Mapping Quantitative Trait Loci for Grain Appearance Traits of Rice Using a Recombinant Inbred Line Population

A linkage map consisting of 221 markers was constructed based on a recombinant inbred line (RIL) population from the cross between Zhenshan 97 and Minghui 63. Quantitative trait loci (QTL) mapping was carried out for grain appearance traits such as grain length, grain width and grain shape in rice in 1998 and 1999. Based on interval mapping method at the threshold LOD≥2.4, six, two and two QTLs were detected for grain length, grain width and grain shape, respectively, in 1998; In 1999, three, two and two QTLs were identified for the three traits, respectively. Of them, seven QTLs were simultaneously identified in both of the years. The QTL with large effects located in the interval RG393-C1087 on chromosome 3 not only controlled the grain length, but also influenced the grain shape. It explained 57.5%, 61.4% and 26.7%, 29.9% of phenotypic variation of the grain length and the grain shape in two years, respectively. The QTL with large effects located in the interval RG360-C734B on chromosome 5 affected the grain width and the grain shape. It explained 44.2%, 53.2% and 32.1%, 36.0% of phenotypic variation of the grain width and the shape in two years, respectively. Eight, five and five QTLs were identified for the grain length, width and shape, respectively, based on mixed linear-model composite interval mapping method at P =0.005. Their general contributions were 58.81%, 44.75%, and 57.47%. One QTL for the grain length was found to be significant interaction with environment.     

The influence of body proportions on femoral and tibial midshaft shape in hunter‐gatherers

Variation in femoral and tibial diaphyseal shape is used as an indicator of adaptation to patterns of terrestrial mobility. Recent experimentation has implied that lower limb diaphyseal shape may be primarily influenced by lower limb length, and less so by mobility patterns. If valid, this would, at most, render previous interpretations of mobility patterns based on analyses of diaphyseal shape questionable, and, at least, require additional standardization that considers the influence of limb length. Although the consequences could be profound, this implication has yet to be directly tested. Additionally, the influence of body breadth on tibial shape (and to a lesser extent femoral shape) remains uncertain. Tibial and femoral cross‐sectional midshaft shape measurements, taken from nine Pleistocene and Holocene skeletal populations, were compared against lower limb length, limb segment length, and bi‐iliac breadth. Generally, limb length and limb segment length do not significantly influence femoral or tibial midshaft shape. After controlling for body mass greater bi‐iliac breadth is associated with a relative mediolateral strengthening of the femoral midshaft, while the influence of a wider body shape (BIB/length) is associated with a relative M‐L strengthening of the tibia and femur of males, and the tibia of females. We conclude that; (1) mechanical interpretations of lower limb diaphyseal shape are most parsimonious due to the lack of evidence for a consistent relationship between segment length and shape; however, (2) further work is required to investigate the influence of bi‐iliac breadth on both femoral and tibial midshaft shape. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.