Flowering and reproductive performance of Iris variegata genotypes in different light conditions

Abstract

Plants grown under canopy shade show a range of responses to the change in light quantity as well as in red/far-red ratio of the ambient light, i.e. light quality. These responses, known as the shade-avoidance syndrome, or near neighbor detection response, are characterized, among others, by changes in flowering phenology and reproductive output. The individual’s flowering pattern is defined by the timing or temporal distribution of flowering (start of flowering, average flowering period), the duration of flowering, as well as the number of flowers produced. We analyzed the genetic variability and phenotypic plasticity of flowering pattern and reproductive success in 97 genotypes of Iris variegata originating from contrasting light habitats in Deliblato Sands and expressed under different experimental light conditions. Rhizome segments were taken from each of these clones and transplanted in the experimental garden near the Institute for Biological Research in Belgrade. Significant differences between genotypes were found for two traits (start of flowering, average flowering time). Genotypes originating from open and understory habitats significantly differed in three traits (number of flowers, number of capsules/number of flowers, seed mass/capsule). Significant effect of light treatment was found for three traits (number of capsules/number of flowers, seed mass/capsule, average seed mass). Statistically significant correlations between explored traits were generally similar but also to some extent habitat- and treatment-specific. Comparing these results with research carried out on congeneric species we noted that there were similar responses for some traits, but also significant differences in some components of flowering and fruiting success.