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Effects of some Iranian Trichoderma isolates on maize seed germination and seedling vigor
B Hajieghrari
African Journal of Biotechnology , 2010,
Abstract: Trichoderma species are commonly used as biological control agents against phytopathogenic fungi and some of their isolates are able to improve plant growth. In the current study, we evaluated some Iranian Trichoderma isolate cultural filtrates as well as their direct effect on seed germination and seedling vigor of maize (Zea mays L. cultivar B73); they are Trichoderma harzianum T 969, T. harzianum T 447, Trichoderma hamatum T 614, Trichoderma roseum T678, Gliocladium virens G525 and the unknown Trichoderma species isolate (Trichoderma sp. T) obtained from the soil of Moghan Area, Ardabil Province of Iran. The culture filtrates reduced the speed of seed germination, but no influence (p0.05) was recorded at the final rate of the seed germination. When maize seeds were exposed to the Trichoderma spore suspension, all the Trichoderma isolates colonized the seed surface and inhibited the seed germination. The maize seed potted in inoculated soil did not emerge from the soil among all tested Trichoderma isolates, except for non-inoculated soil 30 days after potting. When Trichoderma conidia were added on the surface of soil near the emerged seed, significant (p0.01) decrease of seedling treated separately with T. hamatum T614 isolate was observed on the leaves area, fresh root and shoot weight, compared to the non-inoculated seedling. Whereas T. hamatum T447 and T. harzianum T969 reduced markedly (p0.01), seedling fresh root weight and fresh shoot weight were respectively increased as compared to the control. Trichoderma isolates had no influence on chlorophyll content in leaves and root length as well as stomata conductivity, except for Trichoderma spp. isolate T that increased stomata conductivity of seedling significantly (p0.01).
Effect of temperature and pre-germination treatments on seed germination and seedling vigor of Jatropha curcas L
Leandro Henrique de Sousa Mota,Rafael Heinz,Marcos Vinicios Garbiate,Silvana de Paula Quint?o Scalon
Biotemas , 2012,
Abstract: To date, there are no official methods used to test the seed germination of physic nut (Jatropha curcas) and there have only been a few attempts to optimize the germination of this species. The objective of this study was to evaluate the effect of different temperatures and pre-germination treatments on the germination and seedling vigor of J. curcas. The treatments were arranged in a completely randomized factorial scheme with four temperatures (20, 25, 30 and 20-30°C) x two types of seeds (with and without the seed tegument) x six periods of water imbibition (0, 6, 12, 18, 24 and 30h). The seeds were sown using a roller system with four replications of 50 seeds for each treatment. The germination percentage was higher for seeds stored at 25°C, when the seed tegument was maintained. When the time of water imbibition was increased, the germination percentage decreased, as well as the index of germination velocity and the percentage of germination of the first count. Imbibition for up to 12h led to an increase in hypocotyl growth. For this species, the maximum germination potential and highest vigor were obtained at 25°C, for seeds with teguments that were maintained and were not submitted to water imbibition.
Semi-hypogeal germination in Pachyrhizus ahipa (Wedd.) parodi (Fabaceae: Phaseoleae): seedling and sapling morphology
Milanez, Camilla R. Dias;Oliveira, Denise M. Trombert;Moraes-Dallaqua, Marina A.;
Brazilian Archives of Biology and Technology , 2008, DOI: 10.1590/S1516-89132008000200015
Abstract: the aim of this work was to describe the morphology of seedlings and saplings of pachyrhizus ahipa, a cultivated species of phaseoleae (fabaceae), analysing the seedling type and characterizing the structure of cotyledons, eophylls and metaphylls. it was observed that the seedling was semi-hypogeal, a germination type not yet recorded for the phaseoleae tribe. it formed two opposite and unifoliated eophylls with an evident pair of stipels. metaphylls were trifoliolate and had alternate phyllotaxis. both eophylls and metaphylls were pinnate, camptodromous, and brochidodromous.
Effects of Different Seed Treatment Methods on the Percent Germination, Seedling Vigor and Biomass Production of Groundnuts in Ghana
A. Frimpong,G. Nyarko,H. Bayor,J.A. Apeliga
Pakistan Journal of Biological Sciences , 2004,
Abstract: Low plant stand due to poor seed germination accounts for over 70% of the low production and productivity of crops in Ghana. This led to the conduction of an experiment to ascertain the effects of hot water, diathane M45 (D) and maceration (M) treatments on the viability, vigor and biomass production of three groundnut varieties, Chinese, Manipintar and F-mix. Maceration and D produced significantly higher rate of germination in Chinese and Manipintar than their controls. The three main treatments had no significant effect on the speed of germination of F-mix seeds. Hot water at 50oC level (H50oC), M1 and D1 treatments gave significantly higher germination percentage values for Chinese and Manipintar but not for F-mix. M1 and D1 treatments gave mean vigor indices significantly higher than their controls for Chinese, Manipintar and F-mix. However, it was only in Chinese where 50oC hot water treatment produced significantly higher vigor index than the 60oC level. H50oC, M1 and D1 yielded significantly higher biomass than the other treatment levels in Chinese. However, D1 and M1 produced biomass significantly higher than their controls in Manipintar and F-mix, respectively. Chinese seeds treated with various levels of hot water and D1 gave biomass yields significantly higher than seeds treated with hot water without diathane. Speed of germination, seedling vigor, germination percent and biomass production were about two or more times better and significantly higher in Chinese and Manipintar than F-mix, irrespective of the treatment levels. Maceration emerged as the best single treatment and could be adopted by farmers to increase germination percentage and plant stand at farm level since it is readily available to farmers and cheap.
Effects of Seed Hydropriming on Germination and Seedling Vigor during Emergence of Rice under Different Soil Moisture Conditions  [PDF]
Ken-Ichi Matsushima, Jun-Ichi Sakagami
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.48191
Abstract:

Seed priming is a physiological seed enhancement method. Hydro- or osmotic priming can advance germination under adequate moisture conditions. During direct seeding on well-drained paddy and upland fields, rice seeds occasionally encounter low soil moisture conditions. Under these conditions, rice seeds need to undergo rapid germination and secure emergence through improved water absorption capacity and seed bioactive. This study aims to clarify the effects of seed hydropriming on germination and seedling vigor in rice under different soil moisture conditions. The study employed three hydration conditions such as priming, soaking, and control. The seeds to be primed and soaked were submerged in tap water at 30℃ for 12 h. For priming, the seeds were subsequently dried to attain their initial seed weight, but the seeds for soaking were not dried before sowing, and the control seeds were untreated. In addition, different soil moisture conditions, such as 3%, 6%, 8%, 11%, 15%, and 20%, were set. Therefore, emergence time shortened with seed priming at 3%-11% soil moisture contents. In particular, at 8% soil moisture content, priming and soaking decreased emergence time by 26.8 h and 21.7 h, respectively compared with that of the control. At 8%-15% soil moisture contents, shoot elongation rate obtained with the priming seeds increased >1.2 times compared with that obtained with the control and soaking seeds. At >8% soil moisture content, shoot dry weight obtained with the priming seeds increased >1.3 times compared with that obtained with the soaking seeds. Furthermore, at declining soil moisture conditions, the increase in root dry weight is promoted by seed priming compared with that in the control seeds. These results suggest that increased root growth affects plant water absorption under low soil moisture conditions due to priming. This study demonstrates that seed priming facilitates rapid emergence and seedling vigor, unless extremely dry or flooded soil moisture conditions are present at seeding.

Seed Size as Key Factor in Germination and Seedling Development of Copaifera langsdorffii (Fabaceae)  [PDF]
Matheus Lopes Souza, Marcílio Fagundes
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.517270
Abstract:

Seed size is a plastic trait of the plants that directly affect seed germination and seedling recruitment. This study aimed to investigate the relationship between seed size, seed germinability and seedling performance of Copaifera langsdorffii by testing four hypotheses: 1) larger seeds have higher germination percentage; 2) smaller seeds require less time to germinate and for initial development of the seedlings; 3) larger seeds produce more vigorous seedlings and 4) seed size negatively affects seedling root/shoot ratio. In 2011, we selected 30 individuals of C. langsdorffii from which 300 seeds were randomly collected in the plant canopy. All these seeds were weighted and placed in germination tray using vermiculite as substrate. Seed germinability and initial development of seedlings were monitored daily until cotyledons fell. Small seeds have higher germination percentage and germinate faster when compared to large seeds. Nonetheless, seedlings originated from larger seeds have longer development times, resulting in more vigorous seedlings. In addition, seedlings originating from small seeds allocate proportionally greater amount of resources to roots when compared to larger seeds. The fact that small seeds have higher germination percentage and faster germination favors the colonization of transient habitats. However, larger seeds produce more vigorous seedlings, favoring the seedling establishment in more stable habitats. Thus, we argue that high variability in seed size of C. langsdorffii favors its widespread geographic distribution.

Desiccation effects on germination and vigor of King palm seeds
Martins, Cibele C.;Bovi, Marilene L. A.;Nakagawa, Jo?o;
Horticultura Brasileira , 2003, DOI: 10.1590/S0102-05362003000100019
Abstract: the desiccation tolerance of archontophoenix alexandrae (wendl. & drude) seeds was determined and the most sensitive vigor test for assessing seed deterioration of this species was identified. mature fruits were harvested in the palm collection of the instituto agronomico in campinas, brazil. depulped fruits were transported in impermeable packages to the faculdade de agronomia in botucatu, where the seeds were dried. as the seed moisture decreased, germination, seedling length, electrical conductivity and moisture were measured. the seeds of a. alexandrae are recalcitrant, with high germination percentage (over 67%) when undried (47% seed moisture). lowering seed moisture below 31.5% reduced the germination rate significantly (<52.5%). total germination failure was observed when seed moisture reached 15.1%. the electrical conductivity was the most sensitive vigor test to identify seed deterioration.
Desiccation effects on germination and vigor of King palm seeds
Martins Cibele C.,Bovi Marilene L. A.,Nakagawa Jo?o
Horticultura Brasileira , 2003,
Abstract: The desiccation tolerance of Archontophoenix alexandrae (Wendl. & Drude) seeds was determined and the most sensitive vigor test for assessing seed deterioration of this species was identified. Mature fruits were harvested in the palm collection of the Instituto Agronomico in Campinas, Brazil. Depulped fruits were transported in impermeable packages to the Faculdade de Agronomia in Botucatu, where the seeds were dried. As the seed moisture decreased, germination, seedling length, electrical conductivity and moisture were measured. The seeds of A. alexandrae are recalcitrant, with high germination percentage (over 67%) when undried (47% seed moisture). Lowering seed moisture below 31.5% reduced the germination rate significantly (<52.5%). Total germination failure was observed when seed moisture reached 15.1%. The electrical conductivity was the most sensitive vigor test to identify seed deterioration.
Effect of presoaking seeds in biostimulant solution on germination and vigor of Lactuca sativa L.
Maria Beatriz Bernardes Soares,Juliana Altafin Galli,Paulo Espíndola Trani,Ant?nio Lucio Melo Martins
Biotemas , 2012,
Abstract: The objective of this work was to analyze the germination and seed vigor of two lettuce (Lactuca sativa L.) cultivars that were presoaked in biostimulant solutions. The experimental design was a randomized block with four replications in a 2x7 factorial arrangement. Seeds of the cultivars Bariri and Maravilha das Quatro Esta es (MQE) were presoaked for 16h in solutions of 0, 5, 10, 15, 20, 25 and 30mL.L–1 of a commercial biostimulant. The percentage of germination, germination speed index, seedling length at 7 days after sowing and the ratio between the shoot and radicle of the seedlings were evaluated. The cv. Bariri was significantly superior in all aspects. The use of presoaking seeds in plant growth regulator did not affect the germination, but influenced seedling vigor. Presoaking Bariri in 10mL.L–1 resulted in the highest germination speed index (19.60) while for MQE the best result was obtained after presoaking in 15mL.L–1 (17.75). The results suggest that in favorable conditions presoaking lettuce seeds in biostimulant does not alter the germination, but improves germination speed and seedling vigor, and increases the chances of crop establishment.
Polymer coating, germination and vigor of broccoli seeds
Almeida, Celina de;Rocha, Sandra Cristina dos Santos;Razera, Luiz Fernandes;
Scientia Agricola , 2005, DOI: 10.1590/S0103-90162005000300004
Abstract: brassica oleracea var italica occupies a special place in the internal and external market of vegetables seeds. vegetables producers demand seeds with high degree of purity, germination and vigor, since seeds' quality is the basis for the success of the production. in this work, broccoli seeds were coated in a spouted bed, by an aqueous suspension of hidroxy-ethyl-cellulose. effects of the operating variables: spouting air temperature, atomizing air pressure and coating suspension flow rate over the dependent variables: seeds germination, seeds accelerated aging and the speed of seeds germination in soil, were investigated in a factorial scheme trial. the maximum processing time was 120 min. a totally randomized experiment evaluated and compared seeds germination and vigor of the coated and non-coated seeds. there was no identifiable, pronounced difference on germination of coated and non-coated seeds, accelerated aging of seeds, and speed of seeds germination in the soil. coating with hidroxy-ethyl-cellulose in the spouted bed did not alter broccoli seeds physiologic quality. the surface of coated seeds presented satisfactory distribution and spreading of the polymer film, uniform and individual coating and homogeneous aspect.
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