Lily Introgression Breeding Using Triploids Cultivars As Maternal Parents

Lily, belonging to Lilium, is a perennial flower bulb, which is one of the most important cut flowers around the world. Europe and North American have a long history in culturing ornamental lilies. Although there is a substantial wildlife resources and a long history of culturing lilies in China, it is rarely reported about lily breeding in the past because they are mostly regard as food and medicine. Studies on culturing lily cultivars still keep some pace with advanced international standards in China due to the late start. Therefore, we have to import quite a few lily bulbs from abroad to satisfy domestic market demands.The important aim of lily breeding is to combine the delicate features of their wild relatives with the cultivars. Methods of cultivation of lily are numerous, so far, incomputable lily cultivars have been reported. Then, lily hybridization is one of being used wildly among the methods of cultivation of lily. And most of them are accomplished with diploid and tetraploid as the female parent. Hybridizations which take triploid as the female parent are not commonly used. Nevertheless, breeding studies shows lily allotriploid are produced from sexual polyploidization and asexual polyploidy. Although most of them is male sterile due to abnormal meiosis, they can be used to cross with proper male parent as the female parent. In this research we selected two LAA lily cultivars to hybridize diploid and tetraploid Asiatic lily. The following are the results:1.Both LAA X A A and LAA X AAAA were successful.41seeds were obtained from LAA X AA with384seeds from LAA X AAAA. It shows that although lily allotriploid is male sterile, they can be used to hybridize proper male parent as the female parent.2. The results of GISH showed that ’Brindis’ and ’Pavia’ are triploid (2n=3x=36) whose genomes are LAA. Besides,’Brindis’is consist of9Longiflorum chromosomes,22Asiatic chromosomes and5recombinant chromosomes with ’Pavia’(9Longiflorum chromosomes,23Asiatic chromosomes and4recombinant chromosomes). Both ’Brindis’ and ’Pavia’ contained recombinant chromosomes demonstrate that the two cultivars stem from sexual polyploidization.3. All identified hybrids are aneuploids from hybridizations of Longiflorum and Asiatic lilies. The number of chromosomes of the offsprings ranges from39to63whose ploidies are somewhere between triploid and hexaploid. The number of chromosomes of the offsprings ranges from3to7. Based on the male parents, it can be deduced that the number of chromosomes of eggs from the female parents rangs from15to39whose plodies are somewhere between haploid and tetraploid. It is evident that the meiosis is abnormal during lily macrosporogenesis based on.the last changes. Compared the number of recombinant chromosomes and chromosome breakpoints of the female parents with the offsprings’, it showed that the female parents produced new recombinant chromosomes during lily macrosporogenesis.To sum up, although lily allotriploid is male sterile, they can be used to hybridize proper male parent as the female parent to achieve introgression breeding in Lilium. Then, we can demonstrate allotriploid is not bottle neck of introgression breeding in Lilium.