Variation of flower opening and closing times in hybrids of evening flowering species Iris dichotoma and daytime flowering species Iris domestica

Abstract

Different flowering and closing times within a diurnal period play a significant role in reproductive isolation. However, few studies focused on the genetics of flower opening and closing times within a day for the lack of suitable plant materials. Iris dichotoma opens in the afternoon and closes in the evening, while I. domestica opens in the early morning and closes at dusk. Moreover, they have overlapping flowering phenology and produce fertile hybrids, providing an extraordinary opportunity to study the genetics of flower opening and closing times within a day. To illuminate the genetic mechanism regulating flower opening and closing times, the flowering processes of I. dichotoma (Y), I. domestica (S), and their hybrids: F1, F2, F1 × S, Y × F1, (F1 × S) × F1 and F1 × (F1 × S) were observed. The results indicated that flower opening and closing times are controlled by different polygenes. For flower opening time, opening in the early morning as I. domestica is partial dominant to opening in the afternoon as I. dichotoma. For flower closing time, flower closure at dusk is dominant to closure in the evening. K E Y W O R D S flower closing time, flower opening time, genetic mechanism, interspecific hybrids, Iris, reproductive isolation

Chromosome number and phenotypic variations in hybrid populations of diploid and triploid in Hemerocallis

“…In an analysis of the ower opening time of hybrid progeny, ower opening time in the early morning was found to be partially dominant to that in the afternoon, while ower closure at dusk was found to be dominant to closure in the evening. These results indicated that ower opening and closing times are controlled by different polygenes (Liu et al 2018).…”

The Mechanism of Flower Opening and Closing Times Revealed By Transcriptome Profiling

“…Then a plant of the F1 hybrids was arti cially pollinated with pollen of itself to obtain the F2 hybrids. The F2 hybrids varied widely in ower opening time (varied from 7:00 to 14:45) and closing time (varied from 19:00 to 23:00) [24]. All plant materials were cultivated in the open eld of China National Engineering Research Center for Floriculture (40°17′N, 116°39′E) and were given the same soil condition, moisture condition, temperature and light conditions (including light intensity and photoperiod).…”

“…Two individuals with signi cantly different ower opening and closing times were selected from the F2 hybrids of I. dichotoma and I. domestica for transcriptome sequencing. Their owering processes were categorized into 5 stages according to our previous study [24]: ower bud stage (B stage), the stage when ower petals start opening (SO stage), the stage when petals are fully opened (FO stage), the stage when petals start closing (SC stage), the stage when petals are fully closed and form a tube (FC stage) (Fig. 1).…”

“…These rhythms kept robust even in the constant dark condition (unpublished data), suggesting the involvement of circadian clock. Flowers of the two species are ephemeral and show single opening and closure [24], which means the closure is caused by senescence. Flower opening and closing times differ largely between I. dichotoma (starting opening at 16:00 and starting closing at 20:30) and I. domestica (starting opening at 7:00 and starting closing at 17:00), which becomes a key factor driving reproductive isolation between the two species [4].…”

Comparison Analysis Based on Complete Chloroplast Genomes and Insights into Plastid Phylogenomic of Four Iris Species

“…Wilson [ 28 – 30 ] made considerable progress on molecular identification and phylogeny in Iris species. However, taxonomy of the Iris species still remains complicated [ 10 , 11 , 31 , 32 ].…”