Seed aging characteristics of rice was investigated in this study. Seeds of 34 japonica rice (O-ryza sativa subsp. japonica) varieties were held at 451 constant temperature. Changes in seed viability and seed vigor du...Seed aging characteristics of rice was investigated in this study. Seeds of 34 japonica rice (O-ryza sativa subsp. japonica) varieties were held at 451 constant temperature. Changes in seed viability and seed vigor during aging process were measured to study seed viability-losing characteristic and to determine warning index for seed viability loss. As a result, seed viability survival curves were obtained across different rice accessions at 45℃ constant temperature. The curves appeared to be contra-sigmoid survival curves. The loss of seed viability in the aging process consisted of two phases. The first phase took a long duration, in which the viability of vigorous seeds declined slowly. In the second phase, seed viability declined rapidly. It was obvious that seed viability declined inconsistently during storage. It also showed that seed germination was prolonged and the seedling was significantly weakened before the coming of the rapid declining phase of seed viability. These two parameters could be used to indicate seed quality during storage. The rate of compatibility of tests (RCT), coefficient of variation (CV), vigor of seedling, the day the seeds start to germinate could be used as warning indexes to indicate overall quality of a mass of accessions. These warning indexes could also be used in monitoring the viability of seeds stored in the seed genebank.展开更多
Kidney bean seed was dried in a laboratory scale fixed bed. The effect of seed coat on drying dynamic characteristics and the changes of seed coat structure were investigated. A mathematical model was established to s...Kidney bean seed was dried in a laboratory scale fixed bed. The effect of seed coat on drying dynamic characteristics and the changes of seed coat structure were investigated. A mathematical model was established to simulate the drying process and determine the moisture diffusivity. Numerical results agree well with the experimental data. The average moisture diffusivity of the seed with separated coat is 1.67 times larger than that of the seed with coat, and the moisture diffusivity of seed cotyledon is 3.2 times larger than that of the seed coat. It is proved that the seed coat is the most main resistance of mass transfer and is also one of the key points of the optimization of heat and mass transfer for seed drying.展开更多
An experiment was conducted at the Department of Horticulture, College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology, Kumasi （KNUST） Ghana from September, 2009 to April, 20...An experiment was conducted at the Department of Horticulture, College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology, Kumasi （KNUST） Ghana from September, 2009 to April, 2010, to determine the most appropriate drying method, as a post harvest practice, that would ensure high percentage germination ofAnnona squamosa seeds and its subsequent effect on seedling growth. The seeds were sun-dried, air-dried under shade or kept in the fresh state. Five treatments were used, namely, Freshly Sown seeds （Treatment 1, control）, Seeds Air-Dried under Shade for one day （Treatment 2）; Seeds Sun-Dried for one day （Treatment 3）; Seeds Air-Dried under Shade for three consecutive days （Treatment 4）; Seeds Sun-Dried for three consecutive days （Treatment 5）. The experiment was arranged in a Completely Randomized Design （CRD） and replicated three times. Drying of Annona squamosa seeds had significant effect on earliness and number of seeds germinated. Air drying under shade and sun-drying for three consecutive days improved earliness to germination （26 days after sowing） and percent total germination but air-drying under shade had better effect on total seed germination, achieving 90% germination in 42 days after sowing. Furthermore, the prevailing ambient temperature of 30 ℃-32 ℃ enhanced germination of Annona squamosa seeds. The study concluded that for optimum germination, seeds of Annona squamosa should be either air-dried or sun-dried for three consecutive days and be incubated in an ambient temperature range of 30 ℃-32 ℃. In terms of growth, seedling growth in leaf production was better from seeds sun-dried for three consecutive days.展开更多
Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated t...Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying （DSR-AWD） in comparison with direct seeded rice at field capacity （DSR- FC）. Seed priming treatments were osmo-priming with KCI （2.2%）, CaCI2 （2.2%） and moringa leaf extracts （MLE, 3.3%） including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with CaCI2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with CaCI2 in DSR- AWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or CaCI2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or CaCI2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation.展开更多
A seed is the carrier of life,and research on the heat and mass transfer of a seed has already stridden toward the level of microcosm,such as cell protoplasm,cell organism,and molecular membrane.By means of a transmis...A seed is the carrier of life,and research on the heat and mass transfer of a seed has already stridden toward the level of microcosm,such as cell protoplasm,cell organism,and molecular membrane.By means of a transmission electron microscope,the authors of this paper observed the microstructure of cotyledon tissue slices of the Chinese cabbage seed with a moisture content of 13% (on dry basis) and that with a moisture content of 4.3% (on dry basis) for drying 2 h at 45 ℃.The compared result was that only wrinkles had been discovered on the cell walls of the seed dried for 2 h,without any significant change for other organelles.Study on the enzyme activity shows that after a germination for 48 h,the relative activity of α amylase of the Chinese cabbage seed dried for 2 h at 45 ℃,decreased by 5.8%,whereas that of the seed dried 2 h at a temperature of 67 ℃ decreased by 30.1%.This work shows that the drying factors have greatly influence on the seed microstructure,enzyme activity,which is directly positive to seed viability.Combined with the analysis of the critical safe drying temperature of the vegetable seed,it can be concluded that enzyme activity is also the function of the drying temperature,the moisture content and the drying time.展开更多
The probit analysis has been an important tool to predict seed longevity during storage and has been applied for seed drying simulation. Sealed aluminum pouches containing approximately 50 g of canola seed at moisture...The probit analysis has been an important tool to predict seed longevity during storage and has been applied for seed drying simulation. Sealed aluminum pouches containing approximately 50 g of canola seed at moisture range of 7% to 21% of water content web basis （%） were conditioned in water-bath at 50, 60 and 70℃ to obtain the model to evaluate the reduction of canola seed germination. This model was included in the drying simulation program and the estimated germination was compared to the experimental values of germination during drying to validate the model. Canola seeds at 21% of moisture content and germination of 93% were dried at 51℃ and 61 ℃, and the model represented significantly the drying experiments. The aim of this study was to propose a germination model to evaluate the quality of canola seeds during the drying process and to offer the seed producers an important tool to control the drying process. The experimental data validated the objectives of the proposed drying model, optimizing the process at given conditions, managing the energy consumption, according to the minimum germination or maximum moisture content limitation for seed storage. For 51℃, the drying time for canola seed would be about 6 h to maintain germination above 90% and for 61℃, 4 h of drying time maintained germination up to 89%.展开更多
To achieve a good production of a crop, it is essential to know the ability of the species to successfully complete two critical stages in the life cycle such as germination and seedling establishment. In this paper w...To achieve a good production of a crop, it is essential to know the ability of the species to successfully complete two critical stages in the life cycle such as germination and seedling establishment. In this paper we study in comparative form structure of the seed, the importance of tegument in dormancy, the effect of accelerated aging on seed germination and viability, and the early and late growth in J. curcas and J. macrocarpa. External morphology of the seeds allow difference and internally also the embryos show evident differences. J. macrocarpa germination is around 0% - 4%. The total removal of tegument showed a 50% increase and the other treatments between 0% - 10%. Aging accelerated by Tetrazolium test allowed a comparative analysis of VP and GP. J. curcas maintains both to 96 h, while J. macrocarpa the seed viability is registered along the all treatment. J. macrocarpa seeds have less synchronicity than those of J. curcas. ABA and JAs were detected in tegument of J. macrocarpa and J. curcas seeds. JA could have a roll in inhibition of germination of J. macrocarpa seeds. Early and late growth, FW and DW of root, hypocotyl, epicotyl and leaf of J. curcas were significantly different in both species.展开更多
Effects of four different drying methods on the colour, texture, sensory quality, microstructure, bacterial viability and storage stability of probiotic-enriched apple snacks were assessed. The drying methods were air...Effects of four different drying methods on the colour, texture, sensory quality, microstructure, bacterial viability and storage stability of probiotic-enriched apple snacks were assessed. The drying methods were air drying （AD）, freeze drying （FD）, freeze drying followed by microwave vacuum drying （FD＋MVD） and air drying followed by explosion puffing drying （AD＋EPD）. Overall, FD＋MVD can be used as a suitable drying method for the development of probiotic enriched apple snacks in consideration of colour, texture, sensory quality, bacterial viability and storage stability. Probiotic bacteria in FD＋MVD-dried samples remained above 1×106 CFU g 1 for 120 days at 25℃C. Interestingly, bacterial viability in FD＋MVD-dried samples turned out to be significantly higher than FD-dried samples during storage for 120 days.展开更多
Seed vigor is a key factor affecti ng seed quality.The mechanical drying process exerts a sign ificant in fluence on rice seed vigor.The initial moisture con tent(IMC)and drying temperature are considered the main fac...Seed vigor is a key factor affecti ng seed quality.The mechanical drying process exerts a sign ificant in fluence on rice seed vigor.The initial moisture con tent(IMC)and drying temperature are considered the main factors affecting rice seed vigor through mechanical drying.This study aimed to determine the optimum drying temperature for rice seeds according to the IMC,and elucidate the mechanisms mediating the effects of drying temperature and IMC on seed vigor.Rice seeds with three different IMCs(20%,25%,and 30%)were dried to the target moisture content(14%)at four different drying temperatures.The results showed that the drying temperature and IMC had significant effects on the drying performance and vigor of the rice seeds.The upper limits of drying temperature for rice seeds with 20%,25%,and 30%IMCs were 45,42,and 38°C,respectively.The drying rate and seed temperature increased sign ificantly with in creasing drying temperature.The drying temperature,drying rate,and seed temperature showed extremely significant negative correlations with germination energy(GE),germination rate,germination index(Gl),and vigor index(VI).A high IMC and drying temperature probably induced a massive accumulation of hydrogen peroxide(H2O2)and superoxide anions in the seeds,enhanced superoxide dismutase(SOD)and catalase(CAT)activity,and increased the abscisic acid(ABA)content.In the early stage of seed germination,the IMC and drying temperature regulated seed germination through the metabolism of H2O2,gibberellin acid(GA),ABA,and a-amylase.These results indicate that the metabolism of reactive oxygen species(ROS),antioxidant enzymes,GA,ABA,and a-amylase might be involved in the mediation of the effects of drying temperature on seed vigor.The results of this study provide a theoretical basis and technical guidance for the mechanical drying of rice seeds.展开更多
The seeds of a soybean cultivar Zhonghuang 18 were subjected to accelerated aging for 0(population G_0-1), 112(population G_0-2), 154(population G_0-3) and 196 d(population G_0-4), whose germination percentage was fou...The seeds of a soybean cultivar Zhonghuang 18 were subjected to accelerated aging for 0(population G_0-1), 112(population G_0-2), 154(population G_0-3) and 196 d(population G_0-4), whose germination percentage was found to be 98.0%, 95.0%, 81.0%, and 79.0%, respectively. Then, the four populations were regenerated twice in the field. The first descendant populations were marked as G_1-1, G_1-2, G_1-3 and G_1-4, and the second were marked as G_2-1, G_2-2, G_2-3 and G_2-4, respectively. The genetic variation between the control population(G_0-1) and the experimental populations was analyzed using 12 AFLP primer combinations. The results showed that there was no significant difference in genetic similarity between the 11 experimental populations and the control population G_0-1. The genetic similarity between population G_2-4 and G_0-1 was still as high as 0.933 3, indicating that the F_2 generation of the population whose germination percentage was only 79.0% still had a high genetic similarity to the control population. The results of t-tests revealed that the populations G_1-1, G_2-1, G_1-2 and G_2-2 showed no significant difference from the control population G_0-1 in effective number of alleles per locus(Ae), genetic diversity index(H) and Shannon's diversity index(I), while these indices of populations G_0-3, G_0-4, G_1-3, G_1-4, G_2-3 and G_2-4 were significantly reduced. χ~2 tests indicated that the populations G_1-1 and G_2-1 showed little difference, and the populations G_0-2, G_0-3, G_0-4, G_1-2, G_1-3, G_1-4, G_2-2, G_2-3, and G_2-4 showed great difference in allele frequency distribution from the control population G_0-1, and the difference was greater when the seed viability was lower. Compared with the control population G_0-1, the number of rare alleles(Nr) of the populations G_0-2, G_1-1, G_2-1, G_1-2 and G_2-2 showed no significant difference, while that of the populations G_0-3, G_0-4, G_1-3, G_1-4, G_2-3 and G_2-4 declined obviously. These results revealed that compared with the control population, the genetic diversity and Nr for the descendant populations of the populations with 98.0% and 95.0% germination percentages did not change significantly, but declined greatly for the descendant populations of the populations with 81.0.% and 79.0% percentages. The results suggested that the decline in seed viability has a greater impact than the number of generations on genetic structure of soybean germplasm. So, it is suggested that soybean seed with an initial germination percentage of 98.0% should be regenerated before its germination percentage declines to 81.0%.展开更多
In Indonesia, shallot cultivation finds difficulties to produce high viability seed. That low viability is caused by the abnormality of seed＇s structure. Normal shallot seeds have seed structure that consists of： te...In Indonesia, shallot cultivation finds difficulties to produce high viability seed. That low viability is caused by the abnormality of seed＇s structure. Normal shallot seeds have seed structure that consists of： testa, endosperm, and embryo. Normal embryo has curved shape which it has one cotyledon in endosperm. This research purpose is to find shallot viability and structure that is cultivated in tropic area, especially in Indonesia. This research is a deep observation research about water level, seeds viability and seeds structure monitoring by using microscope. To make a clearance about seeds structure composition, seeds are mixed with tetrazolium salt. Monitoring result shows that seed water level at harvest time is 18%, laid away at one month age is 13%, two months age is 12% and three months age is 10%. Seed viability at harvest until twenty nine days, seed that is germinated around 8%. At two months viability seed laid age until twenty two days is 36.6%. Meanwhile three months age laid viability test is done with germination boost compounding shows that IAA is able to fasten germination. At IAA treatment viability seeds are 17.25% that is followed with GA3 treatment around 13%. Another boosting substance that it＇s viability is only below 4%. Low viability is also proved by the seed structure. The result shows that mostly, the seeds has abnormal structure.展开更多
The objective of this study was to characterize environment factors involved in loss of seed viability during storage in open granaries. The temperature and relative humidity of the granary as well as the equilibrium ...The objective of this study was to characterize environment factors involved in loss of seed viability during storage in open granaries. The temperature and relative humidity of the granary as well as the equilibrium moisture content of seeds were determined monthly. Their effects on the loss of viability of maize (<i>Zea mays</i> L.) and cowpea (<i>Vigna unguiculata</i> (L.) Walp.) seeds were examined. The results showed that relative humidity levels > 65% associated with temperatures > 25°C (conditions in the open granary) do not guarantee safe storage of maize lots for a period of 9 to 12 months. Based on these data and the results of seed viability analysis, local environmental conditions in Gandajika (DR-Congo) and seed genetic background are the main factors for the rapid deterioration of seeds during storage. The germination rate correlated negatively with storage duration (<span style="font-family:;" "="">-0.94) and temperature (-0.57) while it correlates positively with the relative humidity (0.58) for both lots of maize analyzed. The same trend was observed with the two-cowpea varieties studied (IT82D-889 and Diamant). Similar work using more varieties in other granaries is required to validate key factors involved in seed viability during storage in targeted regions.</span>展开更多
In this study the effect of initial parameters such as inlet gas temperature, initial particles temperature and gas velocity on temperature changes of solid particles and outlet gas temperature in a fluidized bed drye...In this study the effect of initial parameters such as inlet gas temperature, initial particles temperature and gas velocity on temperature changes of solid particles and outlet gas temperature in a fluidized bed dryer was studied. For testing, an experimental setup was established. With combination of air and Colza seeds belonging to D groups of the Geldart classification (Geldart, 1986) fluidization regime was carried out. With five test series with maintaining the inlet gas temperature, solid particle temperature and outlet gas temperature during time were carefully measured. To analyze these data by using regression analysis to predict solid particle and outlet gas temperature, 2 correlations on initial pa-rameters were presented. The result has shown that temperature gradients in the beginning of fluidization, is very high and therefore the exponential functions in the regression model is used to predict the temperature changes.展开更多
This paper deals with the influence of ultra-lowmoisture content and the rate of desiccation on rice seed viability and physiological property bydesiccating using four kinds of desiccants(phos-
In order to supply quality seed for vegetation restoration in arid and semiarid areas of Northwest China, the effects of Platycladus orientalis seed storage under ultra-drying and accelerated aging were studied. The s...In order to supply quality seed for vegetation restoration in arid and semiarid areas of Northwest China, the effects of Platycladus orientalis seed storage under ultra-drying and accelerated aging were studied. The seeds were dried from 6.8% to 5.1%, 4.4%, 3.7% and 2.2% MC, respectively, in a desiccator with the silica gel. The germination energy, germination percentage, germination index and vigor index of the seed were investigated. After ultra-drying, groups of seeds were carried on the accelerated aging tests in an oven at 50 oC for 10, 20 and 30 d , respectively, and the physiological indexes, including relative conductivity, dehydrogenase activity and α-amylase activity were tested. The results show that the ultra-dried seeds with 3.7% MC have the highest germination energy, germination percentage, germination index and vigor index. After aging, the dehydrogenase activity and α-amylase activity of the group of seeds of 3.7% MC were higher than those of 6.8%, while the relative conductivity of the group of 3.7% is lower than that of 6.8%. It is feasible to ultra- dry the seeds with 3.7% MC.展开更多
A study was conducted to determine the physiological characteristics changes of Aesculus chinensis seeds during natural dehydration in 2003. The results showed that A. chinensis seeds were recalcitrant with being high...A study was conducted to determine the physiological characteristics changes of Aesculus chinensis seeds during natural dehydration in 2003. The results showed that A. chinensis seeds were recalcitrant with being highly desiccation-sensitive. The seed moisture content of fresh fruits was higher than 60%. When the seeds were naturally dried for 30 days, their moisture content declined to 30.2% and their viability was completely lost. The seed germination percentage had a small increase at the beginning of desiccation and then decreased rapidly. The relative electrical conductivity of the A. chinensis seeds increased along with a decrease in seed moisture content. However, there was an abnormal increase in relative electrical conductivity when the seed moisture content was between 53.7% and 50.9%. Superoxide dismutase （SOD） activity decreased rapidly in the period of desiccation except for an abnormality when the seed moisture content was between 53.7% and 50.9%. Malondialdehyde （MDA） content increased slowly at the early stage of desiccation and then rose rapidly after the moisture content was below 50.9%. The soluble sugar content in seeds slowly increased with the increasing period of desiccation. The seed germination percentage was at the high level when seed moisture content was in range of 47%- 60%, which suggests that this was the optimum moisture content for maintaining A. chinensis seed viability.展开更多
Emmenopterys henryi Oliv. (Rubiaceae) is an endangered tree species that is native to China. The wild populations of E. henryi have declined rapidly because of its poor natural regeneration, but the actual regeneratio...Emmenopterys henryi Oliv. (Rubiaceae) is an endangered tree species that is native to China. The wild populations of E. henryi have declined rapidly because of its poor natural regeneration, but the actual regeneration processes are not yet understood. In field tracking surveys and experiments in the Wuyishan Nature Reserve in Southeast China to determine the most important stage that affects the regeneration process, seed bank characteristics, seed germination, and seedling growth dynamics were studied in the typical habitats of E. henryi, Phyllostachys pubescens and broad-leaved forests. Results showed that in both P. pubescens and broad-leaved forests, more than 70% of the E. henryi seeds were distributed in moss and litter layers, and few were found in the soil beneath them. However, seed germination in the soil layer was significantly higher than in the moss and litter layers. Seed density, overall seed quality, and germination rate in the broad-leaved forest were significantly higher than in P. pubescens forest. Seed germination was highest in the microsites around the edge of the crown projection area of E. henryi mother trees. The order of survival rate of the seedlings on different ground surfaces was soil > moss > litter. In both habitats, the average seed density was 24.9 seeds m(-2), and the total germination rate was less than 3.5 parts per thousand. However, seedlings developed from only 1% of the germinated seeds, indicating that the seed germination is the most important stage in the natural regeneration of E. henryi.展开更多
It is important to understand the effects of dew events on non-mucilaginous seed germination of annual desert plant species during dry seasons, which is critical to maintaining long-term soil seed banks in a harsh des...It is important to understand the effects of dew events on non-mucilaginous seed germination of annual desert plant species during dry seasons, which is critical to maintaining long-term soil seed banks in a harsh desert environment. We hypothesize that dew deposition also assists in the non-mucilaginous seed germination of annual desert species. A common field dew treatment experiment was conducted in the Linze Inland River Basin Research Station to investigate the effects of dew deposition on the seed germination of four annual species, including Agriophyllum squarrosum, Corispermum mongoficum, Bassia dasyphylla and Halogeton arachnoideus. The results showed that the presence of dew significantly increased seed germination percentages and decreased the nonviable seed percentages of B. dasyphylla and H. arachnoideus, whereas there was no such trend for the seeds of C. mongolicum and A. squarrosum. The ecological effects of dew on the seed germination and viability of the annual desert plants were species specific. Although dew wetting is insufficient to cause seed germination, it may help in priming the seeds.展开更多
In this paper, seeds of pinus koraiensis which has a characteristic of deep dormancy were selected as an experiment material, and the relation of cellular substance exudation to seed vigour is discussed based on the d...In this paper, seeds of pinus koraiensis which has a characteristic of deep dormancy were selected as an experiment material, and the relation of cellular substance exudation to seed vigour is discussed based on the dormant state, the different measuring parts and the imbibed state of seeds before testing, as well as on the respiration of embryo and endosperm. The major measured results arc as follows: (1) After soaking for 24h, the dry embryo conductivity of sccdlot L is greater that than of sccdlot H: (2) The substance exudation of dry embryo of sccdlot H is less than that of sccdlot L; (3) After seeds imbibed, the substance exudation of dormant embryo of sccdlot H is more than that of sccdlot L; (4) After germination hastening treatment, the substance exudation of H embryos is greater than that of L embryos; (5) After artificially accelerated ageing treatment, the embryo conductivity of imbibed seeds has a positive correlation with seed vigour.展开更多
文摘Seed aging characteristics of rice was investigated in this study. Seeds of 34 japonica rice (O-ryza sativa subsp. japonica) varieties were held at 451 constant temperature. Changes in seed viability and seed vigor during aging process were measured to study seed viability-losing characteristic and to determine warning index for seed viability loss. As a result, seed viability survival curves were obtained across different rice accessions at 45℃ constant temperature. The curves appeared to be contra-sigmoid survival curves. The loss of seed viability in the aging process consisted of two phases. The first phase took a long duration, in which the viability of vigorous seeds declined slowly. In the second phase, seed viability declined rapidly. It was obvious that seed viability declined inconsistently during storage. It also showed that seed germination was prolonged and the seedling was significantly weakened before the coming of the rapid declining phase of seed viability. These two parameters could be used to indicate seed quality during storage. The rate of compatibility of tests (RCT), coefficient of variation (CV), vigor of seedling, the day the seeds start to germinate could be used as warning indexes to indicate overall quality of a mass of accessions. These warning indexes could also be used in monitoring the viability of seeds stored in the seed genebank.
文摘Kidney bean seed was dried in a laboratory scale fixed bed. The effect of seed coat on drying dynamic characteristics and the changes of seed coat structure were investigated. A mathematical model was established to simulate the drying process and determine the moisture diffusivity. Numerical results agree well with the experimental data. The average moisture diffusivity of the seed with separated coat is 1.67 times larger than that of the seed with coat, and the moisture diffusivity of seed cotyledon is 3.2 times larger than that of the seed coat. It is proved that the seed coat is the most main resistance of mass transfer and is also one of the key points of the optimization of heat and mass transfer for seed drying.
文摘An experiment was conducted at the Department of Horticulture, College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology, Kumasi （KNUST） Ghana from September, 2009 to April, 2010, to determine the most appropriate drying method, as a post harvest practice, that would ensure high percentage germination ofAnnona squamosa seeds and its subsequent effect on seedling growth. The seeds were sun-dried, air-dried under shade or kept in the fresh state. Five treatments were used, namely, Freshly Sown seeds （Treatment 1, control）, Seeds Air-Dried under Shade for one day （Treatment 2）; Seeds Sun-Dried for one day （Treatment 3）; Seeds Air-Dried under Shade for three consecutive days （Treatment 4）; Seeds Sun-Dried for three consecutive days （Treatment 5）. The experiment was arranged in a Completely Randomized Design （CRD） and replicated three times. Drying of Annona squamosa seeds had significant effect on earliness and number of seeds germinated. Air drying under shade and sun-drying for three consecutive days improved earliness to germination （26 days after sowing） and percent total germination but air-drying under shade had better effect on total seed germination, achieving 90% germination in 42 days after sowing. Furthermore, the prevailing ambient temperature of 30 ℃-32 ℃ enhanced germination of Annona squamosa seeds. The study concluded that for optimum germination, seeds of Annona squamosa should be either air-dried or sun-dried for three consecutive days and be incubated in an ambient temperature range of 30 ℃-32 ℃. In terms of growth, seedling growth in leaf production was better from seeds sun-dried for three consecutive days.
文摘Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying （DSR-AWD） in comparison with direct seeded rice at field capacity （DSR- FC）. Seed priming treatments were osmo-priming with KCI （2.2%）, CaCI2 （2.2%） and moringa leaf extracts （MLE, 3.3%） including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with CaCI2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with CaCI2 in DSR- AWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or CaCI2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or CaCI2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation.
基金the National Natural Science Foundation of China(No.597361 30 )
文摘A seed is the carrier of life,and research on the heat and mass transfer of a seed has already stridden toward the level of microcosm,such as cell protoplasm,cell organism,and molecular membrane.By means of a transmission electron microscope,the authors of this paper observed the microstructure of cotyledon tissue slices of the Chinese cabbage seed with a moisture content of 13% (on dry basis) and that with a moisture content of 4.3% (on dry basis) for drying 2 h at 45 ℃.The compared result was that only wrinkles had been discovered on the cell walls of the seed dried for 2 h,without any significant change for other organelles.Study on the enzyme activity shows that after a germination for 48 h,the relative activity of α amylase of the Chinese cabbage seed dried for 2 h at 45 ℃,decreased by 5.8%,whereas that of the seed dried 2 h at a temperature of 67 ℃ decreased by 30.1%.This work shows that the drying factors have greatly influence on the seed microstructure,enzyme activity,which is directly positive to seed viability.Combined with the analysis of the critical safe drying temperature of the vegetable seed,it can be concluded that enzyme activity is also the function of the drying temperature,the moisture content and the drying time.
文摘The probit analysis has been an important tool to predict seed longevity during storage and has been applied for seed drying simulation. Sealed aluminum pouches containing approximately 50 g of canola seed at moisture range of 7% to 21% of water content web basis （%） were conditioned in water-bath at 50, 60 and 70℃ to obtain the model to evaluate the reduction of canola seed germination. This model was included in the drying simulation program and the estimated germination was compared to the experimental values of germination during drying to validate the model. Canola seeds at 21% of moisture content and germination of 93% were dried at 51℃ and 61 ℃, and the model represented significantly the drying experiments. The aim of this study was to propose a germination model to evaluate the quality of canola seeds during the drying process and to offer the seed producers an important tool to control the drying process. The experimental data validated the objectives of the proposed drying model, optimizing the process at given conditions, managing the energy consumption, according to the minimum germination or maximum moisture content limitation for seed storage. For 51℃, the drying time for canola seed would be about 6 h to maintain germination above 90% and for 61℃, 4 h of drying time maintained germination up to 89%.
文摘To achieve a good production of a crop, it is essential to know the ability of the species to successfully complete two critical stages in the life cycle such as germination and seedling establishment. In this paper we study in comparative form structure of the seed, the importance of tegument in dormancy, the effect of accelerated aging on seed germination and viability, and the early and late growth in J. curcas and J. macrocarpa. External morphology of the seeds allow difference and internally also the embryos show evident differences. J. macrocarpa germination is around 0% - 4%. The total removal of tegument showed a 50% increase and the other treatments between 0% - 10%. Aging accelerated by Tetrazolium test allowed a comparative analysis of VP and GP. J. curcas maintains both to 96 h, while J. macrocarpa the seed viability is registered along the all treatment. J. macrocarpa seeds have less synchronicity than those of J. curcas. ABA and JAs were detected in tegument of J. macrocarpa and J. curcas seeds. JA could have a roll in inhibition of germination of J. macrocarpa seeds. Early and late growth, FW and DW of root, hypocotyl, epicotyl and leaf of J. curcas were significantly different in both species.
基金financially supported by the Key Projects in the Jiangsu Province Key Research & Development Program,China (BE 2016363)
文摘Effects of four different drying methods on the colour, texture, sensory quality, microstructure, bacterial viability and storage stability of probiotic-enriched apple snacks were assessed. The drying methods were air drying （AD）, freeze drying （FD）, freeze drying followed by microwave vacuum drying （FD＋MVD） and air drying followed by explosion puffing drying （AD＋EPD）. Overall, FD＋MVD can be used as a suitable drying method for the development of probiotic enriched apple snacks in consideration of colour, texture, sensory quality, bacterial viability and storage stability. Probiotic bacteria in FD＋MVD-dried samples remained above 1×106 CFU g 1 for 120 days at 25℃C. Interestingly, bacterial viability in FD＋MVD-dried samples turned out to be significantly higher than FD-dried samples during storage for 120 days.
基金Key Research and Development Program of Zhejiang Province(No.2019C02011)the“San Nong Liu Fang”Science and Technology Cooperation Project of Zhejiang Province(No.2018SNLF004),China。
文摘Seed vigor is a key factor affecti ng seed quality.The mechanical drying process exerts a sign ificant in fluence on rice seed vigor.The initial moisture con tent(IMC)and drying temperature are considered the main factors affecting rice seed vigor through mechanical drying.This study aimed to determine the optimum drying temperature for rice seeds according to the IMC,and elucidate the mechanisms mediating the effects of drying temperature and IMC on seed vigor.Rice seeds with three different IMCs(20%,25%,and 30%)were dried to the target moisture content(14%)at four different drying temperatures.The results showed that the drying temperature and IMC had significant effects on the drying performance and vigor of the rice seeds.The upper limits of drying temperature for rice seeds with 20%,25%,and 30%IMCs were 45,42,and 38°C,respectively.The drying rate and seed temperature increased sign ificantly with in creasing drying temperature.The drying temperature,drying rate,and seed temperature showed extremely significant negative correlations with germination energy(GE),germination rate,germination index(Gl),and vigor index(VI).A high IMC and drying temperature probably induced a massive accumulation of hydrogen peroxide(H2O2)and superoxide anions in the seeds,enhanced superoxide dismutase(SOD)and catalase(CAT)activity,and increased the abscisic acid(ABA)content.In the early stage of seed germination,the IMC and drying temperature regulated seed germination through the metabolism of H2O2,gibberellin acid(GA),ABA,and a-amylase.These results indicate that the metabolism of reactive oxygen species(ROS),antioxidant enzymes,GA,ABA,and a-amylase might be involved in the mediation of the effects of drying temperature on seed vigor.The results of this study provide a theoretical basis and technical guidance for the mechanical drying of rice seeds.
基金Supported by Key Project of the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(2013BAD01B0106)the Special Scientific Research Fund of Shandong Academy of Agricultural Sciences for Young Scholars(2016YQN19)+4 种基金China Agriculture Research System-Green Manure(CARS-22)National Crop Germplasm Resources Platform of China(2012/2013-032)Major Scientific and Technological Innovation Project of Shandong Province(2017CXGC0311)Modern Agricultural Industry Technology System of Shandong Province(SDAIT-15-01)Special Fund of Shandong Academy of Agricultural Sciences for Innovation in Agricultural Science and Technology(CXGC2018E15)
文摘The seeds of a soybean cultivar Zhonghuang 18 were subjected to accelerated aging for 0(population G_0-1), 112(population G_0-2), 154(population G_0-3) and 196 d(population G_0-4), whose germination percentage was found to be 98.0%, 95.0%, 81.0%, and 79.0%, respectively. Then, the four populations were regenerated twice in the field. The first descendant populations were marked as G_1-1, G_1-2, G_1-3 and G_1-4, and the second were marked as G_2-1, G_2-2, G_2-3 and G_2-4, respectively. The genetic variation between the control population(G_0-1) and the experimental populations was analyzed using 12 AFLP primer combinations. The results showed that there was no significant difference in genetic similarity between the 11 experimental populations and the control population G_0-1. The genetic similarity between population G_2-4 and G_0-1 was still as high as 0.933 3, indicating that the F_2 generation of the population whose germination percentage was only 79.0% still had a high genetic similarity to the control population. The results of t-tests revealed that the populations G_1-1, G_2-1, G_1-2 and G_2-2 showed no significant difference from the control population G_0-1 in effective number of alleles per locus(Ae), genetic diversity index(H) and Shannon's diversity index(I), while these indices of populations G_0-3, G_0-4, G_1-3, G_1-4, G_2-3 and G_2-4 were significantly reduced. χ~2 tests indicated that the populations G_1-1 and G_2-1 showed little difference, and the populations G_0-2, G_0-3, G_0-4, G_1-2, G_1-3, G_1-4, G_2-2, G_2-3, and G_2-4 showed great difference in allele frequency distribution from the control population G_0-1, and the difference was greater when the seed viability was lower. Compared with the control population G_0-1, the number of rare alleles(Nr) of the populations G_0-2, G_1-1, G_2-1, G_1-2 and G_2-2 showed no significant difference, while that of the populations G_0-3, G_0-4, G_1-3, G_1-4, G_2-3 and G_2-4 declined obviously. These results revealed that compared with the control population, the genetic diversity and Nr for the descendant populations of the populations with 98.0% and 95.0% germination percentages did not change significantly, but declined greatly for the descendant populations of the populations with 81.0.% and 79.0% percentages. The results suggested that the decline in seed viability has a greater impact than the number of generations on genetic structure of soybean germplasm. So, it is suggested that soybean seed with an initial germination percentage of 98.0% should be regenerated before its germination percentage declines to 81.0%.
文摘In Indonesia, shallot cultivation finds difficulties to produce high viability seed. That low viability is caused by the abnormality of seed＇s structure. Normal shallot seeds have seed structure that consists of： testa, endosperm, and embryo. Normal embryo has curved shape which it has one cotyledon in endosperm. This research purpose is to find shallot viability and structure that is cultivated in tropic area, especially in Indonesia. This research is a deep observation research about water level, seeds viability and seeds structure monitoring by using microscope. To make a clearance about seeds structure composition, seeds are mixed with tetrazolium salt. Monitoring result shows that seed water level at harvest time is 18%, laid away at one month age is 13%, two months age is 12% and three months age is 10%. Seed viability at harvest until twenty nine days, seed that is germinated around 8%. At two months viability seed laid age until twenty two days is 36.6%. Meanwhile three months age laid viability test is done with germination boost compounding shows that IAA is able to fasten germination. At IAA treatment viability seeds are 17.25% that is followed with GA3 treatment around 13%. Another boosting substance that it＇s viability is only below 4%. Low viability is also proved by the seed structure. The result shows that mostly, the seeds has abnormal structure.
文摘The objective of this study was to characterize environment factors involved in loss of seed viability during storage in open granaries. The temperature and relative humidity of the granary as well as the equilibrium moisture content of seeds were determined monthly. Their effects on the loss of viability of maize (<i>Zea mays</i> L.) and cowpea (<i>Vigna unguiculata</i> (L.) Walp.) seeds were examined. The results showed that relative humidity levels > 65% associated with temperatures > 25°C (conditions in the open granary) do not guarantee safe storage of maize lots for a period of 9 to 12 months. Based on these data and the results of seed viability analysis, local environmental conditions in Gandajika (DR-Congo) and seed genetic background are the main factors for the rapid deterioration of seeds during storage. The germination rate correlated negatively with storage duration (<span style="font-family:;" "="">-0.94) and temperature (-0.57) while it correlates positively with the relative humidity (0.58) for both lots of maize analyzed. The same trend was observed with the two-cowpea varieties studied (IT82D-889 and Diamant). Similar work using more varieties in other granaries is required to validate key factors involved in seed viability during storage in targeted regions.</span>
文摘In this study the effect of initial parameters such as inlet gas temperature, initial particles temperature and gas velocity on temperature changes of solid particles and outlet gas temperature in a fluidized bed dryer was studied. For testing, an experimental setup was established. With combination of air and Colza seeds belonging to D groups of the Geldart classification (Geldart, 1986) fluidization regime was carried out. With five test series with maintaining the inlet gas temperature, solid particle temperature and outlet gas temperature during time were carefully measured. To analyze these data by using regression analysis to predict solid particle and outlet gas temperature, 2 correlations on initial pa-rameters were presented. The result has shown that temperature gradients in the beginning of fluidization, is very high and therefore the exponential functions in the regression model is used to predict the temperature changes.
文摘This paper deals with the influence of ultra-lowmoisture content and the rate of desiccation on rice seed viability and physiological property bydesiccating using four kinds of desiccants(phos-
基金This research is subsidized by the project The Study on the Key Technology of Afforestation in Barren Site(2006BAD03A03)which isa part of The Study on Coming Back of Vegetation and Technology of Afforestation in Northwest Farming and Pasturing Mixed Area withbadly Corrosion (2006BAD03A0308).
文摘In order to supply quality seed for vegetation restoration in arid and semiarid areas of Northwest China, the effects of Platycladus orientalis seed storage under ultra-drying and accelerated aging were studied. The seeds were dried from 6.8% to 5.1%, 4.4%, 3.7% and 2.2% MC, respectively, in a desiccator with the silica gel. The germination energy, germination percentage, germination index and vigor index of the seed were investigated. After ultra-drying, groups of seeds were carried on the accelerated aging tests in an oven at 50 oC for 10, 20 and 30 d , respectively, and the physiological indexes, including relative conductivity, dehydrogenase activity and α-amylase activity were tested. The results show that the ultra-dried seeds with 3.7% MC have the highest germination energy, germination percentage, germination index and vigor index. After aging, the dehydrogenase activity and α-amylase activity of the group of seeds of 3.7% MC were higher than those of 6.8%, while the relative conductivity of the group of 3.7% is lower than that of 6.8%. It is feasible to ultra- dry the seeds with 3.7% MC.
文摘A study was conducted to determine the physiological characteristics changes of Aesculus chinensis seeds during natural dehydration in 2003. The results showed that A. chinensis seeds were recalcitrant with being highly desiccation-sensitive. The seed moisture content of fresh fruits was higher than 60%. When the seeds were naturally dried for 30 days, their moisture content declined to 30.2% and their viability was completely lost. The seed germination percentage had a small increase at the beginning of desiccation and then decreased rapidly. The relative electrical conductivity of the A. chinensis seeds increased along with a decrease in seed moisture content. However, there was an abnormal increase in relative electrical conductivity when the seed moisture content was between 53.7% and 50.9%. Superoxide dismutase （SOD） activity decreased rapidly in the period of desiccation except for an abnormality when the seed moisture content was between 53.7% and 50.9%. Malondialdehyde （MDA） content increased slowly at the early stage of desiccation and then rose rapidly after the moisture content was below 50.9%. The soluble sugar content in seeds slowly increased with the increasing period of desiccation. The seed germination percentage was at the high level when seed moisture content was in range of 47%- 60%, which suggests that this was the optimum moisture content for maintaining A. chinensis seed viability.
基金financially supported by the National Natural Science Foundation of China(NSFC) through Grant(Number31360145)
文摘Emmenopterys henryi Oliv. (Rubiaceae) is an endangered tree species that is native to China. The wild populations of E. henryi have declined rapidly because of its poor natural regeneration, but the actual regeneration processes are not yet understood. In field tracking surveys and experiments in the Wuyishan Nature Reserve in Southeast China to determine the most important stage that affects the regeneration process, seed bank characteristics, seed germination, and seedling growth dynamics were studied in the typical habitats of E. henryi, Phyllostachys pubescens and broad-leaved forests. Results showed that in both P. pubescens and broad-leaved forests, more than 70% of the E. henryi seeds were distributed in moss and litter layers, and few were found in the soil beneath them. However, seed germination in the soil layer was significantly higher than in the moss and litter layers. Seed density, overall seed quality, and germination rate in the broad-leaved forest were significantly higher than in P. pubescens forest. Seed germination was highest in the microsites around the edge of the crown projection area of E. henryi mother trees. The order of survival rate of the seedlings on different ground surfaces was soil > moss > litter. In both habitats, the average seed density was 24.9 seeds m(-2), and the total germination rate was less than 3.5 parts per thousand. However, seedlings developed from only 1% of the germinated seeds, indicating that the seed germination is the most important stage in the natural regeneration of E. henryi.
基金funded by the National Basic Research Program of China(2013CB429903)the West Light Program for Talent Cultivation of Chinese Academy of Sciencesthe National Natural Science Foundation of China(41301604)
文摘It is important to understand the effects of dew events on non-mucilaginous seed germination of annual desert plant species during dry seasons, which is critical to maintaining long-term soil seed banks in a harsh desert environment. We hypothesize that dew deposition also assists in the non-mucilaginous seed germination of annual desert species. A common field dew treatment experiment was conducted in the Linze Inland River Basin Research Station to investigate the effects of dew deposition on the seed germination of four annual species, including Agriophyllum squarrosum, Corispermum mongoficum, Bassia dasyphylla and Halogeton arachnoideus. The results showed that the presence of dew significantly increased seed germination percentages and decreased the nonviable seed percentages of B. dasyphylla and H. arachnoideus, whereas there was no such trend for the seeds of C. mongolicum and A. squarrosum. The ecological effects of dew on the seed germination and viability of the annual desert plants were species specific. Although dew wetting is insufficient to cause seed germination, it may help in priming the seeds.
文摘In this paper, seeds of pinus koraiensis which has a characteristic of deep dormancy were selected as an experiment material, and the relation of cellular substance exudation to seed vigour is discussed based on the dormant state, the different measuring parts and the imbibed state of seeds before testing, as well as on the respiration of embryo and endosperm. The major measured results arc as follows: (1) After soaking for 24h, the dry embryo conductivity of sccdlot L is greater that than of sccdlot H: (2) The substance exudation of dry embryo of sccdlot H is less than that of sccdlot L; (3) After seeds imbibed, the substance exudation of dormant embryo of sccdlot H is more than that of sccdlot L; (4) After germination hastening treatment, the substance exudation of H embryos is greater than that of L embryos; (5) After artificially accelerated ageing treatment, the embryo conductivity of imbibed seeds has a positive correlation with seed vigour.
