The aim of this study was to examine genetic variability, heritability and
correlation of seed yield components and seed yield of progenies of
autochthonous populations and cultivars of perennial ryegrass, and that on
the basis of these results distinguish genotypes that would be later used in
the creation of new local cultivars of perennial ryegrass. Research was
carried out on experimental fields and laboratories of the Agricultural
Institute of Republic of Srpska in Banja Luka in 2007. and 2008., on 6
natural populations of perennial ryegrass collected in Bosnia and Herzegovina
and two cultivars, Maja and Calibra as standard. Following parameters were
analyzed: number of generative tillers per plant, time of flowering, spike
length, number of spikelets per spike, seed yield per spike and plant and
1000 seed weight. Analysis of the results of the number of generative tillers
per plant indicates a statistically significant difference in the studied
populations and cultivars of perennial ryegrass. The highest average number
of tillers per plant was found in the cultivar Maja (193.8), and the least
number was detected in population Dragocaj (78.9), so statistical differences
were highly significant. The longest period to beginning of flowering was
determined in cultivar Calibra (56.5 days) and the shortest in population
Laminci (43 days). The average length of spike of perennial ryegrass in the
studied population was 22.78 cm and was significantly lower than cultivar
Maja. Statistically significant differences between populations and variety
Maja in the number of spikelets per spike were detected. The average seed
yield per spike of studied populations was in level with cultivar Maja and
37.5% higher compared with variety Calibra. In the studied populations of
perennial ryegrass seed yield ranged from 5.21 g (Dragocaj population) to
15.40 g (Kupres population). Weight of 1000 seeds was highest in the variety
Calibra (2.60 g) and lowest in population Maglajani (1.94 g). Proportion of
genetic to phenotypic variance for time of flowering, the number of
generative tillers, seed yield per spike and plant and 1000 seed weight
indicate that the variability of these traits in this collection of
genotypes, largely derived from plant genotype. In this investigation, the
presence of a highly significant positive genetic correlation was found
between time of flowering and spike length (0.98), time of flowering and 1000
seed weight (0.97), number of generative tillers and seed yield per plant
(0.91) and spike length and 1000 seed weight (0.98).
Path and correlation analysis of perennial ryegrass (Lolium perenne
L.) seed yield components