December 2013 issue | 2(4) 2013
Southern Cross Publishing Group©2013
Australia
Australia
Research Article Open Access
Chitosan effects on physiochemical indicators of drought-induced leaf stress in cowpea
Saad Farouk1, Amany A. Ramadan2, and Allan T. Showler3*
1Agricultural Botany Department, Faculty of Agriculture, Mansoura University, Egypt
2Botany Department, National Research Centre, Dokki, Giza, Egypt
3 USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory, 2700 Fredericksburg Road, Kerrville, TX, 78028-9184 USA*
Abstract
Water deficit stress in crops is associated a damaging oxidative process that is irreversible once it is initiated. This study was conducted to assess the effect of chitosan, a marine polysaccharide with unique bioactive properties that scavenges for reactive oxygen species; hence, chitosan application to plants has been suggested as an aid for reducing oxidative injury caused by water deficit stress. In a greenhouse, potted cowpea plants, Vigna unguiculata (L.) Walp. (var. Cream 7), were subject to 12 treatments comprised of 70% (low water deficit stress, control), 50% (moderate stress), and 30% (high stress) field capacity irrigation regimes that were sprayed at the initiation of flowering with 0, 125, 250, and 500 mg/l chitosan. Chitosan application reduced hydrogen peroxide (H2O2) accumulation by as much as 37%, lipid peroxidation by as much as 57%, and membrane permeability by up to 16% in leaves from plants under high water deficit stress. The application of chitosan also elevated antioxidant enzyme activities, such as superoxide dismutase by up to 85% and catalase by up to 37%, and accumulations of ascorbic acid, calcium, carotenoids, magnesium, and phenolic compounds that were up to 204%, 29%, 193%, 27%, and 83%, respectively, over leaves of nonsprayed mature plants. Under moderate and severe water deficit, chitosan, particularly at a concentration of 250 mg/liter water, decreased physiochemical indicators of drought stress in leaves, and increased indicators of stress reduction. The greater levels of antioxidants and low H2O2 concentration in the chitosan-treated cowpea leaves suggest that chitosan delays effects of water deficit stress. Chitosan might be useful for crop production in situations where water availability is limited, and to make crop plants less attractive to pests that are favored by water deficit stressed plants.
Pages 135-144 | Full Text PDF
Research Article Open Access
Evaluation of post-emergence herbicide to control weeds of newly planted sainfoin (Onobrychis sativa)
Somayeh Amiri, Hassan Karimmojeni*, Mohammad Mahdi Majidi and Amin Boromand
Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
Abstract
Sainfoin (Onobrychis sativa) is an important forage crop thanks to both high yield and proper compatibility to environmental stress such as drought and nutrient deficiency. Weed competition, especially in newly planted seedling of sainfoin, could cause great yield reduction in forage plants quantity and quality. A field experiment was conducted during 2010 to 2011, to determine proper herbicide treatments for weed control in sainfoin. Seven weed-control treatments, along with weed infested (WI) and weed-free (WF) controls in three replications were arranged in a randomized complete block design. Weed control treatments included bentazone (1920g a.i.ha-1), bentazone (1440g a.i.ha-1), bentazone (1440g a.i.ha-1) plus an adjuvant (tween 80), bentazone (1440g a.i.ha-1) plus an adjuvant (ammonium sulphate), imazethapyr (100g a.i.ha-1), imazethapyr (75g a.i.ha-1), imazethayr (75g a.i.ha-1) plus an adjuvant (ammonium sulphate). Results showed that bentazone and imazethapyr in high dosage as well as in low rates plus an adjuvant (tween 80 or ammonium sulphate) have a good efficiency in weed control. Bentazon herbicide is much more efficient compared to imazethapyr in weed control of sainfoin. Application of low dosage bentazon in combination with adjuvants was shown to be more effective in controling noxious weeds like purslane. However, due to sainfoin biomass loss after applying these treatments, imazethapyr (75g a.i.ha-1) is introduced as the best treatment to control weed and improve yield in newly planted sainfoin.
Pages 145-149 | Full Text PDF
Research Article Open Access
In vitro regeneration of sour orange (Citrus aurantium L.) via direct organogenesis
Mohammad Hosein Rezadost, Mohammad Mehdi Sohani*, Abdollah Hatamzadeh, Mohammad Reza Mirzaii
Biotechnology Department, Faculty of Agricultural Sciences, University of Guilan, P. O. Box: 41635-1314, Rasht, Iran
Abstract
Low cell competency for regeneration and transformation is the main cause of so-called recalcitrance to transform a species or a genotype. A research was conducted to determine the optimum conditions for in vitro plant regeneration involving organogenesis in Citrus aurantium, which is an important rootstock worldwide. Seeds with peeled teguments were germinated in vitro, either kept in dark for 6 weeks or maintained in the absolute dark for 4 weeks followed by 10 days in 16-h photoperiod (56 ΅mol m-2 s-1) at 27 ± 2°C. Epicotyl-originated explants were cultured in MS medium supplemented with 6-benzylaminopurine (BAP) (0, 1, 2 and 3 mg L-1) and Naphthaleneacetic acid (NAA) (0, 0.05, 0.1 and 0.2 mg L-1) to induce organogenesis. Effects of Pre-culture in liquid MS medium (0, 1 and 2 days) on the number of responsive explants (RE) have been also evaluated. In the next step, explants having buds were transferred to MS medium containing Gibberellic Acid (GA3) (0, 0.5 and 1 mg L-1) and the size and number of shoots, which have been produced by RE are then measured. The highest percentage of responsive explants (90%) obtained by using 2.5 mg L-1 BAP in combination with the 0.05 mg L-1 NAA which had 2 days pre-culture period of epicotyls for allowing to grow in the absolute darkness for 4 weeks, followed by 10 days in 16-h photoperiod (56 ΅mol m-2 s-1). The highest number of well-developed shoots was 4.2 shoots per explant and obtained with medium containing 0.5 mg L-1 GA3. These protocols are suitable in association with Citrus aurantium Agrobacterium-mediated genetic transformation.
Pages 150-156 | Full Text PDF
Research Article Open Access
Performance study of combined microwave and acid pretreatment method for enhancing enzymatic digestibility of rice straw for bioethanol production
Renu Singh*1, SapnaTiwari1, Monika Srivastava1, Ashish Shukla2
1Centre for Environment Science and Climate Resilient Agriculture, Indian Agricultural Research Institute, New Delhi, 110012, India
2Civil Engineering, Architecture and Building (CAB), Faculty of Engineering and Computing, Coventry University, Priory Street, Coventry CV1 5FB, UK
Abstract
Utilization of fossil fuel resources at large scale led to global warming alerts and threats. Bio-ethanol as an alternative fuel source can provide combat against these threats. Conversion of rice straw to fuel ethanol involves pretreatments followed by enzyme-catalyzed hydrolysis. In the present study, microwave-assisted H2SO4 is employed for pretreatment in order to enhance enzymatic digestibility of rice straw. Prepared samples of rice straw have first gone under microwave treatment followed by chemical treatment using H2SO4. Chemical concentration of 0.1-2.0 % for the treatment time of 1 to 5 minutes have been used utilizing microwave power range of 70-700 W. Under optimum conditions e.g. reaction time, power, concentration of chemical, maximum reducing sugar obtained through microwave assisted H2SO4 is 1376.99 ΅g/ml. The XRD analyses showed that the crystallinity index of microwave assisted H2SO4 rice straw samples is significantly high (61.36 %) as compared to untreated sample (52.2%). The morphological study performed using scanning electron microscope (SEM) certified that the surface of the samples treated with microwave assisted H2SO4 was more ruptured. Also the silicon waxy structure, ether linkages between lignin and carbohydrates were either damaged or broken down. Study on Indian rice straw proved that microwave assisted H2SO4 pretreatment can successfully remove lignin and increase the enzymatic accessibility.
Pages 157-162 | Full Text PDF
Research Article Open Access
Inheritance pattern of degree of indetermination in mungbean [Vigna radiata (L.) wilczek]
Aziz ur Rehman1, Muhammad Saleem2 and Muhammad Amjad Ali3*
1Pulses Research Institute, Ayub Agricultural Research Institute, Faisalabad, Pakistan
2Department of Plant Breeding & Genetics, University of Agriculture, Faisalabad, Pakistan
3Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan
Abstract
A complete diallel mating system involving eight divergent parents was used to work out the inheritance basis of degree of indetermination and its related parameters like plant height at flowering and maturity in mungbean. Eight parents, viz. 562-1, 56-2, NM-95, NM-92, L.No.1, L. No.21, 6601 and E32-1 were selected from 55 genotypes on the basis of variability for days to flowering and grain yield per plant. Briefly explain how study was conducted. Genotypic differences for male and female parents were significant for all the characters. The results (formal ANOVA and components of variation) advocated the importance of both additive (A) and dominance (D) effects for the all the traits in both generations. However, the value H1 > D for plant height at flowering in F2, plant height at maturity in F1 and degree of indetermination in F1 generation revealed the preponderance of dominant genes while D> H1 demonstrated additive nature of height at flowering in F1, plant height at maturity in F2 generation. Low to moderate estimates of narrow sense heritability indicated occurrence of dominance effects for all the characters. This study suggested the utilization of heterosis breeding for the improvement of indetermination in mungbean due to the involvement of dominance effects in its genetic control.
Pages 163-171 | Full Text PDF
Chitosan effects on physiochemical indicators of drought-induced leaf stress in cowpea
Saad Farouk1, Amany A. Ramadan2, and Allan T. Showler3*
1Agricultural Botany Department, Faculty of Agriculture, Mansoura University, Egypt
2Botany Department, National Research Centre, Dokki, Giza, Egypt
3 USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory, 2700 Fredericksburg Road, Kerrville, TX, 78028-9184 USA*
Abstract
Water deficit stress in crops is associated a damaging oxidative process that is irreversible once it is initiated. This study was conducted to assess the effect of chitosan, a marine polysaccharide with unique bioactive properties that scavenges for reactive oxygen species; hence, chitosan application to plants has been suggested as an aid for reducing oxidative injury caused by water deficit stress. In a greenhouse, potted cowpea plants, Vigna unguiculata (L.) Walp. (var. Cream 7), were subject to 12 treatments comprised of 70% (low water deficit stress, control), 50% (moderate stress), and 30% (high stress) field capacity irrigation regimes that were sprayed at the initiation of flowering with 0, 125, 250, and 500 mg/l chitosan. Chitosan application reduced hydrogen peroxide (H2O2) accumulation by as much as 37%, lipid peroxidation by as much as 57%, and membrane permeability by up to 16% in leaves from plants under high water deficit stress. The application of chitosan also elevated antioxidant enzyme activities, such as superoxide dismutase by up to 85% and catalase by up to 37%, and accumulations of ascorbic acid, calcium, carotenoids, magnesium, and phenolic compounds that were up to 204%, 29%, 193%, 27%, and 83%, respectively, over leaves of nonsprayed mature plants. Under moderate and severe water deficit, chitosan, particularly at a concentration of 250 mg/liter water, decreased physiochemical indicators of drought stress in leaves, and increased indicators of stress reduction. The greater levels of antioxidants and low H2O2 concentration in the chitosan-treated cowpea leaves suggest that chitosan delays effects of water deficit stress. Chitosan might be useful for crop production in situations where water availability is limited, and to make crop plants less attractive to pests that are favored by water deficit stressed plants.
Pages 135-144 | Full Text PDF
Research Article Open Access
Evaluation of post-emergence herbicide to control weeds of newly planted sainfoin (Onobrychis sativa)
Somayeh Amiri, Hassan Karimmojeni*, Mohammad Mahdi Majidi and Amin Boromand
Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
Abstract
Sainfoin (Onobrychis sativa) is an important forage crop thanks to both high yield and proper compatibility to environmental stress such as drought and nutrient deficiency. Weed competition, especially in newly planted seedling of sainfoin, could cause great yield reduction in forage plants quantity and quality. A field experiment was conducted during 2010 to 2011, to determine proper herbicide treatments for weed control in sainfoin. Seven weed-control treatments, along with weed infested (WI) and weed-free (WF) controls in three replications were arranged in a randomized complete block design. Weed control treatments included bentazone (1920g a.i.ha-1), bentazone (1440g a.i.ha-1), bentazone (1440g a.i.ha-1) plus an adjuvant (tween 80), bentazone (1440g a.i.ha-1) plus an adjuvant (ammonium sulphate), imazethapyr (100g a.i.ha-1), imazethapyr (75g a.i.ha-1), imazethayr (75g a.i.ha-1) plus an adjuvant (ammonium sulphate). Results showed that bentazone and imazethapyr in high dosage as well as in low rates plus an adjuvant (tween 80 or ammonium sulphate) have a good efficiency in weed control. Bentazon herbicide is much more efficient compared to imazethapyr in weed control of sainfoin. Application of low dosage bentazon in combination with adjuvants was shown to be more effective in controling noxious weeds like purslane. However, due to sainfoin biomass loss after applying these treatments, imazethapyr (75g a.i.ha-1) is introduced as the best treatment to control weed and improve yield in newly planted sainfoin.
Pages 145-149 | Full Text PDF
Research Article Open Access
In vitro regeneration of sour orange (Citrus aurantium L.) via direct organogenesis
Mohammad Hosein Rezadost, Mohammad Mehdi Sohani*, Abdollah Hatamzadeh, Mohammad Reza Mirzaii
Biotechnology Department, Faculty of Agricultural Sciences, University of Guilan, P. O. Box: 41635-1314, Rasht, Iran
Abstract
Low cell competency for regeneration and transformation is the main cause of so-called recalcitrance to transform a species or a genotype. A research was conducted to determine the optimum conditions for in vitro plant regeneration involving organogenesis in Citrus aurantium, which is an important rootstock worldwide. Seeds with peeled teguments were germinated in vitro, either kept in dark for 6 weeks or maintained in the absolute dark for 4 weeks followed by 10 days in 16-h photoperiod (56 ΅mol m-2 s-1) at 27 ± 2°C. Epicotyl-originated explants were cultured in MS medium supplemented with 6-benzylaminopurine (BAP) (0, 1, 2 and 3 mg L-1) and Naphthaleneacetic acid (NAA) (0, 0.05, 0.1 and 0.2 mg L-1) to induce organogenesis. Effects of Pre-culture in liquid MS medium (0, 1 and 2 days) on the number of responsive explants (RE) have been also evaluated. In the next step, explants having buds were transferred to MS medium containing Gibberellic Acid (GA3) (0, 0.5 and 1 mg L-1) and the size and number of shoots, which have been produced by RE are then measured. The highest percentage of responsive explants (90%) obtained by using 2.5 mg L-1 BAP in combination with the 0.05 mg L-1 NAA which had 2 days pre-culture period of epicotyls for allowing to grow in the absolute darkness for 4 weeks, followed by 10 days in 16-h photoperiod (56 ΅mol m-2 s-1). The highest number of well-developed shoots was 4.2 shoots per explant and obtained with medium containing 0.5 mg L-1 GA3. These protocols are suitable in association with Citrus aurantium Agrobacterium-mediated genetic transformation.
Pages 150-156 | Full Text PDF
Research Article Open Access
Performance study of combined microwave and acid pretreatment method for enhancing enzymatic digestibility of rice straw for bioethanol production
Renu Singh*1, SapnaTiwari1, Monika Srivastava1, Ashish Shukla2
1Centre for Environment Science and Climate Resilient Agriculture, Indian Agricultural Research Institute, New Delhi, 110012, India
2Civil Engineering, Architecture and Building (CAB), Faculty of Engineering and Computing, Coventry University, Priory Street, Coventry CV1 5FB, UK
Abstract
Utilization of fossil fuel resources at large scale led to global warming alerts and threats. Bio-ethanol as an alternative fuel source can provide combat against these threats. Conversion of rice straw to fuel ethanol involves pretreatments followed by enzyme-catalyzed hydrolysis. In the present study, microwave-assisted H2SO4 is employed for pretreatment in order to enhance enzymatic digestibility of rice straw. Prepared samples of rice straw have first gone under microwave treatment followed by chemical treatment using H2SO4. Chemical concentration of 0.1-2.0 % for the treatment time of 1 to 5 minutes have been used utilizing microwave power range of 70-700 W. Under optimum conditions e.g. reaction time, power, concentration of chemical, maximum reducing sugar obtained through microwave assisted H2SO4 is 1376.99 ΅g/ml. The XRD analyses showed that the crystallinity index of microwave assisted H2SO4 rice straw samples is significantly high (61.36 %) as compared to untreated sample (52.2%). The morphological study performed using scanning electron microscope (SEM) certified that the surface of the samples treated with microwave assisted H2SO4 was more ruptured. Also the silicon waxy structure, ether linkages between lignin and carbohydrates were either damaged or broken down. Study on Indian rice straw proved that microwave assisted H2SO4 pretreatment can successfully remove lignin and increase the enzymatic accessibility.
Pages 157-162 | Full Text PDF
Research Article Open Access
Inheritance pattern of degree of indetermination in mungbean [Vigna radiata (L.) wilczek]
Aziz ur Rehman1, Muhammad Saleem2 and Muhammad Amjad Ali3*
1Pulses Research Institute, Ayub Agricultural Research Institute, Faisalabad, Pakistan
2Department of Plant Breeding & Genetics, University of Agriculture, Faisalabad, Pakistan
3Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan
Abstract
A complete diallel mating system involving eight divergent parents was used to work out the inheritance basis of degree of indetermination and its related parameters like plant height at flowering and maturity in mungbean. Eight parents, viz. 562-1, 56-2, NM-95, NM-92, L.No.1, L. No.21, 6601 and E32-1 were selected from 55 genotypes on the basis of variability for days to flowering and grain yield per plant. Briefly explain how study was conducted. Genotypic differences for male and female parents were significant for all the characters. The results (formal ANOVA and components of variation) advocated the importance of both additive (A) and dominance (D) effects for the all the traits in both generations. However, the value H1 > D for plant height at flowering in F2, plant height at maturity in F1 and degree of indetermination in F1 generation revealed the preponderance of dominant genes while D> H1 demonstrated additive nature of height at flowering in F1, plant height at maturity in F2 generation. Low to moderate estimates of narrow sense heritability indicated occurrence of dominance effects for all the characters. This study suggested the utilization of heterosis breeding for the improvement of indetermination in mungbean due to the involvement of dominance effects in its genetic control.
Pages 163-171 | Full Text PDF