A Pink Longiflorum Lily Cultivar, 'Elegant Lady' Suitable for Cut Flower Forcing

摘要

A new pink longiflorum (Lilium longiflorum x (L. longiforum x L. rubellum)) lily cultivar was obtained by integrated intersectional hybridization techniques. The F_1 intersectional hybrid was obtained by crossing between L. longiflorum "Gelria" and wild type L. rubellum. Since the F_1 hybrid was absolutely sterile, amphidiploid of F_1 hybrid was made by using in vitro mitotie chromosome doubling technique to restore its fertility. The amphidiploid of F_1 interspeeife hybrid had relatively high frequency of pollen viability and was used for the subsequent backcrossing progeny. Backcrossing to the L. longiflontm "Snow Queen" using pollen of F_1 hybrid produced a number of BC_1 seedlings. Flower color of F_1 hybrid (L. longiflorum x L. rubellum) was dark pink due to its male parent (L. rubellum) and BC_1 progeny was mainly the same flower color as soft pink with similar flower shape and plant type. Chromosome analysis was performed to analyze the ploidy value and the variation at chromosome level. Theploidy level of the F_1 hybrid was diploid (2n＝2x＝24) as expected. Each genome was transferred into F_1 hybrid from both parents, and the amphidiploid after chromosome doubling was letraploid (2n＝4x＝48) without any chromosomal variation. Genomic insitu hybrid-ization (GISH) result shows that all BC] plant derived from backcrossing was triploid (2n-3x-36) containing two copies of L. longiflorum chromosomes and one copy of L. rubellum chromosomes. Forcing days of F_1 hybrid was intermediate betweenparents, and by back crossing the forcing days was delayed but earlier than its maternal parent L. longiflorum under standard growing conditions. On the other hand, Fusarium resistance was relatively decreased when compared to L. longiflorum. It is the first pink longiflorum as a commercial cultivar through intersectional hybridization between L. longiflorum and L. rubellum and already in favor on the Japanese market.