Because only a few trials reported the leaf:stem ratio (LSR) and harvest index (HI), we calculated these variables using the following formulae: LSR=LDMP/SDMP (PEREIRA et al., 2012; PEREIRA et al., 2015; MOTTA et al., 2017) and HI = LDMP/ TDMP (PEREIRA et al., 2012), respectively.
Hybrids evaluated (H12, H13, H20, and H22) were selected for their higher TDMP, as described by PEREIRA et al.
There was a difference in TDMP between the ecotypes/hybrids (P = 0.0645; Table 1).
Even though hybridization was performed with parents of different species, TDMP of the hybrids and of their male parent P.
TDMP of 'Pensacola' was lower than the averages observed in the hybrids (97%), P guenoarum ecotypes (60%), P.
pauciciliatum ecotypes yielded lower LDMP, which was expected, as they also had lower TDMP (Table 1).
We reported that 33%, 24%, and 17% of TDMP of 'Aruana', P.
Although, cultivar 'Rojas' belongs to the same species, it had greater TDMP, LDMP, and SDMP, which may explain why its values of genetic dissimilarity were close to those of the Azulao and Baio ecotypes.
Analysis of the relative contribution to total variability showed that 78.8% of the genetic divergence occurred as a result of TDMP, whereas LSR, LDMP, SDMP, and HI had a contribution of only 21.2% (Table 4).
The fact that TDMP makes the greatest contribution to variability indicates that it was the most effective variable for expressing the variability among genotypes and demonstrated its importance as a component in the selection of genotypes with superior forage characteristics.
The hybrids exhibited high TDMP, composed mostly of leaves, with a smaller proportion of stems than that observed in the ecotypes with similar or higher TDMP.