Ramona Loredana TOPORAN1; Marinel HORABLAGA1; Ionel SAMFIRA1; 1Banat’s University of Agricultural Science and Veterinary Medicine Timisoara, Faculty of Agriculture, Department of Plant Science, Calea Aradului, no. 119, Timisoara, Romania
The species Lolium perenne has a global distribution becoming a dominant species in temperate grassland ecosystems and covers a wide range of environmental conditions (length of day, humidity, altitude, soil type and chemistry, etc.). Understanding the patterns and magnitude of the genetic diversity of this allogamous forage species is a first step toward identifying several ecological traits. Intra-population genetic diversity can promote the temporal stability of grassland production, and also large-scale genetic variation can be closely linked to the regional productivity of perennial ryegrass-dominated grasslands. It was not until the beginning of the 20th century that varieties of Lolium perenne appeared with good agronomic performance, and the growth of this forage species being concentrated mainly on yield and persistence since the 1970s. Although total dry matter production remains a key objective in increasing the productive yield of fodder ryegrass, increased emphasis is placed on seasonal dry matter production, seed quality and density. One of the most important productive traits is leaf length as an important feature of forage grasses, and the development of the molecular marker is an opportunity to identify quantitative trait sites (QTLs) and to begin dissecting the genetic regulation of complex traits. Reproduction for long leaves or for a high rate of leaf elongation should contribute to an improvement in the intercepted radiation accumulated during regrowth and would be a way to improve the spring dry matter yield, but the seed yield has not improved. Selection pressures on seed production criteria applied to the breeding process should improve seed yields without a negative impact on feed performance. Perennial ryegrass seed yield is low and lacks selection criteria for high seed production, and indirect selection in spaced plants would be effective, but distant plant traits that correlate with seed yield in drilled plots need to be identified. The continued success of pasture farming depends on supporting programs to grow fodder species that are able to produce improved varieties that meet market needs by manipulating the recombination of the genome of these fodder plants.
Lolium perenne, genetic diversity, seed production,
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