Preliminary QTL detection for improving basmati rice in a F₂ population derived from the cross between kernel basmati and pLIA-1 carrying Oryza longistaminata chromosome

Basmati is a premium grade type of rice variety highly valued in the world rice market due to its characteristic aroma and slender grains. However it is low yielding and susceptible to lodging under highly applied fertilizers. At the Institute of Plant Science and Resources (IPSR), a potential Low Input Adaptable line (pLIA-1) derived from Oryza longistaminata and Taichung-65 was developed under non-fertilized conditions. The line was characterized by thick culms and large panicles with a large primary and secondary branch numbers and many spikelets per panicle. To improve the low yield of Basmati, the large panicle of pLIA-1 and thick culm-base diameter is considered to be useful. Hence, QTL analysis was conducted using 88 genome-wide SSR markers in F₂ of the cross between pLIA-1 and Kernel Basmati. In total 21 QTLs for yield-related traits were identified in 2012 and 2013. The QTL for primary branch number was detected in the same location on chromosome 8 in both years and a QTL cluster for secondary branch number and spikelet number per panicle was identified on chromosome 1 in 2013 and in the combined data. In addition, two QTLs for the culm-base diameter on chromosomes 4 and 11 and 4 and 8 were also identified in 2013 and in the combined data, respectively. These results suggest that it is possible to utilize the favorable QTLs from pLIA-1 to improve Kernel Basmati’s yield and confer lodging resistance.