Balram Marathi
Prof. Jayashankar Telangana State Agricultural University
India
Title: Mapping, identification and validation of novel yield-enhancing QTLs from O longistaminata A Chev et Roehr
Biography
Biography: Balram Marathi
Abstract
Increasing the yield potential is the major focus of rice breeding program. One of the main constraints for yield improvement is the narrow genetic base in popular cultivars. Recent reports from molecular mapping studies in different crops including rice indicate that phenotypically inferior wild species can contribute favorable genes for yield and thus providing a novel way for exploitation of wild relatives to broaden the genetic base to improve yield. The AA genome African wild species O. longistaminata is a perennial allogamous species was crossed with IR64 to develop a BC2F2 population for mapping of yield and yield component traits. The mean performance of traits in parents and range of trait values of population indicates transgressive segregation in favorable direction for all traits. Most of the yield component traits were normally distributed and skewed towards cultivated rice. A linkage map was constructed with 158 polymorphic markers and the total length of the map was 1840 cM with average marker interval of 12.6 cM. A total of 30 QTLs were identified for 9 yield and yield contributing traits. Major QTLs for yield traits were validated in Nipponbare/O. longistaminta and Taichung 65/O. longistaminta chromosome segment substitution lines and in IR64/O. longistaminta advanced backcross lines. The major QTLs for yield traits were introgressed into an elite New Plant Type (NPT) variety IR65600-81-5-3-2. The improved NPT lines with introgressed QTL regions from O. longistaminata showed increased panicle size and grain yield compared to the recurrent parent variety.