Molecular Assisted Breeding for Disease Resistance in Lily

Abstract

The Asiatic hybrid lily ( Lilium L.) 'Connecticut King' harbours several beneficial traits such as partial resistance to Fusarium and complete resistance to tulip breaking virus (TBV). The variation in resistance to Fusarium was determined in four different greenhouse tests in four different years on the same 100 descendants of a backcross population. There was considerable variation in Fusarium resistance levels over the years. TBV resistance was determined and segregated, as expected, like a monogenic trait (1:1). In order to identify quantitative trait loci (QTLs) for Fusarium resistance and also to identify linked markers to the TBV resistance a QTL mapping approach was carried out in this backcross population. Segregation of 399 polymorphic AFLP TM (amplified fragment length polymorphism) fragments was determined. Two different enzyme combinations were used, PstI/MseI and EcoRI/MseI, in the latter one extra selective nucleotide was added to the MseI primer. A paternal ('Connecticut King') linkage map was calculated. This map consisted of 24 linkage groups ( Lilium 2n=2x=24) with 251 markers covering 1367 cM. About 25% of the markers remained unlinked. Four QTLs for Fusarium resistance mapped to linkage groups 1, 5, 13 and 16 respectively. The resistance gene for TBV was placed on linkage group 9.

Genetic mapping in Lilium: mapping of major genes and quantitative trait loci for several ornamental traits and disease resistances

“…The second population is an AA population of 100 individuals (Straathof et al. 1996, Van Heusden et al. 2002), which was produced in 1989.…”

“…Four quantitative trait loci (QTL) for Fusarium resistance were identified whereas LMoV resistance was controlled by a single locus. Only the LG bearing the LMoV locus was published (Van Heusden et al. 2002).…”

“…Molecular markers: New NBS and DArT marker data were developed for both populations. Additionally, for AA already existing amplified fragment length polymorphism (AFLP) data (Van Heusden et al. 2002) were included.…”

Development of expressed sequence tag derived-simple sequence repeats in the genus Lilium

“…Abe et al (2002) reported the genetic analysis of floral anthocyanin pigmentation traits in Asiatic hybrid lilies using randomly amplified polymorphic DNA and inter-simple sequence repeat. Van Heusden et al (2002) used amplified fragment length polymorphism markers to map four quantitative trait loci (QTLs) for Fusarium oxysporum and a single locus of LMoV in an Asiatic backcross population. Shahin et al (2011) analyzed QTLs for several ornamental traits and disease resistance with amplified fragment length polymorphism, DArT, and fine-map NBS profiling.…”

Crossing Lilium Orientals of different ploidy creates Fusarium-resistant hybrid

“…Alternatively, the Fusariumresistant genes were recombined into the hybrids by crossing the cultivars of Lilium Asiatic with that of Llilium Oriental (Schenk, 1990;Barba-Gonzalez, 2005;Lim et al, 2000). However, the previous studies showed that the Fusarium resistance of lily was a multi-gene character (Heusden et al, 2002), and the identification of the resistant genes was rather complicated, besides the Fusarium-resistant genes of lily mainly existed in the Lilium Asiatic, which made it necessary to do the distant crosses between different groups of lily. All these resulted in a very low efficiency in breeding of resistant cultivars by gene introgression strategy …”