2.4. Preliminary characterisation of polyploids Field plots were established inMay(2005) to characterise generated polyploids. Because of an insufficient number of polyploids for full field experiments using each genotype (56 tetraploids in Ms11, 48hexaploids inMs19and19hexaploids inMG1)only small, experimental plots could be prepared for preliminary characterisation of generated polyploids. The same plants as those planted in experimental plots were grown in the greenhouse until they reached the second growing season, when the stomatal and pollen grain diameter and the spikelet length were determined. As a consequence of these number limitations, plants derived from experiments on polyploidisation by colchicine treatment of shoots (described in
this work), initial explants and callus tissue (unpublished) and plants from culture in vitro (Głowacka et al., 2009) were used for conducting both field and greenhouse experiments, and the preliminary assumption has been made that neither experimental
conditions used to induce polyploidy nor part of the plant treated alters the subsequent affects of polyploidy on plant characteristics. Both, derived from experiments plants of control ploidy levels and the colchicine-generated polyploids (C0) were in similar developmental stages. Each of the genotypes was represented by two field plots, with control and polyploid plants established in four rows of 10 plants each. Light loamy soils of the 4th classification value were used in the experiment. At the end of the third growing season, agronomic traits such as plant height, tillering (the number of
shoots measuring 20cm above the ground), tuft diameter and stem diameter (measured 5 cm above ground level on producing stems higher than 1m) were measured. Each plot was divided into three parts (the front, middle and back), and 5 randomly chosen plants
from each were measured. Additionally, in December, 15 plants from the central area of each plot were harvested. For determination of the dry matter, the tuft weight biomass was dried to 21% moisture content and measured.