Directorate of Rice Research, Hyderabad, Andhra Pradesh.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
Tungro disease is one of the most devastating and widespread virus diseases of rice caused by Rice tungro bacilliform virus (RTBV) and Rice tungro spherical virus (RTSV). The potential impact of virus resistant lines in reducing tungro incidence in endemic areas is being demonstrated at field level. However, the degree of variation that exists in tungro viruses suggests that the disease resistance genes must be careful considered. Effective utilization of donors to an extent depends on the nature of inheritance of the genes controlling resistance to tungro disease. With the availability of highly saturated microsatellite map of rice, the present study was aimed to identify the microsatellite markers linked to rice tungro resistance in Utrimerah, a resistant donor. We used F2 population consisting 475 plants derived from a cross between TN1 and Utrimerah. The mapping population has been phenotyped for their reaction to rice tungro disease in glasshouse. Fifty-four plants showed resistance with symptom score 1; 51 plants were susceptible with score 7; and the remaining plants were scored 3 to 5. Parental polymorphism was analyzed using 76 evenly distributed and highly polymorphic rice microsatellite markers. The co-segregation of polymorphic markers with the susceptible reaction in mapping population indicated that resistance genes were linked to RM 336 on chromosome 7. This region is being saturated with the recently developed microsatellite markers derived from the sequence information of rice.
