Abnormal Seedlings Research Articles

Karakteristik Dan Viabilitas Biji Gaharu (Aquilaria Microcarpa Baill.) Dari Tanaman Koleksi Kebun Raya Bogor

The characteristics and viability of agarwood (Aquilaria microcarpa Baill.) seed from the Bogor Botanic Garden's collection was investigated. Two batches of seed from intact mature fruit and dehisced mature fruit were tested for viability using germination and tetrazolium test methods. The result showed that although the tetrazolium test indicated a similar level of seed viability between the two batches (i.e. 85 — 93 %), the germination capacity of seed batch derived from dehisced fru,it was greatly reduced (i.e. 46 % total seed germination) compared to that derived from intact fruit (i.e. 97 % total seed germination). The decrease of seed germination capacity indicated the loss of seed vigour and was concomitant with the decrease of seed moisture content from 42.22 % to 24.79 % (fresh weight basis), thus underlining that the seed has a recalcitrant characteristic. Further observation on the seedling growth showed that there was an incidence of abnormal seedlings encountered in the seed batch from dehisced fruit. Detailed information on the morphological characteristics of the fruit, seed and seedling are presented in this paper.

Effect of Pansy (Viola x wittrockiana gams) Seeds Colour and Size on their Germination

Four commercial seed lots from the Polish seed companies of pansy (Viola x wittrockiana Gams) with low germination capacity were sorted into 2 size fractions: small and large: below 4 mm long and above 4 mm and 3 colour fractions: yellow, brown and dark, using hands and colour catalogue of British Royal Horticultural Society. The seeds were then tested for their germination following the ISTA routine rules. The seed size did not affect neither its energy nor capacity of germination. In one of the seed lots, smaller seeds germinated slightly better than the big ones, but in the two others ones, it was opposite. The smaller seed also gave higher amount of abnormal seedlings in the tests. There was a clear effect of seed colour on the seeds' germination. The dark seeds had the highest germination capacity, whereas the yellow ones - the lowest. The carried out experiments proved that color sorting of pansy seeds can improve their germination, mostly due to eliminating light, immature seeds.

EFICIÊNCIA DE PRODUTOS ALTERNATIVOS NO CONTROLE Zabrotes subfasciatus, E SEUS EFEITOS SOBRE A QUALIDADE DAS SEMENTES DE Phaseolus vulgaris

The largest losses caused by insects to seeds occur generally in the storage period with partial or total destruction. Beans seeds are infested in the field by insects flying in areas nearby crops prior to harvest. Even under initial low level attacks night losses to the lot may occur due to the generations originatede from that initial low attack. Emgopa Ouro beans seeds, harvested in the municipality of Anapolis, Goias, were analysed in the School of Agronomy in Goiania, Goias. Seeds were divided in 5kg portions and subjected to the following treatments: soybean oil (3, 5 and 7 ml/kg of seeds); ground pepper variety (2, 4 and 6 g/kg of seeds); piriphosphomethyl (20ml/t of seeds), and control. Seeds were then packaged in jute fabric bags and stored in non-controlled environment. The experiment was completely randomized with three replications. The variables analyzed were: infestation, germination, and abnormal seedlings. The experiment was carried out for eight months. The statistical analysis led to the conclusion that ground pepper at 4g/kg of seeds level was the most efficient treatment for Zabrotes subfasciatus control in beans stored for eight months.

Physiological dormancy in forbs native to south–west Queensland: Diagnosis and classification

Seed physiological dormancy (PD) is reportedly the primary reason why many Australian native plants are not currently used for revegetation of degraded land. However knowledge of germination and dormancy of forb species from semi-arid environments is lacking. Consequently, we investigated germination of 15 Australian forb species from four families, particularly Asteraceae, native to south–west Queensland (Qld). Seeds were tested for viability using tetrazolium chloride (TZ) and sown at 5 to 35 °C. Nine species, including seven Asteraceae, achieved germination exceeding or not significantly lower (P>0.05) than TZ test results. Despite spring dispersal, the majority of species had optimal germination at temperatures reminiscent of winter months. Only six species exhibited low germination across all temperatures investigated when compared to TZ results (P<0.05), i.e. low germination could not be attributed to low seed viability. Of these, Actinobole uliginosum (Asteraceae) had non-deep PD since seeds responded to gibberellic acid (GA3) and dry after-ripening. In contrast, Goodenia fascicularis appeared to exhibit deep PD since seeds did not respond to GA3 or dry after-ripening, and scarification led to germination of abnormal seedlings. It appears that, contrary to expectations, seeds of many forbs native to south–west Qld (9 of 15 in this study), possess negligible or no dormancy and may therefore be suitable for use in land rehabilitation. Other species e.g. G. fascicularis require further work to investigate dormancy mechanisms and develop reliable germination techniques before seeds can be used effectively.

Rhizobacteria able to produce phytotoxic metabolites

To contribute for the development of environmental friendly methods for weed control, a selection of rhizobacteria able to produce phytotoxic substances was carried out. Initially, 35 strains previously isolated from plants in the south of Minas Gerais State (Brazil) were grown in tryptic soy broth. After removal of bacterial cells, the resulting liquids were freeze-dried and extracted with methanol/ethyl acetate (1:1). The extracts were concentrated under vacuum and dissolved in water to be submitted to a lettuce (Lactuca sativa L.) seed assay. Metabolites produced by five strains reduced the number of normal seedlings to values statistically bellow the one observed for the negative control, being the most expressive results obtained with Bacillus cereus Frankland and Frankland, isolated from Ricinus communis L., which was able to cause rotted rootlets to 82.4% of seedlings. The bacterium metabolites also avoided germination of 52% Brachiaria decumbens Stapf seeds and the remaining 48% resulted in abnormal seedlings. Metabolites from B. cereus were submitted to a purification process guided by the lettuce seed assay. As a consequence, one substance causing rotted rootlets to all lettuce seedlings during the seed assay at 0.057 g/L was isolated and will be identified in future studies.

Pepper seed germination assessed by combined X-radiography and computer-aided imaging analysis

A lot of pepper seeds having 87 % germination were subjected to X-ray inspection using a non lethal dose of radiation. Seeds with less than 2.7 % (on the basis of total seed area) of free space area, i.e. the spaces between embryo and endosperm, were classified as highly viable seeds (97–100 % germination) with the lowest level of abnormal seedlings. Seeds X-ray classified as good were subjected to a computerised image analysis to study seed imbibition and radicle elongation. The patterns of seed area increase, chosen as the most accurate indicator of seed swelling, resembled the triphasic curve of water uptake. The first phase was completed at 9 h followed by a second phase that varied widely in time until completion of germination between 52 and 96 h. The proportion of seeds with radicle protrusion between 52–56 h and 64–72 h assessed with the image analysis was significantly higher than that recorded using a conventional germination test. In addition, the rate of increase of seed area during the third phase of imbibition, mostly due to protrusion of the radicle tip and its growth, was highly correlated with the corresponding radicle elongation rate.

An Investigation on the Germination of Seeds of Kwao Kreu Kao (Pueraria candollei Grah. Ex Benth) as Affected by Both Water Soakings and Hot Air Oven Treatments

This experiment was carried out at the Faculty of Technology, Mahasarakham University, Mahasarakham 4400, Thailand to investigate effects of different water-soaking durations and hot air oven treatments on the germination of seeds of Kwao Kreu Kao (Pueraria candollei Grah. ex Benth) plants. The experiment was laid in a Randomised Complete Block Design with four replications. The results showed that after tested for Electrical Conductivity (EC) values for cracking of seeds, all seeds being used were at a normal condition (with an average EC value of 28.56 microS cm(-1) g(-1)) and all seeds were ready for germination. Strength on impermeability of seeds declined after soaking in water for 10 h and onwards then the treated seeds had increased in weights. However, after treated under hot air oven, dry weights of all seeds became similar. Germination percentage of all treatments was most rapid during the first three weeks of germination period and later slowly increased with time. At day 91 after sowing, T2 gave the highest percentage of germination (52%) and the lowest was found with T1 (control) with 31.25%. Again at day 91 after sowing, T2 gave the highest mean value of plant numbers (16.38) and the lowest was found with T1 (7.28). Numbers of abnormal seedlings determined at day 63 after sowing were lowest with T2 (6.25%) and worst with T4 (20.14%). Again at day 63 after sowing, plant height was significantly tallest with T2 (3.88 cm) and the lowest was found with T4 (2.71 cm). Numbers of leaves were not significantly different among the treated plants reaching a highest value of 11.25 leaves plant(-1) for T3. It may be concluded that T2 was the best treatment for use in germinating seeds of Pueraria candollei Grah. ex Benth plants. Further improvements on longevity and high percentage of germination of seeds were discussed and suggested.

Investigation of Seed Vigor and Germination of Canola Cultivars under less Irrigation in Padding Stage and after it

The laboratory experiment was a factorial based on a Completely Randomized Design with four replications during 2005. Factors included two irrigation levels (normal irrigation (irrigation after 60 mm evaporation from class a pan) and less irrigation in padding stage and after it) and six winter cultivars (Licord, Okapi, Orient, SLMO64, Zarfam and Opera). The seeds used in this experiment produced under less irrigation (moderate drought stress) and they were three months in storage. The seed vigor was tested in laboratory experiment by three vigor tests, including Standard Germination test, cold test, Accelerated Ageing Test. Result showed that the accelerated aging test had significant differences on all of character in this study. Mean Comparing, showed canola cultivars had significant effect on Root/ Shoot ratio, abnormal seedling, hard seed, seedling fresh weight, MTG and FGP. Less irrigation levels had significant effect on total and shoot length, ratio root/shoot length and MTG.

Hormonal Effect on Germination and Seedling Development of Hura crepitans Seeds

To establish propagation test and nursery establishment protocols for Hura crepitans. Various concentrations and timing were performed on the seeds of Hura crepitans using growth hormones; Thiourea, Gibberellic acid and Coumain. Gibberellic acid pretreated seeds recorded high cumulative germination (100%) and germination energy (95%). Similarly, high percentages were recorded for Thiourea. However, Coumain showed poor germination as well as recorded high percentage of abnormal seedlings (90%), a poor option for nursery establish of Hura crepitans. Ranked mean for the germinated seedlings was significant at p<0.05 for Thiourea and Gibberellic acid treatments.

Germinação in vitro de urucu

Esse trabalho foi realizado com o objetivo de avaliar a germinação de sementes e o desenvolvimento de eixos embrionários de urucu (Bixa orellana L.), cultivar Casca Verde, em meio de cultivo in vitro, com diferentes concentrações de ágar. O delineamento experimental foi o inteiramente casualizado, com quatro repetições, em esquema fatorial A x B, sendo para o fator A: sementes intactas, sementes sem tegumento e eixos embrionários e para o fator B: quatro níveis de ágar (4, 6, 8 e 10g.L-1) em meio básico "MS". Sementes sem tegumento em meio de cultura contendo 4g.L-1 de ágar apresentaram maior porcentagem de germinação. Maiores porcentagens de plântulas normais foram observadas no desenvolvimento de eixos embrionários em meio de cultura contendo 10g.L-1 de ágar. Sementes intactas apresentaram as menores porcentagens de germinação e de plântulas anormais em 4 e 6g.L-1 de ágar. Maiores massas de matéria fresca e seca das plântulas normais ocorreram na germinação de sementes sem tegumento em meio de cultivo com concentração de 10g.L-1 de ágar.

Boron application affects seed yield and seed quality of sugar beets

SUMMARYSugar beet (Beta vulgarisL.) is one of the most important sugar crops worldwide. Despite the fact that sugar beet crop has high requirements for boron (B), the effect of B applications on seed yield and on seed quality is not known. A 2-year field study was conducted to determine whether soil and foliar B applications during anthesis increase seed set, final seed yield and improve seed quality of sugar beets. Boron solutions were applied at four rates (0, 245, 490 and 735 mg/l of B) as foliar applications and at two rates (1·5 and 3 kg/ha of B) as soil applications to field plots exhibiting no vegetative symptoms of B deficiency. Foliar B application increased the concentration of B in vegetative and reproductive tissues much more than soil application. In addition, foliar B application increased the seed yield by an average of 10% in the first year and by an average of 44% in the second year. The mean seed weight was affected by B application as it was increased in both years. The proportion of larger seeds (&gt;5·00 and 4·5–5·00 mm) increased with increasing application of B. Moreover, seed quality was affected and the proportion of abnormal seedlings was decreased with B application. However, seed vigour was not affected by B application. These data indicate that foliar B application can improve seed yield and seed quality of sugar beet grown for seed production. However, the physiological basis of this effect remains unknown.

Germinação e desenvolvimento de plântulas de melancia em função da salinidade

Sementes de três lotes de melancia (Citrullus lanatus Schrad.), cv. Crimson Sweet, foram expostas a cinco potenciais osmóticos (0,0; -0,2; -0,4; -0,6 e -0,8MPa) utilizando-se substrato umedecido com soluções de NaCl, com objetivo de avaliar os efeitos de diferentes potenciais osmóticos de NaCl na germinação e no desenvolvimento de plântulas de melancia. Avaliaram-se a porcentagem de germinação, primeira contagem de germinação, porcentagem de plântulas anormais, comprimento da plântula e peso da massa seca da plântula. A análise dos resultados permitiu concluir que a diminuição progressiva do potencial osmótico de NaCl do substrato é prejudicial à germinação e, principalmente, ao desenvolvimento de plântulas; os efeitos se acentuam a partir do potencial osmótico -0,4MPa.

Effects of the seed predator Acanthoscelides schrankiae on viability of its host plant Mimosa bimucronata

Seeds of Mimosa bimucronata are heavily infested (pre-dispersal predation) by the bruchid beetle Acanthoscelides schrankiae in Brazil. In this study, firstly we set up experiments to assess seed germination under seven and six different light and temperature regimes, respectively, and then we evaluated the ability of seeds to germinate after predation. We tested the hypothesis that the non-predated seeds from infested fruits may respond differently when set for germination than those seeds of non-infested fruits. We also hypothesized that predation may increase the production of unviable seeds. Seeds under 18 hours of light presented the highest percentage of germination, and the alternating temperature 20-30 degrees C was considered as optimum for germination (abnormal seedlings were not considered as a successful germination). Germination of seeds from non-infested fruits was significantly higher than germination of non-predated seeds from infested fruits, and predation also caused a significant increase in the proportion of dead seeds. Our results also show a positive correlation between proportions of unviable seeds and predated seeds. These results demonstrated that seeds of M. bimucronata are strongly affected by predation because predated seeds did not germinate and non-predated seeds had their viability reduced when located in infested fruits, supporting our hypothesis.

PRESENT STATUS OF ONION BULB AND SEED PRODUCTION IN KHULNA REGION AND EFFECT OF CONTAINERS ON STORABILITY OF ONION SEEDS

A survey was done to collect information on present status of onion bulb and seed production and the status of onion seed market in Khulna region and studies were conducted on the effect of different seed containers on storability of onion bulbs and seeds. The survey was conducted at three upazillas of Khulna district viz. Batiaghata, Dumuria and Paikgacha. From land preparation to harvesting, the operations performed by the farmers following orthodox way of cultivation. They use locally produced seeds collected from different sources, irrigate onion field when they feel necessary, use fertilizers containing macro nutrients solely and do not follow any pest control measure. Only 7.5% traders sell solely onion seeds and rest of the traders sells different spice seeds along with the onion seeds. The traders usually do not use any chemicals to preserve the seeds and they prefer naphthalene to other chemicals in this purpose. Kalashnagari was found best among the three varieties in respect of germination percentage (49.33%) and length of the seedlings (5.428 cm). Despite of polythene bags, tin container showed better performance in storing of onion seeds by showing more germination capacity of seeds (43.82%), comparatively less infection by fungus (14.04%), less number of abnormal seedlings (11.24%) and good length of germinated seedlings (4.96 cm). Minimum weight loss (18.53%), maximum regeneration (89.37%) and maximum length of shoots (18.75 cm) was obtained from the bulbs stored in enclosed chamber in polythene bags, gunny bags and polythene bags respectively.

Effects of Salinity and Temperature on Germination and Seedling Establishment of Sweet Basil (Ocimum basilicum L.)

ABSTRACT Sweet basil (Ocimum basilicum L.) is usually propagated from seed, but establishment of the plant is sometimes difficult as seed germination and seedling emergence may be limited under saline and unfavorable temperature conditions. In this study, salt and temperature tolerance of green and purple types of basil were investigated by subjecting both green and purple basil to selected levels of salinity (0, 1, 3, 6, 9, 12, and 15 dS/m) and temperature regimes (15, 25, and 35°C). Germination and seedling emergence in a saline environment were higher at 25°C than at the other tested temperatures, indicating a temperature stress made sweet basil more susceptible to salt stress. Although seed germination and seedling development were similar to controls at low salinity levels and 25°C, abnormal seedling development was increased and germination reduced at salinity levels of ≥ 12 dS/m for both the green and purple type of sweet basil. Sweet basil can be classified as moderately tolerant to salt stress during seed germination and seedling emergence.

Substrato, temperatura de germinação e desenvolvimento pós-seminal de sementes de Dalbergia nigra

O objetivo deste trabalho foi definir o tipo de substrato e a temperatura mais adequada à germinação de sementes de Dalbergia nigra (Vell.) Fr. All. Ex Benth (jacarandá-da-bahia), e conhecer a morfologia de seu desenvolvimento pós-seminal e caracterizar as plântulas normais, o tipo de germinação e os padrões de anormalidade. As sementes foram semeadas nos substratos sobre papel, rolo de papel e sobre vermiculita, nas temperaturas constantes de 20, 25, 30 e 35°C e alternadas de 20-30°C e 20-35°C. O delineamento estatístico empregado foi o inteiramente casualizado (6x3), com quatro repetições de 50 sementes. Foram analisados os seguintes parâmetros: porcentagem de germinação normal (plântulas normais) e velocidade de emergência de plântulas. Os melhores resultados foram verificados nas temperaturas de 25°C e 20-30°C, nos substratos sobre vermiculita e rolo de papel. Plântulas normais foram caracterizadas como faneroepígeas em relação ao tipo de germinação.

Physiological and cytological response of salt-tolerant and non-tolerant barley to salinity during germination and early growth

Seven barley cultivars (Franklin, Gairdner, YU6472, Numar, CM72, ZND3 and YUQS) were evaluated for NaCl tolerance in relation to physiological and cytological responses during germination. Standard germination techniques were employed using blotting paper saturated with different NaCl solutions (0, –0.3, –0.6, –0.9, –1.2, –1.5 or –1.8 MPa) at 20°C. The results showed significant differences among varieties for germination percentage, frequency of abnormal seedlings, and Na+, K+ uptake. Of the 7 barley cultivars, CM72 was similar in salt tolerance to Numar, while YUQS and ZND3 were the most sensitive to high salinity. The tolerant cultivars showed much higher germination percentage under salinity stress than susceptible varieties. Both CM72 and Numar maintained more than 90% germination at –1.2 MPa osmotic potential while YUQS and ZND3 had only 57% germination at the same level of salinity. The tolerant varieties also showed shorter mean germination time at low osmotic potential. The start of the first mitosis was delayed, while both the frequencies of aberrant anaphases at the first cell divisions, and the numbers of abnormal seedlings were increased in higher salt concentrations. During the seedling stage, tolerant varieties showed significantly higher K+ concentrations, lower Na+ concentrations, lower Na+/K+ ratio and higher photosynthetic rate than susceptible varieties under salinity stress. Screening of barley cultivars or breeding lines could be best achieved by a combination of germination testing and measurement of photosynthetic rate and/or Na/K balance in young seedlings.

Quantitative characteristics of fruits and seeds of Pouteria pachycarpa Pires - Sapotaceae

Pouteria pachycarpa is a tree species, found in the Brazilian Amazon and Bolivia whose wood has been exploited from the native forest. The present research describes the quantitative characteristics of fruits and seeds and quantifies the seed germination of this species. The fruit and seed color were characterized and measurements taken of the mass, length, diameter and number of seeds per fruit, the seed length, width and thickness, the germination percentage, abnormal seedlings and dead seeds. Sowing was carried out on a substrate containing sand and sawdust (1:1), in four replications of 50 seeds. The predominant fruit and seed colors were vivid yellowish orange (9YR) and dark grayish brown (6YR), respectively. Fruit mass, length and diameter ranged from 37.7 to 192.4g, 41.3 to 87.3mm and 39.7 to 71.7mm, respectively. Fruits had from two to seven seeds, and 42.6% were damaged by insects. Seed length, width and thickness ranged from 22.4 to 35.2mm, 9.7 to 15.5mm and 5.5 to 10.8mm, respectively. Seedling emergence began 18 days after sowing. Maximum germination, 86%, was recorded 33 days after sowing. The germination curve was sigmoid, similar to the majority of species. The percentage of abnormal seedlings and dead seeds were 3% and 11%, respectively. Both fruits and seeds show great variation in quantitative characteristics and the germination is slow and non-uniform.

Germinação de sementes de cubiu em diferentes substratos e temperaturas

O cubiu (Solanum sessiliflorum Dunal) é uma solanácea arbustiva nativa da Amazônia, que apresenta potencialidades para a agroindústria devido à alta produção de frutos saudáveis, com elevada concentração de ácido cítrico. Objetivou-se neste estudo analisar o comportamento germinativo das sementes de cubiu sob regime de temperaturas e substratos diferentes. O trabalho foi realizado no Laboratório de Tecnologia e Análises de Sementes do Centro de Ciências Agrárias da Universidade Federal do Espírito Santo (CCA-UFES), Alegre-ES. O delineamento experimental utilizado foi o inteiramente casualizado, num esquema fatorial 6x6 (seis substratos e seis temperaturas) com quatro repetições. A comparação de médias foi feita pelo teste de Tukey, a 5% de probabilidade. Os substratos utilizados foram: sobre vermiculita (V); entre areia (EA); sobre papel (SP); sobre areia (SA); sobre mistura terra + areia + esterco (TAE) e rolo de papel germitest (RP) e as temperaturas foram constantes de 20, 25 e 30ºC e alternadas de 20-25; 25-30 e 20-30ºC. Os resultados obtidos evidenciaram maior porcentagem de germinação das sementes de cubiu semeadas nos substratos sobre areia e entre areia, sendo a temperatura de 20-30ºC, aquela que mais favoreceu a germinação e a velocidade de germinação das sementes.

Control of Leaf Formation and Somatic Embryogenesis in Cultured Zygotic Embryos ofArabidopsis thalianaby 2,4‐Dichlorophenoxyacetic Acid (2,4‐d)

The culture of bent‐cotyledon‐stage zygotic embryos of Arabidopsis thaliana in a medium containing the synthetic auxin 2,4‐dichlorophenoxyacetic acid (2,4‐d) for 10 d induces the formation of early‐stage somatic embryos on the callus formed on the cotyledons. Transferring the callus to an auxin‐free basal medium leads subsequently to the formation of mature‐stage somatic embryos. The timing of formation of mature‐stage somatic embryos in Arabidopsis by 2,4‐d action was studied by monitoring the morphogenetic changes in zygotic embryos transferred to the basal medium and grown in light and/or dark conditions after different periods of treatment in a medium containing 2,4‐d. When embryos subjected to increasing periods of 2,4‐d action are grown in the basal medium, they form, in transitional order, normal seedlings; abnormal seedlings, consisting of a short stem with ovate, spoon‐shaped, and bifid or lobed leaves and adventitious leafy shoots; a callus of cotyledonary origin, bearing a mixture of leaves and tubular somatic embryos with fused, bifid, or lobed cotyledons; and, finally, a callus with mature‐stage tubular somatic embryos with fused, bifid, or lobed cotyledons. During growth in the basal medium in light, cotyledons of somatic embryos formed on zygotic embryos pretreated for suboptimal periods with 2,4‐d acquire the morphological and anatomical features of leaves by the formation of trichomes and the typical venation pattern, consisting of a midvein and secondary veins separating the cotyledon into two or more chambers. Somatic embryos in which cotyledons are transformed into leaves phenocopy zygotic embryos of the leafy cotyledon1 mutant of Arabidopsis. The transformation into leaves of cotyledons of somatic embryos regenerated on zygotic embryos subjected to suboptimal periods of 2,4‐d action indicates that a defective synthesis or maintenance of the local concentration of auxin during embryogenesis might account for this mutation.