Astronautical Mutation Breeding in Alfalfa and its Molecular Analysis

Astronautical mutagenesis is a new breeding technique. In space, the variation are produced by means of the comprehensive effect like high vacuum, microgravity, intense radiation and so on. The mutated seeds by astronautical mutagenesis will be selected to breed the new cultivars. Astronautical mutation breeding opens up a new way for breeding. In this study, the genetic variation of 10 “Zhaodong” Alfalfa mutated lines produced by astronautical mutagenesis were investigated using RAPD method. For RAPD analysis, 90 primers were tested and 21 primers were selected for the detailed RAPD makers. Comparing with the original “Zhaodong” Alfalfa, the genetic variation of mutated lines was very obvious. For the same Primer, there were more one band (a few bands) or less one band (a few bands) between mutant and its original lines. The amplified bands and polymorphic sites were rich, ranging from 250-2000bp.1108 RAPD loci were determined. The quantity of RAPD polymorphic loci ranged from 2-31. The rate of polymorphic sites of the mutants and wild types ranged from 2.06%-31.95%. The mutated line-8, 9, 10 had bigger variation and mutated line-10 has the biggest variation in all mutants, it can be for the further selection and breeding work for the new alfalfa.

Testing for Genetic Purity in Petunia and Cyclamen Seed Using Random Amplified Polymorphic DNA Markers

This study examined the use of random amplified polymorphic DNA (RAPD) markers as a means to identify cultivars of petunia (Petunia hybrida Vilm) seedlings and cyclamen (Cyclamen persicum Mill.) seeds and to determine the genetic purity within cyclamen seeds. Bulked samples of six petunia and five cyclamen hybrid cultivars, respectively, produced consistent RAPD marker profiles. Evaluation of individual seeds from a single cyclamen hybrid produced polymorphic banding patterns that were attributed to genetic variability present in the female and male inbred parents. These results show that RAPD makers can be used to quickly assess the genetic purity of selected cultivars of these two flower seed crops.

MOLECULAR MARKERS FOR CHARACTERIZATION OF GRAPE CULTIVARS II

The work reported here is an extension of studies reported in 1990. The general objective was to develop molecular markers for genotype `fingerprinting', with specific reference to possible clonal differences among `Pinot noir' clones. Leaf DNA from 8 cultivars and 9 `Pinot noir' clones were isolated. RFLP and RAPD markers were identified and used to characterize the genotypes. 65 32-P labelled cloned probes were constructed with the pUC18 plasmid and Hind-III digested `Pinot noir' DNA. The probes were tested for their ability to discriminate among the 8 cultivars. 3 probes pGAD10, pGAD15, and pGAD44 showed polymorphisms among the cultivars. pGAD15 was most useful, with 5 polymorphisms for the 8 cultivars. RAPD makers were also tested for `fingerprinting'. Several primers were tested and polymorphisms were identified among cultivars. However, significant problems with repeatability for some bands were observed. Therefore, a series of experiments were conducted to test the effect of season and extraction method. These factors did not account for the inconsistancy which seemed to be more a function of the primer used. None of these studies showed clear evidence that the `Pinot noir' clones tested were geetically different.