studies on the inheritance of yellow seedcoat in rapeseed (Brassica napus L)
Wu Jiangsheng, Shi Shuwen, Wu Daowan and Liu Houli
Institute of Crop Genetics and Breeding, Huazhong Agricultural University, Wuhan, 430070, People’s Republic of China
ABSTRACT
The yellow-seeded mutant 933044 (Brassica napus L.) was found in a F8 population of composite hybridization cross using black-seeded varieties (lines) as parent. The ratio of yellow-seeded plants derived from the mutant 933044 reached 100% after self pollination for three generations. Reciprocal crossing had been done between mutant 933044 and 22 black-seeded varieties (lines). In their F1, 11 of total crosses produced yellow-seeded plants with a ratio of 86.96-100%. When yellow-seeded mutant 933044 were crossed with black-seeded line 93431 as male, F1 exhibited the character of yellow seed coat and F2 and BC1 segregated with the ratio of 3Y:1b and 1Y:0b, respectively, whereas in the cross using 721-1 as male the character of black seedcoat appeared in F1 and the ratio of 3Y:13b and 1Y:1b were produced in F2 and BC1, respectively. The results indicated that the yellow-seeded trait of 933044 may be controlled by two pairs of dominant genes in the interaction of dominant epistasis and its genotypes would be assumed YcYcbcbc. Mutant 933044 was already used as parent to breed yellow-seeded double low varieties and hybrids in B. napus.
KEY WORDS: Brassica napus; Dominant yellow-seeded mutant; Inheritance of seedcoat colour
INTRODUCTION
Yellow-seeded rapeseed has better traits of thin seed coat, high oil and protein content as well as less fibre etc. than black-seeded types in B. napus (Liu Houli et al., 1992; Wu Jiangsheng et al., 1997; Meng J et al., 1995). Therefore, yellow-seeded rapeseed breeding has been paid much attention in the world. Since 1960’s, some B.napus yellow-seeded materials have been bred but their yellow seed coat is not stable inheritance and their seed yield is lower than that of black-seeded forms. We made an effeort to breed yellow-seeded B.napus and mutant 933044, which is different from above yellow-seeded materials in the trait of yellow seed coat was found in a F8 population of composite hybridized cross in 1993. Present paper reports the genetic pattern of seed coat colour and the application of mutant 933044 in quality and heterosis breeding in B.napus.
MATERIALS AND METHODS
The yellow-seeded mutant 933044 (Brassica napus) was found in a F8 generation derived from the cross Huayou low erucic 821(Huayou 3Marnoo) in 1993. B.napus black-seeded varieties (lines), Zhongyou821, 89008, 93-1 and 93-6 were supplied by Oil Crops Research Institute, CAAS. Other 18 B. napus black-seeded lines, 93431, 721-1 and cms 7133 etc. came from our Rapeseed Research laboratory. In 1994—1996, 933044 was crossed reciprocally with 22 black-seeded parents and the character of yellow seed coat was observed in their Fo, Rfo and F1, RF1 (Table 1). In addition, the seeds of parents 933044, 93431 and 721-1 were sown again in Autumn of 1994 and formed plants were self pollinated by bagging, meanwhile 933044 was crossed reciprocally with 93431 and 721-1 and F1 and RF1 plants from Fo and Rfo seeds were self and back-crossed using 933044 as recurrent parent in Spring of 1995. The seed colour of parents, F1, RF1, F2, RF2 and BC1, RBC1 plants were observed in 1996. Results showed that it is not significantly different between F1 and RF1, F2 and RF2, BC1 and RBC1 within combination in seed coat colour. Thus, seeds of F1 and RF1, F2 and RF2, BC1 and RBC1 were mixed, respectively and analysed.
RESULTS AND DISCUSSION
Seed coat colour
Table 1 showed that 19 of 22 crosses set yellow seeds in Fo plants whereas all crosses set black seeds in Rfo plants when 933044 used as yellow-seeded parent. The ratio of plant with yellow seeds between F1 and RF1 within cross is not significantly different whereas their mean values 0.00--100% among 22 crosses could be divided into three classes, 97.43%, 53.04% and 0.76%(A, B, C). This indicated that each class of black-seeded parents had different effect on the expression of yellow-seeded trait of mutant 933044.
TABLE 1 SEED COAT COLOUR OF HYBRIDS AND RATIO OF YELLOW-SEEDED PLANTS IN F1 AND RF1 (933044 USED AS YELLOW-SEEDED PARENT)
|
Years
|
BS parents |
Seed coat colour |
F1 plants |
RF1 plants |
Ratio of YS |
Classifications |
|||
|
|
|
Fo |
RFo |
YS |
BS |
YS |
BS |
|
|
|
1994-1996 |
93431 |
YS |
BS |
151 |
0 |
142 |
0 |
100 |
|
|
1995 |
7133 cms |
|
BS |
0 |
0 |
9 |
0 |
100 |
|
|
1995 |
1141 cms |
|
BS |
0 |
0 |
68 |
0 |
100 |
|
|
1994 |
5904 |
YS |
BS |
14 |
0 |
9 |
0 |
100 |
|
|
1994 |
5942 |
YS |
BS |
11 |
0 |
9 |
0 |
100 |
|
|
1995 |
Bakow |
YS |
BS |
9 |
0 |
0 |
0 |
100 |
A |
|
1994-1996 |
89008 |
YS |
BS |
43 |
0 |
31 |
0 |
100 |
|
|
1995 |
1141B |
YS |
BS |
14 |
1 |
8 |
0 |
95.65 |
|
|
1995 |
94-9 |
YS |
BS |
19 |
2 |
24 |
0 |
95.56 |
|
|
1996 |
6178 |
YS |
BS |
7 |
0 |
23 |
3 |
90.91 |
|
|
1995 |
7136 cms |
|
BS |
0 |
0 |
20 |
3 |
86.96 |
|
|
1995 |
94-7 |
YS |
BS |
30 |
18 |
26 |
15 |
62.92 |
|
|
1994-1996 |
91806 |
YS |
BS |
10 |
11 |
8 |
0 |
62.07 |
|
|
1994-1996 |
Zhongyou 821 |
YS |
BS |
43 |
2 |
17 |
36 |
61.22 |
B |
|
1995-1996 |
93541 |
YS |
BS |
28 |
19 |
0 |
0 |
59.57 |
|
|
1995 |
94-10 |
YS |
BS |
7 |
20 |
3 |
16 |
21.74 |
|
|
1994-1996 |
721-1 |
YS |
BS |
2 |
137 |
0 |
144 |
0.71 |
|
|
1995 |
94-1 |
YS |
BS |
0 |
22 |
1 |
3 |
3.85 |
|
|
1996 |
950 |
YS |
BS |
0 |
21 |
0 |
22 |
0.00 |
C |
|
1995 |
94-6 |
YS |
BS |
0 |
24 |
0 |
26 |
0.00 |
|
|
1996 |
93-1 |
YS |
BS |
0 |
40 |
0 |
0 |
0.00 |
|
|
1996 |
93-6 |
YS |
BS |
0 |
0 |
0 |
25 |
0.00 |
|
Genetic manner of seedcoat colour
The data in table 2 showed that the segregation ratio of plants with yellow and black seeds in F2 and BC1 is 3:1 and 1:0, respectively and demonstrated that yellow seedcoat of 933044 was controlled by one pair of dominant gene in cross 93304493431. But in cross 933044721-1, 3:13 and 1:1 appeared in F2 and BC1, respectively. This suggested that the trait of yellow seed coat of 933044 was determined by two pairs of dominant genes in the interacted manner of dominant epistasis. Both alleles at two loci were designated as Yc-yc and Bc-bc and the dominant gene determining yellow seedcoat and the epistatic dominant gene governing black seedcoat were presumed to be Yc and Bc which can inhibit the expression of Yc, respectively. Thus, the genotypes of 933044 would be assumed YcYcbcbc and ones of 93431 and 721-1 would be assumed ycycbcbc(homozygous recessive genes governed black-seeded trait) and ycycBcBc, respectively (Fig.1).
933044 (YS) BS (A) 933044 (YS) BS (C)
YcYcbcbc ycycbcbc YcYcbcbc ycycBcBc
F1 933044 F1 933044
YS (Ycycbcbc) YS (YcYcbcbc) BS(YcycBcbc) YS(YcYcbcbc)
F2 BC1 F2 BC1
3 YS (Yc-bcbc) YS(Yc-bcbc) 9 BS(Yc-Bc-) 1YS(Yc-bcbc)
1 BS (ycycbcbc) 3 BS(ycycBc-) 1BS(Yc-Bc-)
YS/BS (3:1) 3 YS(Yc-bcbc) YS/BS(1:1)
1 BS(ycycbcbc)
YS/BS(3:13)
933044(YS) BS (B)
YcYcbcbc ycycBcbc
F1
933044(YS) 1 YS YS/BS(1:1) 1 BS 933044 (YS)
YcYcbcbc Ycycbcbc YcycBcbc YcYcbcbc
BC1 BC1
YS (Yc-bcbc) 1 YS (Yc-bcbc)
YS/BS(1:0) 1 BS(Yc-Bc-)
YS/BS(1:1)
DIAGRAM OF THE GENOTYPES OF THE PROGENIES FROM YELLOW-SEEDED MUTANT 933044 AND BLACK-SEEDED LINES IN BRASSICA NAPUS L.
Application of mutant 933044 in rapeseed breeding
Using mutant 933044, yellow-seeded double low line Y91806 and double low cms hybrids 96331 etc. were bred and 96331 was already identified for its seed yield, protein and oil content. Results revealed that their content of oil and protein is higher than black-seeded double low hybrids.
TABLE 2 RATIO OF THE PLANTS WITH YELLOW-SEEDED AND BLACK-SEEDED IN FILIAL GENERATION (F2, BC1)
|
Combination |
Generation |
Practical observed values |
E |
X2e |
P |
||
|
|
|
YS |
BS |
Ratio |
|
|
|
|
93304493431 |
F2 |
159 |
51 |
3.029:0.971 |
3:1 |
0.0572 |
0.75-0.90 |
|
|
BC1 |
153 |
1 |
0.994:0.006 |
1:0 |
0.0065 |
>0.90 |
|
933044721-1 |
F2 |
53 |
211 |
3.212:12.788 |
3:13 |
0.3046 |
0.50-0.75 |
|
|
BC1 |
133 |
129 |
1.015:0.985 |
1:1 |
0.0610 |
0.75-0.90 |
REFERENCES
1. Chen, B., S.K. Heneen, & R. Jonsson, 1988. Resynthesis of Brassica napus L. through interspecific hybridization between B.alboglabra Bailey and B.campestris L. with special emphasis on seed color. Plant Breeding 101:52-59
2. Liu Houli. 1992. Studies on the inheritance of yellow-seeded Brassica napus L. Acta Agronomica Sinica 18:241-248
3. Meng, J., 1995. Interspecific hybridization and seed coat quality. proceedings of 9th International Rapeseed Congress, Cambridge, UK pp.1128-1133
4. Rashid, A.; G. Rakow & R. K. Downey, 1994. Development of yellow-seeded Brassica napus through interspecific crosses. Plant Breeding 112:127-134
5. Wu Jiangsheng, Liu Houli & Shi Shuwen. 1997. Studies on a new germplasm with yellow seedcoat controlled by dominant genes in Brassica napus L. Journal of Huazhong Agricultural University, 16:26-28