Comparison of quantitative trait loci controlling seedling characteristics at two seedling stages using rice recombinant inbred lines

Abstract

A better understanding of the genetics of seedling characteristics in rice could be helpful in improving rice varieties. Zhenshan 97 and Minghui 63, the parents of Shanyou 63, an elite hybrid developed during the last decade in China, vary greatly with respect to their physiological and morphological traits at the seedling growth stage. In this study, we used a population of 240 recombinant inbred lines derived from a cross between Zhenshan 97 and Minghui 63 to identify quantitative trait loci (QTL) for seedling characteristics. All plant material was grown in hydroponic culture. Data for the following characters were collected at 30 days and 40 days post-sowing: plant height, shoot dry matter weight (SDW), maximum root length, root dry weight (RDW), total dry weight, and root-shoot ratio (the ratio of SDW to RDW). Analysis using composite interval mapping detected 16 QTL for the six traits in 30-day-old seedlings. Of these 16 QTL, Minghui 63 alleles increased trait values at only two of them. The QTL in the vicinity of R3166 on chromosome 5 simultaneously influenced PH, SDW, MRL, RDW, and TDW in the same direction. Twenty QTL were detected for the same traits in the 40-day-old seedlings. However, at this stage Minghui 63 alleles increased trait values at eight QTL. The QTL linked to R3166 also affected PH, SDW, MRL, RDW, and TDW. Only four QTL were common to the two stages. These results clearly indicate that different genes (QTL) control the same traits during different time intervals. Zhenshan 97 alleles had positive effects during the first 30 days of seedling growth, but thereafter the positive effects of Minghui 63 alleles on seedling growth gradually became more pronounced.

Identification of Related QTLs at Late Developmental Stage in Rice (Oryza sativa L.) Under Two Nitrogen Levels

“…In addition, one QTL affecting plant height was mapped on chromosome 2 under N1 level in this present study. Xu et al [20] detected one QTL for seedling height in the vicinity region of qPh2b by using a different population at the seedling stage, suggesting this allele was closely related to rice plant height. Panicle number per plant is one of the major factors limiting rice yields.…”

Molecular Mapping of QTLs for Drought Related Traits at Seedling Stage under PEG Induced Stress Conditions in Rice

“…For instance, Li et al (2005) [13] have reported QTLs for root thickness, root number and root dry weight, while length of mesocotyl by Redona and Mackill (1996) [36] in the same region. Further, Xu et al (2004) [37] and Price et al (2000) [38] have reported QTLs for PH and root number, respectively in the same region. Cui et al (2008) [16] have identified a QTLs cluster in the same region for plant height and shoot fresh weight under well watered conditions.…”

Rice Root Genetic Architecture: Meta-analysis from a Drought QTL Database

“…A total of 80 QTLs for flowering time detected under well-watered conditions were collected from ten papers (Li et al 1995;Yano et al 1997;Lafitte and Courtois 1999;Lin et al 2000;Maheswaran et al 2000;Yamamoto et al 2000;Yu et al 2002;Hittalmani et al 2003;Lanceras et al 2004;Dong et al 2004). A total of 59 QTLs for plant height were collected from ten papers (Li et al 1995;Lafitte and Courtois 1999;Hemamalini et al 2000;Yu et al 2002;Courtois et al 2003;Hittalmani et al 2003;Lanceras et al 2004;Xu et al 2004;MacMillan et al 2006;Gomez et al 2006). All the QTLs are compiled in TropgeneDB.…”

“…At least 24 papers have been published in the last 10 years on quantitative trait locus (QTL) detection for a large number of root parameters in several populations and different growth conditions (Champoux et al 1995;Ray et al 1996;Redona and Mackill 1996;Yadav et al 1997;Price et al 1999Price et al , 2000Price et al , 2002Ali et al 2000;Hemamalini et al 2000;Tripathy et al 2000;Zheng et al 2000Zheng et al , 2003Shen et al 2001;Zhang et al 2001a, b;Kamoshita et al 2002a, b;Courtois et al 2003;Nguyen et al 2004;Xu et al 2004;Li et al 2005b;Horii et al 2006;Yue et al 2006;MacMillan et al 2006).…”