CHANGES IN ALFALFA CELL WALL STRUCTURE DURINGVEGETATION

The investigation was done on 141 samples of one alfalfa cultivar,collected from the same location during the first three growth cycles: springgrowth, the first and the second regrowth. within each growth cycle, sampling wasdone during the whole growing period, commencing when plant height was below150 mm and continuing until plants were bearing ripe seeds. on all collectedsamples the following cell wall characteristics were determined: neutral detergentfibre (ndf), acid detergent fibre (adf), acid detergent lignin (adl), neutraldetergent insoluble crude protein (ndicp), acid detergent insoluble crude protein(adicp). cellulose and hemicellulose were detected on the base of the mentionedchemical parameters. significantly lower (p<0.01) content of andf, adf, adl,adicp and cellulose is found in the second regrowth, while there were nosignificant differences between the other two growth cycles. except in ndicp andadicp, the increase in all accompanying components of the cell wall wasobserved, and expressed in average daily changes. there was no consistent trend inndicp and adicp. during the spring growth from late bud to full-bloom stagethe ’plateau’ was observed. the plateau was represented as almost constant contentof andf, adf, adl and cellulose. the correlations between all components ofthe cell wall were shown. the equation andf = 36.713 + 1.181 × adf isrecommended for conversion of adf into andf in alfalfa.