Analysis of disease resistance and quality characters of F₁ hybrids of crosses between wheat (Triticum aestivum) and spelt (Triticum spelta)

Summary

With the objective of creating new combinations of disease resistance and quality, hybrids between wheat and spelt (spelt is well adapted to cool and wet conditions) were produced and the expression of heterosis was analysed. Three winter wheat varieties were crossed reciprocally with two spelt cultivars and the F₁ hybrids were tested under artificial inoculation with stripe rust, powdery mildew and leaf rust. Disease susceptibility and quality characters (protein content, Zeleny value, grain hardness) were assessed in two year field trials. For stripe rust the F₁ hybrids were resistant if one of the wheat parents was resistant. Combinations with the susceptible wheat cultivar ‘Arina’ were all susceptible irrespective of using a resistant spelt partner. Although the infection with powdery mildew was rather low, a similar reaction was obtained with the susceptible wheat variety ‘Bernina’. Leaf rust revealed very specific varietal influences. The two susceptible wheat varieties ‘Bernina’ and ‘Arina’ resulted in susceptible F₁ hybrids when combined with a moderately resistant spelt. Only when they were crossed with a resistant spelt cultivar the F₁ hybrids were resistant. ‘Forno’, a leaf rust resistant wheat, gave resistant F₁ hybrids in all combinations. Without exception the quality characters tested showed a negative heterosis effect resulting in protein levels and Zeleny values close to or below the values of the lower parent. It appears to be possible to produce resistant F₁ hybrids, mostly dominated by the resistance level of the wheat partner. The quality of the hybrids is mainly suitable for biscuit and spelt specific products; it needs specific screening for combinations with acceptable breadmaking quality.