Registration of a mapping population derived from one of the most widely used restorer rice varieties with a US adapted Calrose type rice variety ‘M-202’

Authors: Jia, Yulin; Jackson, Aaron; Dunlap, Heather; Jia, Melissa; DEREN, CHRISTOPHER - University Of Arkansas

Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/27/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Rice farmers frequently face challenges such as poor grain quality and severe crop losses caused by rice blast fungus, one of the most destructive diseases in rice production worldwide. To address this issue, our research focused on developing genetic stocks that combine essential agronomic traits with durable resistance to multiple races of the blast pathogen. In the present study, we released 248 rice lines combined quality and disease resistant traits from one of the most widely used restorer rice varieties, “Minghui 63’’ and a US adapted Calrose type rice variety ‘‘M-202’’. These newly developed rice lines not only help farmers protect their crops from devastating blast outbreaks but also maintain high yield potential and grain quality. Furthermore, these genetic resources serve as a valuable foundation for breeding programs aimed at creating improved rice cultivars with enhanced resilience and productivity.

Technical Abstract: Rice blast, caused by Magnaporthe oryzae, is one of the most devastating rice diseases worldwide and with the ever-present risk of race shift, genetic resistance to blast is constantly in peril. To facilitate genetic improvements of rice cultivars a mapping population derived from the cross of one of the most widely used restorer rice varieties, “Minghui 63’’ with a US adapted Calrose type rice variety ‘‘M-202’’ was made. This indica and japonica population has been used to identify resistance genes to rice blast and genes involved in productivity of rice. Namely, eight blast resistance QTL were contributed from ‘Minghui 63’ and two QTL from M202. Screening of the ‘Minghui 63’ x ‘M-202’ RIL population with thirteen blast isolates revealed that 80% or more of the lines tested had moderate resistance or better to eight of the isolates. For the remaining five isolates 76% of the RILs were moderately resistant or better to IH1, 59% for IE-1k, 54% for IB1, 53% to IA45, and 52% to IB45. The majority of the RILs classify as medium grain and over 77% of the lines have very low chalk in the range of 5% chalkiness or less. Two hundred and two of the 248 progeny had a plant type score of 2 or lower which is a desirable erect growth habit. The ‘Minghui 63’ x ‘M-202’ RIL population can be used as a source for identifying novel blast resistance genes as well as providing germplasm lines for reduced chalkiness and blast resistance for breeding programs.