Transgressive segregant, interspecific hybrids between lilium ×formolongi and L. martagon with unique morphology

Obtaining seed-propagated, colored L. ×formolongi hybrids with non-obligate vernalization (VER1, VER2) and colored flowers has involved hybridization with close and distantly related Lilium spp. The cross L. ×formolongi [00L-111-343 × 51-202-1] × L. martagon 'Cadense' (Martagon) in previous research (07L-14) produced 111 viable plants. Most hybrids flowered without vernalization, but all had white trumpet flowers despite close molecular marker alignment with 'Cadense'. However, 37 07L-14 seedlings were rosetted (nonflowering). The objective of this study was to analyze morphology of the 07L-14 rosetted progeny after vernalization to determine whether they possess colored flowers, exhibit hybrid breakdown, or transgressive segregants. A comparative but closer cross, L. regale × L. ×formolongi 'Augusta F₁' SD(5) (=06L-11) was also included. Among the 37 rosetted 07L-14 F_1s, six (16.2%) and one 06L-11 hybrid (1/48, 2.1%) had morphology deviating significantly from the parents and all other non-rosetted full-sibs. All of these hybrids had long, thin linear leaves, which were nearly whorled on the main stem axis, had significantly higher leaf counts and l:w ratios than either parent. The leaf phenotype and phyllotaxy resembles the Nicotiana sylvestris lam-1 and Oryza sativa narrow leaf1 (nal1) mutants. Three genotypes were apetalous with severely truncated floral organs (sterile). The other three 07L-14 and one 06L-11 flowered with functional female/male organs (low fertility). Notably, however, the number of sepals and petals equaled two each, making the total corolla count=4 (rather than 3+3=6 in monocots, the Liliaceae and Lilium); there were also n=4 anthers (instead of n=6). All such transgressive segregants had deep golden throat coloration with open-faced flowers similar to Oriental types, rather than the parents (trumpet or Turk's cap).