Volume 35, No. 1, 2013

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Seed Science and Technology Research and Testing Needs (free download)

(pp. 23-34)
Variation in Seed Traits and Germination among Teak Seed Production Areas in Kerala, India
N.H. Prabhu, R.P. Gunaga*, T. Surendran, K.C. Chacko and J.K. Sharma
Fruit quality, productivity and seed germination of teak (Tectona grandis), collected from 38 seed production areas (SPA), were evaluated in 2002–2004. Selected SPA were distributed over five seed zones: Nilambur, Wayanad, Parambikulam, Konni and Achencoil, of Kerala state in India. The study revealed significant variations in fruit yield

(2.34–53.52 kg ha−1), diameter (1.42–1.88 cm), test weight (67.76–118.93 g) and number of seeds per fruit (0.78–1.41), both within and among seed zones. There was no year-to-year variation in seed germination. Overall mean germination of seeds collected in 2002 and 2003 was low, 9.37 and 10.14%, respectively. Significant variation in seed germination was observed in 2002 among the 38 SPA, from 0–35%. Similarly, germination of seeds collected in 2003 ranged from 0.8–35.5%. Seeds collected from SPA within the Wayanad zone exhibited a high degree of dormancy. Among the five seed collection zones, seeds from SPA in Nilambur and Konni had higher germination compared to seeds from SPA in Parambikulam and  Wayanad, in both years.
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(pp. 35-46)
Characterization of Horse Gram Genotypes by Rapid Chemical Tests and Isozyme Polymorphism
K. Uma Rani, S. Narayanaswamy*, N. Nethra, Rame Gowda, Rudraswamy and R. Siddaraju
The maximum genetic diversity of horse gram (Macrotyloma uniflorum) is considered to be in the Old World tropics, especially in India and the Himalayas. Identification of horse gram genotypes is of prime importance to ensure quality seed by identifying off-types in  samples.

Characterization based on morphological characters usually varies with environments, and evaluation of these traits requires growing the plant to maturity prior to identification. Therefore, 22 genotypes of horse gram were identified based on seed response to different chemicals tests, namely standard phenol, modified phenol, sodium hydroxide, potassium hydroxide, as well as isozyme polymorphism. Although no single chemical test was able to distinguish all genotypes, genotypes could be differentiated using an identification key combining the different chemical tests. Most genotypes were identified successfully using electrophoresis of isozymes, especially using esterase  isozyme profiles.
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(pp. 47-60)
Germination Response to Temperature in Different Safflower (Carthamus tinctorius) Cultivars
Benjamin Torabi*, Mahmoud Attarzadeh and Afshin Soltani
Quantitative information about temperature effects on germination components in safflower is scarce. The objective of this study was to describe the trend of cumulative germination at different temperatures and determine cardinal temperatures and thermal time for safflower germination.

Three safflower cultivars, Esfahan, Goldasht and Padideh, were germinated at temperatures ranging from 5–40 °C, with 5 °C intervals. Germination was recorded from 7–14 d in 8–12 h intervals. Fitting a logistic function on cumulative germination data at different temperatures showed that maximum germination was obtained at temperatures of 5–30 °C for Esfahan, 5–20 °C for Padideh, and 10–15 °C for Goldasht. Optimal germination temperature was 30 °C for Esfahan and Padideh, and 25 °C for Goldasht. In addition, beta, dent-like and segmented functions were used to describe the relationship between germination rate and temperature. Response of germination rate to temperature was best described by a segmented function due to higher R2 and lower root mean square of deviations between predicted and observed hours to germination, and lower standard error for estimating function parameters. Using this function, base, optimum and ceiling emergence temperatures were estimated to be 5, 32 and 48 °C, respectively. The physiological hour requirements for germination were 23 h for Goldasht, 17.8 h for Esfahan and 16.4 h for Padideh, equivalent to daily thermal time of 19.7, 28.9 and 16.7 °C d−1, respectively.
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(pp. 61-73)
Fruit Pulp of Juglans nigra Affects Seed Germination and Root Growth
P.C. Flores, D. Poggi, S.M. García, M. Catraro and N.F. Gariglio*
The aim of this work was to quantify the effect of the pulp of Juglans nigra fruit during the stratification process on seed quality and initial root growth of black walnut. The presence of the pulp caused a significant decrease in the germination velocity index, increasing 11.6 times the mean time of maximum germination.

Seed germination capacity was significantly reduced, and the proportion of dead seeds was increased at least 17 times. Furthermore, the presence of the pulp increased nearly four times the proportion of abnormal seedlings, as well as affecting seedling roots. The main root of seedlings from fruits stratified in the presence of the pulp showed lower length and diameter with no secondary roots, compared to fruits from which the pulp was removed after harvest.  Similar effects were observed in lettuce (Lactuca sativa) seeds germinating in different media with increasing concentrations of an aqueous extract of the pulp of black walnut fruits, demonstrating the presence of inhibitors or phytotoxic compounds in pulp tissue. Abscisic acid (ABA) and jasmonic acid were detected in the pulp tissue. Measured ABA concentrations were higher than those reported for Fraxinus seeds that produced similar seed deterioration symptoms reported in this experiment.
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(pp. 75-88)
Image Analysis Techniques to Evaluate Portulaca Seed Morphology and Vigor
Vanessa Neumann Silva*, Mark Bennett, Pablo Jourdan and Silvio Moure Cicero
Internal seed morphology, germination and vigor were examined in Portulaca grandiflora  and P. oleracea seeds using image analysis techniques, to assess the role of seed free space on germination and seedling vigor. Five lots of P. grandiflora and two lots of P. oleracea seeds were first X-rayed, and the radiographs analyzed with Image Pro Plus® to measure the free space between the embryo and endosperm of each seed.

Seeds were then germinated either immediately or after exposure to saturated salt accelerated aging  conditions for 48 and 72 h. Seedling vigor was assessed with the Seed Vigor Imaging System (SVIS®). Free space between the embryo and endosperm in seeds of P. grandiflora ranged from 0 to 4.6% as a proportion of the whole seed area for all lots examined,  whereas for seeds of P. oleracea, the range was from 0 to 10%. The relationship between seed free space and germination of P. grandiflora was variable; two of the five lots showed a reduction in the proportion of normal seedlings as the seed free space increased. While
there appeared to be no direct relationship between increased free space and reduction in germination and vigor of P. grandiflora seeds, for P. oleracea seeds the results indicated a negative effect of extensive free space on germination and vigor.
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(pp. 89-101)
New Blowing Procedure Using Master Calibration Samples and Air Velocity Monitoring: A Model Developed with Orchardgrass and Kentucky bluegrass
Adriel Garay and Sabry Elias*
Test result uniformity across laboratories is critical for seed labeling and marketing. One challenge in grass seed purity testing is separating lightweight inert matter such as empty and under-developed florets. A uniform blowing procedure, without measuring air velocity or using master calibration samples, was used to separate lightweight inert matter from pure seeds in orchardgrass (Dactylis glomerata) and Kentucky bluegrass (Poa pratensis) for decades by the Association of Official Seed Analysts.

However, the method had limitations including length of time required for blower calibration, need for repeated calibrations, and stability of standard calibration samples (SCS) over years. Orchardgrass SCS variation had been suspected by laboratories, leading to inconsistent test results among  laboratories. This study’s objectives were to measure variability among SCS in different laboratories and introduce a new blowing procedure using uniform master calibration samples (MCS) to determine the optimum blowing points (OBP) of orchardgrass and Kentucky bluegrass, and use equivalent air velocity (EAV) values to reproduce the OBP over time. Studies were conducted to develop and test the validity of using MCS and EAV to achieve consistent separation of light inert matter within and across laboratories for orchardgrass and Kentucky bluegrass. Using MCS enabled laboratories to find comparable  OBP in their blowers and reduced variability in light inert matter separation. Using EAV allowed monitoring the correct setting of blowers accurately and quickly (2 min). The new method proved to be accurate, repeatable, simple to use, and assured uniformity in separating orchardgrass and Kentucky bluegrass light inert matter across laboratories.
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(pp. 103-116)
Seed Cryopreservation and Evaluation of Ferula gummosa and Kelussia odoratissima
M. Naderi Shahab*, M. Jebelli, A.A. Shahmoradi and A.A. Jafari
It is presumed that longevity of cells under cryogenic condition can be almost infinitely extended. Pre-cryopreservation treatments such as vitrification and desiccation have a positive effect on the seed’s survival efficiency and the length of the preservation period under cryogenic conditions.

Seeds of two Apiaceae species, Ferula gummosa and the endangered Kelussia odoratissima, were collected from different habitats in Iran. The seed samples were subjected to PVS2 (plant vitrification solution 2), desiccation, and 30%  glycerol before being transferred into liquid nitrogen (LN) or −196 °C for 1 week, 1 month, 1 year and 26 months. After seed removal from LN, seeds were exposed to a heat shock (42°C), washed, and evaluated under laboratory as well as greenhouse (22 ± 4° C) and field conditions. High level of recovery from LN, based on evaluating seed germination and seed and seedling attri utes, under laboratory and greenhouse conditions, revealed the  cryogenic tolerance of the species’ seeds. Plants which originated from cryopreserved seeds grew normally under greenhouse conditions and did not show any abnormalities compared to control plants. Lack of significant differences among most of the  pre-cryopreservation treatments and storage periods indicated the success of long-term seed preservation of the species in LN. Because of high seed germination and other characteristics, in addition to successful Kelussia odoratissima establishment in the field, it is concluded that seeds of Ferula gummosa and Kelussia odoratissima can be preserved under cryogenic conditions using various pre-cryopreservation treatments.
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(pp. 117-124)
Influence of Hydro-Priming on Reserve Utilization of Differentially Aged Chickpea Seeds
Kazem Ghassemi-Golezani* and Ayda Hosseinzadeh-Mahootchi
Priming appears to reverse the detrimental effects of seed aging by modulating pre-germination metabolic activity prior to radicle emergence. However, the impact of these metabolic changes on seed reserve utilization is not clear. This study was conducted to evaluate the effects of hydro-priming on reserve utilization of three differentially aged seed lots (100, 98 and 89% normal germination) of chickpea.

Results showed that reserve utilization rate of the most aged seed lot significantly decreased, compared with other seed lots. The highest conversion efficiency was obtained for the high quality seed lot and decreased with decreasing seed lot quality. Increasing seed aging led to significant reduction in germination rate and seedling dry weight, mainly due to a poor reserve utilization rate. The highest seed reserve utilization rate was recorded for high vigor and primed seed lots. Increasing seed vigor due to hydro-priming also resulted in increasing germination rate and seedling dry weight. The highest improvement in germination rate due to hydro-priming was observed in poor vigor seed lots. Therefore, hydro-priming can improve reserve utilization of differentially aged seeds and thereby enhance their  germination rate and seedling size.
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(pp. 125-134)
Genetic Variability in Vigor Traits among Pea (Pisum sativum) Genotypes
Ishrat Ahmad Lone*, S.D. Tyagi and D.K Bahuguna
Knowledge about genetic variation and association between various seed characters of pea (Pisum sativum) is of vital importance to breeding programs aiming to produce improved varieties with high seed and seedling vigor. Forty genotypes of pea were evaluated for various seed vigor traits to obtain estimates of variability, heritability and genetic advance, as well as correlations, for different seed and seedling characteristics.

Adequate variability was present for 100-seed weight, speed of germination, shoot length, root length, fresh seedling weight and vigor indices. The highest genotypic coefficient of variation was observed in total seedling length and vigor indices. Heritability was high for 100-seed weight, vigor indices, total seedling length and fresh seedling weight. High genetic advance was observed for total seedling length, one of two vigor indices and seedling root length. Seedling shoot length had a positive and significant correlation with seedling fresh weight, and speed of germination was correlated to one vigor index, seedling length and fresh seedling weight. On the basis of this study, it is suggested that test weight, root length, shoot length, germination index and vigor indices be considered in selection programs for seedling improvement of pea.
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(pp. 137-143)
Effect of Pre-Shelling Treatments on Nutmeg Seed Physical Properties
Prashant Pandharinath Said, Rama Chandra Pradhan* and Ashwani Kumar
The objective of this study was to determine the effect of sand roasting and steaming pre-treatments on the physical properties of nutmeg nuts. Pre-treatments contribute to energy consumption of processing, and ultimately the operational costs of shelling.

The effects of pre-shelling treatments are also important for equipment design. Moisture content of nutmeg nuts and kernels significantly varied between the roasting and steaming pre-treatments. Nut length, width, and thickness were significantly affected by pre-shelling treatments, while arithmetic mean diameter, geometric mean diameter, aspect ratio and sphericity index did not differ among pre-treatments. Unit weight, angle of repose and compressive strength of nutmeg seeds were significantly affected by pre-treatments. Pre-treatments resulted in significant differences in bulk and true densities, but not in the porosities, of the nuts. The compressive strength of roasted and steamed nutmeg nuts decreased compared to raw nuts, and the coefficient of friction was significantly affected by both pre-treatments and material surfaces.
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(pp. 145-149)
Effect of Seed Pretreatments on Ziziphus spina-christi Germination
Wondwossen Gebretsadik
Members of the genus Ziziphus are reported to have problems of dormancy that hamper uniform seed germination under nursery conditions. This study was conducted to assess the most viable propagation technique for Ziziphus spina-christi seeds under nursery  conditions of Debre Zeit Agricultural Research Center.

Seed germination was tested following cold and hot water treatments, each with four levels, and sulfuric acid  scarification with five levels. Three independent experiments for each treatment type were conducted, laid out in a completely randomized design with four replications. ANOVA of germination results from cold water treatments showed no significant treatment effect. A significantly higher germination percentage was obtained from seeds treated with hot  water at 85 °C and left to cool at room temperature of 25 °C for 12 h. Additionally, a significantly higher germination percentage was recorded by scarifying seeds with sulfuric acid (98%) for 30 min and subsequent rinsing with cold water before sowing. Very low and very high immersion times in sulfuric acid of 5 and 120 min, respectively, led to a  significant reduction in germination.
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