Page 7 - Triticeae Genomics and Genetics

Triticeae Genomics and Genetics 2011, Vol.2, No.1, 1- 6
http://tgg.sophiapublisher.com
4
results indicated that qTS2A -1 might be the major
QTL associated with the triple spikelet traits. However,
previous genetic analysis showed that the triple
spikelet trait of TTSW-5 might be controlled by two
independent genetic recessive genes, but there was
only a major QTL for triple spikelet trait detected in
this study, indicating that another one should not
detected yet. It might be possible due to limited SSR
markers or too far distance among SSR markers. So
regarding another recessive locus, we managed to us
new genetic population to identify the location and its
effect of the tentative locus.
Figure 2 Location of the qTS2A-1 for triple-spikelet trait on
chromosome 2A in Tibetan triple spikelet wheat
Note: Black arrowhead shows the position of the QTL
2 Discussions
A lot of analysis on genetic models of multiple spike
traits has been made already. Patil (1958) considered
that the branching traits of durum wheat might be
controlled by single recessive gene. Pennell and
Halloran (1983) studied that unstable branching trait
of durum wheat lines AU S4531 controlled by two
recessive genes. Aybeniz et al (2011) found that the
novel branching panicle traits derived from the hybrid
of synthesized wheat line 171ACS and hardy wheat
were also controlled by the single recessive gene. Sun
et al (2009) studies have shown that multiple spikelet
wheat line 51885 was controlled by two pairs of
dominant genes. Koric et al (1996) study suggested
that branching panicle traits of common wheat were
controlled by two pairs of dominant complementary
and pyramiding genes. Our research group has used
the Tibetan triple spikelet wheat to mate with
Chuanmai 38 and SW8488, respectively to generate
F2 and backcross populations for genetic analysis,
indicating triple spikelet trait of Tibetan triple spikelet
was controlled by two independent recessive genes
(Yang et al., 2005; Yang et al., 2004). Although the
genetic model of multiple spikelet traits might be
difference due to using different materials that may
carry different genes, our results in this study had
confirmed the above mentioned conclusions previous
done by our research group (Yang et al., 2005; Yang et
al., 2004).
Klindworth, et al (1990b) found a recessive major
gene associated with branching trait in the chromosome
2AS, but its linkage molecular marker was unavailable.
Qxana et al (2009) had multiple spikelet gene Mrs1
mapped on chromosome 2DS, co-separating with SSR
locus Xwmc453, meanwhile rye multiple spikelet
gene Mol gene mapped on chromosome 2R. Although
in this study the maim effective QTL closely related to
triple spikelet traits was detected on chromosome 2A,
a multiple spikelet locus detected by Qxana, Xwmc453,
using to scan the parents and populations did not
exhibit any correlation with the triple spikelet trait of
Tibetan triple spikelet wheat, indicating that the QTL
detected in this study should be difference from the
Mrs1 locus mapped by Qxana et al (2009).
3 Materials and Methods
3.1 Materials used in this study
Tibetan triple spikelet wheat is a unique landrace in
Tibet of China provided by the Sichuan Agricultural
University, possessing similar triple spikelet trait of
six-rowed barley with more than 60 spiklets and more
than 170 florets, which should be 2 or 3 times than
that of common wheat. TTSW -5 is the triple spikelet
line derived from the progenies of the cross between
the Tibetan triple spikelet wheat and Sichuan wheat
Chuanmai 38. Jian 3 is the breeding line of common
wheat developed by Crops Research Institute of
Sichuan Academy of Agricultural Sciences. Chuanmai
55 is new variety of common wheat developed by
Sichuan Academy of Agricultural Sciences. F 2
populations from the cross between triple spikelet
wheat TTSW -5 and Jian 3 was employed for triple
spikelet trait mapping and QTL detection. F 2
population from the cross of TTSW-5 and Chuanmai
55 were used for further genetic validation on
phenotype.