Heterosis Effect in Hybrid Combinations of Dihaploid Sugar Beet Lines

Agricultural Institute, BG-9700 Shoumen, Bulgaria


KIKINDONOV, G. and Tz. KIKINDONOV, 2001. Heterosis effect in hybrid combinations of dihaploid sugar beet lines. Bulg. J. Agric. Sci., 7: 577-581

The results of the first field tests of dihaploid sugar beet lines necessitate their engaging in the breeding schemes. Subject of the research is the effect of heterosis in hybrid combinations (2x and 3x) of monogerm and multigerm dihaploid lines. It was established a supremacy of the hybrids over the parents in regards to their productivity – yield of roots and white sugar yield. A great part of the hybrid combinations demonstrate proved real and hypothetical heterosis (HP and MP) regarding these indices. With small exceptions, the tested hybrid combinations are with positive values of the competitive heterosis effect (CHE) for root yield. Nearly all the diploid hybrids of the multigerm dihaploids show a negative CHE regarding the sugar content, while in their triploid hybrid combinations the values of CHE for sugar content are positive.
The diploid hybrid MS 31112 × Dh 72 is with the highest value of CHE for white sugar yield. A high competitive heterosis is registered for the hybrids of the multigerm dihaploids 63 and 58. The triploid hybrids of the dihaploid monogerm lines 150-4 and 19-66 are with significantly higher heterosis effect for white sugar yield than their diploid hybrid combinations.
The results of this research confirm the high potential of the dihaploid lines for the heterosis breeding of the sugar beet.

Key words: heterosis, dihaploid lines, hybrids, sugar beet
Abbreviations: HP – real heterosis, MP – hypothetical heterosis, CHE – competitive heterosis effect