PANINI: Improving Low-Resource English-Manipuri Translation in Two Scripts via rsLoRA and Three-Stream Self-Augmentation

Rudali Huidrom, Vikas Kumar, Hoomexsun Pangsatabam, Pinaki Das, K. Kabi Khanganba, Nongmaithem Zeno, Nicholas Khumukcham, Mangalton Okram, Justice Konjengbam, Sai Jamalpoor, Alex Khangembam, Anand Konjengbam, Vikram Goyal


Abstract
We describe team PANINI’s submission to the WMT 2026 Shared Task on Low-Resource Indic Language Translation. We submit primary systems for English↔Manipuri (Meiteilon) in both the Bengali (mni Beng) and Meitei Mayek (mni Mtei) scripts, covering all four directions. Rather than one shared multilingual adapter, we train four independent rank-stabilized LoRA (rsLoRA) adapters over IndicTrans2-1B, one per direction. Each adapter is trained on the authentic bitext plus three filtered synthetic streams the model generates for itself: back-translation, forward translation, and iterative pseudo-labelling, with subword regularisation and a script-aware processing pipeline. Our system obtains a COMET score of 92.31 and a BERTScore of 98.85 on English↔Manipuri (Meitei Mayek), the best in the direction. On the into-English directions, it reaches a COMET of 82.90 for mni Beng↔en and 80.20 for mniMtei↔en. These results show that per-direction adapters combined with self-generated synthetic data are effective even when authentic bitext is limited to a few thousand sentence pairs, and that a script-aware processing pipeline is necessary to produce well-formed output in both Manipuri scripts. The code and resources are released on GitHub.
Anthology ID:
2026.wmt-main.154
Volume:
Proceedings of the Eleventh Conference on Machine Translation
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Barry Haddow, Tom Kocmi, Philipp Koehn, Christof Monz
Venues:
WMT | WS
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
2154–2162
Language:
URL:
https://aclanthology.org/2026.wmt-main.154/
DOI:
Bibkey:
Cite (ACL):
Rudali Huidrom, Vikas Kumar, Hoomexsun Pangsatabam, Pinaki Das, K. Kabi Khanganba, Nongmaithem Zeno, Nicholas Khumukcham, Mangalton Okram, Justice Konjengbam, Sai Jamalpoor, Alex Khangembam, Anand Konjengbam, and Vikram Goyal. 2026. PANINI: Improving Low-Resource English-Manipuri Translation in Two Scripts via rsLoRA and Three-Stream Self-Augmentation. In Proceedings of the Eleventh Conference on Machine Translation, pages 2154–2162, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
PANINI: Improving Low-Resource English-Manipuri Translation in Two Scripts via rsLoRA and Three-Stream Self-Augmentation (Huidrom et al., WMT 2026)
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PDF:
https://aclanthology.org/2026.wmt-main.154.pdf