RFLP and RAPD mapping of the rice gm2 gene that confers resistance to biotype 1 of gall midge (Orseolia oryzae)

Abstract

Gm2 is dominant gene conferring resistance to biotype 1 of gall midge (Orseolia oryzae Wood-Mason), the major dipteran pest of rice. The gene was mapped by restriction fragment length polymorphism (RFLP) analysis of a set of 40 recombinant inbred lines derived from a cross between the resistant variety 'Phalguna' and the susceptible landrace 'ARC 6650'. The gene is located on chromosome 4 at a position 1.3 cM from marker RG329 and 3.4 cM from RG476. Since the low (28%) polymorphism of this indica x indica cross hindered full coverage of the genome with RFLP markers, the mapping was checked by random amplified polymorphic DNA (RAPD)/bulked segregant analysis. Through the use of 160 RAPD primers, the number of polymorphic markers was increased from 43 to 231. Two RAPD primers amplified loci that co-segregated with resistance/susceptibility. RFLP mapping of these loci showed that they are located 0.7 cM and 2.0 cM from RG476, confirming the location of Gm2 in this region of chromosome 4. Use of these DNA markers will accelerate breeding for gall midge resistance by permitting selection of the Gm2 gene independently of the availability of the insect.

Tagging and mapping of a rice gall midge resistance gene, Gm8, and development of SCARs for use in marker-aided selection and gene pyramiding

“…For bulked segregant analysis, an equal quantity of DNA from 12 resistant and 12 susceptible F 4 individuals was pooled to form the resistant and susceptible bulks, respectively (Michelmore et al 1991;Mohan et al 1994). The concentration of DNA of the two bulks and the two parental DNAs was adjusted to 10 ng/μl.…”

“…The amplification conditions have been described previously (Williams et al 1990), with certain modifications (Mohan et al 1994). A total of 1,200 RAPD primers (Operon Technologies, Alameda, Calif., USA) belonging to the A to Z, AA to AZ and BA to BH series were used in this study.…”

“…Of the total nine gall midge resistance genes that are known (Gm1 to Gm9) so far, four [Gm2,Gm4(t), Gm6(t) and Gm7] have been tagged and mapped (Mohan et al 1994(Mohan et al , 1997bNair et al 1995Nair et al , 1996Katiyar et al 2001;Sardesai et al 2002). The development of these markers has been made possible using various molecular marker techniques (Mohan et al 1994(Mohan et al , 1997bNair et al 1995Nair et al , 1996.…”

“…Of the total nine gall midge resistance genes that are known (Gm1 to Gm9) so far, four [Gm2,Gm4(t), Gm6(t) and Gm7] have been tagged and mapped (Mohan et al 1994(Mohan et al , 1997bNair et al 1995Nair et al , 1996Katiyar et al 2001;Sardesai et al 2002). The development of these markers has been made possible using various molecular marker techniques (Mohan et al 1994(Mohan et al , 1997bNair et al 1995Nair et al , 1996. Amplified fragment length polymorphisms (AFLP) have been widely used as a DNA fingerprinting technique (Vos et al 1995) in plant genetic studies (Hill et al 1996;Mackill et al 1996;Maughen et al 1996;Hongtrakul et al 1997;Zhu et al 1998;Bonnema et al 2002).…”

Molecular mapping and tagging of genes in crop plants

“…Considering that, for routine genotyping of a large number of segregants in gall midge resistance breeding programmes, a PCR-based marker is more useful and economical than a RFLP marker, the above study was further extended (Nair et al, 1994). The termini of the two specific RAPD fragments that showed linkage to Gm2 obtained with the primers F08170o and F1060o respectively, were cloned and sequenced.…”