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  • Author or Editor: L. H. Aung x
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Abstract

Gibberellin-like substances (GAs) were demonstrated in the ethyl acetate-soluble basic, acidic and bound fractions of Lycopersicon pimpinellifolium (Jusl.), L. peruvianum (L.) Mill and L. hirsutum Humb. & Bonpl. The distribution of GAs activity differs in the fractions of the 3 species. The total amount of GAs of L. pimpinellifolium was 96-fold and 44-fold that of L. peruvianum and L. hirsutum, respectively. The vegetative growth of the species may be inversely related to the content of GAs.

Open Access
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Abstract

Abscisic acid (ABA) at concentrations ranging from 10-8 to 5 × 10-3M was applied apically with a microsyringe onto seedlings of tall ‘Fireball’ and dwarf ‘Epoch’ tomato (Lycopersicon esculentum Mill). ABA at 10-8M significantly promoted the growth of ‘Fireball’ epictoyl, plumular leaves, final plant weight and leaf area, and at 10-3 to 5 × 10-3M significantly promoted the development of cotyledonary axillary buds. In contrast, the dwarf ‘Epoch’ did not respond to low concentrations of ABA but the growth of the epicotyl, plumular leaves, final leaf area and plant weight were decreased by 5 × 10-3M ABA. However, ABA at the concentrations used had no effect on anthesis date or size of the first 3 inflorescences on the main stem of tall and dwarf tomatoes.

Open Access
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Abstract

The responses of five tomato cultivars to photoperiod × temperature were determined under phytotronic conditions. Leaf nodes, subtended between the cotyledons and first inflorescence of ‘Epoch’ and ‘Michigan-Ohio Hybrid’ were significantly reduced by short photoperiod (9 hours) and 22° (day)/18°C (night) temperature. Flower number in these two cultivars was increased by short photoperiod. Days to first anthesis were decreased by short photoperiod and 26°/22° temperature in four out of the five cultivars when compared to long photoperiod (9 hr + 3 hr dark interruption) and 18°/14° temperature.

Open Access
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Abstract

The initiation of root primordia on the primary root and hypocotyl of tomato seedlings (Lycopersicon esculentum Mill. cvs. Fireball, Epoch, and MD 412-4) was determined under controlled conditions. The first primordium of ‘Fireball’, ‘Epoch,’ and MD 412-4 seedlings was initiated on the primary root 5–6, 7, and 8 days, respectively, after seeding. Primordia on the hypocotyl were initiated acropetally, after initiation on the root. Root initiation in ‘Epoch’ and MD 412-4 lagged behind ‘Fireball’, but the general pattern was similar. Hoagland’s nutrient solution significantly increased the number of primordia on the primary root and hypocotyl. Presoaking seed in 10 μm abscisic acid (ABA) or 6-benzylamino purine (BA significantly increased the number of primordia on the primary root. Application of 50 μ1 of 1 mm 2,3,5 triiodobenzoic acid (TIBA) in lanolin 1 cm below the cotyledonary node reduced the number of primordia on the hypocotyl.

Open Access
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Abstract

Parthenocarpic fruits of chayote were obtained by application of 2 × 10-3 M gibberellin A3 and A4/7 in lanolin on the stigmatic surfaces of pistillate flowers under greenhouse conditions. The role, of gibberellins on fruit development and the significance of seedless fruits are discussed.

Open Access
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Abstract

Determinations of carbohydrates in the plant organs of Rhododendron spp. cv. ‘Sweetheart Supreme’ and ‘Hexe’, were made by chemical analysis, thin-layer chromatography (TLC) and gas-liquid chromatography (GLC). Reducing sugar content was 1.5 times higher in buds than in leaves for ‘Hexe’ with no significant differences for ‘Sweetheart Supreme’. Reducing sugars were also higher in the roots than stems with both cultivars. Sucrose content was 1.4 times greater in leaves than in buds of ‘Hexe’ and 1.6 times greater in ‘Sweetheart Supreme’. Starch was significantly higher in leaves and buds than in stems and roots. The predominant soluble sugars identified by TLC and GLC were sucrose, glucose, and fructose. Small but detectable amounts of raffinose and maltose and an unidentified compound were also found in the plant organs.

Open Access

Abstract

Fish soluble nutrients (FSN) applied at weekly or biweekly intervals gave comparable growth and fruit yield of greenhouse-grown tomatoes (Lycopersicon esculentwn mill.) as plants fertilized with full strength Hoagland’s nutrient solution. FSN fertilization stimulated vegetative growth and delayed flowering and fruit-ripening by 5-8 days depending upon concentration and frequency of application. FSN can be a useful nutrient source for crop fertilization.

Open Access
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Abstract

Intemodal and stem lengths of new growth and plant diameter of dwarf Japanese holly (Ilex crenata Thunb. cv. Helleri) were significantly increased by sprays of 100, 200, or 400 ppm gibberellin A4+7 (GA4+7). GA3 was less effective than GA4+7, but also significantly increased stem length and plant diameter. Leaf size was decreased by GA3 and GA4+7 applications.

Open Access
Authors: and

Abstract

Apical application of varying concentrations of 6-benzylamino purine (BA), and gibberellin A4/7 (GA4/7) alone or in combination promoted hypocotyl and cotyledonary growth in ‘Fireball’ tomato seedlings. Both height and width of the apical meristematic dome were enlarged by 10−4M BA and 10−6M GA4/7 alone and in combination. The length of the hypocotyl cortical cells was unaffected, but width was increased by 10−4M BA. However, 10−6M BA significantly reduced the height and width of the meristematic dome and length of the cortical cells. GA4/7 at 10−6M, on the other hand, significantly increased both the length and width of cortical cells.

Open Access
Authors: and

Abstract

Allium cepa L. bulbs of different genetic constitution were examined for free and bound gibberellin-like substances (GA) by conventional extraction, bioassay, and chromatographic procedures. Both free and bound GA were found in these bulbs. Based on the dwarf-pea bioassay, it was shown that free and bound GA in the extracts varied depending on the source of the bulbs. The total GA of dormant bulbs was greater than that of non-dormant bulbs.

Open Access