Field resistance of new varieties
The resistance control variety ROC 20 was highly resistant to pokkah boeng disease, and the susceptible control variety ROC 25 was highly susceptible in the three replicate samples of newly-planted and ratoon cane grown in the field in Kaiyuan and Lincang. The pokkah boeng resistance of these controls was stable and consistent. The pokkah boeng resistance of each of 60 new varieties was stable and relatively consistent, with 35 (58.33%) found to be highly resistant to moderately resistant, and 25 (41.67%) to be susceptible to highly susceptible. Among them, five new varieties (8.33%), Yuegan 49, Funong 11-2907, Mintang 11-610, Mintang 12-1404, and Guitang 11-1076 were found to be highly resistant. Furthermore, 15 new varieties (25%), Yuegan 46, Yuegan 47, Funong 09-2201, Funong 09-6201, Funong 09-7111, Funong 10-14405, Mintang 06-1405, Guitang 40, Guitang 44, Guitang 06-1492, Guitang 06-2081, Guitang 08-1180, Guitang 08-1589, Yunzhe 11-1074, and Dezhe 07-36, were found to be resistant. Another 15 new varieties (25%), Yuegan 48, Yuegan 50, Funong 07-3206, Funong 09-4095, Funong 09-12206, Funong 10-0574, Mintang 07-2005, Guitang 08-120, Liucheng 09-15, Zhongzhe 1, Yunzhe 11-1204, Yunzhe 11-3898, Yunrui 10-187, Haizhe 22, and Zhongzhe 1202 were found to be moderately resistant. In total, 18 new varieties (30%), Yuegan 43, Yuegan 51, Yuegan 52, Funong 08-3214, Guitang 08-1533, Guitang 13-386, Liucheng 07-150, Zhongzhe 6, Zhongzhe 10, Yunzhe 08-1095, Yunzhe 08-1609, Yunzhe 11-3208, Yunrui 11-450, Yunrui 12-263, Dezhe 09-78, Dezhe 12-88, Haizhe 28, and Zhongtang 1201 were susceptible. Finally, there were seven new varieties (11.67%), Yuegan 53, Liucheng 07-506, Liucheng 09-19, Zhongzhe 13, Yunzhe 09-1601, Yunrui 10-701, and Zhongtang 1301 that were found to be highly susceptible (Table 1).
Table 1 Evaluation of field resistance to pokkah boeng disease in new sugarcane varieties under natural infection conditions
Varieties
|
Kaiyuan
|
Lincang
|
Comprehensive
Resistance responseb
|
Newly-Planted Disease incidencea
(%)
|
Ratoon Disease incidencea
(%)
|
Grade
|
Resistance responseb
|
Newly-Planted Disease incidencea
(%)
|
Ratoon Disease incidencea
(%)
|
Grade
|
Resistance responseb
|
Yuegan 49
|
(0.0±0.0)q
|
(0.0±0.0)o
|
1
|
HR
|
(0.0±0.0)l
|
(0.0±0.0)n
|
1
|
HR
|
HR
|
Funong 11-2907
|
(0.0±0.0)q
|
(0.0±0.0)o
|
1
|
HR
|
(0.0±0.0)l
|
(0.0±0.0)n
|
1
|
HR
|
Mintang 11-610
|
(0.0±0.0)q
|
(0.0±0.0)o
|
1
|
HR
|
(0.0±0.0)l
|
(0.0±0.0)n
|
1
|
HR
|
Mintang 12-1404
|
(0.0±0.0)q
|
(0.0±0.0)o
|
1
|
HR
|
(0.0±0.0)l
|
(0.0±0.0)n
|
1
|
HR
|
Guitang 11-1076
|
(0.0±0.0)q
|
(0.0±0.0)o
|
1
|
HR
|
(0.0±0.0)l
|
(0.0±0.0)n
|
1
|
HR
|
Yuegan 46
|
(7.0±0.6)nop
|
(8.0±1.1)klm
|
2
|
R
|
(6.0±0.9)jk
|
(9.0±0.6)ijkl
|
2
|
R
|
R
|
Yuegan 47
|
(5.0±0.2)pq
|
(6.0±0.2)mn
|
2
|
R
|
(7.0±0.6)jk
|
(8.0±0.9)jklm
|
2
|
R
|
Funong 09-2201
|
(6.0±0.3)op
|
(7.0±0.4)lmn
|
2
|
R
|
(6.0±0.7)jk
|
(8.0±0.2)jklm
|
2
|
R
|
Funong 09-6201
|
(3.0±0.1)pq
|
(5.0±0.4)mn
|
2
|
R
|
(4.0±0.2)k
|
(3.0±0.3)mn
|
2
|
R
|
Funong 09-7111
|
(5.0±0.1)pq
|
(6.0±0.2)mn
|
2
|
R
|
(6.0±0.5)jk
|
(5.0±0.3)lmn
|
2
|
R
|
Funong 10-14405
|
(2.0±0.8)pq
|
(3.0±0.1)no
|
2
|
R
|
(4.0±0.4)k
|
(3.0±0.2)mn
|
2
|
R
|
Mintang 06-1405
|
(7.0±0.5)nop
|
(8.0±0.9)klm
|
2
|
R
|
(6.0±0.2)jk
|
(7.0±0.1)klm
|
2
|
R
|
Guitang 40
|
(5.0±0.4)pq
|
(6.0±0.5)mn
|
2
|
R
|
(7.0±0.5)jk
|
(8.0±0.7)jklm
|
2
|
R
|
Guitang 44
|
(3.0±0.2)pq
|
(4.0±0.4)mno
|
2
|
R
|
(5.0±0.5)k
|
(6.0±0.8)lm
|
2
|
R
|
Guitang 06-1492
|
(4.0±0.8)pq
|
(5.0±0.3)mn
|
2
|
R
|
(7.0±0.3)jk
|
(9.0±0.9)ijkl
|
2
|
R
|
Guitang 06-2081
|
(7.0±0.4)nop
|
(6.0±0.4)mn
|
2
|
R
|
(9.0±0.1)ij
|
(7.0±0.5)klm
|
2
|
R
|
Guitang 08-1180
|
(6.0±0.1)op
|
(3.0±0.5)no
|
2
|
R
|
(5.0±0.0)k
|
(4.0±0.6)lmn
|
2
|
R
|
Guitang 08-1589
|
(2.0±0.4)pq
|
(3.0±0.1)no
|
2
|
R
|
(4.0±0.0)k
|
(5.0±0.7)lmn
|
2
|
R
|
Yunzhe 11-1074
|
(5.0±0.8)pq
|
(4.0±0.6)mno
|
2
|
R
|
(6.0±0.1)jk
|
(5.0±0.8)lmn
|
2
|
R
|
Dezhe 07-36
|
(6.0±1.2)op
|
(4.0±0.2)mno
|
2
|
R
|
(5.0±0.3)k
|
(7.0±0.7)klm
|
2
|
R
|
Yuegan 48
|
(13.0±0.1)lm
|
(12.0±0.7)jk
|
3
|
MR
|
(14.0±1.8)h
|
(15.0±0.3)h
|
3
|
MR
|
MR
|
Yuegan 50
|
(14.0±1.5)lm
|
(13.0±1.8)j
|
3
|
MR
|
(12.0±1.3)hi
|
(13.0±1.7)hij
|
3
|
MR
|
Funong 07-3206
|
(11.0±1.0)mno
|
(12.0±1.8)jk
|
3
|
MR
|
(13.0±1.0)h
|
(15.0±0.6)h
|
3
|
MR
|
Funong 09-4095
|
(12.0±1.0)lmn
|
(11.0±0.4)jkl
|
3
|
MR
|
(13.0±1.2)h
|
(14.0±0.4)hi
|
3
|
MR
|
Funong 09-12206
|
(16.0±1.0)klm
|
(15.0±1.5)ij
|
3
|
MR
|
(14.0±1.5)h
|
(12.0±1.1)hijk
|
3
|
MR
|
Funong 10-0574
|
(12.0±1.5)lmn
|
(11.0±1.0)jkl
|
3
|
MR
|
(14.0±1.1)h
|
(13.0±1.8)hij
|
3
|
MR
|
Mintang 07-2005
|
(15.0±0.6)lm
|
(14.0±0.3)j
|
3
|
MR
|
(14.0±1.4)h
|
(16.0±2.1)h
|
3
|
MR
|
Guitang 08-120
|
(15.0±1.8)lm
|
(13.0±0.5)j
|
3
|
MR
|
(14.0±0.3)h
|
(13.0±0.9)hij
|
3
|
MR
|
Liucheng 09-15
|
(13.0±0.6)lm
|
(12.0±0.0)jk
|
3
|
MR
|
(14.0±1.5)h
|
(15.0±0.3)h
|
3
|
MR
|
Zhongzhe 1
|
(12.0±1.2)lmn
|
(11.0±0.1)jkl
|
3
|
MR
|
(13.0±0.8)h
|
(14.0±1.0)hi
|
3
|
MR
|
Yunzhe 11-1204
|
(12.0±0.1)lmn
|
(11.0±0.7)jkl
|
3
|
MR
|
(13.0±1.0)h
|
(14.0±1.7)hi
|
3
|
MR
|
Yunzhe 11-3898
|
(12.0±1.0)lmn
|
(12.0±0.2)jk
|
3
|
MR
|
(14.0±1.0)h
|
(13.0±0.3)hij
|
3
|
MR
|
Yunrui 10-187
|
(11.0±0.1)mno
|
(13.0±0.1)j
|
3
|
MR
|
(12.0±1.8)hi
|
(15.0±0.8)h
|
3
|
MR
|
Haizhe 22
|
(12.0±1.0)lmn
|
(11.0±0.7)jkl
|
3
|
MR
|
(13.0±1.2)h
|
(14.0±1.0)hi
|
3
|
MR
|
Zhontang 1202
|
(17.0±1.1)jkl
|
(18.0±0.7)hi
|
3
|
MR
|
(15.0±1.1)h
|
(16.0±1.2)h
|
3
|
MR
|
Yuegan 43
|
(21.0±0.6)ijk
|
(23.0±1.2)g
|
4
|
S
|
(22.0±0.3)fg
|
(25.0±1.3)g
|
4
|
S
|
S
|
Yuegan 51
|
(22.0±0.6)ij
|
(23.0±3.0)g
|
4
|
S
|
(25.0±1.5)f
|
(24.0±1.2)g
|
4
|
S
|
Yuegan 52
|
(21.0±0.2)ijk
|
(22.0±1.1)g
|
4
|
S
|
(23.0±0.2)fg
|
(25.0±2.0)g
|
4
|
S
|
Funong 08-3214
|
(23.0±1.3)hi
|
(24.0±1.4)g
|
4
|
S
|
(22.0±1.1)fg
|
(23.0±0.5)g
|
4
|
S
|
Guitang 08-1533
|
(21.0±0.2)ijk
|
(22.0±0.2)g
|
4
|
S
|
(23.0±3.5)fg
|
(24.0±2.2)g
|
4
|
S
|
Guitang 13-386
|
(23.0±1.0)hi
|
(22.0±1.9)g
|
4
|
S
|
(21.0±0.2)g
|
(23.0±0.2)g
|
4
|
S
|
Liucheng 07-150
|
(25.0±0.8)hi
|
(24.0±0.6)g
|
4
|
S
|
(24.0±0.5)fg
|
(25.0±0.8)g
|
4
|
S
|
Zhongzhe 6
|
(23.0±2.1)hi
|
(24.0±2.6)g
|
4
|
S
|
(21.0±0.2)g
|
(23.0±0.5)g
|
4
|
S
|
Zhongzhe 10
|
(21.0±0.3)ijk
|
(23.0±1.5)g
|
4
|
S
|
(22.0±0.4)fg
|
(21.0±1.9)g
|
4
|
S
|
Yunzhe 08-1095
|
(23.0±1.6)hi
|
(21.0±1.3)gh
|
4
|
S
|
(22.0±1.9)fg
|
(24.0±1.2)g
|
4
|
S
|
Yunzhe 08-1609
|
(24.0±0.4)hi
|
(25.0±2.5)g
|
4
|
S
|
(23.0±0.9)fg
|
(25.0±0.0)g
|
4
|
S
|
Yunzhe 11-3208
|
(21.0±1.5)ijk
|
(23.0±1.2)g
|
4
|
S
|
(22.0±1.0)fg
|
(24.0±1.4)g
|
4
|
S
|
Yunrui 11-450
|
(23.0±1.8)hi
|
(25.0±0.5)g
|
4
|
S
|
(21.0±0.7)g
|
(24.0±1.1)g
|
4
|
S
|
Yunrui 12-263
|
(25.0±1.2)hi
|
(24.0±1.6)g
|
4
|
S
|
(24.0±1.4)fg
|
(26.0±1.6)g
|
4
|
S
|
Dezhe 09-78
|
(23.0±2.6)hi
|
(25.0±1.0)g
|
4
|
S
|
(22.0±2.0)fg
|
(26.0±1.6)g
|
4
|
S
|
Dezhe 12-88
|
(22.0±0.5)ij
|
(23.0±0.7)g
|
4
|
S
|
(23.0±1.2)fg
|
(25.0±1.3)g
|
4
|
S
|
Haizhe 28
|
(23.0±0.8)ijk
|
(25.0±1.8)g
|
4
|
S
|
(21.0±0.2)g
|
(24.0±1.9)g
|
4
|
S
|
Zhontang 1201
|
(21.0±0.8)hi
|
(23.0±0.0)g
|
4
|
S
|
(22.0±0.4)fg
|
(24.0±1.0)g
|
4
|
S
|
Yuegan 53
|
(42.0±1.9)fg
|
(48.0±1.0)e
|
5
|
HS
|
(46.0±1.3)d
|
(51.0±1.6)e
|
5
|
HS
|
HS
|
Liucheng 07-506
|
(46.0±2.9)ef
|
(51.0±2.1)de
|
5
|
HS
|
(49.0±2.9)d
|
(54.0±2.0)e
|
5
|
HS
|
Liucheng 09-19
|
(41.0±2.2)g
|
(50.0±2.5)de
|
5
|
HS
|
(47.0±2.8)d
|
(55.0±2.1)e
|
5
|
HS
|
Zhongzhe 13
|
(61.0±2.1)b
|
(70.0±1.4)b
|
5
|
HS
|
(67.0±2.7)c
|
(75.0±2.8)b
|
5
|
HS
|
Yunzhe 09-1601
|
(51.0±1.0)cd
|
(60.0±1.8)c
|
5
|
HS
|
(57.0±1.1)c
|
(65.0±1.8)c
|
5
|
HS
|
Yunrui 10-701
|
(50.0±1.6)de
|
(53.0±1.4)d
|
5
|
HS
|
(57.0±0.6)c
|
(50.0±1.2)e
|
5
|
HS
|
Zhontang 1301
|
(55.0±2.0)c
|
(61.0±1.2)c
|
5
|
HS
|
(57.0±1.7)b
|
(60.0±1.6)d
|
5
|
HS
|
ROC 22 (CK)
|
(28.0±0.6)h
|
(32.0±1.6)f
|
4
|
S
|
(32.0±1.2)e
|
(37.0±1.0)f
|
4
|
S
|
S
|
ROC 20 (PC)
|
(0.0±0.0)q
|
(0.0±0.0)o
|
1
|
HR
|
(0.0±0.0)l
|
(0.0±0.0)n
|
1
|
HR
|
HR
|
ROC 25 (NC)
|
(90.0±0.8)a
|
(95.0±0.5)a
|
5
|
HS
|
(90.0±0.7)a
|
(100.0±0.0)a
|
5
|
HS
|
HS
|
aThe values in the table are the mean±SE. Different lowercase letters indicate significant differences among disease incidence of different varieties at 0.05 level.
bHR: Highly resistant; R: Resistant; MR: Moderately resistant; S: Susceptible; HS: Highly susceptible
Field resistance of main cultivated varieties
The resistance of the newly-planted and ratoon cane of each of the 31 main cultivated varieties, which from different sugarcane areas in the field, was stable and relatively consistent. Of the 31 main cultivated varieties, 15 (48.39%) were highly resistant to moderately resistant and 16 (51.61%) were susceptible to highly susceptible. There were five (16.13%) highly resistant main cultivated varieties, namely ROC 20, Yuetang 83-88, Chuantang 61-408, Yunyin 10, and Guitang 21. There were also five (16.13%) resistant main cultivated varieties: Yuetang 79-177, Yunzhe 05-51, Liucheng 03-182, Guitang 36, and Guitang 44. A further five (16.13%) main cultivated varieties, Yuetang 60, Liucheng 05-136, ROC 16, Mintang 69-421, and Guitang 29 were found to be moderately resistant. Seven (22.58%) main cultivated varieties, ROC 22, Yuetang 86-368, Yuetang 00-236, ROC 10, Yunzhe 05-49, Dezhe 03-83, and Yunyin 3, were found to be susceptible. Meanwhile, nine (29.03%) varieties, ROC 25, Yuetang 93-159, Yingyu 91-59, Liucheng 03-1137, Yunzhe 03-258, Chuantang 79-15, ROC 1, Guitang 11, and Guitang 42, were highly susceptible (Table 2).
Table 2 Evaluation of field resistance to pokkah boeng disease in main cultivated sugarcane varieties under natural infection conditions
Sugarcane fields
|
Varieties
|
Newly-Planted Disease incidencea
(%)
|
Ratoon Disease incidencea
(%)
|
Grade
|
Resistance responseb
|
Comprehensive resistance responseb
|
Yunnan lincang
|
ROC 20
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
HR
|
Yuetang 83-88
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
Chuantang 61-408
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
Yuetang 79-177
|
(7.0±0.7)t
|
(9.0±0.1)qr
|
2
|
R
|
R
|
Yunzhe 05-51
|
(8.0±0.3)st
|
(9.0±0.7)qr
|
2
|
R
|
Liucheng 03-182
|
(6.0±0.4)t
|
(5.0±0.4)rs
|
2
|
R
|
Yuetang 60
|
(16.0±1.1)pqr
|
(18.0±1.3)mnop
|
3
|
MR
|
MR
|
Liucheng 05-136
|
(12.0±0.2)rs
|
(13.0±1.0)pq
|
3
|
MR
|
ROC 22
|
(32.0±1.8)jk
|
(37.0±1.5)fgh
|
4
|
S
|
S
|
Yuetang 86-368
|
(35.0±0.9)ij
|
(31.0±0.8)hij
|
4
|
S
|
Yuetang 00-236
|
(21.0±0.8)mno
|
(25.0±0.3)ijklm
|
4
|
S
|
ROC 25
|
(90.0±0.2)a
|
(100.0±0.0)a
|
5
|
HS
|
HS
|
Yuetang 93-159
|
(75.0±1.3)d
|
(90.0±1.6)b
|
5
|
HS
|
Yingyu 91-59
|
(49.0±1.9)f
|
(60.0±1.2)c
|
5
|
HS
|
Liucheng 03-1137
|
(42.0±0.0)gh
|
(44.0±0.2)ef
|
5
|
HS
|
Yunnan Puer
|
ROC 20
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
HR
|
Yunyin 10
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
Guitang 21
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
Yunzhe 05-51
|
(4.0±0.1)tu
|
(5.0±0.1)rs
|
2
|
R
|
R
|
ROC 16
|
(14.0±1.1)pqr
|
(13.0±0.8)pq
|
3
|
MR
|
MR
|
Yuetang 60
|
(17.0±1.9)opq
|
(15.0±1.3)opq
|
3
|
MR
|
ROC 10
|
(36.0±1.8)ij
|
(39.0±1.5)fg
|
4
|
S
|
S
|
ROC 22
|
(35.0±0.7)ij
|
(32.0±0.8)ghi
|
4
|
S
|
Yuetang 86-368
|
(25.0±2.0)lm
|
(30.0±0.3)hijk
|
4
|
S
|
Yuetang 00-236
|
(23.0±0.2)m
|
(21.0±0.3)lmnop
|
4
|
S
|
Yunzhe 05-49
|
(33.0±0.2)jk
|
(31.0±0.9)hij
|
4
|
S
|
Dezhe 03-83
|
(24.0±0.5)m
|
(22.0±0.3)lmno
|
4
|
S
|
Yuetang 93-159
|
(85.0±0.8)c
|
(100.0±0.0)a
|
5
|
HS
|
HS
|
Yunzhe 03-258
|
(46.0±1.8)fg
|
(42.0±1.7)f
|
5
|
HS
|
Chuantang 79-15
|
(59.0±2.4)e
|
(65.0±2.5)c
|
5
|
HS
|
Yunnan Yuxi
|
Yunzhe 05-51
|
(5.0±0.3)tu
|
(4.0±0.4)rs
|
2
|
R
|
R
|
ROC 16
|
(13.0±1.2)qr
|
(16.0±1.0)nopq
|
3
|
MR
|
MR
|
Mintang 69-421
|
(18.0±1.8)nop
|
(19.0±1.3)mnop
|
3
|
MR
|
ROC 10
|
(29.0±0.3)kl
|
(27.0±0.5)ijkl
|
4
|
S
|
S
|
ROC 22
|
(22.0±0.3)mn
|
(21.0±0.6)lmnop
|
4
|
S
|
Yuetang 00-236
|
(21.0±0.1)mno
|
(23.0±0.3)klmno
|
4
|
S
|
Yunyin 3
|
(39.0±0.7)hi
|
(37.0±0.3)fgh
|
4
|
S
|
ROC 1
|
(90.0±0.3)b
|
(100.0±0.0)a
|
5
|
HS
|
HS
|
Yuetang 93-159
|
(85.0±1.3)c
|
(90.0±1.5)b
|
5
|
HS
|
Guitang 11
|
(49.0±1.9)f
|
(52.0±1.1)d
|
5
|
HS
|
Guangxi Yizhou
|
ROC 20
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
HR
|
Guitang 21
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
Guitang 36
|
(4.0±0.2)tu
|
(5.0±0.4)rs
|
2
|
R
|
R
|
Guitang 44
|
(5.0±0.5)tu
|
(9.0±0.9)qr
|
2
|
R
|
ROC 16
|
(12.0±0.3)rs
|
(15.0±0.6)opq
|
3
|
MR
|
MR
|
Guitang 29
|
(16.0±0.8)pqr
|
(17.0±1.0)mnopq
|
3
|
MR
|
Liucheng 05-136
|
(18.0±1.3)nop
|
(15.0±1.0)opq
|
3
|
MR
|
ROC 22
|
(22.0±1.1)mn
|
(24.0±1.1)jklmn
|
4
|
S
|
S
|
Guitang 42
|
(49.0±1.9)f
|
(50.0±1.5)de
|
5
|
HS
|
HS
|
Liucheng 03-1137
|
(42.0±0.1)gh
|
(41.0±0.5)f
|
5
|
HS
|
Susceptibility control
|
ROC 25
|
(95.0±0.1)b
|
(100.0±0.0)a
|
5
|
HS
|
HS
|
Resistant control
|
ROC 20
|
(0.0±0.0)u
|
(0.0±0.0)s
|
1
|
HR
|
HR
|
aThe values in the table are the mean±SE. Different lowercase letters indicate significant differences among disease incidence of different varieties at 0.05 level.
bHR: Highly resistant; R: Resistant; MR: Moderately resistant; S: Susceptible; HS: Highly susceptible