The role of Molecular Markers in Improvement of Fruit Crops

Abstract

Markers have been used over the years for the classification of plants. Markers are any trait of an organism that can be identified with confidence and relative easy, and can be followed in a mapping population on another hand markers be defined as heritable entities associated with the economically important trait under the control of polygenes. Morphological markers can be detected with naked eye (naked eye polymorphism) or as difference in physical or chemical properties of the macromolecules. In other words, there are two types of genetic markers viz. morphological markers or naked eye polymorphism and non-morphological markers or molecular markers. Morphological markers include traits such as plant height, disease response, photoperiod, sensitivity, shape or colour of flowers, fruits or seeds etc. Molecular markers include biochemical constituents. Morphological markers have many limitations for being used as markers particularly in fruit crops because of long generation time and large size of fruit trees besides being influenced by environment. Consequently, molecular markers could be appropriate choice to study and preserve the diversity in any germplasm. Molecular markers have diverse applications in fruit crop improvement, particularly in the areas of genetic diversity and varietal identification studies, gene tagging, disease diagnostics, pedigree analysis, hybrid detection, sex differentiation and marker assisted selection.

Morphological and molecular characterization and evaluation of mango germplasm: An overview

“…These characters include tree height, growth habit, bearing habit, flowering pattern, disease resistant, inflorescence shape, colour and type of flowers, fruit shape, colour of fruit, shoulder position and seeds (monoembryonic or polyembryonic) (Bhat et al, 2010). The most significant benefits of morphological characterization are that published descriptor lists are easily available for most of the major fruit crop species.…”

“…However, two basic types of markers have been reported i.e. non-morphological makers (molecular markers) and naked eye polymorphism or morphological makers (Bhat et al, 2010). A basic informative descriptor list is developed by "International Plant Genetic Resources Institute" (IPGRI) to assist the identification of mango germplasm (IPGRI, 2006).…”

Genetic Variability of Local Corn Cultivars from Kisar Island Southwest Maluku Regency using Microsatellite Molecular Marker

“…Research on genetic diversity can be done by utilizing a system of genetic markers for both morphological, and molecular markers (Farooq & Azam, 2002;Bhat et al, 2010). Molecular markers is an effective technique in genetic analysis and has been widely applied in the breeding program especially in plants.…”

“…According to Farooq & Azam (2002) some genetic marker-based on polymerase chain reaction (PCR) that has been widely used is randomly amplified polymorphic DNA (RAPD), Sequence Characterized amplified regions (Scars), sequence tagged sites (STS), single strand conformational polymorphism (SSCP), single nucleotide polymorphism (SNPs) and microsatellite or short tandem repeats/short sequence repeats (STRs/SSRs). Some of these genetic markers are relatively simple, easy to use, can be automatically tabulated, and sometimes codominant (Farooq & Azam, 2002;Bhat et al, 2010;Fibriana & Hadiyanti, 2016). One of the genetic markers have also been developed extensively is microsatellites markers.…”

Molecular markers to distinguish ‘Thar Shoba’, a variety of khejri [Prosopis cineraria(L.) Druce], from trees in natural populations

“…A long time is required to examine morphological traits, which delays breeding activities (Bhat et al, 2010). Therefore, the present study was undertaken to develop suitable DNA markers to determine the varietal identity of 'Thar Shoba'.…”