Shot Term Research Articles

MICROPROPAGATION OF GLOBE ARTICHOKE PLANT (Cynara scolymus L.). 1- EFFECT OF SODIUM HYPOCHLORITE CONCENTRATIONS, CYTOKININS AND SUBCULTURES NUMBER ON SHOOTS MULTIPLICATION RATE.

An efficient protocol for both development of aseptic tissue cultures and shoots regeneration for Cynara scolymus L. cv. Herious was established by using in vitro micropropagation technique. Meristem tips of good young offshoots from selected globe artichoke plants were used as explants. Dipping shoot tips (1-2 cm length) in 70% ethanol for 5-10 seconds followed by 0.1% HgCl2 (W/v) for 2 minutes and then in 3% sodium hypochlorite for 20 minutes was the most effective sterilizing and disinfectant treatment for surviving the majority of meristem tip cultures after 5 weeks of culturing. In the establishment stage, adding 0.5 mg thidiazuron (TDZ) /l to MS basal medium gave the best values for both shoots and leaves number but registered middle values for average shoots length compared to the other treatments. Concerning the multiplication stage, among the different cytokinin types and concentrations used such as 2iP, BA and Kin (at 0.5, 2.5 and 5.0 mg /l for each) and TDZ (at 0.05, 0.5 and 1.0 mg /l) in addition to control treatment (hormone-free MS medium), 2iP with all concentrations recorded the highest values in this respect in terms of shoots and leaves number and average shoots length. The multiplication rate of proliferated globe artichoke shoots and average shoots length were markedly increased with increasing subcultures number on MS basal medium augmented with 5.0 mg 2iP /l + 1.0 mg IAA /l till the fourth subculture then declined thereafter during the fifth one.

Effect of co-inoculation of methylotrophic Methylobacterium oryzae with Azospirillum brasilense and Burkholderia pyrrocinia on the growth and nutrient uptake of tomato, red pepper and rice

The present greenhouse study was undertaken to evaluate the effects of co-inoculating methylotrophic Methylobacterium oryzae CBMB20 along with nitrogen-fixing Azospirillum brasilense CW903 or a phosphate solubilizing bacterium Burkholderia pyrrocinia CBPB-HOD on the growth and nutrient uptake of tomato, red pepper and rice. Seed inoculation and soil/foliar application of the bacterial strains alone or under dual inoculation increased the plant growth in terms of shoot or root length and increased the nutrient uptake in the plants studied compared to uninoculated control plants. Co-inoculation of M. oryzae CBMB20 with A. brasilense CW903 or B. pyrrocinia CBPB-HOD improved the N and P concentration of plants, while the results varied among the plant species tested. Also, co-inoculation of the bacterial strains increased the activity of nitrogenase, urease and phosphatase enzymes in soil when compared to uninoculated control or individual inoculations. Though the inoculation effects were analyzed at an early stage of plant growth, the results conclusively suggest that M. oryzae being compatible with other microorganisms in the rhizosphere can potentially be used as individual inoculant or co-inoculated with other plant growth promoting bacteria to increase the production in sustainable agricultural systems.

Role of Arbuscular Mycorrhizae in the Alleviation of Ionic, Osmotic and Oxidative Stresses Induced by Salinity in Cajanus cajan (L.) Millsp. (pigeonpea)

AbstractSalinity stress causes ion toxicity and osmotic imbalances, leading to oxidative stress in plants. Arbuscular mycorrhizae (AM) are considered bio‐ameliorators of saline soils and could develop salinity tolerance in crop plants. Pigeonpea exhibits strong mycorrhizal development and has a high mycorrhizal dependency. The role of AM in enhancing salt tolerance of pigeonpea in terms of shoot and root dry weights, phosphorus and nitrogen contents, K+ : Na+, Ca2+ : Na+ ratios, lipid peroxidation, compatible solutes (proline and glycine betaine) and antioxidant enzyme activities was examined. Plants were grown and maintained at three levels of salt (4, 6 and 8 dSm−1). Stress impeded the growth of plants, led to weight gain reductions in shoots as well as roots and hindered phosphorus and nitrogen uptake. However, salt‐stressed mycorrhizal plants produced greater root and shoot biomass, had higher phosphorus and nitrogen content than the corresponding uninoculated stressed plants. Salt stress resulted in higher lipid peroxidation and membrane stability was reduced in non‐AM plants. The presence of fungal endophyte significantly reduced lipid peroxidation and membrane damage caused by salt stress. AM plants maintained higher K+ : Na+ and Ca2+ : Na+ ratios than non‐AM plants under stressed and unstressed conditions. Salinity induced the accumulation of both proline and glycine betaine in AM and non‐AM plants. The quantum of increase in synthesis and accumulation of osmolytes was higher in mycorrhizal plants. Antioxidant enzyme activities increased significantly with salinity in both mycorrhizal and non‐mycorrhizal plants. In conclusion, pigeonpea plants responded to an increased ion influx in their cells by increasing the osmolyte synthesis and accumulation under salt stress, which further increased with AM inoculation and helped in maintaining the osmotic balance. Increase in the antioxidant enzyme activities in AM plants under salt stress could be involved in the beneficial effects of mycorrhizal colonization.

Symbiotic Status of Two Protected Forests of Acacia nilotica Var. tomentosa in the Senegal River Valley

Soil from two protected forests of Acacia nilotica var. tomentosa, located in the Senegal River Valley, was sampled to assess their rhizobial and mycorrhizal status. Forty-one soil samples (0.5 kg each) were collected at 10–15 cm depth in the rhizosphere of Acacia in the two protected forests of Diarra and Lam Nadie (26 and 15 samples, respectively). Soil extracts were used to test rhizobial nodulation of in-vitro growing seedlings of two varieties of A. nilotica, var. tomentosa and var. adansonii. Arbuscular mycorrhizal (AM) fungi soil infectivity was estimated by the most probable number (MPN) method using Acacia nilotica var. tomentosa as test plant. In the Diarra forest, eight soil samples of the 26 tested contained indigenous rhizobial strains nodulating both A. nilotica var. adansonii and A. nilotica var. tomentosa, whereas only one from Lam Nadie contained rhizobial strains. Fifty-six strains were isolated, purified, and their infectivity and efficiency tested on Acacia nilotica var. tomentosa after 60 days of culture under controlled conditions. Strains ND37 from Diarra and NL2 from Lam Nadie are the more effective in terms of shoot and root dry weight. The estimation of the number of viable propagules using the MPN method showed some significant differences between the populations of AMF of Diarra, which was high, and that of Lam Nadie, which was very low. The percentage of colonization of Acacia nilotica var. tomentosa was correlated with the MPN values. These results are discussed with regards to the state of forests.

Root characteristics and growth potential of container and bare-root seedlings of red oak (Quercus rubra L.) in Ontario, Canada

Root characteristics and field performance of container and bare-root seedlings of red oak (Quercus rubra L.) were compared during the first growing season after planting. Sixty seedlings of each stock type were planted on a clearfell and weed-free site near Restoule, Ontario. Twenty-four additional seedlings from each stock type were compared at the start of the study in terms of shoot and root parameters. Measurement of root and shoot parameters were repeated at three dates during the first growing season in the field. The root systems of container stock had a larger number of first order lateral long roots and were significantly more fibrous than bare-root stock. These differences were sustained throughout the first growing season. In terms of field performance, container seedlings had 100% survival and achieved significant increases in both biomass and shoot extension. Bare-root seedlings suffered 25% mortality, significant shoot dieback and more variable growth. The mean relative growth rate (RGR) of container seedlings increased throughout the study period to a maximum of 30 mg/g/day, whereas the mean RGR of bare-root stock remained close to or below zero. Overall, the container seedlings proved less prone to transplanting shock than the bare-root seedlings, most likely due to favourable root architecture and the pattern of root development. Further work may be warranted in container design, growing regimes and root architecture to fully realise the potential of container systems for the production of high quality red oak seedlings across a range of site conditions.

Growth Responses and Nitrogen-15 Absorption of Desert Saltgrass Under Salt Stress

Saltgrass [Distichlis spicata (L.) Greene var. stricta (Gray) Beetle], accession WA-12, collected from a salt playa in Wilcox, AZ, was studied in a greenhouse to evaluate its growth responses in terms of shoot and root lengths, shoot dry-matter yield, and nitrogen (N) (regular and 15N) absorption rates under control and salt (sodium chloride, NaCl) stress conditions. Plants were grown under a control (no salt) and three levels of salt stress (100, 200, and 400 mM NaCl, equivalent to 5850, 11700, and 23400 mg L− 1 sodium chloride, respectively), using Hoagland solution in a hydroponics system. Ammonium sulfate [(15NH4)2SO4], 53% 15N (atom percent 15N) was used to enrich the plants. Plant shoots were harvested weekly, oven-dried at 60°C, and the dry weights measured. At each harvest, both shoot and root lengths were also measured. During the last harvest, plant roots were also harvested and oven-dried, and dry weights were determined and recorded. All harvested plant materials were analyzed for total N and 15N. The results showed that shoot and root lengths decreased under increasing salinity levels. However, both shoot fresh and dry weights significantly increased at 200 mM NaCl salinity relative to the control or to the 400 mM NaCl level. Shoot succulence (fresh weight/dry weight) also increased from the control (no salt) to 200 mM NaCl, then declined. The root dry weights at both 200 mM and 400 mM NaCl salinity levels were significantly higher than under the control. Concentrations of both total-N and 15N in the shoots were higher in NaCl-treated plants relative to those under the control. Shoot total-N and 15N contents were highest in 200 mM NaCl-treated plants relative to those under the control and 400 mM salinity.

A One-StepIn VitroCloning Procedure for Cranberry (Vaccinium macrocarponAit.)

Abstract An in vitro cloning protocol that enables shoot proliferation and rooting of cranberry (Vaccinium macrocarpon Ait.) genotypes in the same medium was developed. Plantlets of four clones (NC197, NC201, NC216, and NC230) from natural stands in Newfoundland and Labrador and one cultivar, Stevens, were obtained in vitro from nodal explants on a nutrient medium containing the plant growth regulators, N6-[2-isopentenyl]adenine (2iP) or zeatin. Zeatin was more effective than 2iP for shoot proliferation and rooting. The genotypes differed in terms of shoot and root number per explant, length and vigor, number of leaves per shoot, and callus formation at the base of explants; this was manifested with various concentrations of 2iP and zeatin over two culture periods. Shoots proliferated and roots developed best when nodal segments were cultured in the medium supplemented with 2 μM to 4 μM zeatin. Subculturing improved the number of shoots and roots per responding explant, shoot height, root length, and root vigor. Changing the positioning of explants on the medium from vertically upright to horizontal increased shoot number and callus size, but decreased the rooting incidence, roots per explant, and root vigor. The protocol proposed from this study is expected to be applicable for propagating a wide range of cranberry germplasm.

Effects of carbon source and concentration on development of lingonberry (Vaccinium vitis-idaea L.) shoots cultivated in vitro from nodal explants

Abstract Carbohydrate type and concentration and their interactive effects on in vitro shoot proliferation of three lingonberry (Vaccinium vitis-idaea ssp. vitis-idaea L.) cultivars (‘Regal’, ‘Splendor’, and ‘Erntedank’) and two V. vitis-idaea ssp. minus (Lodd) clones (‘NL1’ and ‘NL2’) were studied. Nodal explants were grown in vitro on medium with 2 μM zeatin and either glucose, sorbitol, or sucrose at a concentration of 0, 10, 20, or 30 g l−1. The interactive effects of carbohydrate type and concentration and genotype were important for shoot proliferation. The best response was afforded by sucrose at 20 g l−1 both in terms of explant response and shoot developing potential, although glucose supported shoot growth equally well, and in ‘NL1’ at 10 g l−1 it resulted in better in vitro growth than sucrose. Carbohydrate concentration had little effect on shoot vigor. The genotypes differed in terms of shoots per explant, length, and vigor, leaves per shoot, and callus formation at the base of explants; this...

ユーザの干渉を受ける迂回経路探索 : 意識アーキテクチャに基づく短期学習(環境適応ロボティクス)

ユーザの干渉を受ける迂回経路探索 : 意識アーキテクチャに基づく短期学習(環境適応ロボティクス)

Nursery studies in Terminalia paniculata Roth. Seedlings

A nursery study was conducted in College of Forestry, Kerala Agricultural University, Vellanikkara to find out the effect of potting media containing different types of waste materials like garbage and coir dust on establishment, growth and vigour of seedlings of Terminalia paniculata Roth. The seedlings raised in potting media T1 (Soil: sand: cowdung), T5 (Soil: fresh garbage: cowdung) and T12 (Soil: coirdust: cowdung) recorded 100 per cent success with regard to both initial establishment after one week of planting and final survival after eight months. In most of the treatments, the initial establishment was found to be good. The initial establishment and survival were very poor when fresh garbage alone was used as a planting medium. With regard to growth and vigour in terms of shoot and root growth parameters and other physiological attributes, potting mixtures of soil and cowdung with four weeks decomposed garbage were found to be most promising. Growth and vigour was generally found to be less when seedlings were grown in coirdust. The relative growth rate and other physiological attributes were also found to be less for this treatment. Generally, the chlorophyll A content was found to be slightly higher when compared to chlorophyll B. Stomatal distribution did not show a specific pattern with regard to treatments. Nutrient uptake particularly nitrogen was found to be more when cowdung and partially decomposed garbage were used as components of potting media. However, the potting media did not affect the uptake of potassium and phosphorus.

Effects of Combined Nutrient and Water Stress on the Growth of Hopea Odorata Roxb. and Mimusops Elengi Linn. Seedlings

The growth of Hopea odorata and Mimusops elengi seedlings under drought and various fertilization rates under nursery conditions was investigated. Both H. odorata and M. elengi seedlings responded differently to fertilizer application and drought. Application of slow-release fertilizer (Best Tab, 20:10; 5 NPK) at 30 and 50 g promoted greater height growth for H. odorata and M. elengi seedlings, respectively. M. elengi seedlings were able to tolerate high fertilizer application (50 g), but the resulting form (small trunk diameter and excessive height) was not suitable for urban planting. Growth of H. odorata seedlings was greatly promoted through application of 30 g of fertilizer under well-watered conditions, resulting in a much more balanced growth in terms of shoot and root ratio, which is vital for plants growing in the harsh urban environment where competition for water and nutrients is usually intense.

Potassium uptake efficiency of potato and wheat in relation to growth in flowing solution culture

Uptake efficiency (in terms of shoot K content) of potato decreased with time compared to that of wheat at a deficient K level of 1.5 μM. This resulted from the decrease in root-shoot ratio with time for potato only. Both shoot and root growth rates of potato depended on solution K levels in the initial stages and were greater at higher K levels. At optimum K, uptake efficiency of potato increased with time and this was due to the increased K-influx with time. The K concentration of 4–5% in the potato shoot was sufficient to achieve 90% of maximum shoot growth rate. Plants grown at optimum K concentration attained shoot K content of 4–5% rapidly and achieved maximum shoot growth rate faster than those grown at low K concentration.

中国・寧夏のブドウ‘巨峰’の良好な有核結実，はい珠発育と花粉管成長

Kyoho' grapevines cultivated in Ningxia, China, set a high percent of seeded berries compared with the same cultivar grown in Okayama, Japan which usually sets a lot of seedless shot berries. To clarify the differences in berry set, we compared these 'Kyoho' in terms of shoot and pistil growth, ovule development, and pollen tube penetration into the ovules. Shoot growth was less vigorous and ovule development was less abnormal in 'Kyoho' in Ningxia. Pollen tube penetration into micropyle was more abundant in 'Kyoho' in Ningxia. A better set of seeded berries in Ningxia was discussed as related to its climatic conditions and usage of own-root system.

Root and shoot growth, assimilate partitioning and cell proliferation in roots of sitka spruce ( Picea sitchensis) grown in filtered and unfiltered chambers

Rooted cuttings of clonal Sitka spruce ( Picea sitchensis (Bong.) Carr.) were grown from April to October in 1 m long tubes sunk into the ground inside open top chambers. The same experiment was repeated in each of two consecutive years using a different clone of Sitka spruce each year. Air was either passed directly into the chambers (ambient air) or passed over charcoal filters which removed the majority of gaseous pollutants before entering the chambers (filtered air). Ambient pollution did not appear to influence the growth of Sitka spruce at least over the experimental period used. No significant differences were found between plants exposed to ambient or filtered air in terms of shoot and root dry mass, needle dry mass, root length, carbohydrate content of roots and needles, and in the percentage of meristematic cells close to the apex in each phase or interphase or undergoing mitosis.

Integrated control of root-knot disease in three crop plants using chitin and Paecilomyces lilacinus

Paedlomyces lilacinus, a rhizospherc inhabiting nematophagous fungus, along with chitin was evaluated in sterilized soil for the suppression of Meloidogyne incognita, causal agent of root-knot disease in Solanum melongena, Lycopersicon esculentum and Cicer arietinum. The soil was subjected to various treatments. The plant growth after 30, 60 and 90 days was assessed in terms of shoot and root length, shoot and root fresh and dry wt. and number of galls/g root fresh wt. Combination of fungus with chitin enhanced suppression of Meloidogyne incognita more than using them alone.

The Influence of Temperature Upon Physiological Processes in Early-Flowering and Late-Flowering Strains of Thlaspi arvense L.

This study was initiated to determine net photosynthesis, respiration, and stomatal conductance for early-flowering (EF) and late-flowering (LF) strains of Thiaspi arvense L., and to determine the relative impact of temperature on these processes in the two strains. The strains have been shown to differ by a single gene. Vernalized EF and LF plants were grown under controlled environments at day temperatures of 1 50C, 200C, and 250C (1 6-h photoperiod) each, with 1 50C nights. During the period of floral initiation for the EF strain, net photosynthesis, respiration, and stomatal conductance were determined in both strains. Plants of the LF strain had higher net photosynthesis rates and lower respiration rates. Net photosynthesis was most efficient at 200C days, while respiration rates increased with increasing temperature. Stomatal conductance was greater in the EF strain, which also had larger stomata than plants of the LF strain. Generally, EF plants grew more quickly in terms of shoot dry weight than LF plants. However, at 250C, the LF plants had significantly more shoot dry weight. We suggest that differential net photosynthesis and respiration rates of the EF and LF strains of T. arvense may influence the relative amounts of carbohydrates and nitrogen available to the shoot apices and therefore affect the time to floral transition.

Growth and productivity of crops in association with an Acacia nilotica tree belt

The influence of a single row plantation of Acacia nilotica on the growth and productivity of agricultural crops was assessed in the arid regions of Haryana, India with Triticum aestivum (wheat), Trifolium alexandrinum (barseem), Cicer arietinum (chickpea) and Gossypium hirsutum (cotton) being raised on the southern side of tree belt. Crop density, biomass production (of shoot and root), crop growth (in terms of shoot and root length) and yield of all the four crops increased with increasing distance from the tree canopy. A direct negative correlation (correlation coefficient value 0·9 or above in the majority of characters) between parameters studied and the distance from the tree was noticed. The maximum affect was observed in shoot biomass (reduced by 58, 42, 42, and 41% in T. aestivum, T. alexandrinum, C. arietinum and G. hirsutum, respectively) and minimum affect was on root growth. Yield reduction due to trees up to 15 m distance was 37·8, 49·0, 40·6 and 34·4% in T. aestivum, T. alexandrinum, C. arietinum and G. hirsutum, respectively. It is suggested that farmers holding small parcels of land should not grow crops in association with A. nilotica trees under arid conditions.

幼若性を異にするカキ (Diospyros kaki L.) の培養個体および実生の生長および発根特性の比較

This study describes the influence of the number of subcultures on the rooting ability of persimmon (Diospyros kaki L. cv. Jiro) shoots cultured in vitro, and also investigates the growth characteristics of the acclimatized plants which might be affected by rejuvenation.1. The percentages of rooted shoots from adult plants increased with repeated subcultures. The rooting percentage was only 3.3% after three subcultures increasing to 90% after 38 subcultures. In contrast, shoots from juvenile seedlings had as high as 70% rooting after three subcultures.2. In terms of shoot and root dry weights, the micropropagated plants grew more vigorously than seedling plants in the first growing season. Some of the micropropagated trees bore their first flower in the second growing season, suggesting that partial rejuvenation or reinvigoration, but not true rejuvenation, was responsible for the early flowering and the juvenile characteristics observed in the micropropagated plants.

Relative importance of Ca, N, and P in enhancing mycorrhizal activity inleucaena leucocephalagrown in an oxisol subjected to simulated erosion

Abstract Pot experiments were conducted in the greenhouse to determine the combined effects of lime, nitrogen and phosphorus and the relative importance of each of these nutrients in establishing nodulated and mycorrhizal Leucaena leucocephala (Lam.) de Wit Var. K8 in an oxisol subjected to simulated erosion. Leucaena was grown in the soil inoculated or not with the vesicular‐arbuscular mycorrhizal fungus Glomus aggregatum Schenck and Smith emend Koske, with or without a basal nutrient (basal) consisting of K, Mg, S, Zn, Cu, and B plus lime, N, and P (complete) or one of the latter three supplements. The extent of mycorrhizal colonization of roots as well as mycorrhizal effectiveness, as measured by pinnule P content increased when the eroded soil was amended with combinations of all the nutrients and inoculated with G. aggregatum. Similar trends were observed when symbiotic effectiveness was measured in terms of shoot P, Cu, and Zn status and dry matter yield. Nodule dry matter was also responsive to ame...

Germplasm Assessment in Trifolium Species

AbstractPopulations of 64 taxa of Trifolium were assessed for nitrogen fixation and dry matter production with and without added mineral nitrogen. The number of rhizobia per gram of compost capable of inducing nodulation was tested in 7 species and ranged from 3 to 114, showing interspecific variation for nodulation with indigenous rhizobia. In a sample of 8 species, nitrogen fixation was assessed by acetylene reduction and nodule scoring. There was a good correlation (84 %, P ≤ 0.01) between the two methods, and therefore nodule score was used as a measure of nitrogen fixation in the main assessment. There were large differences between populations in terms of shoot and root dry weight, the shoot: root ratio and nodule score. Added nitrate had a significant effect on all characters, increasing shoot dry weight and the shoot: root ratio and decreasing root dry weight and the nodule score. Results showed the importance of assessing legume germplasm with and without added nitrate in locations where suitable rhizobia for the nodulation of exotic species might not be present.