Rice Breeding for Resistance to Blast Via Marker Assisted Selection

News source: Department of Agriculture and Forestry Extension, MARD, Vietnam
For further information, contact Lu Tuan Nghia,
Agricultural Genetic Institute, Tu Liem, Hanoi, Vietnam.
E-mail: vdt@agri.ac.vn, 2003-10-01

Molecular Markers for Blast Resistance

Blast, caused by the blast fungus Pyricularia grisea, is one of the most serious diseases of rice. Molecular markers with Marker Assisted Selection (MAS) have become an important tool for durable resistance screening; minimizing the time, cost and other breeding problems; and helping detect the target traits at the early stage of rice plants.

Indica Cultivar SHZ 2 with Blast Resistance

Two Indica cultivars, CR 203 and SHZ 2, were used in this study. The first cultivar has good quality and wide ecological adaptation but was susceptible to the blast disease, while another one, SHZ 2, has excellent resistance to blast even in the environment conducive to the disease. The backcross generations were developed from the cross between CR 203 x SHZ 2, and at each next backcross generation, the cultivar CR 203 was used to backcross to the selected rice plants based on DNA analysis.

Selection of Resistant Lines

The resistant lines were selected based on the analysis of the genetic relationship using Resistant Gene Analog (RGA) marker. The eight selected rice lines are: CS 2, CS 11, CS 18, CS 35, CS 36, CS 62, and CS 67. The selected rice inherited the high resistance to blast from the cultivar SHZ 2 and the good agronomic traits from the cultivar CR 203. These promising rice lines can replace the susceptible cultivar CR 203 being grown in the country.

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