BREEDING OF RICE VARIETIES WITH PYRAMIDING GENES TOLERANT TO DISEASES

Abstract

Rice can significantly decrease the harvest of grain when it’s damaged with a dangerous fungus ‘Pyricularia grisea’ (rice blast). Single genes resistant to the pathogen are usually unefficient. That’s why it’s necessary to breed productive rice varieties, resistant to rice blast, having several genes possessing resistance in one genotype. Using molecular markers closely connected with genes which make the plants resistant to the pathogen, significantly facilitates the breeding. The purpose of the work is to breed a line of rice with five genes resistant to rice blast using a molecular marking method. We used the lines of foreign breeding as donors of resistant genes and domestic varieties ‘Boyarin’ and ‘Virazh’ as recipients. In the work there were used micro satellite markers on genes resistant to rice blast. The results were visualized by polymerase chain reaction (PCR) and electrophoresis.At the first stage we received 6 hybrids from a cross breeding of recipients ‘Boyarin’ and ‘Virazh’ and donors Pi-l, Pi-2, Pi-33. At the second stage during the process of pyramiding we managed to receive the varieties with these three genes together. At the third stage we carried out the hybridization with donors Pi-ta and Pi-b to combine 5 genes.As a result of long-term work in introgression of the genes resistant to rice blast with the help of marking selection and PCR-analysis we obtained rice lines, combining five genes Pi-l, Pi-2, Pi-33, Pi-ta, Pi-b resistant to the pathogen.

Keywords

• rice
• hybrid
• rice blast (pyricularia grisea)
• resistance
• pyramiding of genes
• marking breeding (selection)
• pcr-analysis