This study was conducted from 2021 to 2024 at the Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration, Korea, to develop a high-yielding, medium-maturing Italian ryegrass (Lolium multiflorum Lam.) cultivar. The newly developed cultivar, named ‘Aura’ is a tetraploid type characterized by green leaves, a semi-erect growth habit before winter, and an erect growth habit during spring growth. ‘Aura’ headed on May 11, approximately 10 days later than the check cultivar ‘Kowinearly’, confirming its classification as a medium-maturing cultivar. At the heading stage, plant height reached 105 cm, which was greater than that of the control cultivar. In addition, leaf blade width, spike length, and spikelet number were greater in ‘Aura’ indicating vigorous growth. The average dry matter yield of ‘Aura’ across four regions was 10,535 kg/ha, which was significantly higher than that of ‘Kowinearly’ (p<0.05). The crude protein content of ‘Aura’ was 10.5%, which was 2.2 percentage points higher than that of the check cultivar. In contrast, acid detergent fiber and neutral detergent fiber concentrations were lower in ‘Aura’ resulting in slightly greater total digestible nutrient content and relative feed value. Furthermore, ‘Aura’ maintained stable winter survival across all test locations. These results indicate that ‘Aura’ is a promising medium-maturing cultivar with high productivity, stable winter hardiness, and favorable forage quality for cultivation in Korea.

ABSTRACT
Ⅰ. INTRODUCTION
Ⅱ. MATERIALS AND METHODS
    1. Crossing combinations
    2. Establishment of synthetic populations
    3. Performance evaluation and regional adaptation trials
Ⅲ. RESULTS AND DISCUSSION
    1. Morphological characteristics
    2. Winter survival
    3. Dry matter yield
    4. Feed value
Ⅳ. CONCLUSION
Ⅴ. ACKNOWLEDGEMENTS
Ⅵ. REFERENCES

• Yowook Song(Forages Production Systems Division, National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Republic of Korea)
• Chang-Woo Min(Forages Production Systems Division, National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Republic of Korea)
• Bo Ram Choi(Forages Production Systems Division, National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Republic of Korea)
• Jae Hoon Woo(Forages Production Systems Division, National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Republic of Korea)
• Hyung Soo Park(Forages Production Systems Division, National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Republic of Korea)
• Sang-Hoon Lee(Forages Production Systems Division, National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Republic of Korea)
• Ki-Won Lee(Forages Production Systems Division, National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Republic of Korea) Corresponding author