DEVELOPMENT OF RAPD AND ISSR MARKERS FOR DROUGHT TOLERANCE IN SUGARCANE (Saccharum officinarum L.)

Abstract

ugar amounts of cane represent 72% of the world production of crystallized sugar (FAO, 1999). In Egypt, sugarcane crop is one of the important industrial crops and it is the main source of sugar production. Moreover, it is widely used in Egypt for fresh juice consumption and molasses industry. Limitation of irrigation water led to minimizing the cultivated area of sugarcane, so, there is a very limited opportunity to increase it horizontally. Improving agricultural practices, in addition to developing new promising cultivars, became the possible ways of raising sugarcane production. Drought resistance is the ability of plant to resist all adverse conditions created by unfavorable phenomena related to water deficit (Clark et al., 1986). It is well known that sugarcane water requirements are very high compared to our limited share in River Nile, so studying the effect of drought is a major limiting factor in the production of field crops. One effective approach is to develop sugarcane varieties tolerant to drought stress (Abdel-Tawab et al., 1999). Biotechnology has been used as a tool to increase agricultural productivity in the context of sustainable agriculture (Tecson, 2002). Molecular markers have been used for studying genetic diversity, cultivar identification and for marker-assisted selection (MAS) of major crops such as rice, maize, wheat and sugarcane. Moreover, Molecular markers such as RFLP, RAPD, ISSR and SSR have recently shown excellent potentiality to assist selection of quantitive trait loci (QTLs) associated with these markers (Stuber, 1992). The developing of RAPD approach (Williams et al., 1990) has allowed simple, easy and less time-consuming genome analysis at DNA level compared with RFLP. The detection of molecular markers linked to many genes of interest has been widely achieved in this regard. RAPD-PCR as a simple and rapid procedure has gained a worldwide acceptance and application (Michelmore et al., 1991; Paran et al., 1991). Moreover, RAPD markers were detected for salt and drought stresses in sugarcane (Abdel-Tawab et al., 2003a&b; Piperidies et al., 2004), in wheat (Abdel- Tawab et al., 2003c), in maize (Abdel- Tawab et al., 2002) and in sorghum (Abdel-Tawab et al., 1998). ISSRs are semi-arbitrary markers amplified by PCR using a single primer composed of a microsatellite repeated sequences. Such amplification does not require genome sequence information and leads to multilocus and highly polymorphic patterns (Wolfe, 1998). Therefore, ISSRs have proven to be a powerful amplificationbased fingerprinting technique. The aim of this study was to obtain molecular markers for drought tolerance in sugarcane and to assess the genetic relationships among some of its varieties.