Basic HTML Version
Rice Genomics and Genetics 2012, Vol.3, No.2, 8
-
12
http://rgg.sophiapublisher.com
9
2005). In this study, we attempted to build a set of
near-isogenic introgression lines by crossing and
subsequent backcrossing by using eleven wild rice
accessions as donors came from different origins and
using Gangxiang B as recipient, an elite maintainer
to rice cytoplasm male sterility of three-line hybrid
system. The primarily phenotypic screening were
performed for disease resistance, drought resistance,
nutrient efficiency, high temperature tolerance, flooding
and other target traits in order to lay a the foundation
to develop "green super rice".
1 Results and Analysis
1.1 Building Near-isogenic introgression lines
In 2007, we made a series of crosses using Ganxiang
B as maternal parent and employing wild rice as donors
including Dongxiang wild rice, Guangxi wild rice,
Jiangyong wild rice, Chaling wild rice, and Yuanjiang
common wild rice, Hehuatang No.2, No.4, and No.10
as well as a series of wild rice germplsms of 06YD2,
06YD5, 06YD6 and 06YD12 provided by Huazhong
Agricultural University. The backcrossed were carried
out 2 or 3 times by using Ganxiang B as paternal
parent (Individual with more traits of wild rice might
be ackcrossed three times), prior to self-crossing. Until
in 2010, 892 lines including lines of BC
2
F
5
and BC
3
F
4
were achieved in this research (Table 1).
1.2 Screening for tolerance to drought
The weather with consecutive high temperature and
less humidity occurred in Nanchang city from 1
st
to
18
th
, August, 2010, the highest temperature reached 35
℃
or more, which would be facilitate to identify the
drought-resistant materials. Where soil in field appeared
Table 1 Library of near isogenic introgression lines (ILS) by
using Ganxiang B as the recipient
Donors
Total of near isogenic
introgression lines
Dongxiang wild rice
179
Chaling wild rice
142
Jiangyong wild rice
87
Guangxi wild rice
110
Yuanjiang wild rice Hehuatang No.2
16
Yuanjiang wild rice Hehuatang No.4
32
Yuanjiang wild rice Hehuatang No.10
15
06YD2
81
06YD5
29
06YD6
99
06YD12
102
paling, cracking, grass wilting, materials that had poor
drought tolerance appeared the symptoms of leaf
curling and wilting of the whole plant that could not
recovered by rehydration. The 6 996 individuals with
high drought tolerance from 11 combinations were
preliminary screened, while the control varieties
exhibited a strong drought tolerance (Table 2).
1.3 Screening for tolerance to low nitrogen
In the low nitrogen conditions, 892 lines derived from
the different combinations showed significantly
differences in the use of nitrogen, of which some lines
had the superiority of vegetative growth stronger than
that of parental receptors Ganxiang B, mainly exhibiting
excellent characters such as strong tillering, large
panicle, stem thickening, etc., indicating that some of
the NILs should have a strong capacity of tolerance to
low nitrogen. 123 lines with excellent tolerance to low
nitrogen were preliminary screened out (Table 3).
Table 2 The screening results of near isogenic introgression lines for tolerance to drought
Donor
Generation
Total of plants
No. of plants with drought tolerance
Dongxiang wild rice
BC
2
F
5
3 478
386
Chaling wild rice
BC
2
F
5
2 816
556
Jiangyong wild rice
BC
2
F
5
3 438
1 147
Guangxi wild rice
BC
2
F
5
2 400
470
Yuanjiang wild rice Hehuatang No.2
BC
2
F
5
2 136
357
Yuanjiang wild rice Hehuatang No.4
BC
2
F
5
2 892
513
Yuanjiang wild rice Hehuatang No.10
BC
2
F
5
1 570
243
06YD2
BC
2
F
5
4 028
1 035
06YD5
BC
2
F
5
2 686
767
06YD6
BC
2
F
5
2 896
1 022
06YD12
BC
2
F
5
1 380
500