Scanning And Analysis Of Maize DNA In T7 Generation Rice Variants

The research of rice molecular breeding has been carried on since 2002 in our laboratory and some rice variants with stable maize characters were obtained.4 variants,numbered by 08-7-114-11-2-2, 08-7-131-1-1, 08-7(+2)-131-5-2 and 08-7(+2)-135-2-1-2-2 respectively,were select as the study material.By utilizing the Amplified Fragment Length Polymorphism(AFLP) technice and bioinformatics,a series of studys were done to detect the genomic differents between the rice variants,and,analyse aimed genes homology and fountion.Rice variants,rice control and maize control genomes were screened by 64 pair selective primer combinations.The results show that:(1)The total number of fragments in each genome,include rice control and maize control,was 846 to 980,on average 942.The number of fragments in maize control was the lest compare to rice materials include rice control.(2)123 new fragments were found and 142 bands were lost, the total number of new fragments was less that the lost.(3) The difference ration between Rice variants (08-7-114-11-2-2,08-7-131-1-1,08-7(+2)-131-5-2 , 08-7(+2)-135-2-1-2-2) and rice control was 8.2%, 7.5%,5.3% and 6.8% respectively. ( 4 ) The identities between Rice variants (08-7-114-11-2-2, 08-7-131-1-1,08-7(+2)-131-5-2 , 08-7(+2)-135-2-1-2-2) and rice control was 36.7%, 35.1%,33.6% and 34.7% ,respectively,all that was higher than the identities between rice control and maize control which was 30.9%.(5)The aimed fragments in the 4 rice variants (08-7-114-11-2-2,08-7-131-1-1,08-7(+2)-131-5-2 , 08-7(+2)-135-2-1-2-2) was 11,9,8,9 respectively.The 10 aimed fragments were recovered and sequenced in order to get the DNA sequence information. The sequences of 10 aimed fragments were scanned by BLAST in NCBI database, in order to search the homologous DNA sequence.The result show that all the aimed sequences found more than one homologous which identities was higher than 98%.Generally,the number of different base between aimed sequence and homologous was 1or2. The result of 10 scanned scqunses was that 6 aimed fragments were rice nuclear DNA sequences ,2 aimed fragments were rice chloroplast DNA sequences and 2 aimed fragments werer maize mRNA sequences.The function of 2 aimed sequence (P1M8-135(+2)-304 and P5M3-131-349 ) were analysed by use of NCBI database and EBI database.As shown the result,the aimed sequence of P1M8-135(+2)-304 code for hydroxyacylglutathione hydrolase,a proteinase with function such as hydrolysis, Antioxidation, Detoxification.The other sequence, P5M3-131-349,code for cysteine-type endopeptidase/ ubiquitin thiolesterase, a proteinase with function of hydrolysis,peptide synthetic,protein modification , RNA splicing and so on.From what has been discussed above,we may draw a conclution that the variant trait was relate to maize DNA translated into rice cell by Ion Beam.But the revelance was unclearly,so we shoued make a further research.