Showing papers in "Seed Science and Technology in 2008"

Disinfection of vegetable seed by treatment with essential oils, organic acids and plant extract

Abstract: Various essential oils, organic acids, Biosept, (grapefruit extract), Tillecur and extracts of stinging nettle and golden rod were tested for their antimicrobial properties in order to disinfect vegetable seed. In in vitro assays, thyme oil, oregano oil, cinnamon oil, clove oil and Biosept had the highest activity against the seed borne pathogens Xanthomonas campestris pv. campestris, Clavibacter michiganensis subsp. michiganensis, Alternaria dauci and Botrytis aclada. Low antimicrobial activity was found for the organic acids against the fungal pathogens. Seed treatment for 0.5 h with selected essential oils or Biosept in concentrations between 0.1 and 1% eliminated > 99% of total bacteria associated with cabbage seed. It also reduced the percentage of seeds contaminated with fungi in blotter tests from 70% to less than 10%. Extended periods of treatment did not significantly improve results. Cinnamon oil and Biosept used in concentrations exceeding 1% had a negative effect on seed germination. Antimicrobial effects with organic acids were variable, but in general, the organic acids ascorbic acids, propionic acid, acetic acid and lactic acid at concentrations of 2.5% or higher, reduced seed-associated bacteria. Of the organic acids, only propionic acid reduced seed germination at a concentration higher than 1%. Thyme oil was considered the most promising natural compound for reducing seed borne pathogens in seed. Various essential oils, organic acids, Biosept, (grapefruit extract), Tillecur and extracts of stinging nettle and golden rod were tested for their antimicrobial properties in order to disinfect vegetable seed. In in vitro assays, thyme oil, oregano oil, cinnamon oil, clove oil and Biosept had the highest activity against the seed borne pathogens Xanthomonas campestris pv. campestris, Clavibacter michiganensis subsp. michiganensis, Alternaria dauci and Botrytis aclada. Low antimicrobial activity was found for the organic acids against the fungal pathogens. Seed treatment for 0.5 h with selected essential oils or Biosept in concentrations between 0.1 and 1% eliminated > 99% of total bacteria associated with cabbage seed. It also reduced the percentage of seeds contaminated with fungi in blotter tests from 70% to less than 10%. Extended periods of treatment did not significantly improve results. Cinnamon oil and Biosept used in concentrations exceeding 1% had a negative effect on seed germination. Antimicrobial effects with organic acids were variable, but in general, the organic acids ascorbic acids, propionic acid, acetic acid and lactic acid at concentrations of 2.5% or higher, reduced seed-associated bacteria. Of the organic acids, only propionic acid reduced seed germination at a concentration higher than 1%. Thyme oil was considered the most promising natural compound for reducing seed borne pathogens in seed.

Priming enhances germination of spring maize (Zea mays L.) under cool conditions

Abstract: Summary Reduction and delay in the germination of spring maize (Zea mays L.) may be a problem due to low soil temperatures and low water potentials. However, seed priming is used to improve rate and speed of germination, and expand temperature limits for germination under normal and stressful conditions. Therefore, the objective of this study was to assess the physiological and biochemical basis of primed maize seeds under low temperature conditions. Maize seeds were subjected to hydropriming, hormonal priming with 100 mg L

Salinity, temperature and light affect seed germination of Haloxylon salicornicum, a common perennial shrub of the Arabian deserts

Abstract: Summary Haloxylon salicornicum (Moq.) Bunge ex Boiss. has been considered as one of the most promising species for re-seeding deteriorating desert range vegetation, and for sand dune fixation in the Arabian deserts. However, plant communities dominated by this species have become seriously degraded due to overgrazing. Reseeding degraded communities with this species requires information about light and temperature requirements and salinity tolerance at different temperatures of its seed germination. Seeds were germinated in saline concentrations (up to 800 mM NaCl) in incubators adjusted to 15, 20, 25 and 30°C, in both continuous light and dark. In non-saline treated seeds, germination in light conditions was similar for temperatures up to 25°C, but declined significantly at 30°C. Germination in darkness at either 15 or 20°C was significantly greater than at 25 and 30°C. Both final germination percentage and germination rate decreased as salinity increased. In higher salinity levels (500 – 700 mM), germination at moderate temperatures was greater than at both lower and higher temperatures. Recovery germination decreased as temperature increased. The lower salinity tolerance during germination in

The effect of light, temperature and bracteoles on germination of polymorphic seeds of Atriplex centralasiatica Iljin under saline conditions

Abstract: 1 Arid Land Research Center, Tottori University, Hamasaka, Tottori 680-0001, Japan; (E-mail: wqli@ms.sjziam.ac.cn; an.ping@alrc.tottori-u.ac.jp; tsun@alrc.tottori-u.ac.jp) 2 Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, Chinese Academy of Science, Shijiazhuang, 050021 P. R. of China; (E-mail: xjliu@ms.sjziam.ac.cn) 3 Department of Botany, University of Karachi, Karachi-75270, Pakistan; (E-mail: ajmalk@super.net.pk) 4 Faculty of Agriculture, Tottori University, Koyama, Tottori 680-8553, Japan (E-mail: jotanaka@muses.tottori-u.ac.jp)

Changes in hormone concentrations during dormancy release of oil palm (Elaeis guineensis) seeds.

Abstract: UCR::Investigacion::Unidades de Investigacion::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS)

SSR markers associated with seed longevity in soybean

Abstract: 1 National Research Centre for soybean, Khandwa Road, Indore, India 452017 2 Department of Genetics & Plant Breeding, G.B. Pant University of Agriculture & Technology, Pantnagar (Uttranchal), India 3 National Research Center on Plant Biotechnology, IARI, New Delhi, India 110012 * Present Address and author for correspondence: Division of Crop Improvement, Indian Institute of Sugarcane Research, Lucknow, India 226002 (E-mail: ikrps@yahoo.com)

Germination of fourteen endemic species from the Iberian Peninsula, Canary and Balearic Islands after 32-34 years of storage at low temperature and very low water content

Abstract: Final germination percentage and mean germination time of fourteen accessions from the Universidad Politécnica de Madrid (Spain) seed bank were evaluated after 32-34 years of storage. All the accessions chosen, belonging to fourteen genera and twelve different plant families, are of species endemic to the Iberian Peninsula, Canary or Balearic Islands. Three of these taxa are classified as “vulnerable” and one as “rare” according to the IUCN (International Union for the Conservation of Nature) criteria. The seeds had been stored at temperatures between -5oC and -10oC in flame sealed vials containing dehydrated (blue) silica gel. Seed water content was in general lower than 3% after storage. The germination trials were carried out under controlled conditions of light and temperature. In half of the accessions, the highest germination percentage was reached by seeds without any presowing treatment (untreated seeds). In the other seven accessions, the germination was significantly enhanced by soaking in gibberellic acid (GA3) or mechanical scarification. In ten of the fourteen accessions the final germination after storage was equal to or higher than 90%; in two accessions it was over 70% and in the remaining two accessions where germination was lower than 55%, tetrazolium test showed that viability was much higher. Therefore, the seed preservation method based on silica gel and relatively low temperature (-5oC and -10oC) has proven to be highly efficient in the endemic species assayed. The results obtained in this work support the possibility of using ultra-dry methods for long-term storage of orthodox seeds from a range of plant families.

Effect of cryopreservation, gibberellic acid and mechanical scarification on the seed germination of eight endemic species from the Canary Islands

Abstract: Summary Seed germination of eight endemic species of the Canary Islands (Descurainia burgaeana, Lavatera acerifolia, Lotus mascaensis, Pimpinella cumbrae, Ranunculus cortusifolius, Scilla haemorrhoidalis, Solanum vespertilio and Spartocytisus supranubius) was studied after seed storage in liquid nitrogen (LN, -196 oC), soaking in gibberellic acid (GA3) and mechanical scarification. Lotus mascaensis and Pimpinella cumbrae are classified as “vulnerable” (VU) and Solanum vespertilio as “critically endangered” (CR) according to the IUCN (International Union for the Conservation of Nature) criteria. The germination trials were carried out under controlled conditions of light and temperature. For six of the eight species studied, the final germination percentages of cryopreserved seeds were higher than those of control seeds (non-cryopreserved seeds). Furthermore for three of the species this increase was significant. On the other hand for two of the species, seeds that had been cryopreserved reached a germination percentage lower (Solanum vespertilio) and equal (Spartocytisus supranubius) to the control seeds, however these decreases were not significant. The germination of Solanum vespertilio was significantly enhanced by soaking of the seeds in gibberellic acid (GA3) and the scarified seeds of Lotus mascaensis and Spartocytisus supranubius reached a significantly higher germination percentage than untreated seeds. The germination rate, expressed by the mean germination time (MGT), was significantly lower for two samples of cryopreserved seeds, three samples of seeds pretreated with GA3 and three samples of scarified seeds. Therefore, this study proves seed cryopreservation is a suitable procedure for the long-term seeds conservation of several endemic species from the Canary Islands. Experimental and discussion The eight species chosen in this study, belonging to seven different plant families, they are all endemic species of Canary Islands (Bramwell and Bramwell, 1990). Descurainia burgaeana Webb ex Schulz (Brassicaceae) and Lotus mascaensis Burch. (Fabaceae) are small shrubs endemics of Tenerife island. The shrubby species Spartocytisus supranubius (L.) Webb & Berth. (Fabaceae) and the small chamaephyte Pimpinella

Prediction of germination and vigour in naturally aged commercially available seed lots of cabbage (Brassica oleracea var. capitata) using the bulk conductivity method

Abstract: Summary The potential for the electrical conductivity of seed soak water (EC) to predict the germination of cabbage seeds before and after controlled deterioration (CD), an ageing-based vigour test, was examined. The normal germination of naturally aged cabbage seed from commercial sources ranged from 6% to 92% for 11 lots of the white cultivar Yalova 1 and from 61% to 99% for 5 lots of the red cultivar Mohrenkopf. The EC (4 x 100 seeds, each in 40 ml deionised water) after 24 hours was inversely and closely related to normal germination, with R2 values of 0.85 (11 white cultivar lots) and 0.97 (5 red cultivar lots). CD tests at 20% moisture content (mc) for 24 hours at 45°C (CD20) and at 10% mc at 50°C for 2, 4 and 6 days (CD10) also revealed vigour differences. A significant negative correlation between the initial EC (before CD) of all lots and their CD germination resulted from the large range in initial germination. However, the correlations between initial EC and germination after CD were extremely low for the six lots of the white cultivar with >75% normal germination. EC after CD was closely related to total germination after CD20 and, although less so, after CD10 (2 days), indicating that because of the wide range of germinations the dominant influence on EC was the level of germination and not the vigour of the germinable seeds. The same observations were made after CD10 for 2, 4 and 6 days. The potential of EC as a rapid test to predict normal laboratory germination and germination after the CD test is discussed.

乾燥環境において薬物植物として名高いキャンサーブッシュ(Sutherlandia frutescens)の発芽に種子浸漬処理が及ぼす影響

Abstract: Cancer bush (Sutherlandia frutescens L.) is a medicinally important perennial legume native to southern Africa. S. frutescens seeds exhibit dormancy like many other legumes. Experiments using physical, mechanical and chemical pre-sowing treatments were conducted to determine the germination response of this species. Among various treatments, soaking the intact seeds for 30 min in concentrated H2SO4 resulted in a high final germination percentage of 97.5% in day 14 of culture. However, seed dormancy was completely broken by mechanical scarification in which 100% germination was obtained in day 2 of culture. The results indicated that S. frutescens seeds possess exogenous dormancy due to the hard seed coat which is the main inhibitor of germination.

Effects of seed vigour and the duration of cold acclimation on freezing tolerance of winter oilseed rape

Abstract: Summary Winter rapeseed (Brassica napus L.) promises to be an important oil crop in the Northwest regions of Iran. Winter hardiness and freezing tolerance are still problems for producing reliable high yield in these regions. Thus, a factorial experiment on the basis of RCB design was conducted in 2007, to investigate the effects of seed vigour (three vigour levels) and cold acclimation duration (0, 14, 28 and 42 days) on freezing tolerance (-3, -6, -9 and -12°C) capability of winter oilseed rape. Plant survival at freezing temperatures was significantly decreased with decreasing seed vigour level. Plants produced from the highest vigour seed lot (SV1, control) had the greatest freezing tolerance (71.5% survival, -10.56°C LT50), compared with those from two poor vigour seed lots. Seedlings from all seed lots exhibited the greatest survival at 28 days of cold acclimation. On the 28 th day of acclimation, the LT50 of leaf discs decreased by 7.8°C, compared with the non-acclimation treatment. The results clearly suggested that seed vigour can strongly influence freezing tolerance and plant survival in winter oilseed rape, through effects on seedling vigour before frost occurrence.

Water relations of drumstick tree seed (Moringa oleifera): Imbibition, desiccation, and sorption isotherms

Abstract: Interest in seed propagation of drumstick tree (Moringa oleifera) has created a need for information about the water relationships of its seeds. Thus, we studied the imbibition and desiccation kinetics and adsorption/ desorption isotherms of drumstick tree seeds. Seeds absorbed water readily when imbibed at 23oC. After 17 h of exposure to an atmosphere of 100% relative humidity (RH), seed moisture content increased from 10 to 150% on a dry weight basis (dwb). Seeds lost water rapidly in a 1% RH still-air environment, and returned to their original seed moisture content in 24 h, indicating seed covering tissues are highly permeable to water. Adsorption and desorption equilibrium moisture content curves at 25oC were determined using the dynamic gravimetric method. Drumstick tree seeds equilibrated at relatively low moisture contents over all humidities, remaining below 10% (dwb) at RH levels below 80%. Five equations that are used to model seed moisture content as a function of RH were fit to the data using a non-linear regression method (modified Henderson, modified Chung-Pfost, modified Guggenheim-Anderson-de Boer, modified Halsey, and D’Arcy-Watt). The D’Arcy-Watt model resulted in the best fit for predicting the seed moisture content of drumstick tree seeds. In humid environments, drying seeds before long-term storage may increase the longevity of stored drumstick tree seeds.

Estimating seed mass and volume from linear dimensions of seeds

Abstract: Seeds from eight species common in soil banks and covering two orders of magnitude of seed size were individually weighted and measured. Adopting simple but sound assumptions on seeds geometry, seed length and width together or not with thickness were found to be highly accurate estimators of seed mass and volume at intraand inter-specific levels. Thereby, by abstracting the vast amount of published data of seed length and width, seed volume rather than seed mass can be used to investigate ecological and functional aspects of seed size.

Effects of moist-chilling and GA(3) applications on seed germination of three Pedicularis species from Yunnan, China

Abstract: Most species of the genus Pedicularis L. have rather high ornamental value and some species are medicinal plants. Little is known about the germination requirements of these species and it is necessary to obtain fundamental information about seeds germination for the purpose of introduction and cultivation. Six stratification (4 degrees C and darkness) durations (15, 30, 45, 60, 75, 90 days) plus control, as well as 3 GA(3) Solution concentrations (100, 500, 1000 mg/L) were tested on seeds of Pedicularis rex, P. rhinanthoides, and P. longiflora var. tubiformis. The optimal germination conditions varied between species, while as a whole, the highest germination percentage was obtained from treatments of 500-1000 mg/L GA(3) followed by 15-30days stratification, and the lowest value of mean germination time was obtained from treatments of 100-1000ppm GA(3) followed by 15-day stratification.