Mapping New Genetic Markers Associated with CMD Resistance in Cassava (Manihot esculenta Crantz) Using Simple Sequence Repeat Markers

Chokkappan Mohan,Duraisamy Raghu,Natesan Senthil,Ponnusamy Shanmugasundaram,Marappan Maheswaran,Mullath Unnikrishnan

doi:10.5539/jas.v5n5p57

Abstract

Cassava mosaic disease (CMD) is the most serious disease in cassava–in India where it is grown for food, starch and sago purpose. The disease is best kept under control by exploiting the available host plant resistance, which was introgressed from M. glaziovii to cassava and it is known to be polygenic control. In the present study, an attempt was made to construct the genetic linkage map of cassava using SSR markers with the objective of mapping genes associated with CMD. Using single marker analysis (SMA), four CMD resistance markers were detected viz. SSRY28, SSRY235, SSRY44 and NS136. SSRY28 and SSRY235 were located on linkage group G and SSRY44 and NS136 on linkage group P of cassava genetic map developed by Fregene et al. (1997). Among the four markers, three (SSRY235, SSRY44 and NS136) are new markers associated with CMD resistance. The detection of markers SSRY44 and NS136 having association with CMD resistance is a new report indicating the possibility of having another genetic loci for CMD resistance in cassava in addition to the already established on linkage group G. This finding supports the polygenic control of CMD resistance.

Highlights

Cassava, Manihot esculenta Crantz., belonging to the family Euphorbiaceae, is one of the most important staple food crops in tropics and grown widely under diverse environmental conditions
SSRY28 and SSRY235 were located on linkage group G and SSRY44 and NS136 on linkage group P of cassava genetic map developed by Fregene et al (1997)
Three (SSRY235, SSRY44 and NS136) are new markers associated with Cassava mosaic disease (CMD) resistance

Summary

Introduction

Manihot esculenta Crantz., belonging to the family Euphorbiaceae, is one of the most important staple food crops in tropics and grown widely under diverse environmental conditions. This tuberous root crop has its origin in South America. It remains as the most reliable source of food for more than 700 million subsistence farmers in Africa, Asia and Latin America. Cassava mosaic disease (CMD) is the most serious disease in Africa and India, causing yield loss ranging from 20 to 90 per cent. CMD is a viral disease caused by at least seven different geminiviruses. The major spread of this disease is due to propagation of virus infected planting material

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