Volume 37, No. 1, 2016

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Download abstracts (free download) from oral and poster presentations given at the 105th Association of Official Seed Analysts and the 92ⁿd Society of Commercial Seed Technologists (AOSA/SCST) annual meeting held in Tampa, Florida, on May 30–June 4, 2015.
One Size Does Not Fit All!  Not All Native Seed Weights for Purity Are Equal
Donna Grubisic
Statistical Sampling Variability in ELISA Trait Purity Testing
Maranda Mergen* and Brenda Johnson

(pp. 7-21)
Assessment of Carambola Seed Physiological Quality Using Vigor Indices
Marcia Terezinha Ramos de Oliveira and Pedro Amorim Berbert*
The object of this study was to evaluate the immediate and latent effects of different drying conditions on the vigor of carambola seeds, measured as the speed of germination index (SGI) and mean germination time (t-mean). Drying tests were performed at 33, 35 and 38 °C, and seeds were stored for 45, 60, 90, 180 and 270 d at 15 °C.

There was no immediate effect of storage time or drying temperature on the vigor of the seeds based on either SGI or t-mean values. No latent effect of drying at 33 and 38 °C was observed for any of the storage times, based on SGI. However, SGI values revealed differences in the physiological quality of seedlots with similar germination test results. There was no significant effect of storage time on t-mean at any of the tested temperatures. In addition, tmean values for different storage periods did not provide any additional information about the physiological poten tial of the seedlots not already provided by the germination test.  These findings suggested that the two vigor indices cannot be used concomitantly to  obtain accurate information on the physiological quality of carambola seedlots.
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(pp. 23-31)
Effect of Various Chemical Hybridizing Agents on Sunflower (Helianthus annuus) Seed Production
Muhammad Khuram Razzaq, Saeed Rauf* and Naeem Akhtar
Several chemicals are known to induce male sterility in crop species.  Among various chemical hybridizing agents, synthetic detergents are an inexpensive option for induction of male sterility, and can be exploited in developing countries due to their availability. Experiments were carried out on sunflower (Helianthus annuus) genotypes to optimize the concentration of the synthetic detergent and determine the most appropriate plant phenological stage to induce male sterility.

Several concentrations of the chemical detergent Surf excel (0–2%, w/v) were sprayed over four phenological stages
(R1–R4). A detergent concentration of 1.5% applied at the R1 stage produced the highest percentage of floral male sterility. In contrast, synthetic detergent treatments failed to induce any sterility when floral heads were treated beyond the R3 stage.   This detergent treatment was compared to other chemical hybridizing agents (CHAs) using multiple genotypes.  The detergent was similar to gibberellic acid in its efficiency of inducing floral male sterility, but demonstrated a reduced deleterious effect on morphological traits and a high percentage of seed setting, when CHA-treated floral heads were pollinated using control plants.  This study demonstrated that this detergent was an easy CHA option for inducing male sterility, independent of genotypic effects.
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(pp. 33-42)
Storage Life of Cayenne Pepper (Capsicum frutescens) Seeds Following Three Drying Methods
M.A. Adebisi and A.M. Abdul-Rafiu*
Seed longevity of Capsicum species may be affected by seed drying methods.  The effect of three seed drying methods (passive, sun and oven drying) on seed storage life (longevity) of 16 cayenne pepper genotypes (Capsicum frutescens) stored under ambient conditions (26.92 °C, 72.23% RH.) was investigated.

 Seed lots extracted from healthy fruits using maceration were subjected to the different drying methods, to reach a moisture content of 7.9–8.2%.  Dried seed lots packaged in plastic containers were stored under
ambient conditions in the laboratory for 10 mon and evaluated for longevity (germination) at 0, 60, 120, 180, 240 and 300 d intervals.  Probit analysis was used to estimate deterioration rates and storage life. Seed lots stored for 8 mon still retained high viability, irrespective of drying method.  Passively dried seed lots consistently retained the highest germinability during storage.  The predicted storage life was 21.3, 19.14 and 17.77 mon for seed subjected to passive, sun and oven drying, respectively.  Passive drying is recommended as the best pre-storage processing technique for cayenne pepper seeds.
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(pp. 43-51)
Germination Response of Six Sweet Basil (Ocimum basilicum) Cultivars to Temperature
Dongfang Zhou, Jacob Barney, Monica A. Ponder and Gregory E. Welbaum*
Sweet basil (Ocimum basilicum) is a warm-season herbaceous plant typically propagated from seed.  Establishment of direct-seeded basil is often difficult because seed germination may be limited, particularly in cold soils.  To determine base, optimum, and ceiling germination temperatures and possible genetic variation, seeds of six cultivars of sweet basil, Italian Large Leaf, Italian Large Leaf 63-X, Nufar, Genovese, Genovese Compact Improved, and Aroma 2 were tested on a one dimensional thermogradient table from 0–45° C.  

 The average optimum germination temperature range was 34.5–39.0° C and did not differ among cultivars.  Germination rates increased from about 0.05 seeds d−1 near the base temperature to nearly 1.0 seeds d−1 at optimum temperatures for most cultivars.  The ceiling temperatures varied little among cultivars, with an average of 43 ± 1.3° C.  The thermal times to germination averaged 29 °h for new crop seeds but were 40° h for seeds of Italian Large Leaf 63-X stored for 5 y under ambient conditions.  Italian Large Leaf 63-X seeds also exhibited lower vigor, germination, and ceiling temperature, compared with the new crop seeds.  Base temperatures ranged among cultivars from 9.8–13.2° C and were statistically significant, suggesting there is genetic variation that can be exploited to improve the low temperature germination performance of basil.
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(pp. 55-63)
Radish Seed Priming Treatments
Fabio Mielezrski*, Mark A. Bennett, Elaine M. Grassbaugh and Andrew F. Evans
Seed priming can improve the performance of seed lots, such as promotion of high uniformity of germination and seedling emergence.  This technique is also an additional seed enhancement choice for production companies looking for optimal seed quality.  This research aimed to evaluate the effects of drum priming on radish (Raphanus sativus) seeds.  The study was conducted at the Seed Biology Laboratory, Department of Horticulture and Crop Science, Ohio State University, Columbus, OH, using two lots of each of two radish cultivars, Cherry Globe and White Belle.  

Preliminary trials were conducted to establish the appropriate procedures for radish seed drum priming.  Seeds were placed directly in water for 12 h to attain a seed moisture content of around 35%. Germination (percentage, first count and speed) and greenhouse seedling emergence percentage, speed and seedling height) tests were then conducted.  White Globe primed seeds showed improved first count germination results compared to the control.  Although priming of radish seeds of both cultivars did not lead to significant improvement in final germination, speed of germination and greenhouse emergence, drum priming resulted in good seed hydration and therefore has the potential to be an effective method for priming seeds.
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(pp. 65-71)
Relationship of Biochemical Composition and Drupe Size to Seedling Performance of Teak (Tectona grandis)
C.M. Jijeesh* and K. Sudhakara
We studied the variation in the biochemical composition of teak seeds collected from Cherupuzha and Chathamparai plantations, Nilambur Forest Division, Kerala, India, and graded by drupe size as small (9–12 mm), medium (12–15 mm) and large (15–18 mm). Crude oil, protein, soluble, insoluble and total carbohydrate contents were determined using seeds extracted from drupes.

Seed size significantly influenced insoluble carbohydrate content of seeds from Chathamparai, with 4.43% as the highest concentration compared to 4.02% from Cherupuzha.  Crude oil varied from 33–42% by weight, and was generally highest in seeds extracted from large and medium sized drupes. Similarly, soluble carbohydrates were high in seeds extracted from large and medium sized drupes, ranging from 4.2–5.4%.  Seeds obtained from large drupes had the highest content of soluble and total carbohydrates.  A high positive correlation was obtained for vigor index and biochemical constituents with crude oil and soluble and total carbohydrates.  Collar diameter, number of lateral roots and seedling dry weight were also
correlated with vigor index and biochemical constituents.  Based on these results, teak drupe size influenced the biochemical composition of seeds, which in turn was correlated with many seedling performance parameters.
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(pp. 73-80)
Participatory Varietal Selection and a Community-Based Seed System for Restoring Rice Production in Liberia
J.A. Adetumbi*, I. Akintayo, S.A. Ogunbayo and N.S. Baysah
Inadequate seed quality has been one of the major constraints to rice production in Liberia after years of conflict.  A community-based seed production system (CBSS), implemented in two rice growing counties of Liberia, aimed to improve the supply of high quality rice seed and increase locally produced rice.  Ninety-four improved rice varieties (18 upland and 76 lowland) were introduced into the country.  

 Selected varieties were screened for tolerance to iron toxicity, after which 10 mt of foundation seed of three selected varieties, Nerica-L19, Suakoko-8 and Nerica 14, were produced under irrigated conditions and distributed to farming groups trained in the concept of CBSS, to produce quality-declared rice seed.  Over 125 mt of quality-declared seed of several rice varieties were produced.  Availability of high quality rice seed increased Liberian farmers’ interest in growing rice for consumption and commercial purposes.
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(pp. 81-87)
Seed Size Effects on Germination and Seedling Parameters of Soybean Cultivars
T. Vange*, K. Tamen and J.O. Okoh
Five soybean cultivars were evaluated as to the effect of seed size on germination and seedling parameters.  The experiment was carried out at the Plant Breeding and Seed Science Laboratory, University of Agriculture, Makurdi, in 2014.  Soybean seeds from these cultivars were graded into 3 sizes, large, medium and small, by a grader using 6.0, 5.5 and 4.5 mm sieve sizes, respectively.

 Hundred-seed weight from each seed grade was used to verify effectiveness of the grading in the laboratory.  Results showed that large seeds of most cultivars had significantly longer root and shoot length, seedling dry weight and vigor, compared to smaller grades.  Seed size had no significant effect on percentage germination, germination index, and germination rate index. For soybean, seed size influenced seedling growth, but the effect varied according to cultivar.
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(pp. 89-92)
Use of Maize Floret Variation to Increase Seed Yield of Female Parents
Daria H. Schmidt*, Eric Galdi, Brad Johnson, Jennifer Jaqueth, Ryan Oyama, Kevin Simcox and Graziana Taramino
Hybrid seed production is a complex process that involves many steps.  For seed corn (Zea mays), inbred plants must first be crossed under conditions that allow the male pollen to fertilize the silks on female ears to produce seed sold to farmers.  The quantity and quality of seed produced are important metrics in overall production efficiency.  Hybrid seed yield and uniformity can be impacted by optimizing the number of kernels per female parent inbred ear utilizing native genetic floret traits.

 Based on preliminary studies using the floret variant trait “Country Gentleman” (CG or CG trait), kernels kg−1 were increased an average of 38% across three genetic backgrounds.  When present in female inbred parent plants, the CG trait resulted in a large increase in the number of smaller-sized kernels at screen slots ≤ 17.5/64 in (6.95 mm); seed weight of 752 g per 1000 g for ears expressing the CG trait compared to 309 g for ears with typical row orientation.  The CG trait is recessive and multiple genes are involved. Inheritance of the trait is important to ensure that F1 plants produce grain with normal kernel size and row orientation in the farmer’s crop.  Seedsmen benefit from increased seed production efficiency and farmers benefit by having greater availability of preferred seed size options (medium and small flat kernels) that best meet their operations’ needs. Research is ongoing to determine the effectiveness of the CG trait across a broader array of female inbreds.
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(pp. 93-100)
Seed Identification Using Computer Vision—A Proof of Concept Study
Xin Yi, Mark Eramian, Ruojing Wang*, Jennifer Neudorf, Angela Salzl and Janine Maruschak
Use of digital image analysis for seed identification is not yet recognized as a validated method.  However, computer vision for automated seed identification had been suggested more than three decades ago.  This seed identification study considered an image data set containing seed specimens verified to represent their respective species, with typical population variation.

 With representative specimens, the seed texture feature was extracted.  Local image descriptors were calculated from the image at points on a regular grid.  These were encoded to a representation known as the “bag-of-words” model. With the determination of the optimum intervals and scales, computer vision achieved a high recognition rate greater than 97%.
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