DNA POLYMORPHISMS IN BANANA AND SUGAR CANE VARIETIES REVEALED BY RAPD ANALYSIS

摘要

Sugar cane is the fourth most important cash crop of Pakistan and is grown on 1 million hectares of land, with a total production of 37 million tonnes. It does not flower under existing environmental conditions. Sugar cane is vegetatively propagated and the national breeding programme is restricted to the adaptation and multiplication of exotic varieties. Random amplified polymorphic DNA (RAPD) markers were used to establish polymorphisms among various local sugar cane varieties. DNA from the varieties L-118, L-116, BL-4, BF-162, Col-44, Col-54, Triton and Puri was isolated and amplified by polymerase chain reaction using ten nucleotide primers. The amplification profiles of all the sugar cane varieties were compared and the polymorphisms detected. DNA was isolated from the embryogenic calli of sugar cane subjected to gamma irradiation at different doses (0, 0.5, 2.0, 4.0 and 6.0 krad) and salt stresses (NaCl: 0, 50, 100, 150 and 200 mM), and was amplified with random primers to detect the polymorphisms introduced by stress. The banana is another important vegetatively propagated crop in Pakistan. DNA isolation from micropropagated banana was optimized and RAPD analysis performed on several clones of the banana variety Williams. The level of genetic variability revealed from calli and vegetatively propagated sugar cane and banana by RAPD analysis is discussed.