Screening of rice Genebank germplasm for yield and selection of new drought tolerance donors

• 988 IRRI Genebank accessions were screened for yield under drought.
• Most drought-resistant accessions originated from E. India and Bangladesh.
• Disease evaluation was conducted of the top-yielding lines.
• Kataktara Da2, Dular, Shada Shaita, and DA 28 are recommended for drought breeding.

Genebanks are stewards of the world's crop diversity, and represent large potential for sources of stress tolerance. In this study, selected accessions from the Genebank of the International Rice Research Institute (IRRI) were screened under upland and lowland field conditions to identify accessions that could be drought tolerance donors for use in breeding. Accessions that performed well under drought stress were retained and screened again in succeeding years along with additional new accession entries under well-watered and different drought stress treatments. A total of 988 accessions were screened in this study. High biomass production and short growth duration (flowering in less than 100 days after sowing) were related to high grain yield under drought stress. Accessions Binuhangin, Dharia Boalia, Gul Murali, and Kalia produced the highest yields under drought stress in both upland and lowland environments. Accessions Kataktara Da2, L201, Gopal, Gathi Kama Nangarhar, and Kotteyaran exhibited the highest grain yields in both well-watered and drought stress conditions. Most drought-tolerant accessions identified in this study originated from eastern India and Bangladesh. Based on yield results under drought and well-watered conditions across crop seasons combined with a disease-resistance evaluation, accessions Kataktara Da2, Dular, Shada Shaita, and DA 28 are recommended for use in drought breeding programs.