A Study On Cytological And Molecular Systematics Of Secale Cereale Subsp. Segetale From Xinjiang

Secale L.( R genome, 2n = 2x = 14) belongs to Gramineae genus, is one of the most early and successful genetic resources used for wheat breeding as a wheat tertiary gene pool of a constituent of triticale. A weed rye was found in Xinjiang Province of China. The studies described its classification as a subspecies of Secale cereale L. and named Secale cereale subsp. segetale. The characters of S. cereale subsp. segetale in Xinjiang, possessing strong stress tolerance and disease resistance,and the desirable genes exhibiting good yield-related traits, suggested could be a good germplasm resources for the wheat improvement and the forage breeding. However,the wild rye found by our country just was preserved in gene bank after collection.The more system works are necessary for better known and further use for this type rye. The present study did the research on Secale cereale subsp. segetale as following.1. The pollen mother cells chromosome number and karyotype of populations in90R2(more tillers) and Z1670(fewer tillers) and their hybrids F1 was studied with the conventional squashing method, the same process did for populations 90R9(late flowering) and Z1665(early flowering) and their hybrids F1. Cytological observation on 4 F1 hybrid cell revealed that the bivalent number range of 6.745-6.815 per cell pair, the frequency of 96.4%-97.4%. The result showed that weed rye have close relationship with cultivated rye, but the structure in some chromosomes were quite different.2. The genomic DNA of 2 materials of S. cereale subsp. segetale and 4 S.cereale L. were amplified by using 1343 pairs of EST-SSR primers of Agropyron cristatum L.and 786 pairs of EST-SSR primers of wheat. It was revealed that the ratio of effectively amplification of A. cristatum EST-SSR primers(50.6%) was more than that in wheat EST-SSR primers(46.3%), but the polymorphism was higher in wheat EST-SSR primers. The results showed the potential for using that two sources of primers to analyse the Secale L. genome.3. The genetic diversity of 92 Secale cereale subsp. segetaleas populations wasstudied by using 47 pairs of polymorphic EST-SSR primers. Their genetic distance at0.35, ninety-two Secale cereale subsp. segetaleas populations coming from same regions didn’t clustered one group, but the genetic distance between populations from the same region generally showed nearer than between different regions.4. With 33 pair of phlymorphism A. cristatum EST-SSR and 18 pair of wheat EST-SSR the genetic relationships was analyzed to 39 Secale cereale subsp.segetaleas populations, 20 cultivation rye populations and plants of A、B、D genome.The research of the 92 Secale cereale subsp. segetaleas populations’ clustering at 0.3,the genetic distance of R genome and A、B、D genome at 0.6. Secale cereale subsp.segetale as an independent group would be well worth further studies.