ZESZYT Nr 31/ 2017 Abstrakty Volume No. 31/2017 Abstracts |
6. Inheritance of Potato virus Y tolerance introgressed from Nicotiana africana to cultivated tobacco (Short communication) – Grażyna Korbecka-Glinka, Anna Czubacka, Anna Depta, Teresa Doroszewska Abstract. Potato
virus Y (PVY) is an important pathogen of tobacco. Growing resistant
cultivars is the best way to prevent significant losses of the crop
caused by this virus. However, the protection given by the commonly
used resistance factor, called va gene, can be overcome by the highly
virulent PVY strains. Therefore, tobacco breeding for resistance will
benefit from introducing additional PVY resistance/tolerance factors.
BPA is a tobacco breeding line with introgressed PVY tolerance from a
wild species N. africana. This trait is effective against a wide range
of PVY isolates, including the ones that overcome va resistance. Here,
we describe the inheritance of PVY tolerance of BPA. We obtained F1 and
F2 plants from reciprocal crosses between BPA and a susceptible tobacco
cultivar BP-210. Then we performed mechanical inoculation tests using
sap from PVY infected leaves on both generations of plants. Four weeks
later we recorded disease symptoms and subjected all experimental
plants to DAS-ELISA tests. All F1 plants developed vein necrosis which
confirmed their susceptibility to the virus. The proportion of
susceptible and tolerant plants in the F2 fitted 3:1 ratio which was
expected under the assumption that the tolerance is determined by a
single, recessive gene. Moreover, the proportion of the susceptible and
tolerant individuals did not differ between two F2 populations derived
from crosses where BPA was used as a maternal plant or a pollen donor,
hence cytoplasmic factors do not influence the tolerance of that
breeding line. keywords: Potato virus Y, PVY tolerance, Nicotiana tabacum, Nicotiana africana |