http://192.168.1.40:8080/xmlui/handle/123456789/1141 2026-05-31T12:08:39Z http://192.168.1.40:8080/xmlui/handle/123456789/2354 Development of Yellow Mosaic Virus (YMV) resistance linked DNA marker in Vigna mungo from populations segregating for YMV-reaction Basak, J.; Kundagrami, S.; Ghosh, Tapash Kumar Yellow mosaic virus, YMV, causes one of the most severe of biotic stresses in Vignas, an important group of pulse crops. The viral disease is transmitted through the white fly, Bemicia tabaci, and the yield of the plants is affected drastically. YMV-tolerant lines, generated from a single YMV-tolerant plant identified in the field within a large population of the susceptible cultivar T-9, were crossed with T-9, and F-1, F-2 and F-3 progenies raised. The different generations were phenotyped for YMV-reaction by forced inoculation using viruliferous white flies. A monogenic recessive control of YMV-tolerance was revealed from the F-2 segregation ratio of 3:1 (susceptible: tolerant), which was confirmed by the segregation ratio of the F-3 families. Of 24 pairs of resistance gene analog (RGA) primers screened, only one pair, RGA 1F-CG/RGA 1R, was found to be polymorphic among the parents. Selected F, individuals and F, families were genotyped with the polymorphic RGA primer pair and the polymorphism was found to be linked with YMV-reaction. This primer pair amplified a 445bp DNA fragment only from homozygous tolerant and the heterozygous lines. The 445bp marker band was sequenced and named 'VMYR1'. The predicted amino acid sequence showed highly significant homology with the NB-ARC domain present in several gene products involved in plant disease resistance, nematode cell death and human apoptotic signaling. To the best of our knowledge, this is the first report of YMV-resistance linked DNA marker development in any crop species using segregating populations. This YMV-resistance linked marker is of potential commercial importance in resistance breeding of plants. DOI: 10.1007/s11032-004-0238-y 2004-11-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2244 RAPD-based genetic diversity analysis of aromatic rice (oryza sativa. L) Dey, N.; Biswas, S.; Chaudhuri, T.R.; Dey, S.R.; De, M.; Ghose, Tapas Kumar Genetic diversity of a total 38 aromatic rice lines and two non-aromatic controls were assessed using the randomly amplified polymorphic DNA (RAPD) technique. Based on their history of collection and pedigree, the rice genotypes were grouped as traditional Basmati (TB), evolved Basmati (EB), exotic aromatic (EA), indigenous aromatic (IA) and non-aromatic (NA) checks. Five RAPD primers, previously used in rice, amplified a total of 44 DNA bands from the set of 40 rice lines ranging from 500bp to 3.5kb in size. Of the 44 DNA bands 41 were polymorphic. Polymorphism information content (PIC) value of each RAPD primer was computed. Similarity coefficients were calculated from the polymorphism between all pairs of the rice lines and a dendrogram obtained using the unweighted pair group with arithmetic mean (UPGMA) method. The analysis indicate that: (1) there is considerable amount of genetic diversity within the genotypes assessed; (2) with a singular exception, the Basmati genotypes are confined to two clusters; (3) a core group of eight TB genotypes show the least amount of variation while rest of the lines, including the other TB, are more variable; (4) the five RAPD primer-generated polymorphism clearly identified each of the 40 rice genotypes distinctively. 2005-09-01T00:00:00Z