Registration of twoOryza sativatropicaljaponicagermplasm lines selected for panicle architecture and grain size traits

Abstract

Two rice (Oryza sativa L.) germplasm lines, SC14_166 (Reg. no. PI 698103) and SC14_072 (Reg. no. GP-147, PI 698102), containing alleles for increased panicle branching, seeds per panicle, and grain length were developed by the USDA-ARS.They are recombinant inbred lines selected from a cross of 'Estrela' (GSOR 301227) and NSFTV199 (GSOR 301190), both of tropical japonica origin. SC14_166 is a medium grain cultivar and contains alleles for two major genes, SPIKELET NUM-BER on chromosome (chr.) 4 and FRIZZY PANICLE on chr. 7, which result in a greater number of primary branches, seeds per panicle, and panicle weight compared with the parents. SC14_072 is an extra-long grain cultivar and contains alleles for two major genes on chr. 3, GRAIN SIZE 3 and GRAIN LENGTH 3.2, resulting in greater grain length, width, thickness, and kernel weight. The germplasm lines possess Pi-ks, whereas SC_072 also has Pi-z, both of which are major genes for resistance to rice blast disease. These germplasm lines are well adapted to growing conditions in the southern United States and will benefit long-grain and medium-grain breeding programs that desire to increase grain dimensions and panicle architecture traits. Because they are derived from the tropical japonica subpopulation like most U.S. cultivars, they will be highly compatible for making breeding crosses and will contribute novel alleles to the gene pool.

Yield component QTLs identified by genome‐wide association mapping validated in a diverse tropical japonica × tropical japonica rice biparental mapping population

“…To enable breeders to incorporate the increased seed number into elite breeding lines, the SC14_166 germplasm was selected from the Estrela × NSFTV199 population and released (Eizenga, McClung et al., 2021) along with the SNP marker, DB80, associated with FZP to use in a marker‐assisted selection breeding scheme (Eizenga, Jackson et al., 2021). As part of this study, the DB80 marker was also validated in 75 F 6 L‐202 × Trembese RILs targeting FZP in Trembese.…”