Interspecific Crossing between Lilium hansonii Leichtlin and L. brownii var. colchesteri for the Breeding of New Lily Cultivars

Abstract

This study aimed to generate interspecific hybrids between two remote lily species, L. hansonii Leichtlin and L. brownii var. colchesteri. Reciprocal crosses were performed by conventional and cut-style pollination methods, but viable seeds were only obtained when L. hansonii was used as the female parent, indicating that unilateral incompatibility exists between the two species. In the case of immature seeds, embryos with 2~3 mm were carefully removed from testa for further in vitro culture, and they grew as normal plants. A total of 343 progenies was obtained from the crosses, and hybridity of the progenies were examined using the L9 marker, simple sequence repeat (SSR) marker, at the seedling stage and 92 were confirmed as F1 hybrids. Ploidy level of 76 F1 hybrid was examined and confirmed as diploid. F1 hybrids exhibited intermediate morphologies of the parent in outer tepal and leaf length, but flower shape and color were similar to those of L. hansonii. On the other hand, F1 hybrid plants showed increased flower spots, flower size, and bud numbers, which could be important signatures of the F1 hybrid. This study reports the first attempt to generate an interspecific hybrid between the two species, and therefore, our results from this study would be very informative for future lily breeding.

Obtainment and confirmation of intergeneric hybrids between marguerite (<i>Argyranthemum frutescens</i> (L.) Sch.Bip.) and two <i>Rhodanthemum</i> species (<i>R. hosmariense</i> (Ball) B. H. Wilcox, K. Bremer & Humphries and <i>R. catananche</i> (Ball) B. H. Wilcox, K. Bremer & Humphries)

“…Copyright © 2023 Japanese Society for Plant Biotechnology of morphological characteristics as well as chromosome observations, such as fluorescence in situ hybridization and genomic in situ hybridization (Chester et al 2010;Younis et al 2015), flow cytometry analysis (Dolezel 1997), and determination by DNA markers (Ballesfin et al 2018;Kim et al 2022;Olszewska et al 2021;Premjet et al 2019;Punjansing et al 2021), are commonly used. In intergeneric hybrids of Argyranthemum, flow cytometry analysis revealed hybridity with C. nobile and I. carinata (Katsuoka et al 2022;Ueda and Yamada 2005), and genetic markers have been reported to discriminate between hybrids of C. nobile, G. coronaria, I. carinata, and R. gayanum (Katsuoka et al 2022;Morikawa et al 2014;Muto et al 2020aMuto et al , 2020bUeda and Yamada 2005).…”

Embryo Rescue in Plant Breeding

“…The excised embryo is then transferred to a substrate where it can complete its development [57][58][59]. This method produced new genomic combinations in species, genera, and families of dicot and monocot, for instance, Nicotiana [60], Gossypium [61], Brassica [62,63], Helianthus [58], Tulipa [64], Lilium [65], Vanilla [66], Rhododendron subgenera or sections [67], and Vaccinium [68][69][70], among others.…”

“…Kim et al [65] successfully generated interspecific hybrids between two lily species, Lilium hansonii Leichtlin and L. brownie var. colchesteri, using conventional pollination and cutting-style methods.…”

“…Ninety-two hybrids were confirmed by SSR marker analysis. The hybrids exhibited distinct morphological features such as pollen and stigma color, plant height, flower diameter, the number of shoots, tepal size, and flower direction [65] (Table 2).…”