Mapping of Yield Contributing Traits in an Interspecific Tetraploid Cotton using 70K Infinium BeadArray

Development of high-throughput SNP genotyping technologies such as Infinium BeadArray are facilitating construction of high density genetic maps and mapping of complex traits. We used cotton 70K Infinium array for construction a high density genetic linkage map of allotetraploid cotton using 178 recombinant inbred lines derived from cross between G. hirsutum var. DS-28 and G. barbadense var. SBYF-425. A total of 63,058 markers were genotyped with 70K BeadChip with ~90% call rate which helped us to identify 10,102 polymorphic markers between parents. This data was applied for identifying the QTLs associated with seed cotton yield (kg/ha), boll weight (g/boll), boll number (boll/plant), ginning out turn (%), seed index (g) and lint index (g). After phenotypic analysis across three environments and two locations, we found a total of 23 QTLs for yield related traits explaining 6.3-23% of phenotypic variation. A set of five QTLs for seed cotton yield, five for boll weight, seven for ginning out turn, two for seed index and four QTLs for lint index were identified. These results considerably improved QTL resolution compared to the previous reports with high LOD values ranging from 3-7. These markers are expected to serve as effective tools for marker assisted selection for yield improvement in cotton.