CYTOLOGICAL DILEMMA ON THE PROLIFIC REPRODUCTION OF EICHHORNIA CRASSIPES IN LAKE GERIYO ADAMAWA, NIGERIA

Chromosomal and karyological studies were carried out on Eichhornia crassipes and the taxon was found to have 32 individual chromosomes with a haploid chromosome number of 16 (n=16), indicating a clear tetraploid genome of 2n=4x=32. At diplotene and diakinesis, chiasma frequencies per nucleus/bivalent were analyzed revealing a marked reduction of chiasmata at diakinesis as compared to diplotene. The very low terminalization value of 0.43 showed that most of the chiasmata were terminalized at diakinesis and metaphase I. Multivalent associations were frequent suggesting the presence of a translocation heterozygote. Univalents were also of a frequent occurrence. Chromatid bridges, fragments, laggards and eliminated chromosomes were also as frequent at both MI and MII. Secondary association of chromosomes occurred with a preponderance of four and eight over other groups. Eichhornia crassipes has a high propensity to proliferate asexually by means of offsets and this probably accounts for its prolific reproduction rate which has so far defied all known control measures Thus, this investigation revealed that the massive rate of invasion of this plant could be traced to its very high rate of mitosis, a significant deviation from what obtains in other Higher plants. The occurrence of these aberrations might have influence the prolific behaviour of the plant hence the need for further research be carried out in order to find out if there is any relationship between cytological studies and prolific reproduction.