Identification of molecular markers linked to sugarbeet cyst nematode resistance gene(s)

Abstract

Beet cyst nematode (Heterodera schachtii Schmidt). Spreads extensively in different regions of sugar beet cultivation, and therefore many efforts are accomplished to prevent decrease of sugar and root yield caused by the disease. The most appropriate control method of this disease is improvement of resistant varieties. Wild species of procumbentes in Beta are very important because they contain resistance genes against different diseases including beet cyst nematode. Ten-mer primers and specific sequences were selected to identify DNA molecular markers linked to beet cyst nematode resistance genes. For this purpose, at first, segregating populations for resistance genes were selected and after seed sowing in pots in greenhouse, seedlings were inoculated with 1000 nematode larva several times. Resistant plants (with lower than 10 cysts) and susceptible plants (with less than 10 cysts) were identified and divided to two groups. In the next step, RAPD-PCR, finger printing of the samples and comparison the DNA banding pattern of the two groups was done by using selected primers such as: OP-X-02, OP-X-15, OP-G-02, OP-D-13, OP-B-11, OP-Y-10 and Sat-121 specific primers and the oligonncleotides TGAACACCTTTCAAAT (forward) and CGTAAGAGACTATGA (Reverse) and one hundred primers from the operon kits. After calculating of correlation between resistance plants and the presence of special DNA band, OP-D-13 and Sat-121 molecular markers were identified to be linked to resistant genes against beet cyst nematode. In conclusion, these two molecular markers can be used for screening of resistant plants in laboratory conditions.

Keywords

• sugar beet
• resistance
• cyst nematode
• molecular markers