The genetic control of grain weight (GW) remains poorly understood. Quantitative trait loci (QTLs) determining the GW of rice were identified using a natural GW mutant, sgw. Using a segregating population derived from sgw (low GW) and cultivar 9311 ('9311'; indica, high GW), the chromosome segment associated with GW was detected on the short arm of chromosome 7.
Maize with opposite phyllotaxy (OP) and also initiating ears in opposite pairs is an aberrant mutant and also precious material for maize breeding and plant evolution studies. Mapping and identifying the markers closely linked to genes for the OP trait are essential for cloning the gene and marker-assisted selection in breeding. We established H14D, a near-isogenic line of the OP trait with H53 genetic background. We found that the OP trait is regulated by two independent dominant genes with mutually complementary relations, named Opp-1 and Opp-2.