Cross Breeding Of Three Hybrid Groups Of Lily

Crossbreeding is able to integrate the excellent characteristics of the two parents, which is an important mean to create new germplasm. In this experiment, lily cultivars from Asiatic hybrids, Lilium longiflum hybrids and OT hybrids were employed as materials for hybridization.The research studied on 26 crosses with stigma pollination methods and embryo culture in vitro for overcoming incompatibility in lily hybridization, and then ISSR and RAPD were used to identify hybridization, karyotype analysis studied by squash method was used to analyse chromosome of some parents.The main results of the research are as following:1. Karyotype analysis. There are different ploidies in 6 varieties, including diploidy, triploidy and tetraploidy, and the variety’Vermeer’has aneuploid. The mainly karyotype is 3B. The most proportion of chromosomes are st and t chromosomes, the symmetric of the karyotype was bad, which is in line with the view of symmetric original, asymmetric evolutionary.2. Comparation of hybridization affinity of the three hybrids groups. Most of the crosses between Asiatic hybrids were compatible, which could get swelling capsules after stigma pollination. There were 6 crosses which could get seeds with embryo among 13 crosses, but the compatibility in OT hybrids was very weak. Most capsules were thin and the longevity of fruit was very short. However, when ’White Heaven’were used as the female parent, most crosses could get a few number of hybrid embryos. So it is critical for one given variety to be used as femal or male parent. For most Asiatic hybrids, capsule length/width ratio and longevity of fruit, seed setting rate, embryo rate were in inversely proportional relationship, which had showed that the swelling degree and longevity of fruit could be the appearance standards of the hybridization affinity, but with embryo rate as a judgment was more reliable.3. Embryo culture in vitro. After pollination 50-60 days, the embryos were removed from seeds and cultured in vitro. For most hybrid plantlets the optimum culture medium was MS+NAA0.01mg/L+6-BA1.0mg/L+sucrose30g/L. Embryo could grow properly, with theconcentration of sucrose between 3%-6%.4.ISSR and RAPD were evaluated for their potential using in the identification of six hybridies in this study. Of the 16 ISSR primers subjected to screening,4 primers produced reproducible, discrepant and polymorphic fragments. Using these primers,57 discernible DNA fragments were generated with 46 polymorphic bands(80.7%).2 RAPD primers generated 27 discernible DNA fragments, including 20 polymorphic bands(74.1%). The results indicated that most DNA fragments of hybrids were the same with those of their parents. The hybrids had two parents’DNA fragments or seed/pollen parent’s DNA fragments. Meanwhile, some hybrids showed new DNA fragments. The molecular evidence showed that the six hybrids were real hybrids.