Identification of donor lines containing favorable alleles for quantitative traits in Burley tobacco (Nicotiana tabacum L.)

Abstract

Well-adapted local lines might be used as donors to improve existing commercial hybrids. The objective of this study was to identify the best burley tobacco (Nicotiana tabacum L.) line among a group of four lines (SA 130, Bols 334, Barlej T and TN 90) from germplasm collection, for improving an elite single hybrid Bols 335 x TN 86. Values of three quantitative traits (number of leaves, total leaf area and leaf yield) were measured in two-year field experiments. Evaluation of donor lines as sources of new favorable alleles not present in the elite hybrid parent lines was conducted. According to Dudley (1984, 1987) the most significant class for improving quantitative traits is locus class G. Donor line TN 90 had positive values of the parameter μG for number of leaves and for total leaf area. Studied donor lines could not be use directly as the source of new alleles for the improvement of leaf yield in elite hybrid. The improvement of leaf yield in tobacco hybrid Bols 335 x TN 86 would be conducted indirectly via back crossing (TN 86 x TN 90) x TN 86. Significance of GxE interaction for studied traits indicates the same breeding method would be effective in broad range of environmental conditions.

Na bazi srednjih vrednosti u dvogodišnjim ogledima, ispitivane su četiri linije (SA 130, Bols 334, Berlej 5, TN 90) iz kolekcije germplazme, kao potencijalni donori poželjnih alela za poboljšanje osobina (broj listova, površina listova i prinos lišca) elitnog prostog hibrida Bols 335 x TN 86. Analizom po metodu Dudley (1984,1987) konstatovano je da naveden linije mogu poslužiti kao potencijalni donori. Najznačajnija klasa za unapređenje kvantitativnih osobina je bila lokusna klasa G. Linija donor TN 90 ima pozitivne vrednosti parametra μG za broj listova i ukupnu površinu listova. Proučavane linije-donori, ne mogu biti korišćene direktno kao izvor novih alela za unapređenje prinosa lišća elitnog hibrida. Unapređenje prinosa kod hibrida Bols 335 x TN 86 je moguće indirektno, preko povratnog ukrštanja (TN 86 x TN 90) x TN 86. Značajnost interakcije GxE za proučavane osobine ukazuje da isti oplemenjivački metod može biti primenjen u širokom rangu ekoloških uslova.