Preparation and Evaluation of Test Cross Hybrids Resistant to Rhizomania and Cyst Nematode Based on New Single Crosses in Sugar Beet

To prepare and evaluate test cross hybrids resistant to rhizomania and cyst nematode based on new single crosses, 48 test cross hybrids produced were evaluated in 2021 in the augmentation design along with Iranian and commercial hybrid varieties in six regions )Karaj, Mashhad, Shiraz, Kermanshah, Miandoab, and Hamadan(. Genotypes mean comparison showed that BTS2015N had the highest root yield in Karaj, Mashhad, Shiraz, Kermanshah, and Hamadan and an average of six locations with an average of 133.97, 114.45, 77.14, 102.80, 97.08, and 104.91 t/ha, respectively. The Wawilow cultivar also had the highest sugar content in Karaj, Mashhad, Shiraz, and Kermanshah and an average of six locations with an average of 17.61, 18.31, 24.06, 19.57, and 18.62 percent, respectively. In addition, in a total of six locations, there was no significant difference among hybrids 39, 40, 31, and 35 in terms of root yield and hybrids 24 and 47 in terms of sugar content with the external control cultivar BTS2015N. In this study, new hybrids 40, 38, 23, Nika, and Bifort cultivars have the lowest ASV values with 0.062, 0.117, 0.154, 0.245, and 0.256, respectively, were considered stable genotypes in terms of root yield. Also, based on the results of the GGE biplot method, the new hybrids 13, 24, 32, 23 had the highest general stability. In this study, the BTS2015N cultivar for the environments of Karaj, Kermanshah, Shiraz, and Hamadan and the Annamira KWS cultivar for the Miandoab environment showed high specific adaptability.