Protein ranged from 7,9 to 10,6% (summer-autumn crop). In winter-spring crop, protein content of rice varieties ranged from 7,8-10,6%. The result of two-way ANOVA show that protein content of rice variety was dependent on genetic factors.
3.3.2. Starch content
Starch content of rice grain ranged from 65,7 to 73,0%
(summer-autumn crop) and from 65,5 to 74,6% (winter-spring crop).
3.3.3. Amylose content
Amylose content of varieties ranged from 2,0 to 26,8%
(summer-autumn crop), Khang Dan had the highest amylose percentag, IRRI 352 variety had the lowest amylose content. In winter-spring crop, amylose content of varieties ranged from 2,1- 27,0%. IRRI 352 is sticky rice with the lowest amylose content.
3.3.4. Lipid content
In summer-autumn crop, samples had lipid content from 1,9- 2,1% and from 1,9-2,2% (winter-spring) (Table 3.7). Lipid content in varieties had no change between two crops.
3.3.5. Alkali spreading value and gel consistency
IRRI 352 variety had score 4 for spreading (swollen with collar complete and wide). BG 367-2, Sai Duong Kien An and Loc Nuoc had score 3 (Swollen with collar incomplete or narrow).
Table 3.4. Gel consistency of rice samples
In summer-autumn crop, among the rice varieties, the length of the blue gel was highest in IRRI 352 (93,6 mm) and lowest in Khang Dan (28,7 mm). In winter- spring crop ranged from 25,3- 91,9 mm.
3.3.6. Grain shape and chalkiness
Chalkiness in endosperm was classified into white belly, white centre and white back based on the position and orientation of
chalkiness. The Khang Dan, BG 367-2, Sai Duong Kien An and Loc Nuoc varieties having low amount of chalkiness is consider as good quality grains in comparison with chalky once which decrease the rice grain quality (scale 1: less than 10%); Loc Nuoc had medium amount of chalkiness (scale 5: 11-20%). Among the rice varieties studied, the IRRI 352 recorded the lowest L/B ratio and belongs to short bold. The grain size and shape of other rice varieties is varieties as medium slender grains.
Table 3.7. Grain quality of rice varieties
Varieties Protein (%) Tinh bột (%) Amylose (%) Lipid (%) Gel consistency (cm)
HT ĐX HT ĐX HT ĐX HT ĐX HT ĐX
KD 7,9A±0,0 7,8A±0,1 67,4±1,0 68,7A±0,8 26,8A±0,7 27,0A±0,1 2,0±0,2 2,2A±0,0 28,7A±0,7 25,3A±0,3 L1 9,6B±0,2 9,8B±0,5 66,3±4,4 66,3A±1,8 2,0B±0,1 2,1B±0,0 2,1±0,2 2,1AB±0,1 93,6B±1,3 91,9B±1,3 L3 10,6C±0,0 10,6C±0,0 65,7±1,2 65,5A±3,7 23,6C±1,6 23,7C±0,3 2,0±0,2 1,9B±0,1 43,8C±1,0 42,8C±0,5 L25 9,6B±0,0 9,7B±0,2 65,9±4,9 66,5A±1,3 22,7C±1,9 22,8D±0,2 2,0±0,3 2,1AB±0,0 50,2D±0,6 49,7D±0,5 L27 10,1D±0,1 10,0BC±0,2 73,0±2,0 74,6B±0,4 23,4C±0,3 23,7C±0,0 1,9a±0,2 2,2Ab±0,0 42,8C±0,8 42,1C±0,3
Table 3.8. Interactions between variety and season effects on the significant changes of grain quality
Parameter F and (P value)
Df Variety Season Variety*Season
Protein (%) 4 150,41 (<0,001) 0,13 (0,72) 0,63 (0,65) Starch (%) 4 9,69 (<0,001) 0,51 (0,48) 0,13 (0,97) Amylose (%) 4 921,05 (<0,001) 0,25 (0,63) 0,23 (0,99) Lipid (%) 4 0,65 (0,63) 4,32 (0,05) 1,19 (0,35) Gel consistency 4 5644,67 (<0,001) 24,53 (<0,001) 3,07 (0,04)
3.4. Evaluation for resistant capacity of rice varieties 3.4.1. Evaluation for resistant capacity in greenhouse and field
* Greenhouse test
+Test tube: Reaction of 5 rice varieties to population of brown planthopper in Hue were done by scoring damage of their two-leaf age seedlings after 5 and 7 day releasing 3 the second instars. After 5 days, rice varieties resisted well to BPH population in Thua Thien Hue (scale: 1,8-2,5), Khang Dan resisted moderately to BPH (scale: 4,5).
However, after 7 days Khang Dan (sclae 5,8) was susceptible to BPH, IRRI 352, BG 367-2, Sai Duong Kien An and Loc Nuoc resisted moderately to BPH (scale: 3,7-4,3) .
+ Seedbox test: After 5 days, rice varieties resisted well to BPH (1,8-2,3), Khang Dan was quite susceptible to BPH (scale 5,2). After 7 days BG 367-2, Sai Duong Kien An and Loc Nuoc resisted moderately
to BPH (scale: 3,8-4,3), Khang Dan (sclae 6,2) was susceptible to BPH, IRRI 352 (scale: 4,7) was quite susceptible to BPH.
The results show that Sai Duong Kien An and Loc Nuoc resisted to BPH, Khang Dan was susceptible to BPH (Table 3.9).
Table 3.9. Scoring damage of rice varieties
Varieties SLN 5 SLN 7
Test tube Seedbox Test tube Seedbox
KD 4,5A 5,2A 5,8A 6,2A
L1 2,5B 2,2B 4,2B 4,7B
L3 2,2B 1,8B 4,3BC 4,3BC
L25 2,0B 2,3B 3,7CD 3,8CD
L27 1,8C 1,8C 3,8D 3,8D
KD 5,5D 7,3D 8,3E 9,0E
* Field test
Table 3.10. BPH quantity on rice varieties
Varieties
45 NSG 52 NSG 59 NSG 66 NSG 73 NSG 80 NSG
HT ĐX HT ĐX HT ĐX HT ĐX HT ĐX HT ĐX
KD 1,7A±0,1 0,0 22,4A±0,4 0,0 27,5Aa±0,5 3,6Ab±0,2 30,4Aa±1,4 35,6Ab±1,6 150,2Aa±2,2 65,4Ab±2,4 545,4Aa±15,4 52,8Ab±1,8 L1 2,7B±0,4 0,0 25,1B±0,9 0,0 46,1Ba±0,3 1,5Bb±0,0 56,3Ba±1,3 14,4Bb±0,4 278,6Ba±8,6 46,1Bb±1,1 524,7Aa±9,6 25,1Bb±1,9 L3 1,5A±0,0 0,0 16,5C±1,2 0,0 25,5Ca±0,5 1,0Cb±0,1 26,2Ca±2,0 12,5BCb±0,5 120,2Ca±5,2 50,2Bb±0,2 295,6Ba±5,6 27,6BCb±0,6 L25 1,9A±0,2 0,0 18,6D±0,6 0,0 36,3Da±0,3 2,6Db±0,1 39,4Da±0,4 9,7Db±0,7 112,4Ca±4,4 25,5Cb±2,5 186,3Ca±3,3 16,5Db±2,5 L27 2,1A±0,2 0,0 18,2CD±0,2 0,0 27,4Aa±0,4 1,7Bb±0,2 31,3Aa±1,3 10,3CDb±0,3 109,1Ca±9,1 27,5Cb±1,5 163,0Ca±3,0 22,4Cb±1,4
Table 3.10. BPH quantity on rice varieties (cont)
Varieties
87 NSG 94 NSG 101 NSG 108 NSG 115 NSG 122 NSG 129 NSG
HT ĐX HT ĐX HT ĐX HT ĐX HT ĐX HT ĐX HT ĐX
KD 170,3Aa±10,3 42,5Ab±2,5 48,2A±1,2 50,4A±1,4 10,5Aa±0,5 300,4Ab±16,4 0,0 498,8A±28,8 0,0 204,4A±14,4 0,0 32,4A±2,4 0,0 13,6A±0,6 L1 193,6Ba±6,6 34,1Bb±1,1 57,4Ba±1,4 76,1Bb±1,1 7,5Ba±1,0 218,2Bb±18,2 0,0 345,6B±9,6 0,0 293,6B±11,4 0,0 20,2B±1,2 0,0 9,6B±0,6 L3 70,2Ca±0,2 30,1Bb±0,1 43,9A±6,1 47,3A±0,3 1,2Ca±0,1 216,2Bb±17,9 0,0 184,2C±4,2 0,0 121,3C±1,7 0,0 10,5C±0,5 0,0 3,5C±0,3 L25 73,9Ca±1,9 25,4Cb±2,4 58,2Ba±1,8 26,0Cb±2,0 4,5Da±0,5 120,2Cb±4,8 0,0 124,7D±3,7 0,0 72,8D±2,8 0,0 8,5C±1,5 0,0 3,6C±0,2 L27 94,0Da±1,0 12,0Db±1,0 46,2Aa±1,2 30,4Db±1,4 5,4Da±0,4 150,2Cb±2,2 0,0 245,4E±5,4 0,0 110,3E±3,3 0,0 12,5D±0,5 0,0 6,7D±0,7
BPH infest at tillering stage.
At heading stage, a large of BPH number: 109,1 BPHs/m2 (Loc Nuoc) - 278,6 BPHs/m2 (giống IRRI 352). To Fullheading time, BPH quatity was maximum, among them Khang Dan (545,4 BPHs/m2) (Fig 3.5).
Figure 3.5. Change of BPH quatity on rice varieties
(summer-autum crop)
BPH infest at 60 days after seedling. From April to May, BPH number increased rapidly and reached maximum at Fullheading stage: Khang Dan (498,8 BPHs/m2) (Fig 3.6).
This study revealed that there is relatively between greenhouse test and field test.
Sai Duong Kien An and Loc Nuoc resisted to BPH, Khang Dan was susceptible to BPH.
Figure 3.6. Change of BPH quatity on rice varieties
(winter-spring crop)
Table 3.11. Interactions between variety and season effects on the significant changes of BPH resistance
Parameter F and (P value)
Df Variety Season Variety*Season
SLN 5 (test tube) 4 207,47
(<0,001) 0,14 (0,71) 1,39 (0,25) SLN 7 ( test tube ) 4 67,90
(<0,001) 0,83 (0,37) 0,20 (0,94) BPHs/m2(45 NSG) 4 10,21
(<0,001) 1007,1
(<0,001) 10,21 (<0,001) BPHs/m2(52 NSG) 4 65,24
(<0,001) 10834,8
(<0,001) 65,24 (<0,001) BPHs/m2 (59
NSG) 4 1111,0
(<0,001) 69437,3
(<0,001) 1157,7 (<0,001) BPHs/m2(66 NSG) 4 238,98
(<0,001) 2328,95
(<0,001) 356,63 (<0,001) BPHs/m2(73 NSG) 4 409,56
(<0,001) 4130,77
(<0,001) 310,61 (<0,001) BPHs/m2(80 NSG) 4 1402,6
(<0,001) 18631,6
(<0,001) 1126,9 (<0,001) BPHs/m2(87 NSG) 4 376,01
(<0,001) 3722,37
(<0,001) 233,57 (<0,001) BPHs/m2(94 NSG) 4 136,04
(<0,001) 31,47
(<0,001) 107,84 (<0,001) BPHs/m2(101
NSG) 4 81,31
(<0,001) 299,88
(<0,001) 72,68 (<0,001) BPHs/m2(108
NSG) 4 330,86
(<0,001) 5973,36
(<0,001) 330,86 (<0,001) BPHs/m2(115
NSG) 4 329,66
(<0,001) 5409,93
(<0,001) 329,66 (<0,001) BPHs/m2(122
NSG) 4 147,18
(<0,001) 2177,61
(<0,001) 147,18 (<0,001) BPHs/m2(129
NSG) 4 200,22
(<0,001) 2997,63
(<0,001) 200,22 (<0,001)
*Analyze the correlation of BPH infestation time and yields Optimal Fomula (Table 3.6)
Production = 58,07 – 3,69 * 45d + 0,18 * 66d – 0,06 * 73d + 0,01 * 80d + 0,05 * 87d – 0,04 * 108d + 1,05 * 129d
The results show that BPH infestation time : 45NSG, 66NSG, 73NSG, 80NSG, 87NSG, 108NSG and 129NSG impressed to 62%
production with P = 0,0015.
Table 3.11. The correlation of BPH infestation time and yields
Ordinal Fomula AIC
1 Production ~ 45NSG + 52NSG + 59NSG + 66NSG + 73NSG + 80NSG + 87NSG + 94NSG + 101NSG + 108NSG + 115NSG + 122NSG + 129NSG
56,35 2 Production ~ 45NSG + 59NSG + 66NSG + 73NSG +
80NSG + 87NSG + 94NSG + 101NSG + 108NSG + 115NSG + 122NSG + 129NSG
54,39 3 Production ~ 45NSG + 59NSG + 66NSG + 73NSG + 80NSG
+ 87NSG + 94NSG + 101NSG + 108NSG + 122NSG + 129NSG 52,84 4 Năng suất ~ 45NSG + 59NSG + 66NSG + 73NSG +
80NSG + 87NSG + 94NSG + 101NSG + 108NSG + 129NSG
51,57 5 Production ~ 45NSG + 59NSG + 66NSG + 73NSG +
80NSG + 87NSG + 101NSG + 108NSG + 129NSG 51,45 6 Production ~ 45NSG + 59NSG + 66NSG + 73NSG +
80NSG + 87NSG + 108NSG + 129NSG 51,68 7 Production ~ 45NSG + 66NSG + 73NSG + 80NSG +
87NSG + 108NSG + 129NSG 49,26
(Intercept) 45d 66d 73d 80d 87d 108d 129d
58,07 -3,69 0,18 -0,06 0,01 0,05 -0,04 1,05
R2 = 0,62 p-value = 0,0015 Optimal Fomula:
Production = 58,07 – 3,69 * 45d + 0,18 * 66d – 0,06 * 73d + 0,01 * 80d + 0,05 * 87d – 0,04 * 108d + 1,05 * 129d
3.4.2. Molecular biological characteristics related to the BPH resistance
* Identify of bph1 gene
The analysis of electrophoresis revealed that there were PCR products amplifying by BpE18-3 primer as expected. Amplification of DNA from examined cultivars with the primer BpE18-3F/R gave a band approximate to 523-bp in samples. As a result, we came to the following conclusion IRRI352, BG 367-2, Sai Duong Kien An and Loc nuoc cultivars contain the Bph1 gene in the genome.
Figure 3.7.Amplification of BpE18-3 STS marker
SM: Standard marker (1kb DNA Ladder)
+ Analysis of sequences of BpE18-3- linked with Bph1 gene
Figure 3.8. Nucleotide sequence of BpE18-3 and BpE18-3-L1.
Note: BpE18-3 nucleotide sequences in genebank; BpE18-3- L1 nucleotide sequences of samples
* Identify of bph3 gene
Amplification of DNA from examined cultivars with the primer RM589F/R gave a band approximate to 187-bp in samples. As a result, we came to the following conclusion BG 367-2, Sai Duong Kien An and Loc nuoc cultivars contain the bph3 gene in the genome.
Figure 3.9. Amplification of RM589 marker
+ Analysis of sequences of RM589- linked with bph3 gene
Figure 3.10. Nucleotide sequence of RM589 and RM589-L3.
Note: RM589 nucleotide sequences in
genebank; RM589-L3 nucleotide sequences of samples
* Identify of bph4 gene
Amplification of DNA from examined cultivars with the primer RM586F/R gave a band approximate to 276-bp in samples. As a result, we came to the following conclusion BG 367-2, Sai Duong Kien An and Loc nuoc cultivars contain the bph4 gene in the genome.
Figure 3.11. Amplification of RM586 marker
+ Analysis of sequences of RM586- linked with bph4 gene
Figure 3.12. Nucleotide sequence of RM586 and RM586-L25.
Note: RM586 nucleotide sequences in genebank; RM586-L25 nucleotide sequences of samples
* Identify of bph10 gene
Amplification of DNA from examined cultivars with the primer RFLP RG457 F/R gave a band approximate to 750-bp in samples (Fig 3.13). Restriction site for HinfI is present in PCR
product for BG 367-2 with the size of 300, 250 and 200 bp. For IRRI 352, BG 367-2, Sai Duong Kien An with the size of 500, 200bp. As a result, we came to the following conclusion BG 367-2 contain the bph10 gene in the genome.
Figure 3.13. Amplification of RG457FL/RL
Figure 3.14. After digestion with HinfI
* Identify of bph14 gene
+ Amplification of cds region of bph14 gene
The analysis of electrophoresis revealed that there were PCR products amplifying by primers M1, M2, M3 and M4 as expected (Figures 3.15 A,B,C,D). Amplification of DNA from examined cultivars with the primer M1F/R gave rise approximate to 1500-bp product for IRRI 352, BG 367-2, and Sai Duong Kien An. Primer M2F/R gave rise approximate to 1500-bp product for Sai Duong Kien An and Loc nuoc. Primer M3F/R gave rise approximate to 1000-bp product for four rice cultivars. Primer M4F/R gave rise approximate to 1000-bp product for BG 367-2, Sai Duong Kien An and Loc nuoc. In rice cultivars, Sai Duong Kien An and Loc nuoc has four fragments. As a result, we came to the following conclusion Sai Duong Kien An and Loc nuoc cultivars contain the bph14 gene on the genome.