Study On The Offspring Of EGSR Rice About The Inherit Variation And The Prilimirary Research Of Interspecies Hybridization Between Rice And Maize

The parents and the hybrid progenies with the characteristic of EGSR what was generated homologous triploid crossing with a normal diploid have been studied in the molecular level.At the same time,the fertilization and embryo development of a cross between rice and maize was studied.The main results were:1.The results of the SSR marker,cloning and sequencing:The SSR markers were used in order to determine genotypic changes of F₁ progenies.The results of SSR analysis showed that there were 52 of the 446 polymorphic SSR markers in F₁ progenies which were different from their parents.The mass of the other 394 markers generated bands were same to their parents,but there were several markers generated bands different from their parents.44 of the 52 polymorphic SSR markers in these progenies were same to their male parents.These molecular markers showed clearly that the F₁ progenies were almost homozygous.Only 8 markers exhibited the heterozygous bands of both parents.The only 3 markers RM 163,RM279 and RM218 generated a new band which was different from the male parent,but another bands were the same as the female parent.The special F₁ hybrids were self-fertilized to produce F₂ population,in which the individual genotype was detected by SSR markers.The homozygous sites in F₁ hybrids could be inherited to all the F₂ individuals.The heterozygous sites in F₁ hybrids had inheritance consistent with Mendel rules.At the same time,the results of theï¿ 12,R368 and the F₁ hybrid by using of the SSR marking technique were similar to the F₁ hybrid ofï¿ 1/R188.The results of sequenced showed that there were about 200bp in all sequences.In all sequence,the parents had high homology,reached more than 95%,generally only a few differences were between the bases,but their parents and the progenies of the sequence were significant differences,which had a very low homology.We made the F₁ sequences reverse complementary;which results in a significant change between different primers. The result indicated that:RM169 sequence in the F₁ generation was normal genetic. RM521 sequence in the F₁ generation was inversed on chromosome,and then for a missing sequence AACTAGATGCAGCTTGTTGTATGTGCGAGAGAGA.RM582 sequence in the F₁ generation was inversed on chromosome,and then increased many bases of GA.But RM110 sequence in the F₁ generation was same to the patents in 5-and 3-,which about 100bp in the middle was different from the parents.When we researched the sequence in NCBI,we found the sequence was likely to coming from NO.2 chromosome.This indicated that a bit of fragments on NO.2 chromosome instead of the fragments on NO.12 chromosome.2.The results of using the AFLP marker:The parents and their offspring were studied by using AFLP technique,and the result indicated that primer-combinations among 10 pair of primers amplified 162 bands,include 111 bands which the progenies were same to their parents,accounting for 68.5%.The other special cases account for about 30%,including only the progenies,the progenies was similar to the female or male parents.Different primers had different bands.Some were amplified more than 20 bands,the others primers only amplified several bands.3.The results of embryonic observation of distant crossing between rice and maize: The results showed that the pollen grains of maize could enter into the tissue of style of rice,and reached at the embryo sac and released the sperms.Maize sperm might fuse with rice egg or polar nucleus and formed zygote or primary endosperm.But the embryo and endosperm could not be developed normally,and result in the underdeveloped hybrid seeds was formed.The reason was probably that the parental genomes could not coordinate well.The results of the SSR marker and AFLP marker showed that homologous recombination on chromosome when homologous triploid crossing has been taken place at F₁ generation with a normal diploid.The results of embryonic observation showed:Maize sperm entered into the rice gastrula occurred at a very high frequency.It was possible that maize sperm fused with rice egg when it fused with polar nucleus,because maize sperm fused with rice egg has been found.