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July 2009
Articles
July 2009 [ 3(4) 2009]
Table of Contents
Evaluation of GABA, crude protein and amino acid composition from different varieties of Malaysian’s brown rice
Shahin Roohinejad, Hamed Mirhosseini, Nazamid Saari, Shuhaimi Mustafa, Ismail Alias, Anis Shobirin Meor Hussin, Azizah Hamid and Mohd Yazid Manap
Abstract
The main objective of present study was to investigate the Ý-aminobutyric acid (GABA), crude protein and total glutamic acid composition of Malaysian’s brown rice varieties. Significant (p < 0.05) difference was observed among the content of GABA, crude protein and total glutamic acid of thirty five Malaysian’s brown rice varieties. As shown in results, GABA contents in Malaysian brown rice seeds ranged between 0.01 and 0.1 (mg/g). The quantity of glutamic acid and protein contents varied between 10.1-15.2 (mg/g) and 6.99-10.17 %, respectively. A significant (p < 0.05) positive correlation (r² = 0.820) exists between the concentration levels of protein and glutamic acid. On the other hand, a significant (p < 0.05) positive correlation (r² = 0.507) was also observed between the glutamic acid and GABA contents.
Key words: Brown rice; Aminobutyric acid; Glutamic acid; Protein
(Pages 184-190) PDF Text
Micropropagation of thornless trailing blackberry (Rubus sp.) by axillary bud explants
A Jafari Najaf-Abadi and Y Hamidoghli
Abstract
The purpose of this study was to establish best condition for in vitro propagation of thornless trailing blackberry (Rubus sp.). Axillary buds were used as explants. After sterilization, explants were placed into MS medium supplemented with 2 mg.l-1 BA. Two weeks after that, in shoot proliferation stage, 12 culture media containing MS supplemented with 3 concentrations of BA (0, 2 and 3 mg.l-1), alone or in combination with GA3 (0, 0.2, 0.5 and 1 mg.l-1) were compared. The greatest number of shoots with average of 3.33 and the maximum shoot length with average of 5.87 cm were produced in medium containing 2 mg.l-1 BA and 0.5 mg.l-1 GA3 . In the rooting experiment, rooting medium comprised MS medium in combination with different concentrations of IBA (0, 0.5, 1 and 2 mg.l-1). A concentration of 2 mg.l-1 IBA gave a greater number of roots and maximum root length. In this medium four roots with root length average of 7.83 cm were produced.
Key words: axillary bud; blackberry; in vitro; micropropagation
(Pages 191-194) PDF Text
Identification of a microsatellite marker associated with stem rust resistance gene Sr35 in wheat
Ebrahiem Babiker, Amir M.H. Ibrahim, Yang Yen and Jeff Stein
Abstract
A segregating population from the cross ‘2137’/CRL-Sr35 was made to identify molecular markers linked to the stem rust resistance gene Sr35 that provides resistance against many devastating races, including QTH and TTKS (or Ug99), in wheat. Ninety-eight F2 plants were inoculated with a stem rust isolate of race QTH. Infection type and severity were evaluated 10 days after inoculation. Twenty-one microsatellite primer pairs were tested for polymorphism among parental lines and F2 population. Resistance was conferred by a dominant gene (X2=1.01, P=0.48). Out of four primer pairs (Xgwm155, Xgwm391, Xgwm497 and Xfca2076) only two markers (i.e. Xgwm391 and Xcfa2076) retained significance at a = 0.05. GWM391 revealed a polymorphic fragment of 200 bp found only in the susceptible bulk and 2137. In contrast, Xcfa2076 amplified polymorphic fragments of 210 bp in the resistant bulk and CRL-Sr35. Using linkage analysis Xgwm391 was found to be relatively close to Sr35 with a genetic distance of 12.2 cM. Although they have not retained significance at a = 0.05, the markers Xgwm155 and Xgwm497 have genetic distances of 4.6 and 12.1 cM from the Sr35 gene. While searching for closer marker continues, wheat breeders should be obviously benefited by using these markers in their selection of Sr35 in their battle against the brutal stem rust race Ug99. Further mapping attempts in this chromosomal region with more markers and larger F2 and/or F2:3 sample sizes are warranted to identify closer and more efficient markers for Sr35.
Keywords: Triticum aestivum; Sr35; stem rust resistance; SSR markers.
(Pages 195-200) PDF Text
Differential cDNA-AFLP screening of transcripts associated with brown planthopper resistance in rice (Oryza sativa L.)
N. S. Gamalath, P.N. Sharma, N. Mori and C. Nakamura
Abstract
We have previously constructed a pyramid line, in which two major BPH resistance genes, Bph1 and Bph2 on the long arm of rice chromosome 12, were introgressed into a susceptible japonica cultivar, Tsukushibare. To identify transcripts that are derived from the introgressed chromosomal segments carrying the resistance genes, we analyzed mRNA profiles using amplified fragment length polymorphism-based mRNA fingerprinting (cDNA-AFLP). After this differential screening using 423 primer combinations, 41 polymorphic fragments were selected that were specific either to the pyramid line or Tsukushibare. Among them, 10 fragments expressed only in the pyramid line were cloned and sequenced. According to the genome database, at least two were from the proximity of the introgressed Bph1 locus. Our results suggest that cDNA-AFLP screening of differentially expressed fragments is a useful means to identify BPH resistance and/or infestation associated genes.
Keywords: Nilaparvata lugens Stål; RFLP; transcripts ; cDNA; resistance
(Pages 201-206) PDF Text
Evaluation of wheat breads supplemented with Teff (Eragrostis tef (ZUCC.) Trotter) grain flour
Mariam I.O. Mohammed, Abdelmoneim I. Mustafa and Gammaa A.M. Osman
Abstract
The aim of this study was to evaluate the effect of Supplementations of teff (Eragrostis teff (ZUCC.) Trotter) grain flour to wheat flour at 0, 5, 10, 15 and 20% levels on organoleptic and nutritional evaluation of the supplemented bread. Protein, moisture, ash and falling number as well as rheological evaluation were estimated for prepared flour blends and dough. Besides, organoleptic assessment tests for their breads were carried out. Substitution of wheat flour by teff flour caused significant increases in ash and substantial reduction in protein content. Falling Number increased significantly as the percentage of teff flour was increased. However, the results indicated that addition of teff flour caused non-significant increase in water absorption and also, with exception of 15% and 20% substitution of teff flour, no significant change was observed in development time. Data on the gluten quality of flour blends indicated that the gluten contents decreased significantly as the percentage of teff flour substitution increased. Nevertheless, additions of 5% teff flour to wheat flour substitution; gives parameter values at least as good as the control sample and produce acceptable bread, in terms of weight, volume, specific weight, taste and texture. However, high level of teff flour resulted in higher negative changes in organoleptic characteristics. It may be concluded that breads supplemented with teff flour, up to a 5% level, are organoleptically and nutritionally acceptable.
Key words: Teff flour; wheat flour; bread; gluten; loaf.
(Pages 207-212) PDF Text
Yield stability analysis of Ipomoea batatus L. cultivars in diverse environments
Osiru M.O, O.M. Olanya, E. Adipala, R. Kapinga and B. Lemaga
Abstract
Sweet potato is an important food crop in tropical and sub-tropical regions of the world. There is limited published research on yield stability of sweet potato in tropical environments. To identify cultivars with improved agronomic and stable yield characteristics, five elite genotypes obtained from the sweet potato breeding program in Uganda and International Potato Center (CIP) and five land race genotypes were evaluated for yield stability at 12 environments. The Additive Main Effects and Multiplicative Interaction (AMMI) model was used for stability analysis. The analysis of variance of yield data (t ha-1) for genotypes x locations, genotypes x seasons and locations x seasons was highly significant (P < 0.01) showing the variable response of the genotypes across environments and seasons. The average root yield of sweet potato genotypes was significantly (P < 0.01) greater at Kachwekano (KARDC) than at Namulonge (NAARI) and Serere (SAARI) locations. Based on AMMI statistical model, Araka Red and Tanzania were the most stable genotypes; while NASPOT 6 and NASPOT 2 had the lowest stability. The model predicted the highest yield from Dimbuca cultivar in 4 of 12 environments and New Kawogo as the cultivar with the lowest yield in 6 of 12 environments. Within each environment and cropping season, the ranking of the genotypes for yield stability was not consistent. Selective deployment of cultivars across environments can improve Sweet potato tuber yield in the lowland and highland tropics.
Key words: Sweet potato; AMMI model; Yield; Cultivars; Genotype × Environment
(Pages 213-220) PDF Text
Salt tolerance in two rice cultivars differing salt tolerant abilities in responses to iso-osmotic stress
Suriyan Cha-um, Thippawan Trakulyingcharoen, Prasartporn Smitamana,
Chalermpol Kirdmanee
Abstract
The aim of this investigation was to study on the salt tolerant ability of Thai jasmine (KDML105) salt sensitive and Homjan (HJ) salt tolerant cultivars grown under iso-osmotic stresses. Growth, ion contents, relative electrolyte leakage (REL), photosynthetic pigments and net photosynthetic rate (Pn) in iso-osmotic stressed seedlings were collected. Growth characters including shoot height, fresh weight, dry weight and leaf area of salt-stressed rice seedlings were inhibited, depending on NaCl concentrations and rice genotypes. Sodium ion (Na+) in salt-stressed tissues was rapidly accumulated, especially in KDML105, while potassium ion (K+) was quickly decreased. Na:K ratio and proline content in salt-stressed leaves were increased, relating to salt concentrations. The Na+ accumulation in the salt stressed seedlings was positively related to osmolarity, causing to membrane injury or high REL with pigment degradation. The degradation of total chlorophyll (TC) and total carotenoids (Cx+c) in salt-stressed seedlings grown under osmotic stresses were positively correlated with Pn, leading to growth retardation. The salt tolerant mechanisms in HJ salt tolerance should be further investigated as well as utilized as parental line for salt-tolerant breeding program.
Keywords: aromatic rice; net photosynthetic rate; Oryza sativa L. spp. indica; pigments; relative electrolyte leakage; salt stress.
(Pages 221-230) PDF Text
Power requirement for particle size reduction of wheat straw as a function of straw threshing unit parameters
H. Tavakoli, S.S. Mohtasebi, A. Jafari, D. Mahdavinejad
Abstract
Wheat straw at moisture content of 8.5 % w.b. was threshed using a straw thresher machine. Power requirement for size reduction of the straw was measured at different conditions. The thresher parameters were: drum speed at three levels: 400, 540, and 800 rpm, two screen sizes (2.5 and 4 cm), and two states for number of blades on each flange (4 and 8 blades). Based on the results obtained, the power requirement increased with increasing drum speed and with decreasing screen size and number of blades on each flange. The power requirement increased from 1.506 to 5.144 kW and 1.134 to 4.093 kW, for screen sizes of 2.5 and 4 cm, respectively, with an increase in the drum speed from 400 to 800 rpm. The maximum power requirement (5.377 kW) occurred at 2.5 cm screen size and drum speed of 800 rpm with 4 blades on each flange, while the minimum power requirement (0.985 kW) occurred at 4 cm screen size and drum speed of 400 rpm with 8 blades on each flange.
Keywords: Size reduction; straw thresher; power requirement; drum speed; screen size
(Pages 231-236) PDF Text
Table of Contents
Evaluation of GABA, crude protein and amino acid composition from different varieties of Malaysian’s brown rice
Shahin Roohinejad, Hamed Mirhosseini, Nazamid Saari, Shuhaimi Mustafa, Ismail Alias, Anis Shobirin Meor Hussin, Azizah Hamid and Mohd Yazid Manap
Abstract
The main objective of present study was to investigate the Ý-aminobutyric acid (GABA), crude protein and total glutamic acid composition of Malaysian’s brown rice varieties. Significant (p < 0.05) difference was observed among the content of GABA, crude protein and total glutamic acid of thirty five Malaysian’s brown rice varieties. As shown in results, GABA contents in Malaysian brown rice seeds ranged between 0.01 and 0.1 (mg/g). The quantity of glutamic acid and protein contents varied between 10.1-15.2 (mg/g) and 6.99-10.17 %, respectively. A significant (p < 0.05) positive correlation (r² = 0.820) exists between the concentration levels of protein and glutamic acid. On the other hand, a significant (p < 0.05) positive correlation (r² = 0.507) was also observed between the glutamic acid and GABA contents.
Key words: Brown rice; Aminobutyric acid; Glutamic acid; Protein
(Pages 184-190) PDF Text
Micropropagation of thornless trailing blackberry (Rubus sp.) by axillary bud explants
A Jafari Najaf-Abadi and Y Hamidoghli
Abstract
The purpose of this study was to establish best condition for in vitro propagation of thornless trailing blackberry (Rubus sp.). Axillary buds were used as explants. After sterilization, explants were placed into MS medium supplemented with 2 mg.l-1 BA. Two weeks after that, in shoot proliferation stage, 12 culture media containing MS supplemented with 3 concentrations of BA (0, 2 and 3 mg.l-1), alone or in combination with GA3 (0, 0.2, 0.5 and 1 mg.l-1) were compared. The greatest number of shoots with average of 3.33 and the maximum shoot length with average of 5.87 cm were produced in medium containing 2 mg.l-1 BA and 0.5 mg.l-1 GA3 . In the rooting experiment, rooting medium comprised MS medium in combination with different concentrations of IBA (0, 0.5, 1 and 2 mg.l-1). A concentration of 2 mg.l-1 IBA gave a greater number of roots and maximum root length. In this medium four roots with root length average of 7.83 cm were produced.
Key words: axillary bud; blackberry; in vitro; micropropagation
(Pages 191-194) PDF Text
Identification of a microsatellite marker associated with stem rust resistance gene Sr35 in wheat
Ebrahiem Babiker, Amir M.H. Ibrahim, Yang Yen and Jeff Stein
Abstract
A segregating population from the cross ‘2137’/CRL-Sr35 was made to identify molecular markers linked to the stem rust resistance gene Sr35 that provides resistance against many devastating races, including QTH and TTKS (or Ug99), in wheat. Ninety-eight F2 plants were inoculated with a stem rust isolate of race QTH. Infection type and severity were evaluated 10 days after inoculation. Twenty-one microsatellite primer pairs were tested for polymorphism among parental lines and F2 population. Resistance was conferred by a dominant gene (X2=1.01, P=0.48). Out of four primer pairs (Xgwm155, Xgwm391, Xgwm497 and Xfca2076) only two markers (i.e. Xgwm391 and Xcfa2076) retained significance at a = 0.05. GWM391 revealed a polymorphic fragment of 200 bp found only in the susceptible bulk and 2137. In contrast, Xcfa2076 amplified polymorphic fragments of 210 bp in the resistant bulk and CRL-Sr35. Using linkage analysis Xgwm391 was found to be relatively close to Sr35 with a genetic distance of 12.2 cM. Although they have not retained significance at a = 0.05, the markers Xgwm155 and Xgwm497 have genetic distances of 4.6 and 12.1 cM from the Sr35 gene. While searching for closer marker continues, wheat breeders should be obviously benefited by using these markers in their selection of Sr35 in their battle against the brutal stem rust race Ug99. Further mapping attempts in this chromosomal region with more markers and larger F2 and/or F2:3 sample sizes are warranted to identify closer and more efficient markers for Sr35.
Keywords: Triticum aestivum; Sr35; stem rust resistance; SSR markers.
(Pages 195-200) PDF Text
Differential cDNA-AFLP screening of transcripts associated with brown planthopper resistance in rice (Oryza sativa L.)
N. S. Gamalath, P.N. Sharma, N. Mori and C. Nakamura
Abstract
We have previously constructed a pyramid line, in which two major BPH resistance genes, Bph1 and Bph2 on the long arm of rice chromosome 12, were introgressed into a susceptible japonica cultivar, Tsukushibare. To identify transcripts that are derived from the introgressed chromosomal segments carrying the resistance genes, we analyzed mRNA profiles using amplified fragment length polymorphism-based mRNA fingerprinting (cDNA-AFLP). After this differential screening using 423 primer combinations, 41 polymorphic fragments were selected that were specific either to the pyramid line or Tsukushibare. Among them, 10 fragments expressed only in the pyramid line were cloned and sequenced. According to the genome database, at least two were from the proximity of the introgressed Bph1 locus. Our results suggest that cDNA-AFLP screening of differentially expressed fragments is a useful means to identify BPH resistance and/or infestation associated genes.
Keywords: Nilaparvata lugens Stål; RFLP; transcripts ; cDNA; resistance
(Pages 201-206) PDF Text
Evaluation of wheat breads supplemented with Teff (Eragrostis tef (ZUCC.) Trotter) grain flour
Mariam I.O. Mohammed, Abdelmoneim I. Mustafa and Gammaa A.M. Osman
Abstract
The aim of this study was to evaluate the effect of Supplementations of teff (Eragrostis teff (ZUCC.) Trotter) grain flour to wheat flour at 0, 5, 10, 15 and 20% levels on organoleptic and nutritional evaluation of the supplemented bread. Protein, moisture, ash and falling number as well as rheological evaluation were estimated for prepared flour blends and dough. Besides, organoleptic assessment tests for their breads were carried out. Substitution of wheat flour by teff flour caused significant increases in ash and substantial reduction in protein content. Falling Number increased significantly as the percentage of teff flour was increased. However, the results indicated that addition of teff flour caused non-significant increase in water absorption and also, with exception of 15% and 20% substitution of teff flour, no significant change was observed in development time. Data on the gluten quality of flour blends indicated that the gluten contents decreased significantly as the percentage of teff flour substitution increased. Nevertheless, additions of 5% teff flour to wheat flour substitution; gives parameter values at least as good as the control sample and produce acceptable bread, in terms of weight, volume, specific weight, taste and texture. However, high level of teff flour resulted in higher negative changes in organoleptic characteristics. It may be concluded that breads supplemented with teff flour, up to a 5% level, are organoleptically and nutritionally acceptable.
Key words: Teff flour; wheat flour; bread; gluten; loaf.
(Pages 207-212) PDF Text
Yield stability analysis of Ipomoea batatus L. cultivars in diverse environments
Osiru M.O, O.M. Olanya, E. Adipala, R. Kapinga and B. Lemaga
Abstract
Sweet potato is an important food crop in tropical and sub-tropical regions of the world. There is limited published research on yield stability of sweet potato in tropical environments. To identify cultivars with improved agronomic and stable yield characteristics, five elite genotypes obtained from the sweet potato breeding program in Uganda and International Potato Center (CIP) and five land race genotypes were evaluated for yield stability at 12 environments. The Additive Main Effects and Multiplicative Interaction (AMMI) model was used for stability analysis. The analysis of variance of yield data (t ha-1) for genotypes x locations, genotypes x seasons and locations x seasons was highly significant (P < 0.01) showing the variable response of the genotypes across environments and seasons. The average root yield of sweet potato genotypes was significantly (P < 0.01) greater at Kachwekano (KARDC) than at Namulonge (NAARI) and Serere (SAARI) locations. Based on AMMI statistical model, Araka Red and Tanzania were the most stable genotypes; while NASPOT 6 and NASPOT 2 had the lowest stability. The model predicted the highest yield from Dimbuca cultivar in 4 of 12 environments and New Kawogo as the cultivar with the lowest yield in 6 of 12 environments. Within each environment and cropping season, the ranking of the genotypes for yield stability was not consistent. Selective deployment of cultivars across environments can improve Sweet potato tuber yield in the lowland and highland tropics.
Key words: Sweet potato; AMMI model; Yield; Cultivars; Genotype × Environment
(Pages 213-220) PDF Text
Salt tolerance in two rice cultivars differing salt tolerant abilities in responses to iso-osmotic stress
Suriyan Cha-um, Thippawan Trakulyingcharoen, Prasartporn Smitamana,
Chalermpol Kirdmanee
Abstract
The aim of this investigation was to study on the salt tolerant ability of Thai jasmine (KDML105) salt sensitive and Homjan (HJ) salt tolerant cultivars grown under iso-osmotic stresses. Growth, ion contents, relative electrolyte leakage (REL), photosynthetic pigments and net photosynthetic rate (Pn) in iso-osmotic stressed seedlings were collected. Growth characters including shoot height, fresh weight, dry weight and leaf area of salt-stressed rice seedlings were inhibited, depending on NaCl concentrations and rice genotypes. Sodium ion (Na+) in salt-stressed tissues was rapidly accumulated, especially in KDML105, while potassium ion (K+) was quickly decreased. Na:K ratio and proline content in salt-stressed leaves were increased, relating to salt concentrations. The Na+ accumulation in the salt stressed seedlings was positively related to osmolarity, causing to membrane injury or high REL with pigment degradation. The degradation of total chlorophyll (TC) and total carotenoids (Cx+c) in salt-stressed seedlings grown under osmotic stresses were positively correlated with Pn, leading to growth retardation. The salt tolerant mechanisms in HJ salt tolerance should be further investigated as well as utilized as parental line for salt-tolerant breeding program.
Keywords: aromatic rice; net photosynthetic rate; Oryza sativa L. spp. indica; pigments; relative electrolyte leakage; salt stress.
(Pages 221-230) PDF Text
Power requirement for particle size reduction of wheat straw as a function of straw threshing unit parameters
H. Tavakoli, S.S. Mohtasebi, A. Jafari, D. Mahdavinejad
Abstract
Wheat straw at moisture content of 8.5 % w.b. was threshed using a straw thresher machine. Power requirement for size reduction of the straw was measured at different conditions. The thresher parameters were: drum speed at three levels: 400, 540, and 800 rpm, two screen sizes (2.5 and 4 cm), and two states for number of blades on each flange (4 and 8 blades). Based on the results obtained, the power requirement increased with increasing drum speed and with decreasing screen size and number of blades on each flange. The power requirement increased from 1.506 to 5.144 kW and 1.134 to 4.093 kW, for screen sizes of 2.5 and 4 cm, respectively, with an increase in the drum speed from 400 to 800 rpm. The maximum power requirement (5.377 kW) occurred at 2.5 cm screen size and drum speed of 800 rpm with 4 blades on each flange, while the minimum power requirement (0.985 kW) occurred at 4 cm screen size and drum speed of 400 rpm with 8 blades on each flange.
Keywords: Size reduction; straw thresher; power requirement; drum speed; screen size
(Pages 231-236) PDF Text
