Cytogenetics of Lippia alba (Mill.) Brown from Lules, Tucumán

Abstract

Lippia alba (Mill.) Brown is an aromatic, rhizomatous bush with thin branches and violet flowers. It is widely distributed in tropical and subtropical zones of South America. Its medicinal use is for haemorrhage and its leaves have digestive properties. There are some studies of meiosis in Verbenaceae family that report abnormal behaviour of chromosomes. For L. alba it was reported a chromosomal number of 2n = 30. The aim of this work is to analyze the chromosomal number and behaviour in meiosis of L.alba from Lules, Tucumán, Argentina. It was made a squash of anthers and root tips with 2% haematoxylin and 1% ferric citrate. The determined chromosomal number was 2n = 30 with formation of bivalents, laggard chromosomes in telophase I and micronuclei. Taking into account these results, a percentage of inviable pollen grains, and a low production of viable seeds could be obtained. This species resorts to multiplication by means of both seeds and rhizomes, as a strategy of the species perpetuation. The presence of rhizomes could be an adaptation to the low viability of seeds. This topic will be explored in next studies.