MOLECULAR CHARACTERIZATION OF FOUR POTATO CULTIVARS (SOLANUM TUBEROSUM L.) COMMERCIALLY GROWN IN EGYPT

Abstract

The present study aims to identify four different cultivars (i.e. Cara; Lady Rossita; Nicola and
Spunta) of potatos (Solanum tuberosum L.) that are commonly planted in Egypt the tissue culture of
each. In this respect, the tissue culture of each was established, while Spunta explants were considered
best than others for invtro responses, when cultured on. Than different tissues (green leaves; calli and
regenerated shoots) each cultiver used for biochemical and molecular analysis to measure genetic
relationship among them when MS medium supplemented with 0.5mg/L NAA; 2.24mg/L 6-BAP and
8mg/L GA3. Each cultivar differed for isoesterase and isoperoxidase electrophoretic patterns, as the
highest differential expression of esterases and peroxidases were screened for regenerated shoots and
callus tissues, respectively which may be due to a differential protein activation during with developing
tissues. Furthermore, RAPD analysis fingerprints provided a number of useful DNA markers to
distinguish and identify the four cultivars. According to the data of the six primers for all cultivars, the
highest percentage of DNA polymorphism was screened for regenerated shoots. Such feature may be
due to the somaclonal variation for in vitro culture, which is producing sequence dissimilarity among
the original genotypes. Probably, due to this phenomenon, RAPD based dendrograms for green leaf;
callus and regenerated shoot genomes revealed different genetic relationships among the four cultivars.
Therefore, it may be concluded that plant leaves are preferred to design dendrograms of similarities and
relationships among different cultivars. However, generally the somaclones may be a way of generating
useful genetic variation and selection of desired traits for in vitro Plantlets.