October 2012 

October 2012 [6(10) 2012]

Table of Contents

Southern Cross Publishing Group©2012

Australian Journal of Crop Science (AJCS)
Alleviation of salt stress in fine aromatic rice by seed priming 

Irfan Afzal, Adeel Butt, Hafeez Ur Rehman, Shahzad Maqsood Ahmad Basra and Aneela Afzal

Seed Physiology Lab, Department of Crop Physiology, University of Agriculture, Faisalabad-38040, Pakistan
Department of Sociology, PMAS - Arid Agriculture University. Rawalpindi, Pakistan

This study investigated the potential of seed priming for induction of salt tolerance in rice. The seeds of two fine aromatic rice cv. Shaheen Basmati (salt tolerant) and Basmati-2000 (salt sensitive) were soaked in aerated solutions of CaCl2 (
?s=-1.25 MPa), KCl (?s=-1.25 MPa), and H2O2 (50 mM) each for 36 h. Seeds soaked in distilled water and non-primed seeds were taken as control for comparison. Two experiments were conducted in vitro and primed seeds were exposed to 0, 40 and 80 mM NaCl in petri dishes and sand culture during germination and emergence respectively. Priming with CaCl2 followed by KCl were more effective in inducing salt tolerance of both rice cultivars owing to enhanced germination capacity, speed of germination, seedling length and dry weight in saline medium. Incremental salinity reduced total chlorophyll percentage (TCP) by two fold in both cultivars but higher TCP was found at all salinity levels from CaCl2 primed raised seedlings in salt tolerant cultivar. Decreased leaf Na+ accumulation and increased K+ uptake were found in CaCl2 primed seedlings at moderate salinity in both cultivars but effect was more pronounced in Shaheen Basmati. Delayed germination and seedling growth with H2O2 pre-treatment indicates sensitivity of H2O2 primed seeds to salts and might be the result of higher Na+ uptake and less chlorophyll contents in rice seedlings. Nonetheless, enhanced germination and seedling growth, high Na+/K+ exclusion indicates Shaheen Basmati tolerance to salinity than Basmati-2000 and seed priming with CaCl2 seems more promising in induction of salinity tolerance in fine aromatic rice. 

Pages 1401-1407 | Full Text PDF
Enhancement of sweet pepper (Capsicum annuum L.) growth and yield by addition of Nigari, an effluent of salt industries in soilless culture

Md. Jahedur Rahman and Haruhisa Inden

Laboratory of Advanced Horticulture, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan

Nigari, an effluent of salt industries, is a less expensive alternative fertilizer source. Without testing its effect on growth and yield, it may not be suitable for use as an alternative fertilizer in a sustainable production system. Greenhouse trials were conducted over two years in response to application of Nigari. Sweet pepper cultivars ‘Papri new-E-red’ and ‘AVRDC PP046-6006’ were grown under soilless culture with three Nigari concentrations at 0, 2, 4 mL L-1 and additional NPK to equal standard level. Yield, plant dry weights, relative growth rate (RGR), and net assimilation rate (NAR) with their related traits were evaluated. All of them significantly increased with application of Nigari at 2 mL L-1 treatment compared to the no addition control, but were reduced by Nigari applied at 4 mL L-1 treatment. On the contrary, pH, total soluble solid (oBrix), titratable acidity (TA) and maturity index (MI) of fruit improved with increasing rate of Nigari. Mineral composition in leaves and fruits improved with application of Nigari at 2 mL L-1 treatment compared to the control. In both years, ‘Papri new-E-red’ performed better than ‘AVRDC PP046-6006’ when Nigari was applied at 2 mL L-1 in respect of improved physiological growth, plant dry weights and yield. Therefore, higher yield and improved growth with high quality fruit would be achieved by application of Nigari at 2 mL L-1 treatment in sweet pepper cv. ‘Papri new-E-red’ in soilless culture.

Pages 1408-1415 | Full Text PDF
Development of yield and some photosynthetic characteristics during 82 years of genetic improvement of soybean genotypes in northeast China

Guoning Liu, Chunwu Yang, Kezhang Xu, Zhian Zhang, Dayong Li, Zhihai Wu, Zhanyu Chen

Department of Agronomy, Jilin Agricultural University, Changchun 130118, Jilin Province, China

The aim of this work was to investigate development of some photosynthetic characters and their relationship with seed yield during the genetic improvement of soybean. For this objective, we grew 38 soybean cultivars representing genetic improvement progress in northeast China, released from the period of 1923 to 2005 (82 years). The experiment was performed in 2005 and 2006. Some photosynthetic characteristics such as leaf area, chlorophyll content and specific leaf weight (SLW) were measured at R2 stage (flowering stage). Days to maturity and yield were measured in each plot. The results of two years study showed that number of days to maturity decreased from 140.3d to 125.6d depends on the year of release, but soybean seed yield increased significantly from 1282.3 Kg to 2310.7 Kg during the 82 years of breeding. The net photosynthetic rate (Pn), stomatal conductance (Gs), apparent mesophyll conductance (Pn/Ci), transpiration (Tr), chlorophyll content and SLW all increased in bred cultivars during the improvement, but contrastingly the leaf area and ratio of Ci/Ca (intercellular CO2 concentration, Ci; ambient CO2 concentration, Ca) decreased in the same time. Yield was positively correlated with Pn, Tr, Gs, Pn/Ci, chlorophyll content and SLW, whereas the leaf area, Ci/Ca and WUE were negatively correlated. Our results revealed that Pn and Pn/Ci are the effective selection indexes for seed yield and can be used in future soybean breeding programs. We also found that the increase of Tr is higher than Pn. As a result, WUE is decreased as the increase of yield with year of release. Therefore, the main cost of high yield in new cultivars is water expense.

Pages 1416-1422 | Full Text PDF
The spatial distribution of rodent damage in Australian macadamia (Macadamia integrifolia) orchards

Matthew Whitehouse, James Eldridge, David Elmouttie and Grant Hamilton

Discipline of Biogeosciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia

The Black Rat (Rattus rattus), a global pest within the macadamia production industry, causes up to 30% crop damage in Australian orchards. During early stages of production in Australia, research demonstrated the importance of non crop adjacent habitats as significant in affecting the patterns of crop damage seen throughout orchards. Where once rodent damage was limited to the outside edges of orchard blocks, growers are now reporting finding crop damage throughout entire orchards. This study therefore aims to explore the spatial patterns of rodent distribution and damage now occurring in Australian macadamia orchards. We show that rodent damage and rodent distribution in these newer production regions differ from that shown in previous Australian research. Previous Australian research has shown damage patterns which were associated with the edges of orchard blocks however this study demonstrates a more widespread damage distribution. In the current study there is no relationship between rodent damage and the orchard edge. Arboreal rodent nests were identified within these newer orchard systems, suggesting rodents are residing within the tree component of the orchard system and not dependent on adjacent non-crop habitat for shelter. Results from this study confirm that rodents have modified their nesting and foraging behaviour in newer orchards systems in Australia. We suggest that this is a response of increased and prolonged availability of macadamia nuts in newer production regions enabling populations to be maintained throughout the year. Management strategies will require modification if control is to be achieved.

Pages 1423-1427 | Full Text PDF
Study of inheritance and environment on tropane alkaloids within Hyoscyamus species

Fatemeh Nejadhabibvash, Fatemeh Rahmani, Reza Heidari, Rashid Jamei and Farzaneh Azimi

Department of Biology‚ Faculty of Science‚ Urmia University‚ Urmia, Iran
Agriculture Research Center of Ardabil Herbarium, Ardabil, Iran

In the present study, HPLC technique was applied to determine scopolamine and hyoscyamine contents in five Hyoscyamus species including H.niger L., H.reticulatus L., H.pusillus L., H.arachnoideus Pojark., and H.kurdicus Bornm., collected from different geographical origins of North West of Iran. The range of genetic similarity was obtained between 91.07 and 99.89 within Hyoscyamus accessions based on scopolamine and hyoscyamine alkaloids composition. Estimated heritability was high for both traits and ranged from 0.82 to 0.99. The existance of high GCV indicates the genetical control of tropane alkaloids which leads us to achivement of genetic improvement by selection of desirable plants for breeding. Our data also implies the positive assosiation between N, P, K, Ca & EC and alkaloids yield in plants which will be useful for production programs in the future.

Pages 1428-1434 | Full Text PDF | Supplementary data
A comparison between foliar application and seed inoculation of biofertilizers on canola (Brassica napus L.) grown under waterlogged conditions

Farhad Habibzadeh, Ali Sorooshzadeh, Hemmatollah Pirdashti and Seyyed Ali Mohammad Modarres Sanavy

Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
Department of Agronomy and Plant Breeding, Genetics and Agricultural Biotechnology Institute of Tabarestan, Sari Agricultural Sciences and Natural Resources University, Sari, Mazandaran, Iran

Waterlogging restricts canola growth via different physiological changes. The objective of this work was to compare the effects of the foliar and seed application of two biofertilizers on some physiological and morphological responses in canola plants (Brassica napus L. cv. Hayola 401) under waterlogging stress conditions. Plants at 5-leaf stage were exposed to flooding conditions for two weeks. Two biofertilizers; AAP (Azotobacter chroococcum, Azospirillum spp. and Pseudomonas spp.) and APB (Azospirillum spp., Pseudomonas fluorescens and Basillus subtilis) were applied by seed inoculation or foliar spray at different times i.e. before waterlogging, after waterlogging and, before and after waterlogging. The results showed that the flooding stress significantly decreased the dry weight and length of the shoots and roots. The activity of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX) were reduced, whereas lipid peroxidation and ethylene production in the leaves were increased under waterlogging stress. The adverse effects of the flooding stress were significantly alleviated by the seed inoculation and foliar application once (before the stress) of both biofertilizers compared to the waterlogged control. However, among two methods, inoculating the seeds with the biofertilizers is cost efficient and advisable to alleviate waterlogging damage in canola.

Pages 1435-1440 | Full Text PDF
Pulsed microwave drying kinetics of fig fruit (Ficus carica L.)

Faroogh Sharifian, Asad Modarres Motlagh and Ali M. Nikbakht

Department of Agricultural Machinery, Faculty of Agriculture, Urmia University, Urmia, Iran

The main objective of this study was to investigate the effects of microwave power intensity and pulsing ratio on drying behavior of fig fruit in a laboratory scale microwave dryer. During experiments, weight and temperature of the samples were recorded at regular intervals (10 s). The results showed that drying time of products increased by approximately 200% under pulsing ratio of 1.5 to 4. In contrast drying time decreased by approximately 500% under microwave power intensity of 0.5 to 2.5 W/g. Furthermore, 11 different thin layer drying models were analyzed for investigation of moisture variation of fig fruit. The performance of these mathematical models were compared based on the three statistical criteria, such as coefficient of determination (R2), standard error of estimate (SEE) and residual sum of square (RSS). According to the results, Quadratic and Logarithmic models described the drying kinetics of fig with the mean coefficient of determination (R2) of 0.9984. Additionally, microwave power intensity resulted in the raised sample temperature leading to better removal of moisture. The mass transfer was also attenuated with the pulsing ratio.

Pages 1441-1447 | Full Text PDF
The development of highly-performing open-pollinated maize lines via single-plant selection in the absence of competition

Vasileios Greveniotis, Vasilia A. Fasoula, Ioannis I. Papadopoulos, Evangelia Sinapidou, Ioannis S. Tokatlidis

Department of Agricultural Development, Democritus Univ. of Thrace, Orestiada, 68200, Greece
Center for Applied Genetic Technologies, Univ. of Georgia, 111 Riverbend Road, Athens, GA 30602, USA
Technological Education Institute of W. Macedonia, Florina, 53100, Greece

Selfing and high selection pressures under ultra-low plant densities that ensure absence of competition have been recommended as a means to exploit the additive genetic effects and develop maize (Zea mays L.) lines approaching the yield performance of hybrids. Additionally, low plant densities could promote self-pollination due to the better synchronization of pollen and silk emergence. To address these hypotheses selection was applied for three generations using as starting material the F2 of the maize hybrid ‘Costanza’ under open-pollination conditions and a density of 0.74 plants m-2. The selection was based on two equations: one to estimate the yield genetic potential of single plants and the other the yield genetic potential of entries/ lines. The results were promising in terms of enhanced gene fixation and exploitation of additive gene action. The high selection pressures applied led to fairly homogeneous half-sib lines that approximate the productivity and stability levels of ‘Costanza’. Utilization of such lines in the production of hybrids is expected to increase the crop yield potential, while progressive line improvement could ultimately reduce the line-to-hybrid gap. Concluding, progressive replacement of less by more favorable additive alleles is accomplishable when ultra-low plant densities are used so as to maximize pollen production and diminish the anthesis-to-silking interval, thus promoting selfing. The application of the procedure in commercially successful hybrids is recommended in order to develop highly homogeneous lines of superior performance; the hybridization between such lines is bound to lead to less heterogeneous hybrids and reduced seed cost.

Pages 1448-1454 | Full Text PDF
Effects of NaHCO3 stress on Na+ absorption in tobacco (Nicotiana tabacum Linn.)

Zhonghua Zhang, Hua Wang, Zhonghua Tang, Yuangang Zu,Ying Liu, Hongzheng Wang

Key Laboratory of Forest Plant Ecology of the Ministry of Education, Northeast Forestry University, Harbin 150040, China
Engineering Research Center of Forest Bio-preparation, Ministry of Education, Northeast Forestry University, Harbin 150040, China

Soil alkalization and salinization are widespread environmental problems. Alkaline salt-affected soil is typically characterized by an accumulation of sodium carbonate and bicarbonate. Little attention has been paid to the ion absorption characteristics of a plant under NaHCO3 stress. This study aims to compare NaHCO3 stress with NaCl stress to determine transient ion exchange and Na+ toxicity on root surfaces. A non-invasive ion flux technique was applied and laser scanning confocal microscopy was conducted to investigate the effects of NaHCO3 on Na+ absorption in salt-sensitive tobacco (Nicotiana tabacum Linn.). NaHCO3 shock treatment significantly increased the net H+ efflux compared with the NaCl shock and control treatments. At the same time, vacuolar pH from 2',7'-bis-(2-carboxyethyl)-5- (and-6)-carboxyfluorescein, acetoxymethyl ester (BCECF-AM) staining increased from 5.3 to 6.6. Exposure of roots to NaHCO3 for 3 d resulted in both higher membrane permeability and higher Na+ flux. Na+ efflux was not inhibited by sodium orthovanadate, an inhibitor of the plasma membrane. These results indicate that NaHCO3 addition induces high H+ efflux and intracellular alkalization. Destruction of membrane permeability and the ion transport system led to uncontrolled Na+ flux. The effect of NaHCO3 reduces the resilience of plants for Na+ osmotic stress, and increases the harm to the plant.

Pages 1455-1461 | Full Text PDF
Somatic embryogenesis and plant regeneration from bulb, leaf and root explants of African blue lily (Agapanthus praecox ssp. minimus)

Jamilah Syafawati Yaacob, Anis Idayu Mad Yussof, Rosna Mat Taha and Sadegh Mohajer

Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia

The African blue lily (Agapanthus praecox ssp. minimus) is a valuable plant, reported to contain medicinal compounds such as saponins, sapogenins and phytoecdysteroids, besides gaining popularity as an ornamental and landscape species. This paper reports on high efficiency and rapid in vitro propagation of Agapanthus praecox ssp. minimus via somatic embryogenesis from tissues derived from sterile root, leaf and bulb explants obtained from one-month-old aseptic seedlings of this species. Detailed observations on developmental stages of somatic embryos (from globular to coleoptilar) of this monocotyledonous species were also reported in the present investigation. Friable callus which gave rise to high plant regeneration rate (95%) was lucratively produced within 1-2 months after the explants were cultured on Murashige and Skoog (MS) medium supplemented with picloram, 2,4-D, TDZ and combinations of NAA and BAP (0.5 mg/L to 2.0 mg/L). Subsequently, the proliferated calli were transferred onto the same media compositions at 2 weeks interval to encourage extensive production of somatic embryos, followed by transferring to plant growth regulator-free MS medium for complete plant regeneration. Analysis of results showed that explant types highly influenced the degree of response to hormone treatments, whereby root explants were the most responsive. Picloram (a systemic herbicide) was the most effective in inducing somatic embryogenesis from leaf explants, while 2,4-D had excellent influence on root and bulb explants. Further development of somatic embryos to complete plantlets was achieved on MS basal medium. Regenerated plantlets were then hardened and acclimatized on black (peat) soil with 86.67
± 6.31% survival rate. Scanning electron microscopic studies on leaf tissues showed no morphological variations between the in vivo and in vitro grown plants, hence mass propagation through tissue culture for true-to-type production of this species is feasible.

Pages 1462-1470 | Full Text PDF
Impact of reclamation practices on the content and qualitative composition of exchangeable base cations of the solonetz soil

Milivoj Belic, Ljiljana Nešic, Miodrag Dimitrijevic, Sofija Petrovic, Vladimir Ciric, Saša Pekec, Jovica Vasin

Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
Institute of Lowland Forestry and Environment, University of Novi Sad, Novi Sad, Serbia
Institute of Field and Vegetable Crops, Novi Sad, Serbia

This paper shows the impact of long-term reclamation practices on the content and qualitative composition of exchangeable base cations of the solonetz soil. Based on the results of field visits and laboratory analyses, chemical and agrotechnical reclamation practices (phosphogypsum application 25 t ha-1 or 50 t ha-1, drainage pipes distance 20 m, trenching 50 cm, fertilization, soil tillage and cropping) have been applied to the solonetz soil. Analyses of cation exchange capacity (CEC) have shown that calcium (Ca+2) and sodium (Na+) cations prevailed over magnesium (Mg+2) and potassium (K+) cations in the soil exchange complex in all variants and all depths. Comparisons among variants and soil layers have shown that the contents of individual exchangeable base cations varied significantly (P = 0.05). The highest changes in exchangeable calcium content were achieved to the depth of 30 cm, in both treated variants, and these changes were still higher in the variant with 50 t ha-1 of phosphogypsum. The content of exchangeable Na+ decreased by 43 % to 71% in variant I and by 23% to 64% in variant II in comparison with the control variant. The application of the reclamation practices caused changes in the composition and proportions of cations in the layers of the solonetz soil to the depth of 50 cm. When compared with CEC in the control variant, the exchangeable sodium percentage (ESP) in the treated variants decreased by 6% to 15% after fifteen years.

Pages 1471-1480 | Full Text PDF