Variable expressivity and heritability of multiflorous spikelets in oat panicles

Abstract

AbstractMultiflorous spikelets are found in oat Avena sativa L. subsp. nudisativa, which is characterised by elongated rachilla and variable number of florets per spikelet. One of the main factors limiting the exploration of multiflorous spikelets in oats, aiming to produce naked grains, is its variable expressivity. This work aimed to detect the environmental influence on the variable expressivity of multiflorous spikelet formation in oats and to estimate the heritability of this trait by analysing its expression in lower, middle and upper third of the panicle in 94 inbred lines of two crosses each. Two populations of recombinant inbred lines were screened for the spikelet formation in 2 years and sowing dates under field experiments. The results demonstrate that the variable expressivity of the multiflorous spikelet formation was highly influenced by the environmental conditions. The variable expressivity varied according to the genetic background, as well as the panicle third where spikelets were produced. The upper third of the panicle showed greater stability for the multiflorous spikelet formation, which is confirmed by the highest heritability coefficients observed in this third, regardless of the assessed population. Our results provide substantial evidences of the contribution exerted by environmental conditions in multiflorous spikelet formation in oats.