Interactive Effects of Light Quality, Temperature and Rht Genotypes on Coleoptile Elongation in a Winter Wheat Variety

Abstract

Coleoptile elongation in wheat is influenced by complex interactions between environmental and genetic factors. In this study, we examined the effects of light quality (white, far-red, white + far-red, blue), light intensity (normal and low), temperature (10°C and 20°C) and six different Rht alleles (rht, Rht1, Rht2, Rht3, Rht1 + 2, Rht2 + 3) on coleoptile growth of a winter wheat variety (‘Maris Widgeon’). Effect size analysis identified genotype and light spectrum as the strongest factors influencing coleoptile length, while temperature and light intensity also showed substantial effects. Far-red light and low light intensity promoted elongation, while blue light and Rht mutations reduced it. Notably, the combined effects of temperature, light and genotype indicate that Rht-dependent photomorphogenic responses are influenced by the growth environment. These findings highlight the integrative regulation of early wheat growth by light and thermal environments, mediated by gibberellin sensitivity and photoreceptor signalling.