Molecular Plant Breeding 2016, Vol.7, No.12, 1
-
19
1
Research Article Open Access
Quantitative Trait Locus Analysis for Grain Size Related Traits of Rice
Zeng Wei
1*
, Cai Zhongquan
3*
, Wang Yongliang
1
, Jiang Qigui
1
, Wang Jun
1
, Li Shurong
1
, Peng Lu
1
, Qin Baoxiang
1,3
, Chen Baoshan
1,2
,
Li Rongbai
1,3
Luo Jijing
1,2
1 College of Life Science and Technology, Guangxi University, Nanning, 530004, China
2 State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, 530004, China
3 Agriculture College, Guangxi University, Nanning, 530004, China
* These authors have contributed equally to this work
Corresponding authors Email
Molecular
Plant
Breeding,
2016,
Vol.7,
No.12
doi:
Received: 15 Mar., 2016
Accepted: 30 Mar., 2016
Published: 06 Apr., 2016
Copyright © 2016
Zeng et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Zeng W., Cai Z.Q., Wang Y.L., Jiang Q.G., Wang J., Li S.R., Peng L., Qin B.X., Chen B.S., Li R.B., and Luo J.J., 2016, Quantitative Trait Locus Analysis for
Grain Size Related Traits of Rice, Molecular
Plant
Breeding, 7(12): 1-19 (doi
Abstract
Grain shape and size, which are characterized by grain length, grain width, grain thickness, and length to width ratio, are
the key determinants of grain weight. In this study, a 188-individual F
2
population, which derived from a cross between large grain
Indica
cultivar Nangyangzhan and medium grain
Indica
cultivar Ce253, were used to analyze grain size related QTLs with 110
molecular markers. Inclusive Composite Interval Mapping (ICIM), was applied to genome-wide detection of QTLs underlying grain
size related traits. For grain length, 4 QTLs were detected on chromosome 1, 3, 4, and 9, respectively.
qGL-3
, a major effect QTL,
explained 27.60% phenotypic variation of grain length. Four QTLs for grain width were detected on chromosome 2, 3, and 5. Among
them,
qGW-5a
was major QTL for grain width, which explained 21.30% of phenotypic variation. Five QTLs for length to width ratio,
which were distributed on chromosome 2, 3, 5, and 12, were identified. The range of their phenotypic contribution varied from
8.60% to 16.86%. For TGW QTLs, only two were identified on chromosome 5 and 6, respectively, with which 13.26% and 9.04%
phenotypic contribution. In our results,
qGL-4
and
qGL-9
for grain length were novel loci. They have not seen reported in literature
previously. Our results shed new light on further fine mapping and understanding the molecular genetic mechanism of novel grain
size QTLs.
Keywords
Digenic epistasis; Genetic linkage map; Grain size traits; QTL; Rice (
Oryza sativa
)
Introduction
Rice (Oryza sativa L.), one of the most widely grown food crop in the world, feeds more than half of the world
population. The increasing rice grain yield is of great strategic significance for world food security. Rice grain
yield is determined by grain weight, number of grains per panicle, and number of panicles per plant (Fan et al.
2006). Wherein, grain weight is determined by grain size, which defined as the combination of several grain
associated characters, including grain length (GL), grain width (GW), grain thickness (GT), and length to width
ratio (LWR) (Lou et al., 2009). In breeding application, rice grain size is significantly correlated with grain
weight, and therefore, usually being used to evaluate grain weight, as defined by 1000-grain weight (TGW)
(Zuo and Li, 2014). Thus, the dissection of molecular genetic mechanism of rice high yield related characters
has gradually been a hotspot in recent. Most grain size related traits are known to be regulated by multiple gene
loci, referred to as quantitative trait loci (QTLs) (Tan et al., 2000). The genetic basis of grain size traits is
complex and easily affected by the environment. Therefore, understanding the molecular genetic basis of grain
size traits is of great significance for rice grain yield improvement.
In the last two decades, the development of molecular marker technology and the QTL mapping strategy
facilitates QTL identification and cloning. Many grain size related QTLs have been identified and some major
effect loci have been cloned and functional investigated (Tan et al., 2000). To date, more than 400 QTLs for rice
grain size and grain weight have been identified from different genetic backgrounds and different mapping
populations, in which 103 QTLs have been reported to be associated with grain length, 95 QTLs reported to be
