July 2014 issue | 3(1) 2014
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Plant Knowledge Journal | July 2014
Research Article Open Access

Evaluation of cellular responses of the halophyte Aeluropus littoralis to salinity stress through cell growth, sugars and polyamines content

Ehsan Sadegh-Nejad1, Hossein Askari2*, Morteza Gholami2

1Department of Plant Biology, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran
2Department of Biotechnology, Faculty of New Technologies Engineering, Shahid Beheshti University, Tehran, Iran

Abstract
The tolerance mechanisms of salt stress in halophyte plants can be used for sensitive plants to salinity for creating stress-tolerant crops. The cell suspension of Aeluropus littoralis plant was cultured under MS medium supplemented with 4 mgL-1 2, 4-dichlorophenoxyacetic acid (2,4-D) and 0.2 mgL-1kinetin. Seven levels of NaCl (0, 30, 60, 90, 120, 150, 180 and 210 mM) was also applied as salinity treatment in cell culture suspension. The cellular growth of Aeluropus littoralis was determined during three weeks of subculture. The starch and soluble sugar accumulation and free polyamines were evaluated in stationary phase of cellular growth curve related to different concentrations of salt. The results showed that starch content was significantly decreased in 120 mM (71%), 150 mM (46%) and 180 mM (39%) salt treatments than control treatment and increased in the concentration of 210 mM (17%) than control treatment that it was not significant. The soluble sugars content was also increased in 30 mM salinity (32%) and remained approximately constant during different concentrations from 120 till 210 mM of salinity than control treatment. Polyamines (PAs) content of cells was decreased with increase of salinity. However, free Putrescine (Put) and Spermine (Spm) were found in higher levels in the 30 mM salt treatment, that it can be the reason for increasing of cell growth than control treatment. In addition, Spm content showed to be slightly changed with different salinity levels from Put or Spermidine (Spd). It is proposed that PAs and sugars have a significant role in the adaption mechanism of Aeluropus genus under saline conditions.

Pages 1-7 | Full Text PDF
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Research Article
Open Access

Variations of genotypes, seasons and genotype by season interactions for yield, yield components and agronomic traits in finger millet (Eleusine conaracana L. Gaertn)

Goitseone Malambane1*, Prasit Jaisil1,2, Jirawat Sanitchon1,2, Bhalan Suriharn1,2, Darunee Jothityangkoon1,2

1Department of Plant Science and Agricultural Resources, Khon Kaen University, Khon Kaen, Thailand 40002
2Plant Breeding Research Center for Sustainable Agriculture, Khon Kaen Univesity, Khon Kaen 40002, Thailand

Abstract
The socio-economic importance of finger millet for African and Asian countries is quite high and the crop has considerable potential in dryland farming systems of semi-arid and arid regions. An experiment was undertaken to determine the magnitude and nature of the genotype by season interaction and the response of genotypes to different seasons. Thirty-five finger millet accessions were evaluated in the dry season 2010/11 and the rainy season 2011. Combined analyses showed significant differences among seasons, genotype and genotype by season interactions for yield per plot, 1000 seed weight, finger length, plant height and days to flowering. Season contributed to a large proportion of variations on yield per plot (97.4 %), 1000-seed weight (93.5 %), finger length (62.8%), plant height (94.6%) and days to flowering (78%). However, variations due to genotype were (38.5%) for finger number, finger width (41.8%) and days to flowering (16.8%). Accession IE 3618 showed low variation in yield for the two seasons while IE 4565 had the highest variations when evaluated in the two seasons for yield per plot. Because of high yield and low variation, IE 3618 is promising for production in both the dry season and the rainy season.

Pages 8-14 | Full Text PDF
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Research Article
Open Access

Growth, lipid peroxidation, antioxidant enzymes and nutrient accumulation in Amrapali mango (Mangifera indica L) grafted on different rootstocks under NaCl stress

Vishambhar Dayal1, Anil Kumar Dubey1*, Om Prakash Awasthi1, Raghunath Pandey2, Anil Dahuja3

1Division of Fruits and Horticultural Technology, IARI, New Delhi, India
2Division of Soil Science and Agricultural Chemistry, IARI, New Delhi, India
3Division of Biochemistry, IARI, New Delhi, India

Abstract
Ion (Na+ and Cl-) exclusion and upregulating antioxidant activities in mango scion cultivar through grafting on salt tolerant rootstocks could extend the mango cultivation in salt affected area with commercially viable production. Thus, the selection of rootstock-scion combinations with enhanced tolerance to salinity requires a better understanding of rootstock influence on ion exclusion and biochemical changes. To achieve this goal, two polyembryonic, Olour and Kurakkan and one monoembryonic viz., non-descript seedling (common mango rootstock) grafted with the scion Amrapali were tested under NaCl stress. Grafted plants were irrigated with water containing 0.0 or 50 mM NaCl at four days interval for 90 days. In the tested rootstock-scion combinations, minimum reduction in plant height and leaf numbers under salinised condition was found in graft with non-descript seedlings and Olour rootstocks, respectively. However, malondialdehyde (MDA) content and catalase (CAT) activity were similar in all rootstock-scion combinations. The higher peroxidase activity (213.43 Ab560 U g-1 leaf fresh weight) and proline accumulation (215.98 g g-1 of fresh weight) was observed in plants grafted with Olour rootstock. Graft with non-descript seedlings had reduced accumulation of Na+ in leaf concentration while graft Olour inhibited the accumulation of leaf Cl- concentration in the presence of NaCl. Olour seems to be good Cl- excluder rootstocks while non-descript seedling could effectively exclude Na+ from leaf tissues of scion cultivar.

Pages 15-22 | Full Text PDF
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Research Article
Open Access

Evaluation of the usefulness of senescing agent potassium iodide (KI) as a screening tool for tolerance to terminal drought in soybean

Virender Singh Bhatia1*, Kanchan Jumrani2 and Govind Prakash Pandey2

1National Research Centre for Soybean, Khandwa Road, Indore 452 001, India
2School of Life Sciences, DAVV, Khandwa Road, Indore 452001, India

Abstract
Drought at seed fill stage is a major limitation to soybean productivity in countries where crop is mainly grown on seasonal rains. Improved translocation of stem reserves to developing seeds under such a condition could play an important role in improving the productivity of soybean.  However, uncertain nature of rains makes it difficult to evaluate large number of genotypes for this trait under field conditions. Chemical desiccants such as potassium iodide (KI) have been successfully used to evaluate genotypes for terminal drought in many crops, but their use in soybean has not been reported. In this study, efforts were made to evaluate the usefulness of KI in identification of soybean genotypes tolerant to terminal drought. Three concentrations of KI (0.1, 0.2 and 0.3 %) were sprayed on soybean variety JS 335 at the beginning of seed fill (R5 stage) and, 7, 14, 21 and 28 days after R5 stage for two years (2008 and 2009). Based on relative losses in seed yield and 100 seed weight as compared to untreated control, it was observed that spraying of 0.1 to 0.2 % KI between 7 to 14 days after R5 stage can simulate terminal drought appropriately. Subsequently, 200 soybean genotypes were evaluated under field condition for relative tolerance to terminal drought by spraying 0.2 % KI at 10 days after plants reached to R5 stage. Three genotypes (EC 538828, JS 97-52 and EC 602288) were identified as showing relative tolerance to terminal drought as compared to other genotypes. These genotypes were further tested under natural drought at seed fill stage in rainout shelters. The reduction in seed yield (20-31 %) was relatively less in the identified genotypes as compared to other genotypes (34-60 %). It is concluded that KI can be used as chemical desiccant for field evaluation of large number of soybean genotypes and identification of genetic sources for tolerance to terminal drought.

Pages 23-30 | Full Text PDF | Supplementary Data PDF
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Research Article
Open Access

Effects of copper, nickel and zinc on biochemical parameters and metal accumulation in gouan, Aeluropus littoralis

Leila Rastgoo1, Abbas Alemzadeh2, Ali Mohammad Tale2, Sara Esmaeili Tazangi3, Tahereh Eslamzadeh4

1Biotechnology Center, College of Agriculture, Shiraz University, Shiraz, Iran
2Department of Crop Production and Plant Breeding, College of Agriculture, Shiraz University, Shiraz, Iran
3Biotechnology Department, School of Agriculture, Shahid Bahonar University, Kerman, Iran
4Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran

Abstract
To study the effects of three heavy metals (Cu, Zn and Ni) on Aeluropus littoralis, a halophytic plant, a research was carried out in greenhouse. The study was laid out in a randomized complete block design with 5 replicates. Two different concentrations (50 M and 100 M) for each metal were used. Some cellular oxidative biomarkers such as activity of three main antioxidant enzymes (superoxide dismutase (SOD), guaiacol peroxidase (GPx) and catalase (CAT)), as well as accumulation of proline, phenolic compounds, photosynthetic pigments and soluble protein content were investigated. The results showed that the proline and phenolic compounds accumulated with increasing heavy metal concentrations, while total chlorophyll content decreased in all treatments. Heavy metals contents in shoots increased with the increasing of heavy metals concentration without any important morphological changes. In all treatments SOD activity increased, but GPx activity decreased while CAT activity and soluble protein only decreased in Ni and Cu treatments, respectively. The results showed that chlorophyll a was more sensitive to Zn and Ni, but chlorophyll b was more sensitive to Cu. In addition, it was revealed that each heavy metal has unique biotoxicities or biofunctions and affects the analyzed parameters plant in particular way. Consequently, A. littoralis heavy metal tolerance depends on the species and concentration of metal.

Pages 31-38 | Full Text PDF
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