Morphogenetic Effects on Vegetative Plants of Poa pratensis L. of 6-Azauracil, (2-Chloroethyl)- phosphonic acid, and (2-Chloroethyl) trimethyl-ammonium chloride and their Interaction with Gibberellic Acid

Fresh and dry weights and leaf size of Poa pratensis were reducedwhen treated with 6-azauracil (AzU), (2-chloroethyl)phosphonicacid (CEPA), or (2-chloroethyl)trimethylammonium chloride (CCC).AzU and CEPA inhibited epidermal cell division without inhibitingcell elongation, while CCC inhibited mainly cell elongationand cell division to a small extent. The ratio of blade lengthto sheath length and the blade length/width ratio were reduced,but leaf emergence and tillering were increased by AzU and CEPA.CCC affected only the latter three features. Like GA₃, CEPAinduced stem formation, but internodes were shorter. GA₃ was ineffective in preventing leaf-growth inhibition byAzU, which inhibited Ga₃-induced cell elongation. The inhibitoryeffect of CEPA on leaf growth was apparently reversed by GA₃,but this was due solely to increased cell elongation, the reductionin cell number being unaffected. Ga₃ reversed the effect ofCCC on leaf length, as well as on cell size and number. Simultaneousapplication of the inhibitors produced a complex interactionin reducing leaf length and number and size of epidermis cells.It is postulated that AzU, CEPA, and CCC have different modesof action because they have specific effects on plant growthand different effects on GA₃-induced cell elongation.     

Seasonal pattern in food gathering of the weaver ant Oecophylla longinoda (Hymenoptera: Formicidae) in mango orchards in Benin

Prey capture and food scavenging activities of Oecophylla longinoda were monitored through regular weekly samplings during two consecutive years (2009–2010) in a large mango orchard of the Borgou Department of Benin, West Africa, a main mango production area located in the Sudan agro-ecological zone. In both years, interspecific competition with other ants occurred mainly during the dry season (January to March) resulting in increased captures of Formicinae, Myrmicinae and Ponerinae. More prey was caught during the rainy season (end April to end October) than during the rest of the year, with Diptera and Coleoptera prey peaking in May and June, respectively, along with the mango season. As insect prey quickly decreased during November to December weaver ants increasingly collected seeds and plant debris. A total of 241 species of insects were captured including 61 species (25.3%) associated with mango and a few with cashew, among which 48 mango pest species (78.7% of species associated with mango tree). Only five species (2.1%) of beneficial insects were captured. It is concluded that the presence of O. longinoda colonies is beneficial to perennial tree cropping systems such as mango and cashew.     

Effect of (2-Chloroethyl)phosphonic Acid on CCC-Induced Delay of Fruit Ripening

(2-Chloroethyl)phosphonic acid (CEPA) which is known to releaseethylene in plant tissue, and (2-chloroethyl)trimethylammoniumchloride (CCC) were applied to ripening tomato and red pepperfruits. CEPA enhanced and CCC inhibited chlorophyll degradationand carotenoid formation. The inhibitory effects of CCC on fruitripening were counteracted by CEPA treatment. These resultsand those of other authors on gibberellin action in fruit ripeningsuggested that both CCC and gibberellin may interfere with theaction of ethylene in ripening fruit.     

Production and Characterization of Wine from Mango Fruit (Mangifera indica L)

Summary Mango (Mangifera indica L) is the most popular and the choicest fruit of India. A major portion (nearly 60–70%) of the total quantity produced is locally consumed and a sizable portion is exported to other countries. In the present study, six varieties of mango, which are abundantly available in the region were selected for wine production and the conditions for juice extraction were optimized. It was found that the mango juices were similar to grape juice in terms of sugar and acidity. After fermentation, the ethanol concentration was 7–8.5% w/v, the methanol concentration was slightly higher than that of grape wines and other volatile compounds were present in comparable amounts. From the physicochemical characteristics of the mango wine produced, it was observed that aromatic components were comparable in concentration to those of grape wine.     

Biodegradation of mango kernel by Syncephalastrum racemosum and its biological control

Poor germination of mango seed due to fungal decay is a common problem in mango nurseries. The main causal fungus behind this problem is a black spore producing fungus, Syncephalastrum racemosum. This fungus exhibited high amylolytic activity and hence utilised the starch present in mango kernel for its own growth, thereby resulting in the death of emerging radical and plumule, which ultimately causes the death of emerging seedlings. A simple biocontrol device has been worked out by modifying the storage conditions of the mango seeds from aerobic to facultative. This change resulted in yeast growth on the pulp sticking to the mango seed, which in turn produced alcohol and prevented the growth of this fungus. The germination of such seeds has been found to be about 85–90%.     

Influence of chlorocholinechloride and ethrel on chlorophyll content and the “epinastic response” of the primary leaf of wheat seedlings

Wheat seedlings were cultivated in nutrient solutions containing 10^-3 M CCC, 10^-3 M CEPA or 5 × 10^-4 M CCO and CEPA, respectively. CCC applied alone or mixed with CEPA increased chlorophyll content per unit fresh matter but had no influence on the epinastio response of the primary leaf. In contrast, CEPA had no influence on chlorophyll content but greatly increased the epinastic response. The different response to the application of these substances with regard to chlorophyll content ha been claimed in a previous paper to be due to their different effect on cell extension and cell division. The epinastic response of the primary leaf suggests that ethylene participates in the reaction chain of CEPA effect on plant tissues.     

Hormonal Changes Associated with Vegetative Malformation of Mango (Mangifera indica L.)

Malformed seedlings of mango showed lower mean content of indole-3-acetic acid, gibberellic acid and a higher mean content of zeatin, abscisic acid and ethylene than healthy seedlings.     

Activities of enzymes of amino-acid metabolism in Pennisetum seedlings grown in the presence of 2-chloroethylphosphonic acid

The plant growth regulator 2-chloroethylphosphonic acid (CEPA) slightly inhibited the elongation of growth in Pennisetum typhoides seedlings, but greatly stimulated the activity of alanine aminotransferase (GPT), asparate aminotransferase (GOT), as well as glutamate dehydrogenase (GLDH).     

Ethylene modulates the susceptibility of the root for nodulation in actinorhizal Discaria trinervis

Ethylene is produced by plants in response to a wide variety of environmental signals and mediates several developmental processes in higher plants. We investigated whether ethylene has a regulatory function in nodulation in the actinorhizal symbiosis between Discaria trinervis and Frankia BCU110501. Roots of axenic D. trinervis seedlings showed aberrant growth and reduced elongation rate in the presence of ethylene donors [i.e. 2-aminocyclopropane carboxylic acid (ACC) and 2-chloroethylphosphonic acid (CEPA)] in growth pouches. By contrast, inhibitors of ethylene synthesis (aminoethoxyvinylglycine, AVG) or perception (Ag⁺) did not modify root growth. This indicates that the development of D. trinervis roots is sensitive to elevated ethylene levels in the absence of symbiotic Frankia . The drastic response to higher ethylene levels did not result in a systemic impairment of root nodule development. Nodulation occurred in seedlings inoculated with Frankia BCU110501 in the presence of ethylene donors or inhibitors. Overall, the ability of the seedlings to shut down nodule formation in the younger portions of the root (i.e. to autoregulate nodulation) was not significantly impaired by a modification of endogenous ethylene levels. In contrast, we detected subtle changes in the nodulation pattern of the taproots. As a result of exposing the roots to CEPA, less nodules developed in older portions of the taproot. In line with this observation, AVG or Ag⁺ caused the opposite effect, i.e. a slight increase in nodulation of the mature regions of the taproot. These results suggest that ethylene is involved in modulating the susceptibility for nodulation of the basal portion of D. trinervis seedling roots.     

Antibodies to human-related H3 influenza A virus in Baikal seals (Phoca sibirica) and ringed seals (Phoca hispida) in Russia

Antibodies to influenza A virus were detected using enzyme-linked immunosorbent assay (ELISA) in the sera from two of seven Baikal seals (Phoca sibrica) and from five of six ringed seals (Phoca hispida) in Russia. In a hemagglutination-inhibition test using H1-H15 reference influenza A viruses, ELISA-positive sera from one Baikal seal and four ringed seals reacted to A/Aichi/2/68 (H3N2) and A/Bangkok/1/79 (H3N2) strains. One ringed seal serum sample reacted to A/seal/Massachusetts/1/80 (H7N7). The present results suggested that human-related H3 viruses were prevalent in Baikal seals and ringed seals inhabiting the central Russian Arctic.     

Seasonal abundance and spatial distribution of larval and adult thrips (Thysanoptera) on weed host plants in mango orchards in Penang,Malaysia

The spatial distribution of larval and adult thrips (Thysanoptera) was studied on mango panicles, Mangifera indica L., on Penang Island, Malaysia, during two consecutive mango flowering seasons from December 2008 to March 2009 and from August to September 2009. Larval and adult thrips were sampled from mango panicles using the carbon dioxide (CO₂) collection technique weekly in treated and untreated orchards. Seasonal abundance and dispersion pattern of thrips were investigated on weed host plants in the treated orchard between June 2008 and March 2009. Spatiotemporal dynamics of larvae and adults was analyzed using Taylor’s Power Law (TPL), Lloyd’s Index (LI), and Green’s Index (GI). Thrips hawaiiensis (Morgan) was the dominant thrips species recovered from mango panicles and weeds in the treated orchard, whereas Scirtothrips dorsalis (Hood) was the most abundant species captured in the untreated orchard. Thrips adults and larvae analyzed via dispersion indices were found to be aggregated in mango panicles in both orchards. The value of the aggregation index (b) of TPL for the total number of adult thrips was significantly higher in the treated orchard than in the untreated orchard, whereas slopes of TPL for the total number of larval thrips did not differ significantly between treated and untreated orchards. All adult thrips species were distributed regularly on the weed plants; however, their larvae were aggregated. It is concluded that pesticide treatment caused adult thrips to become more aggregated on mango panicles, hiding in flower parts that were less exposed to the chemicals.     

Influence of ethylene and Ag+ on hypocotyl growth in etiolated lupin seedlings. Effects on cell growth and division

Lupin seeds treated with 1-amino-cyclopropane-1-carboxylic acid (ACC) or2-chloroethylphosphonic acid (CEPA) produced hypocotyls showing a typicalethylene growth response (reduced elongation and increased thickness), whichcould be efficiently counteracted by the presence of silver thiosulfate (STS).The fact that ACC and CEPA stimulated the ethylene produced in different zonesalong the hypocotyls suggests that these compounds, which are stored in theseeds during treatment, were transported to and along the hypocotyl. The same istrue in hypocotyls from STS-treated seeds, which indicates that stress ethyleneis induced by metal toxicity. CEPA was more effective than ACC in both producingethylene and influencing growth due to the high capacity of the hypocotyl toconjugate ACC. At the same time that CEPA inhibited hypocotyl elongation, thehypocotyl diameter increased and ethylene production exceeded the maximum valueof the control. The subsequent recovery of hypocotyl elongation coincided with adecrease in ethylene production and involved cell elongation. The final celllength was similar (in ACC-) or higher (in CEPA-treated plants) than in thecontrol, although the hypocotyls were shorter in both cases, while the number ofcells per column was reduced to half that observed in the control. Thisinhibition of cell division caused by ethylene was selective since the number ofcell layers did not change. The variations in cell diameter in the epidermisand, especially, in the cortex and pith were correlated with the variations inhypocotyl diameter produced by ACC, CEPA and STS. The results show that theethylene-induced hypocotyl thickening was irreversible and mainly due to anincrease in cell diameter, while the inhibition of hypocotyl elongation wasreversible and involved irreversible inhibition of cell division and,paradoxically, stimulation of cell elongation to produce cells longer than thoseof the control.     

Alternate Infiltration Irrigation Improves Photosynthetic Characteristics and Water Use Efficiency in Mango Seedlings

Journal of Plant Growth Regulation - The growth status of mango (Mangifera indica L.) seedlings directly affects the yield and quality of mango, but there are few reports on water management at the...     

Occurrence of Malformin-like Substances in Seedlings of Mango (Mangifera indica L.)*

The ether soluble extracts from stem and root tissues of malformed seedlings of mango showed four malformin-like substances on chromatograms in the corn root curvature test at Rf 0–0.1 (M₁), 0.1–0.2 (M₂), 0.8–0.9 (M₉) and 0.9–1.0 (M₁₀). M₁₀ was identified as a malformin A-like substance(s). Stems and roots of malformed seedlings contained high levels of malformin A-like substance(s) (42.0 μg/g and 41.0 μg/g) respectively, which were absent in stems and roots of healthy seedlings.     

Plant regeneration via somatic embryogenesis in pigeonpea (Cajanus cajan L. Millsp)

Efficient plant regeneration via somatic embryogenesis has been developed in pigeonpea. Cotyledon and leaf explants from 10-day-old seedlings produced embryogenic callus and somatic embryos when cultured on Murashige and Skoog (MS) medium supplemented with 10 μm thidiazuron (TDZ). Subsequent withdrawal of TDZ from the induction medium resulted in the maturation and growth of the embryos into plantlets on MS basal medium. The rooted plantlets were transferred and acclimatized on vermiculite where they showed normal morphological characters. Received: 23 December 1996 / Revision received: 22 July 1997 / Accepted: 2 August 1997     

Growth, Sex Expression and Yield of Squash Melon (Citrullus vulgarisvar. fistulosus) as Influenced by 2(chloroethyl)phosphonic acid, 2,3,5-tri-iodobenzoic acid and (2-chloroethyl) trimethyl-ammonium chloride

Single aqueous sprays of 2(chloroethyl)phosphonic acid (CEPA) 250, 500 and 1000 mg/1; 2,3,5-triiodobenzoic acid (TIBA) 25, 50 and 100 mg/1; and (2-chloroethyl) trimethyl-ammonium chloride (CCC) 250, 500 and 1000 mg/1 were applied to squash melon (Citrullus vulgaris Schrad. var. fistu-losus Stocks.) at the 2–3 leaf stage. Though the final length of the main axis and number of lateral branches were not affected by any treatment, CEPA retarded growth of young plants by reducing the internodal length. It did not change the flowering pattern but delayed flowering and reduced the production of both pistillate and staminate flowers. However, it increased the per cent femaleness as a result of comparatively more suppression of staminate flowers. The TIBA 25 and 50 mg/1 and CCC 500 mg/1 did not affect the staminate flower production but increased the pistillate flowers, which increased the per cent femaleness. The CEPA decreased while both TIBA 25 and 50 mg/1, and CCC 500 mg/1 increased the number of fruits per plant and the yield. The mode of action of the chemicals has been discussed.     

Ringed seal (Pusa hispida) tooth annuli as an index of reproduction in the Beaufort Sea

Multi-decadal time-series of biological indices that reflect the state of a population are rare in ecological studies, but invaluable for assessing environmental regulation of population dynamics. We utilized canine teeth extracted from ringed seals (Pusa hispida) killed by polar bears (Ursus maritimus) in the Beaufort Sea, Canada, in 1985–2011, to obtain widths of annual growth layers in the cementum. Canine teeth for 75 individuals were measured and compared across years using a proportional width index (PWI) spanning 1965–2007. PWI was positively correlated with ringed seal ovulation rate obtained independently from other studies and was significantly lower than normal during ringed seal reproductive declines in 1974–75, 1984–87, 1991–93, and 2004–05, suggesting that PWI reflects ringed seal reproductive capacity. The PWI was also examined against climatic and sea ice factors to assess environmental regulation of ringed seal reproduction. Results suggest that ringed seals benefit from cyclonic circulation regimes in the Beaufort Sea, and an earlier breakup of sea ice in summer that may positively influence the quality and quantity of food during the open water season. Results highlight how cementum annuli in the canine teeth of ringed seals can provide an index of body state and linkages to sea ice conditions. Canine teeth from ringed seals can function as a means to monitor the effects of past Arctic marine variability on area-specific populations for which there are few independent empirical data.     

Einfluss von Chlorcholinchlorid und Ethrel auf Zellteilung und Zellstreckung bei Primärblättern von Weizenkeimpflanzen

Both chlorcholinchloride and ethrel are used as growth retardants in cereal cultivation. Wheat seedlings were cultivated in nutrient solutions containing 10^-3M CCC, CEPA or 5 × 10^-4M CCC and CEPA, respectively. The epidermis of full-grown primary leaves was analysed. CCC relatively equally decreases the length of leaves and long epidermal cells, whereas CEPA mainly inhibits cell division. Leaf growth is always a little more inhibited than the number of stomata and trichomes is reduced by CCC or CEPA. This results in an increased frequency of stomata and trichomes by about 14 to 16 per cent. This means that retardants can strongly influence the length of leaves and the length or number of long epidermal cells but, due to the mechanism of programmed determination, the frequency of stomata and trichomes is kept constant within relatively narrow limits. Furthermore it can be concluded that long epidermal cells function as pace-makers in the growth of leaves of monocotyledonous plants.      

Control of mango seed weevils (Sternochetus mangiferae) using the African Weaver Ant (Oecophylla longinoda Latreille) (Hymenoptera: Formicidae)

The mango seed weevil, Sternochetus mangiferae (Fabricius), is among the major threats to mango production in Tanzania. Sternochetus mangiferae is primarily a quarantine pest whose presence inside the fruits restricts access to new foreign markets and leads to rejections of fruits destined for export. Management options for the pest have largely been dependent on field sanitation and application of synthetic insecticides with some success. Thus, more sustainable methods are needed to substitute insecticides, as this may also open up opportunities for organic markets. We conducted field experiments for two fruiting seasons in a mango plantation at Mlandizi, Kibaha district, along the coastal belt of Tanzania to evaluate and compare the effectiveness of the predaceous ant Oecophylla longinoda Latreille with foliar insecticidal sprays of Dudumida (70 WDG Imidacloprid) in controlling S. mangiferae. Mango seed weevil infestation was assessed fortnightly based on infestation marks on developing fruits starting eight weeks after fruit set to early ripening phase. Between 50 and 64 fruits were sampled, well labelled in jute bags, secured and transported to the laboratory at Kibaha Biological Control Unit (KBCU) for incubation at room temperature using rearing transparent containers. Two weeks later, the fruits were dissected and inspected for the presence of S. mangiferae developmental stages. Field and laboratory results indicated that fruits from trees that were occupied by O. longinoda and from those treated with insecticide showed significantly (P < 0.0001) lower incidences and infestation rates by S. mangiferae than from untreated trees. Furthermore, there were no significant differences between the insecticide and the weaver ant treatments. We conclude that in our experiments, O. longinoda is an efficient biological control agent for a long‐term control programme and is comparable to insecticide (Dudumida) in suppressing S. mangiferae and may be used in Tanzanian mango plantations.     

巴基斯坦为害杧果树的短须螨属一新种(蜱螨亚纲,细须螨科)

在对巴基斯坦杧果种植区苏加堡的杧果树螨类区系研究中,发现短须螨属(蜱螨亚纲：细须螨科)1新种：礼短须螨。文中记录并描述了该新种。新种的背饰特点是：前背中侧近分颈沟处具网状纹、外侧具纵向条纹;具6对末体背侧毛。雄螨 未采到。正模♀,1994年1月1日采自巴基斯坦,苏加堡杧果园的落叶中;副模1,1994年11月3日采自马尔坦南3km处的杧果树叶,曼苏采。模式标本保存于农业大学农业昆虫系螨类研究室,费沙拉堡,巴基斯坦。新种的背饰独特,略与短须螨属中具7对末体背侧毛的种相像,但具6对末体背侧毛的种皆无此种背饰。