Phenotypic Variations and Heritability in Hybrid Populations of Bearded Iris

Abstract

<jats:p>Bearded iris (<jats:italic>Iris</jats:italic> ×<jats:italic>hybrida</jats:italic> Hort.) is a large horticultural hybrid complex in the <jats:italic>Iris</jats:italic> genus, and the lack of understanding about its inheritance laws has seriously hindered the breeding process. From parental bearded iris ‘Indian Chief’ and ‘Sugar Blues’, four hybrid populations—including F<jats:sub>1</jats:sub>, F<jats:sub>2</jats:sub>, BC<jats:sub>1</jats:sub>P<jats:sub>1</jats:sub>, and BC<jats:sub>1</jats:sub>P<jats:sub>2</jats:sub>—were generated through hybridization. Fifteen key phenotypic traits, including plant height (PH), scape height (SH), length of fall (LF), width of fall (WF), length of standard (LS), width of standard (WS), and so on, were measured, and several genetic parameters (e.g., trait variation, heritability, trait correlation, distribution of flower color) were analyzed. The variation of phenotypic traits indicated that the F<jats:sub>1</jats:sub> generation could produce larger flowers and a greater number of blooming stems than other generations, whereas backcrossing was beneficial at producing more flowers on one scape in the offspring of ‘Indian Chief’ and ‘Sugar Blues’. WF had the greatest broad-sense heritability (73.91%) among the 15 phenotypic traits, whereas the broad-sense heritability of SH was the lowest (2.06%). The correlation between a vegetative trait (PH) and a reproductive trait (WS) provided a path to early selection of germplasm. Furthermore, four important floral traits (LF, WF, LS, and WS) also correlated significantly to each other, thus simplifying the selection of larger flowers. Genes regulating fuchsia flower color were dominant over those for bluish purple flowers. Genetic effects of flower color in recurrent parents could be reinforced by backcrossing, thereby providing a potential way to modify flower color through hybridization.</jats:p>

Heritability of floral traits in Allium cepa L. populations from biparental crosses

“…These findings suggest that a substantial proportion of the variance is explained by genetic factors in traits with heritability values above 0.50. Similar values have been reported for crosses and hybrid populations of various species, such as Chrysanthemum morifolium Ramat., Argentina anserine (L.) Rydb., Iris × hybrida Hort., and Crocus sativus L. In these studies, broad‐sense heritability ranging from 0.34 to 0.92 accounted for different floral traits associated with flower size and shape (Baghalian et al., 2010; Fan et al., 2019; Koski & Ashman, 2013; Yang et al., 2023). Our results of broad‐sense heritability remained consistently stable across the three evaluated populations.…”