International Journal of Plant Production
Volume:3 Issue: 4, Oct 2009

Bulblet production from node explant grown in vitro in hybrid lilies

Abstract :An attempt was made to regenerate bulblets from ex vitro node explants of hybrid lilies in the year 2007. Node sections (3-4 mm) isolated from the middle part of the stem in hybrid lilies were cultured on Murashige and Skoog (MS) medium supplemented with several combinations of NAA and BA. Growth regulator-free medium was not effective in inducing bulblet regeneration. A significant increase in the percent of explant producing bulblets and number of bulblets per explant was observed when 2 mg/l NAA was used in combination with 1.5 or 2 mg/l BA. The heaviest bulblets were obtained with 2 mg/l NAA in combination with 1.5 mg/l BA after 90 days of culture. The cultivar Apeldoorn produced greater number of bulblets whereas more weighty bulblets were produced in the cultivar Beartix. 1 or 2 mg/l IBA was most effective in producing roots. The rooted bulblets were hardened with 80-82% survival success after 30 days of transfer in the pots. Keywords: Asiatic hybrids; Bulblet; Growth regulators; Micropropagation; Node explant; Oriental hybrids

The effect of abscisic acid (ABA) and excess benzyladenine (BA) on the formation of shoot from tea (Camellia sinensis L. assamica × sinensis) leaf was investigated in this research. Callus was formed and grew well when explants were cultured on LS basal medium supplemented with (in mg/L) thiamine-HCl, 1.25; pyridoxine-HCl, 0.625; nicotinic acid, 0.625; indole-3-acetic acid (IAA), 30; naphthaleneacetic acid (NAA), 30; kinetin, 0.1; myoinositol, 100; as well as 3% (w/v) sucrose. After two months, the calli were transferred to a modified B5 medium in order to regenerate plant. As a result, we observed root formation in the transferred calli to B5 medium after one month. Subsequently, the calli were transferred to the aforesaid B5 medium supplemented with ABA (2 mg/L) and excess BA (400 mg/L) to form shoot. The calli turned green and showed differentiation of globular and heart embryos when transferred to the modified B5 medium, without formation of shoot. These findings showed that the applied concentration of ABA may cause inhibition of conversion of globular and heart embryos to shoot. The increased level of BA, however, was not able to ameliorate the effect of ABA.

Antioxidant activity of Berry (Morus alba var. nigra) was investigated. For superoxide anion radical assay, the superoxide anion radicals were generated by a pyrogallol auto oxidation system, Nitric oxide radical inhibition by the use of Griess Illosvoy reaction and reducing power was determined according to the Oyaizu method. At least this sample was represented a potential antioxidant capacity that was increased with increase in concentration of extract.

Sustainability of rice production under limited water conditions is threatened by increasing irrigation water scarcity. Therefore, physiological and morphological responses of rice to varying water stress management strategies should be determined. The physiological and morphological responses of a semi dwarf rice (Hashemi cultivar) to water stress intensities (mild and severe, i.e., short-duration of stress with early recovery and long-duration stress with late recovery, respectively) and timing (mid-tillering, booting and 50% of flowering) were studied in a pot experiment. The severe water stress at mid-tillering significantly (P<0.05) decreased plant height and the number of panicle per hill and delayed flowering. The severe water stress at different growth stages caused substantial yield losses by large percentage of unfilled grains. Root weight was highest under mild water stress at 50% of flowering followed by severe water stress at mid-tillering. Relative transpiration (RT) was not lowered until the thresholds of the fraction of transpirable soil water (FTSW), plant available water (PAW) and soil water tension (h) reached to 0.46 (-), 0.9 (-) and 78.0 kPa, respectively. These values were approximately close to those obtained for the relative leaf development rate (RL), as 0.44 (-), 0.91 (-) and 74.6 kPa, respectively. These results indicated that transpiration and leaf development rates have the same sensitivity to water deficits. However, in the mid-tillering, RL was more sensitive to water deficit than RT. The results of thresholds for RT indicated that booting stage is more sensitive than other stages. It is concluded that water tension of 1500 kPa as considered for permanent wilting point is not suitable for rice. Therefore, PAW can not be a suitable soil-water criteria for rice plants that are sensitive to water deficit. Furthermore, It is concluded that Hashemi cultivar is very sensitive to mild and severe drought stress during reproductive stage.

Drought is one of the major problems affecting crops production, including corn, in many parts of Iran. In order to detect drought tolerant grain corn hybrids, an experiment with twenty corn hybrids was conducted during 2006 in Qom Province, Iran, using a complete randomized block design with four replications, under optimal moisture and drought stress condition. Results showed diversity among hybrids in response to moisture conditions. BC504 and BC652 produced the highest yields and BC678 and NS504 produced the lowest yields under optimal and stress conditions, respectively. Assessing hybrids according to some selection indices lead to introduce BC504, BC652, BC404, KSC302, KSC320 and KSC647 as drought tolerant ones. It seems likely that Stress Tolerance Index, Geometric Mean Productivity, and Harmonic Mean indices, which showed the highest correlation with grain yield under both optimal and stress conditions, can be used as the best indices for maize breeding programs to introduce drought tolerant hybrids.

Storage conditions of oil seeds before industrial extraction might influence the quality of the crude oil. The aim of present study was to clarify the storage able potency of high and low oleic cultivars of sunflower based on oil and fatty acid changes of seeds and their viability. The seed samples of four sunflower cultivars (two high oleic and two low oleic) were stored in three different temperature conditions (4-5 ºC, 21-22 ºC, and 35 ºC) in a period of four months. Results show that quality parameters of seeds such as oil content, fatty acid composition and protein content were significantly influenced by storage conditions in most cases. In all experimental cultivars oil content was significantly influenced by storage time. Indeed, the longer storage times the higher oil reduction and vice versa. In most cases the oleic acid reduced as storage time progressed. Free fatty acid content of crude oil increased in longer storage time and higher temperature. No clear effect of storage time and storage temperature was observed on seed germination of used cultivars. Generally it can be conclude that the storage life of sunflower seed can be decreased by longer storage time and higher storage temperature.

The effects of supplemental potassium were studied on growth, ion concentration and anatomical parameters in one year old olive trees, Olea europaea L., grown in sand culture in greenhouse at different levels of NaCl for 80 days. The experiments were conducted in a completely randomized design as a factorial. Factor one was salinity (0, 40 or 80 mM NaCl) and the second factor was potassium levels of 4 and 8 mM. Salinity caused a significant decrease in the growth of plants; however, the supplemental potassium could partly ameliorate the adverse effects of salinity on growth. Due to salinity Na and Cl- ions accumulated and the K /Na ratio decreased in the plants. The lower relative water content and the higher cortex /stele ratio in plants under salinity indicate
water deficit. Under salinity, however, the supplemental potassium led to lower Na and higher K and P concentration which probably reduced the toxicity. The ratio of cortex to stele became normal as salt-grown plants were supplemented with potassium. Supplemental potassium increased palisade cell layer thickness in leaves under salinity that may be accompanied with increased potential for photosynthesis. The results indicate that supplemental potassium can be useful in ameliorating salinity stress effects in olive plants.

Genetic diversity between fifteen commercial cultivars of rose were evaluated, using Ten decamer primers (A-J). All primers detected polymorphism among the cultivars. In total, 126 bands were produced, 73 of which were polymorphic. Primers E and F produced the highest, while primer H produced the lowest number of bands. The percentage of polymorphic bands ranged from 37% to 81% with an average of 63.9%. The average number of polymorphic bands produced was 7.3 per primer. Only the amplified DNA fragments ranging in size between 220 to 3000 bp were used for statistical analyses. Cluster analysis based on the presence or absence of bands was performed by Jaccard’s similarity coefficient, based on Unweighted Pair Group Method with Arithmetic Averages (UPGMA). Genetic similarity ranged between 0.12 to 0.53. The dendrogram revealed two main clusters. Each cluster was divided into subgroups. This investigation showed that genetic diversity was relatively considerable among these cultivars. Also, the results propose that RAPD marker is a useful tool for evaluation of genetic diversity and relationships amongst different rose cultivars.

The present study was conducted in two different experiments based on complete randomized design to evaluate the effects of calcium (0, 1, 2, 4 mM) and magnesium (0, 1.02., 2.04, 4.08 mM) on carrot petiole somatic embryogenesis in B5 medium. A difference on somatic embryogenesis was observed among different levels of calcium and magnesium. The number of globular embryos in medium with low magnesium (0, 1.02 mM) was significantly low. The number of cotyledonary or plantlet embryos in medium containing 4.08 mM magnesium was significantly higher than those of other levels of magnesium. The result indicated that magnesium and calcium plays important roles in carrot embryogenesis. Generally it can be concluded that the presence of both calcium and magnesium in both induction and realization stages of carrot petiole embryogenesis is necessary.

On a survey during the period of 2006-2007 a number of tylenchids were found associated with Zea mays in Kashmir valley such as Pratylenchus sativus kaul, 1985, Aphelenchoides srinagrensis Kaul, 1985 and Tylenchorhynchus zeae Sethi and G. Swarp, 1968. These species were found to have morphometric variations probably due to habitat alteration from the originally described ones. As a part of the programme it was to look for management of these nematodes through organic soil amendments such as Poultry manure, Pigeon manure and Saw dust. It was found that the population densities of nematodes were reduced by the organic amendment to a varied extent and Poultry manure caused greatest reduction of nematode populations.