Differential expression of lodging resistance related QTLs in rice (Oryza sativa L.) uri icon

abstract

  • Traits related to plant development and lodging resistance in 292 rice recombinant inbred lines (RILs) were investigated by dissecting QTLs affecting four basal internodal traits of the main stem, lengths of five elongated internodes contributing to plant height (PH), and three traits related to heading date (HD). The RILs showed tremendous transgressive segregation for all the traits and a total of 41 genomic regions associated with one or more measured traits were detected. These included 17 QTL regions affecting one or more basal internodal traits, 21 associated with one or more PH and related traits, and 12 for HD and/or its component traits. Of the 21 genomic regions associated with PH traits, two QTL clusters on chromosomes 6 and 10 were expressed consecutively during rice development, and the remaining 19 QTLs appeared to be expressed at one or more specific developmental stages, revealing an important aspect of the relationship between PH and its component traits. The transition from the vegetative growth to the reproductive stage in rice appeared to have a large effect on QTL expression, reflected by the different behaviors of most QTLs affecting panicle length from other PH QTLs. The 17QTL regions associated with one or more basal internodal traits plus nine QTLs affecting two lower elongated internodes were expected to contribute to lodging resistance (LR) of rice. The large allelic differences at these QTLs between japonica and indica parents imply that improved LR in rice can be readily achieved by combining large numbers of QTL alleles affecting stem length, strength, and thickness in indica/japonica crosses. Specific expression patterns of the identified QTLs; and their contributions to morphological traits related to plant development and LR are expected to provide important information for marker-assisted improvement of the target traits in rice and cloning genes underlying QTL of interest. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

publication date

  • 2008
  • 2008
  • 2008