May 2013 | Australian Journal od Crop Science

Existence of bioactive flavonoids in rhizomes and plant cell cultures of Boesenbergia rotunda (L.) Mansf. Kulturpfl.

Fri, 17 May 2013 17:29:42 GMT

Nor Azma Yusuf 1,2, M. Suffian M. Annuar1 and Norzulaani Khalid1*
1Centre of Biotechnology for Agriculture Research, Biotechnology and Bioproduct Research Cluster, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
2Faculty of Plantation and Agrotechnology, University Technology MARA (UiTM) 40450 Shah Alam, Selangor, Malaysia
Abstract
Callus and cell suspension cultures were explored as alternative sources of selected flavonoids and compared to those produced from rhizome of Boesenbergia rotunda (L.) Mansf. Kulturpfl. B. rotunda or fingerroot ginger is a medicinally important Zingiberaceae species. HPLC analysis showed the presence of alpinetin, pinocembrin, cardamonin, pinostrobin and panduratin A in the rhizomes, callus and cell suspension cultures of B. rotunda. Among the flavonoids, pinostrobin was predominant compared to panduratin A from the three sources. The rhizome extract of B. rotunda produced the highest quantity: a total of 5 selected flavonoids at 12975.52 ± 71.78 µg g-1 dry weight (DW). In contrast, callus and cells suspension extracts yielded 120.61  0.01 and 3.14  0.12 µg g-1 DW of the total selected flavonoids, respectively. However, this is the first report on the production of alpinetin, pinocembrin, cardamonin, pinostrobin and panduratin A from in vitro cultures of B. rotunda (L.) Mansf. Kulturpfl. Although the amount of flavonoids from invitro cultures was not comparable to the rhizome, it is crucial to initially establish invitro cultures and to proof the existence of these compounds in the cultures. This is a pre-requisite to enhance the accumulation of targeted bioactive compound through either metabolic engineering or chemical elicitation in future studies.

Wheat TaWRKY10-1 is involved in biological responses to the salinity and osmostresses in transgenic Arabidopsis plants

Fri, 17 May 2013 17:29:40 GMT

Ming Li1，Bo Ding1，Junbin Wang1，Wenli Yang1，Rui Wang1, Shuguang Bao1, Silin Zhong2，Xiaodong Xie1 *
1Tianjin-Bristol Research Centre for the Effects of Environmental Change on Crops, Depar tment of Agronomy, Tianjin agricultural University, Tianjin (300384), China
2Boyce Thompson Institute for Plant Research, Cornell University (14853), USA
Abstract
Wheat TaWRKY10 is an uncharacterized group II member of the WRKY superfamily transcription factor and is regulated by high salinity and PEG. In order to study the diverse biological functions of TaWRKY10, we cloned a 783 bp cDNA fragment of this gene from the wheat accession Yangmai 158 (Triticum aestivem L.). Subsequent sequence analysis revealed that the cloned fragment contains UTRs and coding region and shows 96% sequence identity to the TaWRKY10 gene in Genbank. The amino acid sequences analysis identified 15 amino acid differences, mostly at the C-terminus of this protein of 222 amino acids, compared with the TaWRKY10, suggesting that it is likely to be a novel allele of TaWRKY10. Hence we designated it as TaWRKY10-1. RT-PCR results showed that TaWRKY10-1 gene was up-regulated by NaCl and PEG in wheat. To further elucidate its function, we constructed a chemical-inducible TaWRKY10-1 over-expression plasmid, pKIGW-TaWRKY10-1, via Gateway cloning technology and transformed it into Arabidopsis plants. Over expression of TaWRKY10-1 gene increases the sensitivity of transgenic plants to NaCl, PEG and mannitol, indicating TaWRKY10-1 might act as a negative regulator in response to the salinity and osmostresses. This work provides the key basis for further functional analysis of wheat TaWRKY10-1 gene．

Identification of new SRAP markers linked to leaf chlorophyll content, flag leaf senescence and cell membrane stability traits in wheat under water-stressed condition

Tue, 30 Apr 2013 20:03:15 GMT

Adel Ahmed Elshafei13, Mohamed Saleh2, Abdullah Abdlulaziz Al-Doss1, Khaled Ahmed Moustafa1, Fahed Hamed Al-Qurainy2 and Mohamed Najeb Barakat14*
1Plant Production Department, College of Food Sciences and Agriculture, King Saud University, Riyadh 11451, Riyadh, Saudi Arabia
2Botany& Microbiology Department, College of Pure Science, King Saud University, Saudi Arabia
3Genetics and Cytology Dept., Genetic Engineering and Biotechnology Division, National Research Centre, El-Dokki, Cairo, Egypt
4Biotechnology Laboratory, Crop Science Department, Faculty of Agriculture, University of Alexandria, Egypt
Abstract

A segregating F4 population from the cross between drought sensitive (Yecora Rojo) and drought tolerant (Pavon 76) genotypes was made to identify SRAP markers linked to leaf chlorophyll content, flag leaf senescence and cell membrane stability traits in wheat (Triticum aestivum L.) under water-stressed condition. The parents and 150 F4 families were evaluated phenotypically for drought tolerance using two irrigation treatments (2500 and 7500 m3/ha). Using 98 different SRAP primer combinations tested for polymorphism in testing parental and F4 families genotypes, the results revealed that quantitative trait locus (QTL) for chlorophyll content was associated with five SRAP markers and explained phenotypic variation ranged from 38 to 53 %. The genetic distance between chlorophyll content QTL and SRAP markers ranged from 10.4 to 22.7 cM. QTL for flag leaf senescence was associated with five SRAP markers and explained phenotypic variations ranged from 35 to 45 %. The genetic distance between flag leaf senescence QTL and SRAP markers ranged from 10.7 to 23.5 cM. QTL for cell membrane stability was associated with five SRAP markers and explained phenotypic variations from 25 to 44 %. The SRAP markers for cell membrane stability had genetic distances ranged from 7.3 to 17.1 cM. We suggest that these SRAP markers linked to the QTLs of drought-induced physiological traits, leaf chlorophyll content, flag leaf senescence and cell membrane stability can be further used in breeding for drought tolerance in wheat.

Molecular detection of QTL for agronomic and quality traits in a doubled haploid barley population

Tue, 30 Apr 2013 20:03:11 GMT

Xifeng Ren1, Dongfa Sun1, *, Genlou Sun1, 2, Chengdao Li3 and Wubei Dong1

1College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
2Biology Department, Saint Mary’s University, 923 Robie Street, Halifax, NS, B3H3C3, Canada
3Department of Agriculture & Food/Agricultural Research Western Australia, 3 Baron-Hay Court, South Perth, WA 6155, Australia

Abstract

In order to efficiently use new dwarf germplasm Huaai 11 for breeding program, it is important to identify the QTL of agronomic and quality traits. In the present study, QTL analysis was performed for ten agronomic and one quality traits using a DH population of a 122 lines derived from the cross of Huaai 11 × Huadamai 6. Composite interval mapping procedures detected a total of 17 QTL which were mapped onto five chromosomes. Six QTL, Qhd2-12, Qmsl2-15 and Qmsl7-7, Qgwp7-7, Qgws7-7and Qtgw7-10 were detected in all years. Ten QTL were found on chromosome 7H. The QTL on chromosome 7H has effect on grain weight per plant, grain protein content, and main spike length, which accounted for 35.11%, 45.74% and 54.88% of phenotypic variation, respectively. Positive transgressive segregation was found for all traits. Some of QTL identified in this study could be targeted for an efficient transfer into new cultivars by applying MAS.

Effect of deep placement of nitrogen fertilizer on growth, yield, and nitrogen uptake of aerobic rice

Tue, 30 Apr 2013 20:03:05 GMT

Jing Xiang1*, Van Ryan Haden2, Shaobing Peng3, Bas A.M. Bouman4, Jianliang Huang3, Kehui Cui3, Romeo M. Visperas4, Defeng Zhu1, Yuping Zhang1, Huizhe Chen1

1State Key Lab Rice Biology, China National Rice Research Institute, Hangzhou 310006, Zhejiang, Peoples R China
2Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14850, USA
3Crop Physiology and Production Center (CPPC), National Key Laboratory of Crop Genetic Improvement, MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070, China
4Crop and Environmental Sciences Division, International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, Philippines

Abstract

Recent studies have reported that poor growth of aerobic rice associated with urea induced ammonia toxicity when applied at early growth stage. The objective of this study was to examine the effect of different methods of nitrogen application on plant growth of aerobic rice grown in continuous aerobic rice system. Micro-plot experiment was conducted in 2008 dry season in a field where aerobic rice has been grown for fourteen seasons in International Rice Research Institute (IRRI) farm. Two Pot and pot-diffusion incubations experiments were done with the soil from same field where micro-plot experiment was conducted and aerobic rice has been grown for 14 seasons in greenhouse and growth chamber. Apo, an upland rice variety, was grown under aerobic conditions with different application method of nitrogen in field and pot experiments. The field micro-plot experiment showed that urea and urea super granules (USG) deep placement increased grain yield of aerobic rice by 1.66 t ha-1 in continuous aerobic rice cultivation. Pot experiments studying the effects of different application methods of nitrogen indicated that N incorporation into soil and placement at a depth of 5-10cm in the soil increased the vegetative growth parameters, and plant growth parameters of aerobic rice under ammonium sulfate were significantly higher than urea at all applied treatments. In pot-diffusion incubations experiment, N placement at a depth of 5.0 cm in the soil significantly reduced nitrogen loss by ammonia volatilization. Our results suggested that there is a possibility of improving aerobic rice yield in the continuous aerobic rice system by using right N source or changing conventional method of nitrogen application to deep placement.

Effect of mild vacuum packaging on cut Matthiola incana L. flowers vase life

Tue, 30 Apr 2013 20:03:00 GMT

Silvia Pacifici1, Antonio Ferrante2, Anna Mensuali-Sodi1*

1Scuola Superiore Sant’Anna, Pisa – Italy
2Dept. Agricultural and Environmental Sciences, Università degli Studi di Milano, Milano, Italy

Abstract

Mild vacuum (MV) packaging was compared with conventional cold wet storage on cut stock (Matthiola incana L.). The cut stock flowers were selected and cut to 50 cm and stored in water (wet storage) or placed in plastic bags under MV at 4 °C for six days. The effect of storage was compared with non-stored cut flowers. The postharvest quality of cut flowers was evaluated by monitoring vase life, water uptake, alcohol dehydrogenase activity (ADH), ethylene production, total chlorophyll and SPAD measurements. The MV packaging allowed storing the stock flowers for three days, without any visible injury and with a vase life of about 7 – 8 days. MV storage caused an accumulation of ethylene and CO2 in bags, 919.9 pl ml-1 and 21382 µl l-1, respectively. Only flowers stored for 6 days in mild vacuum showed quality reduction. The leaves appeared dehydrated; with local transparencies of cuticles and a green-gray colour. The ADH was higher in open flowers (2.9 nmol mg-1 protein min-1) compared with other organs in MV storage method, and the highest concentration was recorded after 6 days storage. At the end of vase life stock flowers wet stored showed a greater production of ethylene (0.75 nl h-1 g-1 FW) then MV (0.3 nl h-1 g-1 FW). The MV system can be used in M. incana if storage or transportation is limited to three days.

Fumigant toxicity of essential oil from Salvia leriifolia (Benth) against two stored product insect pests

Tue, 30 Apr 2013 20:02:56 GMT

Bahman Hosseini*, Alireza Estaji

Department of Horticulture, Faculty of Agriculture, Urmia University, P.O. Box 57135–165, Iran

Abstract

Salvia is an important genus of the Lamiaceae family that includes more than 700 species which are spread throughout the world. Salvia leriifolia (Benth) were collected from Iran, during the month of March 2011. Dry ground leaves were subjected to hydrodistillation using a Clevenger−type apparatus and the chemical composition of the volatile oil was studied by gas chromatography−mass spectrometry (GC−MS). The major components of the essential oil were 1, 8−cineole (20.36), β−pinene (16.94), and α−pinene (15.89%). The toxicity of S. leriifolia essential oil against granary weevil, Sitophilus granarius (L.), and lesser grain borer Rhyzopertha dominica (F.) was evaluated by fumigation at 24, 48, and 72 h exposure times. Rhyzopertha dominica was more susceptible than S. granarius for all exposure times. Insecticidal activity varied with essential oil concentration and exposure time. LC50 values at 24 h were estimated at 79.17 μL L–1 for S. granarius, and 25.87 μL L–1 for R. dominica. Furthermore, with increasing the exposure time and essential oil concentration, LC50 values decreased. When insects were fumigated for 72 h, an oil concentration of 12 μL L–1 was necessary to cause 50% mortality (LC50) for R. dominica, while in case of S. granarius, concentrations up to 36 μL L–1 was enough to cause equal mortality. These results suggested that S. leriifolia essential oil might have potentials as a control agent against S. granarius and R. dominica. In the light of the recent interest by agrochemical companies in developing plant−based pesticides, oil extracted from S. leriifolia could be used as a safe and environmental-friendly chemical.

Cytomorphological and molecular evidences of synthesis of interspecific hybrids between Brassica rapa and B. fruticulosa through sexual hybridization

Tue, 30 Apr 2013 20:02:52 GMT

Arun Kumar, Binay K. Singh*, Vijay V. Singh and Jitendra S. Chauhan

Directorate of Rapeseed-Mustard Research, Sewar, Bharatpur -321 303, Rajasthan (India)

Abstract

Six successful interspecific hybrid plants were obtained through sexual hybridization between Brassica rapa var. yellow sarson (NRCYS-05-02) (2n = 20, AA) and a wild species B. fruticulosa (2n = 16, FF), using the latter as pollen parent. Morphological, cytological and sequence tagged microsatellite sites (STMS) based molecular analyses were carried out to confirm the hybrid nature of F1 plants. The hybrid plants (2n = 18) were intermediate for most of the morphological attributes. A severe reduction (8.6%) in pollen fertility was recorded in F1. Nevertheless, few seeds were obtained from open pollination. Meiotic analysis revealed a mixture of bivalents and univalents in all the pollen mother cells (PMCs) analysed. However, 2II + 14I was the most frequently observed chromosome association. Presence of large number of univalents indicates lack of homology between pairing partners. Besides, bivalents and univalents, a trivalent was also observed in three PMCs, indicating segmental homology between chromosomes. The study suggests that B. fruticulosa has partial genome homoeology with B. rapa which could be exploited in crop improvement programmes, particularly breeding for tolerance to insect pests, especially mustard aphid.

Effects of potassium on organic acid metabolism of Fe-sensitive and Fe-resistant rices (Oryza sativa L.)

Tue, 30 Apr 2013 20:02:47 GMT

Yue-Ping WANG1, Yu-Huan WU2, Peng LIU1*, Guo-Hong ZHENG1, Jian-Ping ZHANG1, Gen-Di XU1

1Key Laboratory of Botany, Zhejiang Normal University, Jinhua, Zhengjiang, 321004, P R China
2College of Life and Environmental Science, Hangzhou Normal University, Hangzhou 310036, P R China

Abstract

Rice is the world’s number one staple food and feeds half the world’s population. Excessive iron (Fe) is a major abiotic stress factor that contributes to crop yield losses and decline in the nutritional quality of rice worldwide. Effects of potassium on rice plant stature, production, acid metabolism, and content were studied by hydroponic experiments. The plants were subjected to three different potassium levels, i.e., 100, 200, and 400 mg L−1. The Hoagland's solution was applied as base nutrients solution. Excessive Fe2+(250 mg L-1) significantly inhibited the growth of both Fe-sensitive cultivar IIyou838 and Fe-resistant cultivar xieyou9308, including the shoot and root lengths, root and shoot fresh weights, and dry weight. The aconitase and phosphoenolpyruvate carboxylase activity decreased significantly (p < 0.05) in both the root and leaf, especially the aconitase activity in the leaves of xieyou9308 and IIyou838, which decreased by 51.85% and 54.55%, respectively. Citrate synthase and malate dehydrogenase activities as well as the malic acid content increased significantly. Citric acid also increased, however no obvious difference among different treatments was observed. The addition of potassium can alleviate iron toxicity, but a certain difference occurs compared with the control. The results indicated that potassium can alleviate iron toxicity to a certain degree. Under iron toxicity, changes in plant height, root length, biomass, organic acid contents, and enzyme activities of IIyou838 were greater than those of xieyou9308, showing its sensitivity to iron toxicity.

Phenotypic variation and the relationships among jute (Corchorus species) genotypes using morpho-agronomic traits and multivariate analysis

Tue, 30 Apr 2013 20:02:41 GMT

Ranjit Kumar Ghosh1, Tanee Sreewongchai1, Sutkhet Nakasathien1 and Chalermpol Phumichai1*

1Department of Agronomy, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand

Abstract

Twenty-five morpho-agronomic traits of 63 jute genotypes, including 2 varieties with 37 accessions of C. capsularis and 1 variety with 23 accessions of C. olitorius, were evaluated to assess the extent and patterns of variability and their relationships. Seed traits exhibited a wider range of variation than fiber traits and the genotypes in C. olitorius varied the most than those in C. capsularis. Qualitative traits were also the most informative. Significant positive correlations were recorded of fiber yield with days to 50% flowering (0.60), plant height at average flowering (0.72), plant base diameter (0.74) and fresh weight (0.90), whereas, leaf angle was negatively (-0.52) correlated. Seed yield was significantly positively correlated with pod length (0.72) and seeds per pod (0.79). The clustering patterns suggested that the two jute species are distantly related. The highest diversity (0.69) was observed between clusters IX and IV, whereas clusters III and IV showed the greatest similarity (0.14). Principal component (PC) analysis revealed that the first five PCs having eigenvalues >1 explained 75.93% of the total variation. The variance explained by PC1 was mostly due to traits related to fiber and seed yield, whereas PC II was mostly related to color traits. Two-dimensional scatter plots supported the grouping patterns of cluster analysis. The accessions BRA/4792 and BRA/4794 and variety O-9897 of C. olitorius were identified as the most promising genotypes, based on their phenotypic variability and high yield performance, for use as genetic material for future jute breeding programs and for germplasm conservation.

Quantitative trait loci controlling amino acid contents in wheat (Triticum aestivum L.)

Tue, 30 Apr 2013 20:02:36 GMT

Xiaoling Jiang1, 2, Zhiying Deng1 Zhengang Ru2, Peng Wu1, Jichun Tian1,*

1State Key Laboratory of Crop Biology, Group of Quality Wheat Breeding of Shandong Agricultural University, No. 61 Daizong Road, 271018 Taian, China
2College of Life Sciences, Henan Institute of Science and Technology, Eastern Hualan Road, 453003 Xinxiang, China

Abstract

Quantitative trait locus/loci (QTL) for amino acid content (AAC), 17 individual amino acid and total amino acid (TAA) contents of wheat were studied using a doubled haploid (DH) population containing 168 progeny lines derived from a cross between ‘Huapei 3’ and ‘Yumai 57’, Chinese bread wheat cultivars. The inclusive composite interval mapping (ICIM) was applied on wheat meals from 2008 and 2009 in Shandong province, China using QTL IciMapping 2.2. The results indicated that total 32 QTL were detected in wheat meals from 2008, contributing to 4.86-30.95% of total phenotypic variation. Total 53 QTL, accounting for 4.39-23.87% of total phenotypic variance, were detected in wheat meals from 2009. Most QTL were co-localized, forming 13 QTL clusters in two cropping seasons, whereas 4 QTL clusters were coincident in two years. Especially, the loci near marker Xbarc86 on chromosome 3A detected in both years influenced 13 amino acids, and also controlled protein and wet gluten contents, which could be used for marker for protein and amino acids contents.

Indices of competition and bio-agroeconomic efficiency of lettuce and tomato intercrops in greenhouses

Tue, 30 Apr 2013 20:02:32 GMT

Arthur Bernardes Cecílio Filho1 *, Francisco Bezerra Neto2, Bráulio Luciano Alves Rezende3, Leilson Costa Grangeiro2, and Jailma Suerda Silva de Lima2

1Universidade Estadual Paulista, UNESP, Jaboticabal, SP 14884-900, Brazil
2Universidade Federal Rural do Semi-Árido, UFERSA, Mossoró, RN 59625-900, Brazil
3Instituto Federal de Educação, Ciência e Tecnologia, IFECT, Vila Velha, ES 29106-010, Brazil

Abstract

Intercropping is a cropping system for the production of greenhouse vegetables. It uses space more efficiently, thus reducing the cost of production. Intercropping tomato and lettuce has not been studied, but knowledge of the competitive and agroeconomic indices of these vegetables can help in the management of the intercropping system. The objectives of this study were to assess, through biological and agroeconomic indices, the competition between species and the profitability of intercropping tomato and lettuce at different times of transplantation over two growing seasons (autumn-winter and summer-winter) in greenhouse conditions. In autumn-winter, two experiments were conducted with a randomised complete-block design and five replicates. Tomato and lettuce were the main crops in the individual experiments. Treatments were arranged in a factorial of two cropping systems (intercropping and individual crops) with four transplants of the secondary crop (0, 10, 20 and 30 days after) plus an additional treatment (individual main crop). These two experiments were repeated in summer-winter. Tomato was the dominant crop regardless of transplant order. Intercropping systems established with transplants of both species on the same day had higher values of indices of competition and bio-agroeconomic efficiency than systems with longer periods of transplants between main and secondary crops. The intercropping of lettuce and tomato in greenhouses, regardless of transplant time or order, had bio-agroeconomic advantages over individual crops. The transplantation of tomato after lettuce is recommended for greater profitability.

Growth response and plant water status in forage sorghum [Sorghum bicolor (L.) Moench] cultivars subjected to decreasing levels of soil moisture

Tue, 30 Apr 2013 20:02:28 GMT

Ahmad Sher1, Lorenzo Barbanti2*, Muhammad Ansar1 and Muhammad Azim Malik1

1Department of Agronomy, PMAS - Arid Agriculture University, Rawalpindi, Pakistan
2Department of Agricultural Sciences, University of Bologna, Italy

Abstract

A pot experiment was conducted to determine the response of two recent forage sorghum cultivars (JS-2002 and Chakwal Sorghum) and an old one (JS-263) to three levels of soil moisture (30%, 50% and 70% field capacity). Several traits were assessed addressing plant morphology, functional growth, leaf water status, biomass yield and water use efficiency (WUE). Soil moisture variation greatly affected all traits, while cultivars significantly differed in the response to drought. At low moisture the three genotypes showed similar net assimilation rate, specific leaf area, root and shoot dry weight. Conversely, at high moisture JS-2002 exhibited a higher potential than Chakwal Sorghum, in turn passing JS-263. As it concerns plant height, leaf area, leaf water potential (LWP) and relative water content (RWC), the three cultivars consistently behaved across moisture levels maintaining the same ranking between best (JS-2002) and worst performer (JS-263). Especially LWP and RWC gap between JS-263 and JS-2002 (LWP, -1.84 vs. -1.55 MPa; RWC, 71 vs. 78% in the two respective cultivars) points out the old genotype inadequacy to face drought. WUE outlined an increasing difference between most (S-2002) and least efficient cultivar (JS-263) at rising moisture. JS-263 also showed a higher yield response factor to water supply, meaning a stronger yield decrease under water deficit. The resilience to drought shown by recent varieties (JS-2002 and Chakwal Sorghum) is a good premise for their use in areas subjected to dry spells. Further research at field plot scale is nevertheless needed to assess actual gains in varying moisture conditions.

Studies on the resistance of Australian chickpea (Cicer arietinum L.) to Phytophthora root rot disease

Tue, 30 Apr 2013 20:02:21 GMT

Wenhua Du1, 2*, Xiaochun Zhao2, Tokachichu Raju2, Phil Davies2, Richard Trethowan2

1College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, The People’s Republic of China
2University of Sydney, Plant Breeding Institute, 107 Cobbitty Road, Camden, NSW 2570, Australia

Abstract

Phytophthora root rot (PRR) is a disease of chickpea (Cicer arietinum L.) caused by the Phytophthora megasperma Drechs. f. sp. medicaginis (Pmm). It is the most serious disease for this crop in Australia because there is no strong resistance exists in current cultivars. Therefore, it is vitally important to identify the new source of resistance for the improvement of chickpea cultivars. A range of chickpea genotypes were evaluated in this study to identify sources of resistance to this disease. Three Australian chickpea varieties (Jimbour, Flipper, and Yorker) were used to assess the pathogenicity of 4 Pmm isolates (4019, 4021, 4027, and 4046). The most aggressive pathogenic isolate 4027 and a mixture of two other isolates were selected to assess the resistance of 16 international and Australian chickpea genotypes to PRR. The general score (GS) (0.5 × plant infection rate＋0.5 × plant death rate) was used in this study to indicate the severity of the disease. According to the GS value derived from the most aggressive isolate 4027, 4 genotypes (FLIP97-114C, ICCV 05111, ICCV 98818, and ICCV 96852) were considered moderately resistant with a GS of 3.9 - 4.4, 3 genotypes (Bumper, ICCV 98801, and Yorker) were classified as resistant with a GS of 4.7 - 4.9, and the rest of them were susceptible with GS scores above 5.8. The large variation in pathogenicity observed for these isolates suggested that the 4 Pmm isolates represented different pathogen strains. Significant differences in plant infection rate, plant death rate, and disease development were observed among the chickpea genotypes. These findings indicated that the basis of resistance differed among the chickpea genotypes evaluated. The PRR resistance in chickpea is a multi-gene controlled trait. These resistant genotypes provided different sources of resistance and could be combined in breeding program to produce durable and high level of resistant cultivars.

Rhizobium inoculation and the supply of molybdenum and lime affect the uptake of macroelements in common bean (P. vulgaris L.) plants.

Tue, 30 Apr 2013 20:02:17 GMT

Joachim H.J.R. Makoi1, Sylvia Bambara1 and Patrick A. Ndakidemi2,*

1Faculty of Applied Science, Cape Peninsula University of Technology, Cape Town Campus, Keizersgracht, P.O. Box 652, Cape Town 8000, South Africa. 2The Nelson Mandela African

Institute of Science and Technology. P O Box 447, Arusha-Tanzania.

Abstract

This study was conducted to investigate the effect of Rhizobium inoculation and the supply of Mo and lime on the uptake of macroelements in P. vulgaris. To achieve this aim, experiments were conducted at the glasshouse of the Cape Peninsula University of Technology, Cape Town (i.e. from August 2008 to January 2009) and field experiment at the Agricultural Research Council (ARC) Nietvoorbij site in Stellenbosch, South Africa (i.e. during the summer seasons from October 2008 to March 2009). A randomised complete block design was used in a 3-factorial arrangement with 2 levels of Rhizobium inoculation (with and without rhizobia), 3 levels of Mo (0, 6 and 12 g kg-1 seeds) and 3 levels of lime (0, 2 and 3 t ha-1) with 4 replications per treatment. The result showed that Rhizobium inoculation significantly (P ≤ 0.05) increased the uptake of P, K, Ca and Mg in the plant parts attributed to increased soil pH. Similarly, Mo significantly (P ≤ 0.05) increased the uptake of P, K, Ca and Mg in all organs of P. vulgaris but decreased the S content in roots. Application of lime significantly increased the uptake of the macroelements in shoots and whole plant only in the glasshouse probably due to differences in soil volumes between the glasshouse and the field conditions. There was significant interaction between Rhizobium × Mo on P, K and S in roots, shoots and pods of P. vulgaris in glasshouse and field experiments; Rhizobium × lime on the amount of S in shoots and whole plant of P. vulgaris grown in the field experiments; Mo × lime on the uptake of P in roots and Ca in pods in glasshouse as well as P in roots in field studies. Regardless of the type of interaction, combining Rhizobium and Mo at 12 g g-1 seeds and/or lime at 3 t ha-1 maximised the uptake of P and K in roots and Ca in pods compared with zero control. These results suggest that Rhizobium inoculation and the supply of Mo and lime can be of great benefit to farmers growing grain legumes such as P. vulgaris in acidic soils ranging from pH 6.1 to 6.2. Furthermore, these inputs have shown to improve the uptake of P, K, Ca and Mg, which are greatly required by the plant for growth, nodulation and N2 fixation.

cDNA cloning and expression analysis of the chalcone synthase gene (CHS) from Polygonum minus

Tue, 30 Apr 2013 20:02:12 GMT

Nur Diyana Roslan1,2, Cheng-Seng Tan1,2, Ismanizan Ismail1,2 and Zamri Zainal1,2*

1School of Biosciences and Biotechnology, Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
2Institute of Systems Biology (INBIOSIS), University Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

Abstract

Flavonoids are secondary metabolites that are present at high levels in the Polugonum minus. In recent years, flavonoids have attracted the interest of researchers because of their antioxidant properties .Flavonoids are synthesised via the condensation of 4 coumaryl-CoA and 3 malonyl-CoA by the action of Chalcone synthase. A cDNA encoding a chalcone synthase was isolated from the leaves of Polygonum minus by rapid amplification of cDNA ends (RACE) and designated pmCHS (GenBank accession no. JQ801338). The full-length cDNA of P. minus pmCHS was 1472 bp with a 1179 bp open reading frame (ORF) that corresponded to a predicted protein of 392 amino acid deduced protein. In silico analysis showed that the calculated molecular weight and theoretical isoelectric point (pI) of pmCHS were 43.1 kDa and 5.78, respectively. Several important motifs, such asthe product binding site, active site and dimer interface, were also successfully identified from the deduced amino acid sequence. Multiple sequence alignment indicated that the pmCHS sequence was highly conserved and shared high sequence identity (>90%) with chalcone synthases from other plants. Gene expression analysis via qRT-PCR showed that pmCHS was most highly expressed in the roots, showing a10-fold increase compared to leaves and a 15-fold increase compared to stems . The specific mechanism underlying the high expression of pmCHS in the roots requires further investigation.

Antioxidant response of some Georgian wheat species to simulated acid rain

Tue, 30 Apr 2013 20:02:07 GMT

Nani Kacharava, Eva Chkhubianishvili, Gulnara Badridze*, Shota Chanishvili, and Lamara Mazanishvili
Department of Plant Physiology, Institute of Botany of Ilia State University, Botanikuri 1, Tbilisi 0105, Georgia
Abstract
Influence of artificial acid precipitations on the content of antioxidants, namely ascorbic acid, carotenoids, anthocyanins, total phenols and proline, and the activity of antioxidative enzymes, peroxidase and catalase, was investigated in endemic species of Georgian wheat: Triticum timopheevi Zhuk. (Georgian–Zanduri), and three cultivars of T. persicum V.–var. fuliginosum Zhuk. (Georgian–black Dika), var. rubiginosum Zhuk. (Georgian–red Dika) and var. stramineum Zhuk. (Georgian–white Dika). The experimental plants were sprayed with water solution of a mixture of sulfuric and nitric acids 2:1, with pH1.5, since the stem rising phase, at intervals of 5 days, till the end of vegetation. Control variants of the same species were sprayed with distilled water. Analyses were made in the flowering phase, a week after the last spraying. Spraying wheat plants with high acidity (pH1.5) solution caused an increase of ascorbic acid content in white Dika (by 29%, compared to control), synthesis of carotenoids and anthocyanins was activated in white Dika and red Dika (by 31% and 73% - carotenoids, and by 5% and 17% - anthocyanins respectively). Content of proline enhanced in leaves of all acid sprayed plants (by 7%, 30% and 72% compared to corresponding controls). Content of soluble phenols increased in all varieties of T. persicum compared with their controls (by 28%, 15%, and 37%). Activity of catalase raised in white Dika and.black Dika, while activity of peroxidase was higher in Zanduri and white Dika, compared with their controls. We conclude that high acidity (pH1.5) stress caused changes in the metabolism of the antioxidative system of the Georgian wheat species, but these changes were not unidirectional. Alterations in antioxidative system, which is responsible for plant resistance to stress, indicate that Georgian endemic wheats are resistant to high acidity (pH1.5), and may be recommended as reliable material for cultivation under progressively polluting environmental conditions.

Comparison of the effectiveness of ISSR and SSR markers in determination of date palm (Phoenix dactylifera L.) agronomic traits

Tue, 30 Apr 2013 20:02:02 GMT

HammadiHamza*, Mohammed Ali Ben Abederrahim, Mokhtar Elbekkay and Ali Ferchichi
Arid and Oases Cropping Laboratory, Arid Area Institute, Medenine 4119, Tunisia
Abstract
Date palm (Phoenix dactyliferaL.) is extensively cultivated in the Middle East and in North Africa. Seven ISSR markers and five SSR loci were selected and used to evaluate genetic diversity in twenty-six Tunisian cultivars. ISSR primers amplified a total of 43 polymorphic DNA fragments. The average was 6.1 fragments per primer. The microsatellites examined in this study were highly polymorphic possessing a great number of alleles with an average of 7.2 alleles per locus. Principal component analyses based on Nei Genetic distances showed groups of cultivars with a common maturity period and a common fruit consistency. SSR markers discriminate the fruit characteristics subpopulations in a more convincing way than ISSR markers. The Mantel test emphasizes a significant correlation between genetic distance and fruit consistency. A significant difference was observed between soft and dry subpopulations using ISSR data and between semisoft and the other fruit consistency subpopulations using SSR data.

Cryopreservation of Malayan kumquat (Fortunella polyandra) embryonic axes by vitrification

Tue, 30 Apr 2013 20:01:55 GMT

Omar Mahmoud Al Zoubi1 and Normah Mohd Noor2*
1School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
2Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
Abstract
Cryopreservation of embryonic axes of Fortunella polyandra was investigated using a vitrification-based technique. Plant vitrification solution 2 (PVS2) was added to cryovials containing embryonic axes (2 mm) and kept for 0, 5, 10, 15, 20, 25 or 30 minutes at 25°C and for 0, 15, 30, 45, 60 or 75 minutes at 0°C before plunging into liquid nitrogen. Another set of embryonic axes with the same treatment but not exposed to liquid nitrogen was used as a control. The highest survival percentage of the embryonic axes was 50.0% with 15 minutes exposure to PVS2 at 25°C and 53.30% with 60 minutes exposure at 0oC. Gradual increase in exposure to PVS2 from 50% to 100% at PVS2 in one to four steps was also studied at both temperatures. The embryonic axis survival rates of 50.0-56.7% obtained for 2- to 4-step PVS2 treatments at both temperatures were significantly better than those of embryonic axes directly exposed to PVS2 (survival of 30%), showing that the period of exposure to PVS2 and sequential applications of PVS2 to the embryonic axes are important for successful cryopreservation of F. polyandra.

Delayed softening of papaya (Carica papaya L. cv. Sekaki) fruit by 1-methylcyclopropene (1-MCP) during ripening at ambient and low temperature storage conditions

Tue, 30 Apr 2013 20:01:50 GMT

Azhane Ahmad1, Zainon Mohd. Ali1 and Zamri Zainal1,2,*
1School of Bioscience and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
2Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

*Corresponding author: zz@ukm.my, azhane_ahmad@yahoo.com

Abstract

Ripening of climacteric fruit such as papaya (Carica papaya L. cv.Sekaki) fruit depends on the ethylene action which later accompanied by softening process that can influence postharvest quality and storability of the fruit. Ethylene action inhibitors, 1-Methylcyclopropene (1-MCP) has been found to inhibit ethylene action and thus it can delay the fruit ripening process. The effects of 1-MCP on softening related changes were determined through skin color, weight loss, fruit firmness and activities of the cell wall degrading enzymes including α-galactosidase, β-galactosidase and pectinmethylesterase (PME) during ripening. In this study, fruit were treated with 90 ppb concentration of 1-MCP gaseous vapors for 12 hours in airtight container maintained at 20 oC. After treatments the fruit were randomly divided into two different storage temperature conditions; ambient temperature (28 oC) and low temperature (10 oC). Papayas at 10 oC conditions were packaged in polyethylene plastic stored for 4 weeks (28 days) and taken out on day 29 and left to ripen at ambient temperature (28 oC).Fruit treated with 1-MCP experienced a significant delayed in skin color development, weight loss and reduced firmness loss compared to the fruit without 1-MCP treatment. As softening progressed, activity of the cell wall degrading enzymes in fruit without 1-MCP treatment increased significantly coincident with a rapid declined in fruit firmness for both storage conditions. With 1-MCP, fruit demonstrated a delay in activity of cell wall degrading enzymes but continued to increase until 100 % yellow. Furthermore, the treated 1-MCP papaya fruit stored at 10 oC can retain shelf life for 5 days at ambient temperature without any spoilage from chilling injury (CI).Thus it may be concluded that the 1-MCP treatment may aid in delaying the softening process and further storage at low temperature extended the postharvest life and maintained the quality of the papaya fruit.

Morphology of trichomes in Pogostemon cablin Benth. (Lamiaceae)

Tue, 30 Apr 2013 20:01:46 GMT

Amalia Rusydi1, 4, Noraini Talip1*, Jalifah Latip2, Ruzi Abdul Rahman1, and Idris Sharif3
1School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
2School of Chemical Science and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
3Scanning Electron Microscopy Unit, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
4Biology Department, Mathematics and Science Faculty, Syiah Kuala University, 23111 Darussalam, Banda Aceh, Indonesia
Abstract
Pogostemon cablin is also known as patchouli or nilam. This species is an aromatic plant which has economic importance due to its essential oil which is widely used as raw material for the perfume industry. This study was conducted in order to determine the types, anatomy and micromorphological features of the trichomes (glandular and non-glandular) on the patchouli leaf lamina. The findings of this study showed that there were eight distinct types of trichome (two non-glandular and six glandular trichomes). The non-glandular trichomes are simple unicellular and multicellular. The glandular trichomes are short-stalked capitate, long-stalked capitate, peltate, digitiform, clavate filiform and fusiform.

Effects of potassium on yield, photosynthate distribution, enzymes’ activity and ABA content in storage roots of sweet potato (Ipomoea batatas Lam.)

Tue, 30 Apr 2013 20:01:41 GMT

Hongjuan LIU, Chunyu SHI *, Haifeng ZHANG, Zhenzhen WANG, Shasha CHAI
Agronomy College, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai’an 271018, China
Abstract
Effects of supplying K2O at 0, 12, 24 and 36 g m2 soils on distribution of photosynthates (carbohydrates produced by photosynthesis) were studied in plants of Ipomoea batatas Lam (Beijing 553). Storage roots yield, photosynthate distribution, sucrose synthase and insoluble acid invertase activities, as well as abscisic acid content in storage roots were determined. The storage root yield first increased and then decreased as the increase in potassium fertilizer supply, with the highest increase of 36.42% under treatment of 24 g K2O m2 (K24) which was determined to be the optimal amount of fertilization. Under the K24 treatment, the chlorophyll content and PN of functional leaves were improved in the early growth stage, as was the leaf area index. This treatment also increased the sucrose synthase activity and abscisic acid content of storage roots by 16.47% and 18.27%, respectively, for the whole growth stages, and improved insoluble acid invertase activity by 5.75% in the late growth stage. Larger increases of abscisic acid content appeared in late growth stage. More photosynthates were unloaded to storage roots as a result of the improved sucrose synthase, insoluble acid invertase activities and abscisic acid content which contributed to sink strength. The dry matter distribution rate of storage roots was significantly higher (69.45%) in plants with K24 treatment. In summary, sweet potatos under K24 treatment not only supplied more photosynthates during the early and middle growth stages but also had higher sink strength of storage roots which lead to higher photosynthate distribution in storage roots mainly in the late growth stage. The optimal amount was K2O 24 g m-2.