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New Fossil Plant and Insect Records Bearing on Cretaceous Climate of Western Gobi, Mongolia
Valentin Krassilov,
Dmitry Vassilenko,
Alexandra Sokolova,
Sophia Barinova
Issue:
Volume 2, Issue 2, May 2017
Pages:
43-48
Received:
30 October 2016
Accepted:
14 December 2016
Published:
22 February 2017
DOI:
10.11648/j.ajpb.20170202.11
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Abstract: The paper examines new fossil plant and insect findings in the Cretaceous of the western Gobi as a source of climatologic inference. The isophlebiid dragonflies at the base of the Cretaceous sequence witness to an extension of the Late Jurassic climate warming to the earliest Cretaceous. Climatic fluctuations through the late Neocomian – Cenomanian are indicated by a series of paleofloristic events. The allochtonous localities of Phoenicopsis (Czekanowskiales) in the basal members of the Mogotuin Formation, Manlay depression, and Khurendukh Formation, Choyr Basin, are evidence of temperate arboreal vegetation on the bordering basement ridges. A mass occurrence of Otozamites, a thermophilic bennettitalean plant in the upper part of the Mogotuin Formation near its boundary with the redbeds of Manlay Formation heralds a xerothermic trend of climatic evolution. The first appearance of Sequoia at the top of the Barun Bayan redbeds marks reversion of the trend at about the Albian – Cenomanian boundary.
Abstract: The paper examines new fossil plant and insect findings in the Cretaceous of the western Gobi as a source of climatologic inference. The isophlebiid dragonflies at the base of the Cretaceous sequence witness to an extension of the Late Jurassic climate warming to the earliest Cretaceous. Climatic fluctuations through the late Neocomian – Cenomanian...
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Comparison of Yields of Paddy Rice Under System of Rice Intensification in Mwea, Kenya
Jackline Alinda Ndiiri,
Norman Uphoff,
Bancy Mbura Mati,
Patrick Gathogo Home,
Benson Odongo
Issue:
Volume 2, Issue 2, May 2017
Pages:
49-60
Received:
6 March 2017
Accepted:
24 March 2017
Published:
14 April 2017
DOI:
10.11648/j.ajpb.20170202.12
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Abstract: Rice (Oryza sativa L.) is the world’s most important food crop and a major food grain for about half its population. It is also the greatest consumer of water among all crops and uses about 80% of the total irrigated freshwater resources in some countries. The conventional paddy system of rice production depends on a continuous supply of water for irrigation. With rapid population growth, and a change in eating habits due to urbanization, annual demand for rice continues to grow, and it presently exceeds the Kenya national annual production by about 200%. To meet the demand for rice with the limited water resources in a sustainable way, new innovative ways of rice crop production are needed. System of Rice Intensification (SRI) is an innovation that offers farmers an opportunity to reduce their water demand while increasing rice yield. Field experiments were conducted in 2010 and 2011 seasons at the Mwea Irrigation Agricultural Development (MIAD) centre located in the Mwea Irrigation Scheme (MIS), Kenya to compare yields of three rice varieties (Basmati 370, BW 196, and IR 2793-80-1) grown under SRI management with reduced water applications versus conventional practices of continuous flooding (CF). SRI gave the highest yields and water savings for all three rice varieties, on average increasing yield 1.7 t ha-1, 3.4 t ha-1 and 3.3 t ha-1 for the Basmati 370, BW 196, and IR 2793-80-1 varieties, respectively, while the water savings were 2,983 m3 ha-1 3,714 m3 ha-1 and 3,791 m3 ha-1. Similarly, water productivity for the three varieties averaged 140% higher under SRI management (1.2 kg m-3 vs. 0.5 kg m-3). These findings are consistent with similar evaluations in other countries.
Abstract: Rice (Oryza sativa L.) is the world’s most important food crop and a major food grain for about half its population. It is also the greatest consumer of water among all crops and uses about 80% of the total irrigated freshwater resources in some countries. The conventional paddy system of rice production depends on a continuous supply of water for ...
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In Vitro Evaluation of Antifungal Activities of Six Plant Extracts Against Colletotrichum lindemuthianum Sensu-lato
Issue:
Volume 2, Issue 2, May 2017
Pages:
61-65
Received:
10 March 2017
Accepted:
29 March 2017
Published:
19 April 2017
DOI:
10.11648/j.ajpb.20170202.13
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Abstract: This study examined the effect of six plant extracts on growth, conidial germination and sporulation on C. lindemuthianum in vitro. Six plant extracts namely; Tridax procumbens, Jatropha gossypifolia, Sida acuta, Blighia sapida, Ricinus communis and Datura stramonium were tested against Colletotrichum lindemuthianum. Three concentrations (30, 50 and 65%) of the extracts were tested to determine their effects on conidia germination, growth and sporulation of C. lindemuthianum in vitro. Results showed that all the plant extracts had no significant inhibitory effect on conidia germination and sporulation but growth rates reduced significantly compared to the control. The rate of inhibition of growth was concentration dependent, being higher at 65% for all the extracts. D. stramonium was the most effective extract followed by R. communis and J. gossypifolia while B. sapida caused the least inhibition of growth. At 30, 50 and 65% concentrations, the rates of inhibition of growth were 10, 16 and 33% for D. stramonium and 2, 8 and 10% for B. sapida respectively. The study showed that the plant extracts has the potential for the inhibition of the pathogen.
Abstract: This study examined the effect of six plant extracts on growth, conidial germination and sporulation on C. lindemuthianum in vitro. Six plant extracts namely; Tridax procumbens, Jatropha gossypifolia, Sida acuta, Blighia sapida, Ricinus communis and Datura stramonium were tested against Colletotrichum lindemuthianum. Three concentrations (30, 50 an...
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In Vitro Regeneration via Somatic Embryogenesis of Schizozygia Coffeoides Baill (Mpelepele)
Bashiloni Naaty,
Cecilia Mweu Mbithe,
Aggery Bernard Nyende,
Peter Njenga,
Joshua Kiilu Muli
Issue:
Volume 2, Issue 2, May 2017
Pages:
66-72
Received:
20 March 2017
Accepted:
29 March 2017
Published:
19 April 2017
DOI:
10.11648/j.ajpb.20170202.14
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Abstract: Schizozygia coffeoides (Mpelepele) is an endangered medicinal shrub with substantial antifungal and antibacterial properties. The sustainable utilization of this shrub is hindered by its limited regeneration potential since there exists no protocol for In vitro regeneration of not only this plant but the entire Apocynaceae family. The aim of this study was to develop an appropriate sterilization and regeneration protocol for In vitro regeneration of S. coffeoides using leaf discs, with the specific aims of determining the best NaOCL concentrations for explant sterilization as well as the appropriate plant growth hormone combinations for development of embryogenic calli, shoot development and rooting. Sterilization was optimized using NaOCl at the concentrations of 5.2mM, 7.8mM, 10.4mM and 13mM at exposure times of 10, 15, 20 and 25 minutes. The different concentrations of NaOCl had a significant effect on the survival of explants to sterilization (P=<0.0001), with the lower concentrations (5.2mM and 7.8mM) showing high levels of explant contamination and high concentration (13mM) leading to explant scotching. Similarly, the time explants were subjected to the sterilization substances was also found to significantly affect their ability to survive the sterilization process (P=0.0027). The best time and NaOCl concentration interaction for the sterilization of leaf explants was found out to be 10.4mM for 20 minutes. This time-NaOCl concentration interaction was found out to significantly produce a higher number of clean surviving explants than all other interactions (P=<0.0001). The best callus formation frequency of 68% was observed in MS media supplemented with 2.0mg/lBAP+0.8mg/lKin+0.4mg/l NAA+0.5mg/lTDZ, compared to a 39% callus formation frequency observed in media supplemented with 1.5mg/lBAP+0.8mg/lKin+0.4mg/lNAA+0.5mg/lTDZ and a 13% callus formation frequency observed in media supplemented with 1mg/lBAP+0.4mg/lKin+0.2mg/lNAA+0.05mg/lTDZ. Although somatic embryos formed in all media types, only media supplemented with 2.0mg/lBAP+0.8mg/lKin+0.4mg/lNAA+0.5mg/lTDZ formed most somatic embryos which survived to maturity and formed shoots, as most calli and embryos forming in other PGR supplementations died with subsequent subcultures. Roots only formed in shoots cultured in media supplemented with 1.0 BAP+0.5 IBA. The successful development of this regeneration protocol is expected to greatly contribute to mass production and conservation of this important shrub.
Abstract: Schizozygia coffeoides (Mpelepele) is an endangered medicinal shrub with substantial antifungal and antibacterial properties. The sustainable utilization of this shrub is hindered by its limited regeneration potential since there exists no protocol for In vitro regeneration of not only this plant but the entire Apocynaceae family. The aim of this s...
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Phytochemical Compositions and Antimicrobial Activities of Ananas comosus Peel (M.) and Cocos nucifera Kernel (L.) on Selected Food Borne Pathogens
Dabesor A. P.,
Asowata-Ayodele A. M.,
Umoiette P.
Issue:
Volume 2, Issue 2, May 2017
Pages:
73-76
Received:
15 February 2017
Accepted:
28 February 2017
Published:
1 May 2017
DOI:
10.11648/j.ajpb.20170202.15
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Abstract: Plants like pineapple and coconut are able to exhibit inhibitory effect against the growth of most food borne pathogens,due to the presence of various secondary metabolites. The aim of this study is to investigate the phytochemical constituents and antimicrobial activities of aqueous and ethanolic extracts of pineapple (Ananas comosus) peel and coconut (Cocos nucifera) kernel on some selected food borne pathogens. Antimicrobial analysis of aqueous and ethanolic extracts prepared from coconut kernel and pineapple peel were done by using the agar well diffusion method against the selected food borne pathogens. The ethanolic kernel extracts of coconut showed a remarkable inhibition zone against Bacillus cereus (18.0±0.13mm) followed by Klebsiella pneumonia (15.0±0.18mm) and Staphylococcus aureus (12.0±0.4mm). Whereas, the aqueous kernel extracts of coconut showed maximum inhibition zone against B. cereus (16.0±0.6mm) followed by S. aureus (15.7±0.9mm) and Escherichia coli (15.0±0.10mm). In addition the ethanolic peel extract of pineapple showed maximum inhibition zone against B. cereus (15.0±0.6mm) followed by S. aureus (14.0±0.22mm) and E. coli (12.3.0±0.12mm), whereas its aqueous peel extract resulted in maximum inhibition zone against B. cereus, (14.0±0.5mm), S. aureus (14.0±0.11mm) and K. pneumonia (14.0±0.10mm). Streptomycin, the reference antibiotic, had inhibitory zones on the tested organisms ranged between 10.0 and 24.0 mm. The minimum inhibition zone of the tested extracts against the tested organisms ranged from 5.0 mm to 14.0mm. The phytochemical analysis showed presence of oxalate, alkaloids, phytate, tannins and glycoside. The antimicrobial activities of the extracts of both C. nucifera kernel and A. comosus peel have capable of inhibitory effect against the target organisms.
Abstract: Plants like pineapple and coconut are able to exhibit inhibitory effect against the growth of most food borne pathogens,due to the presence of various secondary metabolites. The aim of this study is to investigate the phytochemical constituents and antimicrobial activities of aqueous and ethanolic extracts of pineapple (Ananas comosus) peel and coc...
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