Volume 38, No. 2, 2017

Download Cover and Contents

Editorial (free download)

(pp. 99-113)
Nonlinear Regression Analyses of Sugar Beet Germination Parameters under High Temperatures
Mohammad Malmir, Ali Sorooshzadeh*, Rahim Mohammadian, Ali Mokhtassi-Bidgoli and Mohammad Abdollahian-Noghabi
Global warming is a serious problem in many areas of the world, including Iran.  Sugar beet (Beta vulgaris) is a strategic crop for Iran with an important role in sugar production. The purpose of this study was to investigate the germination behavior of sugar beet cultivars at high temperatures.

In addition, the accuracy of different regression models in predicting maximum germination, temperature to reach 50% of maximum germination, and optimum germination temperature, was compared. Germination tests were conducted
using four cultivars, Aria, Paya, FD-415 and Rosaflor, at constant temperatures ranging from 20–44° C., with 3° C. intervals. Per cent age germination and seed vigor index were calculated, and radicle, plumule and seedling length were measured. Different Hill, sigmoid, logistic, Gompertz, symmetric and Gaussian models were used to predict germination characteristics.  All germination characteristics decreased with temperature increase.  Paya was the most resistant to high temperature. The highest optimum temperature for germination, predicted by the 4-parameter symmetric model, was 24.80° C
for Paya, and the lowest was for Aria (21.64° C.).  Optimum temperature ranges predicted by 4-parameter symmetric and two types of Gaussian models for radicle length, plumule length and seedling length were higher than predicted optimum temperatures for germination. Nonlinear models with higher parameters were more accurate. Use of regression models was reliable for screening sugar beet germplasm resistant to heat at the germination stage.
Download entire article

(pp. 115-121)
Effect of Alternating and Static Magnetic Fields on Coriander Seed Germination
Rouzbeh Abbaszadeh*, Mina Rostamza and Behnam Gohari
Magnetic fields as physical pre-treatments are a relatively new approach to improving quality and quantity of biological products without relying on chemical treatments. Coriander has both high nutritional value and medicinal properties.  In this study, the effect of static and alternating magnetic fields on germination parameters of coriander seeds were investigated. 

A magnet cube was used for producing a static magnetic field.  To apply an alternating magnetic field, a system was designed and built; its main components included a Hemholtz coil, an auto-transformer, a multi meter, and a Tesla meter.  Generated magnetic flux density was 1 mT and exposure times were 15, 60 and 120 min. Results showed that germination increased by 20.5% compared to the control when seeds were exposed to alternating magnetic fields. In contrast, magnetic fields had no effect on germination rate.  Neutral or negative effects of both static and alternating magnetic fields on mean germination time were observed.  Optimized treatments could improve seed germination slightly.  Otherwise, magnetic fields could have a positive or negative effect on coriander seed germination.
Download entire article

(pp. 123-130)
Seed Quality of China-Aster as Influenced by Seed Maturity Stage
K. Ambia*, A. Naznin, M.R. Bhuyin, F.N. Khan and K.A. Ara
A study was conducted to determine the optimum maturity stages of China-aster (Callistephus chinensis) seed under Bangladesh growing conditions.  Two genotypes, Standard white and Standard pink, and 6 maturity stages of 21, 28, 35, 42, 49 and 56 DAF (days after flowering) were included in this study.

  Standard pink performed better in terms of seed yield attributes such as capitulum diameter (3.92 cm), capitulum weight (1.27 g) and seed weight per capitulum (0.20 g).  In case of seed quality attributes, parameters differed significantly between the two genotypes, except for 1000 seed weight and shoot length.  As expected, parameters varied significantly with maturity stage. Percentage germination was highest 49 DAF (67.91%), closely followed by seeds harvested 42 DAF (66.15 %).  Root length, shoot length, seedling dry weight and seedling vigor index were highest 42 DAF (3.38 cm, 3.27 cm, 12.10 mg seed−1, and 439.56, respectively).
Download entire article

(pp. 133-140)
Hydroponic Production of Chinese Water-Chestnut Corms for Use as a Functional Vegetable
J.B. Morris
Chinese water-chestnut is used as a canned or raw vegetable worldwide.  The accessions in the USDA, ARS, Plant Genetic Resources Conservation Unit do not produce very many or healthy corms when grown in plastic pots containing flooded sand in Griffin, GA.  This study was conducted to evaluate a drip irrigating hydroponic system for maximizing high quality corm production from normally low corm producing accessions.

  Five Chinese waterchestnut accessions were planted in a drip irrigated hydroponic system
inside a greenhouse at Griffin, GA, during 2013 and 2014.  One mature corm per accession was planted in buckets containing perlite within the hydroponic system during the spring and summer of 2013 and 2014, respectively.  After approximately 210 d, corms were harvested, counted and weighed.  Significantly more corms (102–241) and weights (429–476 g) were produced in the drip irrigated hydroponic system compared to the flooded sand method, where corm numbers ranged from 47–49, weighing 77–224 g, for all accessions during both years.  Production system interaction effects were detected
for both live number and weight of corms when drip-irrigation-produced corms were compared to those grown in flooded sand. Drip irrigated hydroponics was successful in maximizing corm production for regeneration.
Download entire article

Lipid Profile and Total Phenolics of Cissus verticillata Seed and Leaf Extracts
Fiona Downs, Andrea Goldson Barnaby* and Raymond Reid
Cissus verticillata (syn. Cissus sicyoides) leaf and seed samples were evaluated for their free radical scavenging activity, total phenolics, and lipid content. 

  The DPPH assay was used to determine the free radical scavenging activity and the Folin-Ciocalteu method to determine total phenolics.  Lipids were Soxhlet extracted, methylated and fatty acids identified by gas chromatography-mass spectrometry.  Leaves exhibited greater free radical scavenging activity (68.9 ± 0.8%) compared to seeds (10.3 ± 0.5%), with a total
phenolic content of 6.28 and 1.78 mg gallic acid g−1 DW, respectively.  Seeds, however, had a greater lipid content (14.4%) consisting mainly of linoleic acid (63.5%), palmitic acid (23.2%), and stearic acid (6.9%).  The total lipid content of leaves was 0.9%, mainly consisting of linolenic acid (28.9%), palmitic acid (23.9%), linoleic acid (10.2%) and stearic acid (8.6%).  Cissus verticillata seeds are currently underutilized and are a potential oil source rich in the essential omega-6 fatty acid, linoleic acid.
Download entire article

(pp. 147-157)
Abstracts from oral and poster presentations given at the 2017 International Seed Testing Association the 107th Association of Official Seed Analysts and the 94th Society of Commercial Seed Technologists (ISTA/AOSA/SCST) annual meeting held in Denver, Colorado, on June 14–24, 2017

Download entire article
(free download)