DNA markers tightly linked to a gall midge resistance gene (Gm2) are potentially useful for marker-aided selection in rice breeding

Abstract

We have developed a polymerase chain reaction (PCR)-based assay that could effectively reduce the time period required to screen and select for Gall Midgeresistant rice lines under field conditions. The primers for the assay were designed on the basis of sequence information of two phenotype specific random amplified polymorphic DNA fragments which were found to be tightly linked to Gall Midge biotype-1 resistance gene (Gm2). The two RAPD fragments, F81700 in the susceptible parent 'ARC6650' and F10600 in the resistant parent 'Phalguna', were identified after screening 5450 loci using 520 random primers on genomic DNAs of 'ARC6650' and 'Phalguna'. These primers, when used in a multiplexed PCR, amplified specifically a 1.7-kb and 0.6-kb fragment in the susceptible and resistant parents, respectively. When this assay was performed on genomic DNAs of 44 recombinant inbred lines derived from 'ARC6650' x 'Phalguna' and 5 lines derived from other crosses where one of the parents was 'Phalguna', 'ARC6650' or their derivatives, the primers amplified a 1.7-kb fragment in all of the susceptible lines or a 0.6-kb fragment in all of the resistant ones. These markers can be of potential use in the marker-aided selection of Gall Midge biotype-1 resistant phenotypes. As screening for resistance can now be conducted independent of the availability of insects, the breeding of resistant varieties can be hastened.

A Physically Anchored Genetic Map and Linkage to Avirulence Reveals Recombination Suppression Over the Proximal Region of Hessian Fly Chromosome A2

“…This region was associated with 6 markers that corresponded to the middle of the long arm of chromosome X1. The fourth genetic position is cen- Tanksley et al 1992;Boyko et al 2002). Nonetheless, the most interesting parallel to the low incidence of tered at 51.5 cM on LG X2.…”

“…Further, al. 2001;Boyko et al 2002), and reduced recombination near the centromere is not unusual (Roberts 1965; this low coefficient of genetic exchange was indepen-chromosome interference, a normal characteristic of the proximal region of Drosophila chromosome 3 (Green 1975;Sinclair 1975;Denell and Keppy 1979), may also be characteristic of the proximal region of Hessian fly chromosome A2. We observed among the 87 individuals segregating for markers flanking the chromosome A2 centromere (L023, 23-201, and 28-178) in population 2 (Table 2) that the expected frequency of double recombination between the three DNA markers was 0.0004.…”

“…plant (Nair et al 1995;Mohan et al 1997; Behura et Characterization of the BAC library used in this invesal. 2001;Bentur et al 2003).…”

Development of scar markers for the dna‐based detection of the Asian long‐horned beetle, Anoplophora glabripennis (Motschulsky)

“…Although the RAPD technique appears to be the simplest and the most flexible method, the low annealing temperature and short primer size used for polymorphism generation may affect amplification reproducibility, and may make this technique inappropriate for diagnostic purposes. Among the molecular markers that have been developed thus far, SCAR markers appear to be one of the most reliable methods (Michelmore et al, 1991;Paran and Michelmore 1993;Nair et al, 1995Nair et al, , 1996. There are several advantages to the use of SCAR markers.…”

The development of molecular markers for use across all plant species using expressed sequence tags

“…Also, because RAPDs are dominant markers, heterozygous and homozygous states cannot be determined (Nair et al, 1995).…”