Importance of QTL Mapping for Heading Date in Rice

Heading date in rice is one of the most important indices in rice breeding being governed by multiple genes known as quantitative trait loci (QTLs). This character along with grain yield determines the commercial potential of any rice cultivar. In the last three decades the development of DNA markers have led to the precise analysis of QTLs. Various mapping populations are being used to explore QTLs for yield related parameters including heading date in rice. Like F , RILs, NILs, DH, BCs and SSSLs. To date among reported QTLs of 2 heading date, 20 QTLs have been identified and cloned. The purpose of the present review is therefore to consolidate our existing knowledge about the progress that so far have been made in mapping of QTLs for heading date character. In addition to that requirements of QTL mapping and different QTL mapping methods have also been discussed. The information could be useful for further identification of QTLs for heading date that can be successfully incorporated in marker assisted breeding programs aiming to develop early maturing widely adaptive and high yielding rice cultivars.