Inheritance of RAPD and ISSR markers in hybrid derivatives of inter-specific coffee hybrid (Coffea congensis Froehner x Coffea canephora Pierre): Implications on genetic improvement and plant variety protection

Abstract

An inter-specific hybrid involving Coffea congensis x Coffea canephora is popularly known as C x R coffee hybrid in India. This hybrid was developed with the primary objective of reducing the plant size for high density cultivation and also to improve the coffee beverage quality. Though this hybrid is popularly cultivated in India, segregation of this hybrid due to cross pollination either within the hybrid or with other diploid species of Coffea is one of the major problems to achieve seed purity and higher yield. To utilize DNA marker assisted selection (MAS), two dominant DNA markers (RAPD and ISSR) were analyzed for their utility. About 24 RAPD and 15 ISSR primers were tested for screening the effective primers and only three RAPD and five ISSR primers were found suitable for discriminating the parent. These selective RAPD and ISSR primers produced nine and 23 polymorphic bands respectively with size range of 400 bp – 1200 bp in RAPD and 100 bp – 2000 bp in ISSR. Species specific RAPD and ISSR markers were found in female (Coffea congensis) and male (Coffea canephora) parent of the hybrid and certain of these RAPD and ISSR markers and they are found to inherit into F1 and backcross progenies. The primers for suitability for marker assisted selection were evaluated with parameters such as Polymorphic information content (PIC), effective multiplex ratio (EMR), marker index (MI) and resolving power (RP). Importance of these markers in genetic improvement of this hybrid is discussed.