F.C.A (UNMDP)-E.E.A.INTA, Balcarce, Agronomy Department, c.c.276,7620 Balcarce, Buenos Aires province, Argen?tina

DOI: https://doi.org/10.37855/jah.2008.v10i02.31

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Abstract: In the 2004 and 2005 seasons, experiments were carried out at INTA Balcarce, Argentina on potato cultivars Kennebec, Innovator and Shepody, with different susceptibility to Rhizoctonia solani Kuehn. A randomized block design with four replications was created. Visual observations during the crop cycle were carried out in order to record the number of healthy and infected plants, with symptomatology of stem canker produced by R. solani. After harvest, the potatoes in each block were washed and weighted, the total yield recorded and the marketable and "seed" potatoes were classified into healthy, cracked or malformed tubers. The best results on the reduction of infected plants were obtained with the highest dose of fluazinam (as Frowncide 50SC) and pencycuron (as Monceren 25SC). Commercial and "seed" tuber yields in the Spunta cultivar showed no significant differences among treatments, but with the Shepody cultivar, when the severity of the disease was high (2004) both fungicide treatments surpassed the untreated check. When the severity of the disease was low (2005), all chemical treatments registered higher commercial and "seed" tubers yields than the untreated check. In Kennebec and Spunta cultivars, all the treatments - except the lowest dose of fluazinam - accomplished a higher quantity of healthy tubers and surpassed the untreated check; although only the highest doses showed the highest yield of healthy tubers, showing a positive relationship with respect to the applied dose. Only the highest doses of fluazinam considerably reduced diseased tuber incidence in comparison to the untreated check.

Plant Physiology and Biotechnology Laboratory, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.

DOI: https://doi.org/10.37855/jah.2008.v10i02.32

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Abstract: The study was carried out to investigate the effect of ethanol (ET) at different concentrations on longevity and senescence delay in bougainvillea flowers. The treatments were water (control), 2, 4, 8, 10, 20, 30, 40, 50 and 70% ET. Positive response was found in case of 4, 8 and 10% of ET after a certain period of treatment application. Dry weight was higher in lower concentrations of ethanol and lower in higher concentrations. Flower longevity was 2 days longer in 4, 8 and 10% ET than in water control and other concentrations of ethanol. Petal wilting and abscission occurred 2 days later in 4, 8 and 10% ET than in control. Perianth abscission also appeared 2 days later in 4, 8 and 10% ET than in control. However, petal discoloration (color change) was later in control, 2, 4, 8 and 10% than in 20, 30, 40, 50 and 70% ET. The results showed that flower vase life was significantly affected by ethanol concentrations as well as longevity was longer in 4, 8 and 10% ET than in water control and other concentrations.

Department of Horticultural Sciences, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.

DOI: https://doi.org/10.37855/jah.2008.v10i02.33

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Abstract: The purpose of this study was to investigate the effect of exogenous putrescine on postharvest life and quality of sweet cherry fruit, cultivar "Surati-e Hamedan" at 2?C. Fruits were treated with 0.5, 1, 2, 3 and 4 mM putrescine as well as distilled water (Control) for 10 minutes, then transferred into the fridge (2?C). The rate of ethylene production, weight loss, tissue firmness, soluble solids content, titratable acidity and pH of fruits were determined 5, 10, 15, 20 and 25 d after the beginning of storage. Parameters associated with ripening processes, including softening and loss of titratable acidity, significantly decreased by application of putrescine. Soluble solids content of cherries also increased by the putrescine treatment. In addition, cherries treated with higher concentrations of putrescine showed lower rate of ethylene production. Weight loss of the fruits was affected by putrescine in a concentration dependent manner, while putrescine did not affect pH of fruit juice.

Scientist, Department of Pomology, Dr. Y S Parmar University of Horticulture and Forestry, Solan, HP-173 230 India; Research Officer(R & D Agriculture), Rashtriya Chemicals & Fertilizers Lmited (GOI), Chembur, Mumbai-74, India.

DOI: https://doi.org/10.37855/jah.2008.v10i02.34

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Abstract: The present investigation was undertaken with the objective to find out the nutritional status of mango orchards cv. Dashehari located in north- western Himalayan region of India and to establish the relationship of soil microflora especially, arbuscular mycorrhizal (AM) fungi and Azotobacter with growth, fruit yield, and soil and leaf nutrient contents. The study revealed that the correlation between AM spore population and shoot extension growth, leaf area, fruit yield, available Cu and Zn content and leaf N, P, Cu, Zn and Mn contents was found to be positive and significant, whereas, the relationship with soil as well as leaf K content was negative but significant. Azotobacter count was positively and significantly correlated with fruit yield, soil organic carbon (OC) and leaf Fe content, while, it was negative and significant with leaf K content. The relationship of per cent root colonization with soil OC and available N content of orchard soil was found to be positive and significant, and with shoot extension growth, leaf area, fruit yield, electrical conductivity, available P, K, Cu, Zn and Mn content and P, K and Cu contents of leaf, it was negative but non-significant.

Department ofBiology, Faculty of Science, Addis Ababa University, P.O.Box 1176, Addis Ababa, Ethiopia; Leibniz Insti?tute of Plant Genetics and Crop Plant Research (IPK), Plant Reproductive Biology, Correnstrasse 3, D-06466 Gatersleben, Germany

DOI: https://doi.org/10.37855/jah.2008.v10i02.35

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Abstract: Effects of seed sterilization, storage time, and temperature as well as extent of seeding survival and establishment under glasshouse versus nursery conditions were studied for E. kebericho. Seeds sterilized for 9 and 5 minutes in 70 % ethanol and in 10% sodium hypochlorite, respectively, germinated best (95.2 ? 1.2%) on Murashige and Skoog medium, supplemented with 10 g L^-1 phytoagar. Further increases or decreases in sterilization time decreased germination percentage and increased contamination, respectively. Unsterilized seeds (control) were completely contaminated before the emergence of radicle as a result of fungal growth. Seed germination percentage declined with increasing storage time and dropped from 94.6 ? 0.4 % to 32.2 ? 1.2% in 15 months. 25 ^oC was an optimal temperature for best germination (94.6 ? 2.4%) of seeds. Seeds sown in pots containing a mixture of sand, nursery soil, and animal manure in a ratio of 0.5: 2.5: 0.5 respectively, germinated significantly (P< 0.05) compared to other soil ratios. Increase in sand or animal manure ratios decreased germination, while increase in nursery soil increased percentage and rate of germination. High percentage (96.0 ? 0.5%) germination was obtained with the seeds sown in nursery soil-surface mixed additives compared with the control. Seedlings of nursery bed origin survived best compared to those in vitro or pot origin seedlings. Ultimately, seedlings growth with vigorous and orthotropic developmental pattern was obtained under nursery conditions, compared to those in the glasshouse, which showed stunted and plagiotropic developmental pattern. The study found that seeds stored for less than 5 months, and at 25 ^oC, were the most suitable for in vitro and ex vitro propagation of E. kebericho.

Universidad Nacional de Mar del Plata. Argentina, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET). Argentina.

DOI: https://doi.org/10.37855/jah.2008.v10i02.19

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Abstract: Changes in ascorbic acid contents, microbial population and sensory attributes of cut Romaine lettuce subjected to thermal shocks were investigated. Immersion of cut lettuce in the thermal baths produced reduction in the ascorbic acid contents between 190 and 300 g kg^-1, with the greater losses corresponding to the higher bath temperatures. However, the rate of ascorbic acid degradation during refrigerated storage was independent of the thermal treatment and all samples presented a sharp decrease during the first day of storage and a gradual decrease thereafter. Thermal shocks did not reduce the initial microbial population. During storage, an increment in microbial counts was observed, being more notorious in samples that had been exposed to the highest shock temperature (50 ?C). The thermal treatment at 50 ?C was the only one to delay the onset of midrib and edge browning up to four days of refrigerated storage. This midrib and edge browning was considered to the most relevant to the overall visual quality of the product.

Scuola Superiore S. Anna di Studi Universitari e di Perfezionamento, Piazza Martiri della Liberta 33, 56100 Pisa, Italia.

DOI: https://doi.org/10.37855/jah.2008.v10i02.20

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Abstract: The aim of the research was to study the morphological and histochemical evolution of the bud meristems of 'Lavinia' nectarine cultivar. Moreover, the effectiveness of Release LC (a gibberellin chemical compound) in controlling the rate of flower bud differentiation was also evaluated. During a two-year period, the Release LC was applied in postharvest to avoid problems of possible chemical residues on marketable fruits. To determine the effect of treatment, several biological parameters such as initial flower and vegetative bud number, flower bud drop, evolution of the flower bud phenological stages, rate of bloom and fruit set were recorded. To establish the floral differentiation stage, the meristematic apices were collected before and after treatment and microscopically observed. The thin sections were analysed using histological (apex size, developmental stages of meristematic apex, co-axial stage), and histochemical (RNA fluorescent staining) techniques. In 'Lavinia' cv., the critical phase of the meristematic apex evolution occurred from May to June (60 and 90 days after full bloom): the presence of triple apices increased rapidly, the co-axial phase was achieved, the width and height of the meristematic dome increased markedly and the RNA appeared by a weak staining. As regards the flower bud differentiation control by exogenous treatments with Release LC, the different results obtained in our experiments indicate that the efficacy of treatment strictly depends on the growth stage of a meristematic apex.

College of Agriculture, Ibaraki University, Ami, Ibaraki, 300-0393, Japan, Graduate School of Agricultural and Life Sciences, Bunkyo-ku, Tokyo, 113-8657, Japan.

DOI: https://doi.org/10.37855/jah.2008.v10i01.03

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Abstract: Fruit growth of the gynoecious cucumber 'NK x AN8' was measured non-destructively to clarify whether the presence of fruit at lower nodes caused the abortion of fruit at upper nodes. When only one fruit per plant was allowed to grow, fruit growth could be divided into two phases: slow exponential and fast exponential. Phase change from slow to fast occurred when cumulative temperatures (CTs) after anthesis reached 38 and 54?C d for pollinated and parthenocarpic fruit, respectively. The CT was calculated as the sum of the differences between daily temperatures and 5?C. When fruit at nodes 4 and above were allowed to grow, the first growth phase was prolonged. Furthermore, parthenocarpic fruit aborted frequently when the sum of the relative growth rate (RGR) with respect to the CT (the sum of RGRs) for fruit at lower nodes exceeded 0.1 g g^-1 (?C d)^-1. Pollination with pollen of the monoecious cucumber '028' strongly suppressed fruit abortion; a large number of fruits could develop to a commercial size even when the sum of RGRs for fruit at lower nodes exceeded 0.1 g g^-1 (?C d)^-1. These results suggested that fruit abortion is more related to the existence of actively growing fruit than to the absolute amount of dry mass accumulation in the fruit.

Central Institute of Medicinal and Aromatic Plants, Resource Centre, Allalasandra, Bangalore 560 065, India.

DOI: https://doi.org/10.37855/jah.2008.v10i01.04

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Abstract: In periwinkle (Catharanthus roseus), pink, white and red-eyed (white corolla with red centre) are three common corolla colours, which are due to epistatic interaction between two genes R and W. Violet corolla, which is not found commonly in natural populations, is reported to be due to another gene B which blues the pigment in pink genotypes (R- W-). Recently, another gene O and its allele O^m have been reported to determine two uncommon corolla colours, orange-red and magenta corolla, respectively. Since, the relationship between genes determining violet, orange-red and magenta corolla was not known, a strain possessing violet corolla and white eye (VI) was crossed with strains possessing orange-red corolla and white eye (OR) and magenta corolla and white eye (MJ-1) to study: (i) the relationship between genes involved in the production of violet, orange-red and magenta corolla, (ii) to study the possibility of producing novel corolla colours and (iii) to determine the validity of the gene interaction models proposed earlier. The F₁ plants of both crosses, VI x OR and VI x MJ-1, had violet corolla. The F₂ generation of the cross VI x OR segregated into plants with (i) violet corolla, (ii) pink corolla, (iii) orange-red corolla, and (iv) white corolla in the ratio of 45:12:3:4, while the progeny of the backcross F₁ x OR segregated into three types of plants, (i) violet corolla, (ii) pink corolla, and (iii) orange-red corolla in the ratio of 2:1:1. The F₂ generation of the cross VI x MJ-1 segregated into five kinds of plants viz., (i) violet corolla, (ii) pink corolla, (iii) magenta corolla, (iv) rose corolla, and (v) white corolla in the ratio of 144:48:12:36:16, while the progeny of the backcross, F₁ x MJ-1 segregated into four types of plants viz., (i) violet corolla, (ii) magenta corolla, (iii) rose corolla and (iv) pink corolla in the ratio of 1:1:1:1. The results suggested that genes involved B, R, W, O/O^m and J were inherited independently and that the gene B blued the corolla pigment in B-RRwwO- genotypes but not in B-RRwwO^m-jj and B-RRwwO^m-JJ genotypes. No new corolla colours were observed in the studied crosses due to the interaction between genes governing violet, orange-red and magenta corolla. The observed segregation for different corolla colours in the studied crosses was same as that expected from independent segregation and known interactions between the genes involved, validating the earlier proposed models.

Department of Plant Molecular Biology and Biotechnology, Centre for Plant Molecular Biology, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu, India, Department of Biochemistry, Centre for Plant Molecular Biology, Tamil Nadu Agricultural

DOI: https://doi.org/10.37855/jah.2008.v10i01.05

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Abstract: Tomato (L. esculentum Mill), a popular vegetable in tropics is an excellent source for vitamin A, C, carotenoids and other health related components. It tops the list of industrial crops because of its outstanding processing qualities. It is valued for both its fresh and processed forms. Biochemical analysis in different wild species, varieties and hybrids of tomato showed the wild species, Lycopersicon pimpinellifolium LA 1593 to be a rich source for lycopene specific genes. Partial cDNA of lycopene specific Phytoene desaturase gene TNAU P was isolated from L. pimpinellifolium LA 1593 by RT-PCR technique. Sequence analysis of the partial cDNA showed 99.6% similarity with already available Phytoene desaturase gene from L. esculentum. Also, the sequence showed considerable homology with Phytoene dehydrogenase, Zeta carotene desaturase and Phytoene desaturase genes from Gentian, Oryza, Momardica, citrus and pea. The high intensity of the amplified product in L. pimpinellifolium coupled with 99.6 % homology to L. esculentum inferred that the level of expression of Phytoene desaturase is more in L. pimpinellifolium. Isolation of Phytoene desaturase genes can be further exploited to produce transgenic plants with increased content of lycopene by transferring the genes from wild species to cultivars.

Graduate School of Agricultural Sciences, Tohoku University, Sendai 981-8555, Japan. Present address: GraduateSchool of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan.

DOI: https://doi.org/10.37855/jah.2008.v10i01.01

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Abstract: 'Lillipot' carnation, which is usually cultivated as a potted ornamental, was transformed with a cDNA for carnation 1-aminocyclopropane-1-carboxylate (ACC) oxidase. Two lines, which harbor an sACO transgene, had a vase life of cut flowers more than twice longer than that of the non-transformed (NT) control. Flowers of the long vase life lines senesced with discoloring and browning in petal margins, which is typical to ethylene-independent senescence in carnation flowers. They produced negligible amount of ethylene for the first 8 day, whereas flowers of the NT control showed a climacteric ethylene production with a maximum on day 3. Transcripts for DC-ACS1 and DC-ACO1 were absent in petals of the long vase life flowers undergoing senescence. The present study revealed that transformation with sACO transgene may be useful to generate potted carnation plants with a long display time.

Faculty of Horticulture, Chiba University, Matsudo, Chiba 271-8510, Japan.

DOI: https://doi.org/10.37855/jah.2008.v10i01.06

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Abstract: Hypericin and pseudohypericin are the major bioactive constituents of floral parts of Hypericum perforatum L., mainly used for the treatment of neurological disorders and depression. The principle objective of the current study was to evaluate the effect of blue, blue and red mixed, and red light on flowering time and concentration of hypericin, pseudohypericin and hyperforin in the floral tissues of H. perforatum plants. The results revealed that red light promoted flowering and production of the three major medicinal components, indicating the influence of spectral characteristics of light on flowering of H. perforatum plants. Spectral quality of light was found to be an important factor in controlling the flowering of H. perforatum plants.

Department of Horticulture, Clemson University, Clemson, SC 29634-0375 USA; Coastal Research and Education Center, Charleston, SC 29414-5332 USA; Department of Packaging Sciences, Clemson University. Clemson, USA; Department of Plant Pathology and Physiol

DOI: https://doi.org/10.37855/jah.2008.v10i01.07

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Abstract: Feverfew (Tanacetum parthenium [L.] Schultz-Bip., Asteraceae) products have shown high variability in the market. The objective of this study was to determine whether environmental factors affect the composition of key phytochemicals in feverfew. Plants of feverfew were exposed to water stress in greenhouse and commercial field conditions. The highest yield of parthenolide (PRT) was found in plants that received reduced-water regimes. Phenolics concentration was higher in plants grown under adequate-water conditions. The effect of time of harvest on PRT concentration and phenolics content was also investigated. Increased PRT was found during afternoon hours whereas total phenolic compounds decreased during the photoperiod and increased at night. When plants were exposed to artificial light during night hours, the phenolics content remained low. Our results revealed that manipulating the environment to favour increased accumulation of PRT resulted in a decline of phenolics content in feverfew. These findings have implications on standardization of herbal products.

Department of Agriculture, University of Arkansas at Pine Bluff, Pine Bluff, AR 71601, USA.

DOI: https://doi.org/10.37855/jah.2008.v10i01.08

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Abstract: Cowpea is a highly recalcitrant nutrient-rich leguminous vegetable crop. Efforts to genetically transform cowpea with insect-resistant genes remains a challenging task due to lack of an efficient regeneration system. We have established an efficient regeneration system in cowpea through shoot meristem. Shoot meristems were isolated from embryos that were precultured for 3-5 days on Murashige and Skoog (MS) medium containing 8.9 uM benzylaminopurine (BA). The isolated shoot meristems were cultured on MS medium containing 0.89 uM BA. After 3-4 weeks, multiple shoots were separated from the explant and cultured on half-strength MS medium for elongation and rooting. More than 90% of the regenerants formed roots. The rooted plantlets were transferred first to peat pellets and subsequently to the greenhouse. The plants were allowed to flower and set seed. The efficiency of regeneration in all four cultivars ranged from 76-87%, demonstrating a significant improvement over the published protocols (1-32%). At least six to seven plantlets were obtained from each meristem. The protocol using shoot meristems is simple, efficient, rapid and genotype-independent and may be amenable for transformation through particle bombardment.

Plant Tissue Culture Division, CSIR National Chemical Laboratory, Pune - 411 008, India

DOI: https://doi.org/10.37855/jah.2008.v10i01.09

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Abstract: Grapevine genotypes differ in tissue culture requirements and thus require optimized culture conditions for in vitro propagation. Single node segments of Crimson Seedless cultured on six different basal media i.e. Murashige and Skoog (MS), Eriksson (ER), Gamborg (B5), Nitsch and Nitsch (NN), Woody plant medium (WPM) and Chee and Pool (C₂d) showed different percentage of shoot initiation and morphogenetic responses. The maximum shoot initiation (90.0%) was observed in MS medium. Except ER, all other media induced rooting at the base of nodal segments in varying percentages though number and quality of roots and their establishment on transfer to pots varied greatly. WPM induced the maximum rooting in nodal segments (69.1%) with establishment rate of 100.0%. Induction of multiple shoots in nodal segments was achieved on inclusion of 6-benzyl adenine (BA) (8.87 uM) and indole-3-butyric acid (IBA) (1.48 uM) in the MS medium. In second sub-culture i.e., at 90 days, shoot bud proliferation could be increased many fold on transfer of these initial shoot clumps to glass bottles instead of culture tubes. The maximum average number of primary shoots (19.5 per explant) was achieved on MS with BA (8.87 uM) and IBA (1.48 uM). Elongation of shoots was achieved on MS with BA (2.22 uM) + a-naphthalene acetic acid (NAA) (0.54 uM). Induction of ex vitro rooting and establishment of rooted shoots after transfer to pots was achieved in different efficiencies when shoots were given pulse treatment of indole-3-acetic acid (IAA) or IBA or NAA at 57.08, 49.0 and 53.71 uM, respectively, for 5 or 10 min. Survival of in vitro and ex vitro-rooted shoots on potting was 90.0 and 100.0%, respectively.