatulate organ rudiments lacking differentiation into anther and filament. In 1A buds after carpel fusion and as the normal stigma is differentiating, stamens form a distinctly stigmatoid tip subtended by a short filament bearing the initials of lateral outgrowths. The stigmatoid tip then enlarges to a green, bulbous recurved structure and there is considerable extension growth of the filament. Histological study of developing and mature teratological stamens showed complete absence of sporogenous tissue and also confirmed the true stigmatic nature of the tip region. The results are discussed in relation to regulation of sex determination.