EST sequencing and SSR marker development from cultivated peanut (Arachis hypogaea L.)

Guo Qi Song
High-Tech Research Center
Shandong Academy of Agricultural Sciences
Key Laboratory for Genetic Improvement of Crop, Animal and
Poultry of Shandong Province
Key Laboratory of Crop Genetic Improvement and Biotechnology, Huanghuaihai
Ministry of Agriculture, Ji′nan 250100, People’s Republic of China 

Meng Jun Li
High-Tech Research Center
Shandong Academy of Agricultural Sciences
Key Laboratory for Genetic Improvement of Crop, Animal and
Poultry of Shandong Province
Key Laboratory of Crop Genetic Improvement and Biotechnology, Huanghuaihai
Ministry of Agriculture, Ji′nan 250100, People’s Republic of China 

Han Xiao
High-Tech Research Center
Shandong Academy of Agricultural Sciences
Key Laboratory for Genetic Improvement of Crop, Animal and
Poultry of Shandong Province
Key Laboratory of Crop Genetic Improvement and Biotechnology, Huanghuaihai
Ministry of Agriculture, Ji′nan 250100, People’s Republic of China 

Xing Jun Wang*
High-Tech Research Center
Shandong Academy of Agricultural Sciences
Key Laboratory for Genetic Improvement of Crop, Animal and
Poultry of Shandong Province
Key Laboratory of Crop Genetic Improvement and Biotechnology, Huanghuaihai
Ministry of Agriculture, Ji′nan 250100, People’s Republic of China
E-mail: xingjunw@hotmail.com 

Rong Hua Tang
Cash Crops Research Institute
Guangxi Academy of Agricultural Sciences
Nan’ning 530007, People’s Republic of China 

Han Xia
High-Tech Research Center
Shandong Academy of Agricultural Sciences
Key Laboratory for Genetic Improvement of Crop, Animal and
Poultry of Shandong Province
Key Laboratory of Crop Genetic Improvement and Biotechnology, Huanghuaihai
Ministry of Agriculture, Ji′nan 250100, People’s Republic of China 

Chuan Zhi Zhao
High-Tech Research Center
Shandong Academy of Agricultural Sciences
Key Laboratory for Genetic Improvement of Crop, Animal and
Poultry of Shandong Province
Key Laboratory of Crop Genetic Improvement and Biotechnology, Huanghuaihai
Ministry of Agriculture, Ji′nan 250100, People’s Republic of China 

Yu Ping Bi
High-Tech Research Center
Shandong Academy of Agricultural Sciences
Key Laboratory for Genetic Improvement of Crop, Animal and
Poultry of Shandong Province
Key Laboratory of Crop Genetic Improvement and Biotechnology, Huanghuaihai
Ministry of Agriculture, Ji′nan 250100, People’s Republic of China

*Corresponding author

Keywords: Arachis hypogaea L., cultivars, EST-SSR, polymorphism, wild-type peanut.

Making use of the gene resources of wild type peanuts is a way to increase the genetic diversity of the cultivars. Marker assisted selection (MAS) could shorten the process of inter-specific hybridization and provide a possible way to remove the undesirable traits. However, the limited number of molecular markers available in peanut retarded its MAS process. We started a peanut ESTs (Expressed Sequence Tags) project aiming at cloning genes with agronomic importance and developing molecular markers. In this study we found 610 ESTs that contained one or more SSRs from 12,000 peanut ESTs. The most abundant SSRs in peanut are trinucleotides (66.3%) SSRs and followed by dinucleotide (28.8%) SSRs. AG/TC (10.7%) repeat was the most abundant and followed by CT/GA (9.0%), CTT/GAA (7.4%), and AAG/TTC (7.3%) repeats. Ninety-four SSR containing ESTs were randomly selected for primer design and synthesis, of which 33 pairs could generate good amplification and were used for polymorphism assessment. Results showed that polymorphism was very low in cultivars, while high level of polymorphism was revealed in wild type peanuts.