(pp. 7-11) Professional Development and Seed Technology Training for Seed Analysts/Technologists at Land-Grant Universities
Gregory E. Welbaum
Most seed technologists and other seed industry professionals have little spare time to devote to professional development. A leave of absence to take college courses is not an option for most technologists or their employers. Yet new developments in seed biology make continuing education more important than ever.
To help working seed industry professionals maintain proficiency and develop new skills, several seed technology programs/ courses have been created at land-grant universities that are offered on the worldwide web. These web-based distance-learning programs can be completed at home as time permits without on campus residence. Three such programs are the Iowa State University MS and Certificate Programs in Seed Business and Technology (http://www. seedgrad .iastate .edu/ sb), the Consortium for International Seed Technology Training (CISTT, http:// www . seed consortium .org/index.html) coordinated by The Ohio State University and partner universities in Brazil and Chile, and the National Seed Science and Technology Certificate program and the Seed Technology Education Certificate program, both offered through Colorado State University (CSU), http:// step.colo state.edu. Oregon State University, Virginia Tech, and University of Kentucky also offer web-based distance-learning courses. Download entire article
(pp. 15-25) Germination Characteristics along Altitudinal Gradients in Three Intermountain Allium spp. (Amaryllidaceae)
Nathan C. Phillips,* Daniel T. Drost, William A. Varga, Leila M. Shultz and Susan E. Meyer
Understanding the relationship between life cycle events of native species and their prevailing environmental conditions provides a framework in which site-specific propagation strategies can be developed. We examined the ecophysiological aspects of seed germination in three Allium species native to the Intermountain West (A. acuminatum, A. brandegei, and A. passeyi) to evaluate ecotypic variation in relation to the altitude of the collection site.
Three populations of each species were evaluated along an altitudinal gradient. The study consisted of two laboratory experiments: 1) germination trials assessing the effects of moist chilling temperatures on germination per centage in each species; and, 2) germination trials measuring the response within and among species from contrasting habitats to moist chilling duration. The data demonstrate a strong among-species pattern of increasing dormancy with increasing elevation. Although germination in all three species responded favorably to moist chilling at 3 °C, there was significant variation in the chill duration required to break dormancy. The presence of a non-dormant fraction only in the lowest A. acuminatum collection, and all three of the A. passeyi collections also indicates a higher level of selection pressure against this trait in sites with longer and more predictable winters. The observed pat terns in seed germination are typical of survival strategies in other spring ephemerals. This current understanding of the influence of habitat on germination traits in these Intermountain Allium species will aid in the development of seed-source specific propagation protocol. Download entire article
(pp. 26-36) Floret-infesting Thrips in Grass Seed Crops: Crop Host Range and Seed Loss
Sujaya Rao,* Stephen Alderman and Alexzandra Murphy
Thrips that feed within florets on developing embryos in grass seed crops reduce yield and pose a risk of global dispersal as they remain cryptic within the lemma and palea in harvested seeds. In some species, a single thrips develops within one floret, and hence one seed is lost with each thrips-infested floret, irrespective of seed size. The objectives of this study were to determine the grass seed crop host range and percent seed loss due to floret-infesting thrips.
The two-year study was conducted in western Oregon, a key grass seed production region in the USA. Three fields were surveyed for each crop, and 3,000 seeds were examined per field by stereomicroscope observation of 100 florets from each of 30 inflorescences in 2005 and 200 florets from 15 inflorescences in 2006. Crops surveyed include bentgrass (Agrostis castellana Boiss. & Reut.), annual ryegrass (Lolium multiflorum Lam.), perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea Schreb. subsp. arundinacea), Chewing’s fescue [Festuca rubra ssp. Fallax (Thuill.) Nyman] and orchardgrass (Dactylis glomerata L.). In both years, 94.4% of all fields surveyed were infested. Adults of one or two thrips species, Chirothrips manicatus Haliday and Limothrips cerealium Haliday, were recorded in florets of all grasses. Average percentage seed loss per crop ranged from 0.03% to 4.42%. In one perennial ryegrass field, however, 11.4% seed loss was recorded. The impact of thrips size and life cycle on crops infested, seed loss and potential risk of global dispersal based on harvest schedules is discussed. Download entire article
(pp. 37-45) Imbibition Duration, Seed Treatment, Seed Mass and Population Influence Germination of Annatto (Bixa orellana L.) Seeds
Nisha Joseph, E.A. Siril* and G.M. Nair
An investigation on germination of annatto (Bixa orellana L.) was conducted. Water uptake studies showed that seeds were fully imbibed after 24 h. Soaking in water for 24 h enhanced germination (82%) compared to the untreated control (57%).
Germination was improved to 93% and was coupled with a significant (p < 0.001) reduction in mean time to germination (MTG, 3.64 d) by soaking seeds in a 50 ppm gibberellic acid (GA3) solution for 24 h. Germination capacity for medium (97%) weight class seeds was higher than light (40%) or heavy seeds (60%). Significant (p < 0.001) germination variability was recorded among eight seed collections. Seeds collected from populations in Kariavattom (82%) and Kulathupuzha (80%) produced significantly higher germination coupled with a low mean time to germination. Download entire article
(pp. 46-53) Fatty Acid Composition in Seeds of Jack-bean [Canavalia ensiformis (L.) DC.] and Sword-bean [Canavalia gladiata Jacq.) DC.] Germplasm from South India: A DIVA-GIS Analysis
N. Sivaraj,* N. Sunil, S.R. Pandravada, V. Kamala, B.V.S.K. Rao, R.B.N. Prasad, E.R. Nayar, K. Joseph John, Z. Abraham and K.S. Varaprasad
Twenty one accessions of germplasm of Canavalia (C. ensiformis-12; C. gladiata-9), a wild edible legume collected from Andhra Pradesh, Kerala and Tamil Nadu in South India were analyzed for oil content and fatty acid composition. The oil content in Canavalia ranged between 0.4–2.3%. The variability for oil content and fatty acid composition is presented in this paper.
Seed lipids of all Canavalia accessions contained higher amounts of unsaturated fatty acids (69.1–81.8%) compared to saturated fatty acids (18.2– 30.9%). Oleic acid was found to be the major component in all the seed lipids. Grid maps were generated using DIVA-GIS for the analysis of diversity based on total unsaturated fatty acids and total saturated fatty acids. IC310951, a C. ensiformis accession collected from Andhra Pradesh recorded the highest omega-3 fatty acid (linolenic acid, 11.4%) which forms an essential fatty acid.
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(pp. 57-62) Conservation of Mantisia spathulata Schult. and Mantisia wengeri Fischer, Two Critically Endangered and Endemic Zingibers of Northeast India
Sudipta S. Das Bhowmik, Suman Kumaria* and Pramod Tandon
Mantisia spathulata Schult and M. wengeri Fischer are critically endangered and endemic ornamental zingibers restricted to a few pockets of Mizoram, Northeast India. Plants are decreasing at an alarming rate due to natural calamities and few countable representatives of both species exist in their wild habitats.
To develop a system for rapid mass recovery and sustainability of the genetic diversity of the few existing plants, seeds of both species were germinated under in vivo and in vitro conditions. In vivo germination of seeds was very low (20% and 24% for M. spathulata and M. wengeri, respectively). However, germination in vitro was significantly enhanced. A maximum of 90.0% and 96.6% germination was recorded for M. spathulata and M. wengeri within 2 wk in MS medium supplemented with 4.3 μM and 7.2 μM GA3, respectively. Seedlings of both species were transferred to an experimental garden and maintained as a field gene bank that could be utilized for studying genetic variability.Download entire article
(pp. 63-68) In vitro Seed Germination of Fagopyrum tataricum (L) Gaertn. from Different Land Collections in the Western Himalayans
Garima Kishore,1,2* Shashi Ranjan,1 Vikas Singh Jadon,1 Anjana Pandey2 and Sanjay Gupta1
The standardization of in vitro seed germination of Tartary buckwheat [Fagopyrum tataricum (L) Gaertn.] under ideal conditions has been studied. Seed samples were collected from different locations in Uttarakhand, northern India, covering maximum regions of cultivation for the species. Seeds were inoculated to germinate in glass flasks on agar using MS medium supplemented with different concentrations and combinations of two growth regulators, 6-Benzylaminopurine (BAP) and α-Naphthalene acetic acid (NAA).
Cultures were inoculated under illumination (16 h daylight/8 h darkness) and in continuous darkness at 25 ± 2 °C. In vitro culture conditions improved the percentage and rate of seed germination. Average maximum germination was 87% in seeds treated with combination of BAP (1 mg·L−1) and NAA (0.3 mg·L−1) in the light conditions, which was significantly higher than in the dark conditions (78%). In light conditions, germination was 67% and 59% for cultures supplemented with BAP (3 mg·L−1) and NAA (0.3 mg·L−1), respectively. It has been concluded that light has a direct relationship with seed germination.Download entire article
(pp. 69-72) Evaluating Seed Quality in Sesame (Sesamum indicum L.) by the Accelerated Ageing Test
Farshid Ghaderi-Far,* E. Bakhshandeh and R. Ghadirian
The effect of combinations of temperature and time for the accelerated ageing test (AA) were investigated using five lots of sesame (Sesamum indicum L.) seed. Sesame seed lots, which initially had a standard germination above 96%, were subjected to AA at temperatures of 47 and 49 °C for 24, 48, 72, 96 and 120 h.
The results showed that 47 °C/72 h provided a better separation to evaluate the physiological quality of sesame seed lots than other temperature/time combinations. Thus, it can be concluded that this combination, 47 °C/72 h, could be used to evaluate the seed vigor of sesame seeds. However, further work is required to confirm these results and make final recommendations.Download entire article