Early detection of abnormality in the micropropagated Lakatan banana plants using methylation-sensitive ISSR

Abstract

Somaclonal variations in banana tissue culture is not uncommon. In our tissue culture laboratory, the tissue-cultured Lakatan variety exhibited abnormalities (i.e., malformed bunches/ fingers, stunted growth or sterility) that affect the fruit yield. Using a methylation-sensitive inter-simple sequence repeats (ISSR) approach, the genomic DNA digested with methylation-sensitive restriction enzyme MspI of 274 tissue-cultured Lakatan plants were screened. The ISSR profile of the abnormal samples were identical but different from the normal samples by the absence of 997 bp band in the abnormal samples. The sensitivity of the marker employed in this study is estimated to be 93.4%. We suggest that this abnormality in the tissue-cultured Lakatan is a result of epigenetic changes which could have been induced in the banana tissue culture process. Our study also showed that this abnormality can be transmitted to the next generation through asexual propagation. The methylation-sensitive ISSR method adopted in this study is a promising tool for early detection of such abnormality in the micropropagated Lakatan banana plants.