Identification of RAPD markers linked to pubescent trait in cassava (Manihot esculenta CRANTZ)

Abstract

The presence of pubescence on the leaves of cassava confers resistance to mealybug, an important pest of cassava in Africa. We therefore, investigated RAPD markers linked to the pubescent trait in four descendants of cassava clone TMS 4(2)1425, namely, diploid (2X) 4(2)1425 pubescent, diploid (2X) 4(2)1425 non-pubescent, tetraploid (4X) 4(2)1425 pubescent and tetraploid (4X) 4(2)1425 non-pubescent as well as forty-eight F1 plants obtained from crossing diploid pubescent and diploid non-pubescent lines. Segments of the extracted DNAs were amplified under standard amplification conditions using Operon primer series A, B, and C making a total of 60 primers. Most primers produced monomorphic fragments. However, two primers, OPA 13 and
OPC 19 produced 798bp and 752 bp polymorphic fragments respectively. These were present in non-pubescent but absent in pubescent clones. The 48 F1 hybrids segregated for these markers in a ratio close to 1:1. The markers 798bp-OPA13 and 752bp-OPC19 may be useful for distinguishing between pubescent and non-pubescent cassava clones.