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

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