Survival Of Seeds Research Articles

Seed survival of the tropical treeCryptocarya aschersoniana(Lauraceae): Consequences of habitat disturbance

Seed survival in soil could be strongly influenced by habitat characteristics, but little is known about the behaviour of seeds sensitive to desiccation in seed banks installed in natural or disturbed habitats. Cryptocarya aschersoniana seeds disperse at the end of the rainy season but do not germinate immediately; thus, they may form seed banks in soil. This study evaluated the behaviour of C. aschersoniana seed banks induced in the natural environment of the species and in a disturbed area. Recently harvested C. aschersoniana germination units were characterized according to their water content, germination and viability. In 2011 and 2012, seed banks were established by burying samples of seeds in the understory of a semi-deciduous forest. In 2012, samples were also buried in a disturbed area. The seed banks were sampled at certain time intervals, and the samples were characterized as described above. Precipitation and air temperature data were collected. As a result, seeds in the seed bank established in the natural environment form a transient seed bank and showed the same behaviour in both years studied. A germination peak was observed starting 210 days after burial (coinciding with the onset of the rainy season) and reached germination percentages higher than 80% at the end of the experiment for both years. Seed mortality did not exceeded 28% in the natural environment. However, in the disturbed environment, the seeds lost their viability more rapidly, with 90% of the seeds becoming unviable 240 days after burial. Germinated seeds in the disturbed environment (maximum 21%) were not able to establish seedlings. These results underscore the importance of maintaining a natural, undisturbed forest for the conservation of this species.

Loss of adaptation following reversion suggests trade-offs in host use by a seed beetle.

Experimental evolution has provided little support for the hypothesis that the narrow diets of herbivorous insects reflect trade-offs in performance across hosts; selection lines can sometimes adapt to an inferior novel host without a decline in performance on the ancestral host. An alternative approach for detecting trade-offs would be to measure adaptation decay after selection is relaxed, that is, when populations newly adapted to a novel host are reverted to the ancestral one. Lines of the seed beetle Callosobruchus maculatus rapidly adapted to a poor host (lentil); survival in lentil seeds increased from 2% to > 90% in < 30 generations. After the lines had reached a plateau with respect to survival in lentil, sublines were reverted to the ancestral host, mung bean. Twelve generations of reversion had little effect on performance in lentil, but after 25-35 generations, the reverted lines exhibited lower survival, slower development and smaller size. The most divergent pair of lines was then assayed on both lentil and mung bean. Performance on lentil was again much poorer in the reverted line than in the nonreverted one, but the lines performed equally well on mung bean. Moreover, the performance of the nonreverted line on mung bean remained comparable to that of the original mung-bean population. Our results thus present a paradox: loss of adaptation to lentil following reversion implies a trade-off, but the continued strong performance of lentil-adapted lines on mung bean does not. Genomic comparisons of the reverted, nonreverted and ancestral lines may resolve this paradox and determine the importance of selection vs. drift in causing a loss of adaptation following reversion.

Regurgitation by waterfowl: An overlooked mechanism for long-distance dispersal of wetland plant seeds

Birds commonly regurgitate indigested particles after foraging. Many frugivorous birds regurgitate seeds ingested with the flesh of fruits, which importantly contributes to plant dispersal in terrestrial ecosystems. In freshwater ecosystems, waterbirds are known to defecate viable seeds in their faeces, but little is known about regurgitation as a potential additional seed dispersal mechanism. We experimentally fed eight mallards (Anas platyrhynchos) with a high and low volume of seeds of ten wetland plant species, and monitored regurgitation and defecation of intact seeds over 24h. Regurgitation occurred at least once in all individual mallards and was induced by two different mechanisms: (i) feeding of high food volumes was significantly associated with regurgitation of all seed species from the crop after retention times of 1–3h, and (ii) large indigestible seeds were expelled from the gizzard 11 or more hours after feeding. Seed regurgitation was much less plant species-specific than survival of seeds passing digestion, which suggests it is a particularly suitable dispersal mechanism for plant species unable to disperse by endozoochory (such as plant species with large, soft-bodied seeds). Observations of regurgitation by wild waterbirds are needed to improve our knowledge on this additional role of waterbirds in ecosystem functioning.

Pondberry (Lindera melissifolia, Lauraceae) seed and seedling dispersers and predators

Pondberry (Lindera melissifolia(Walter) Blume) is an endangered dioecious, clonal shrub that grows in periodically flooded forests of the southeastern United States. The probability of survival of dispersed pondberry seeds and new germinants is unknown, but few seedlings are noted in the forest. This study was undertaken to: (1) identify herbivores and predators of pondberry seeds and seedlings, (2) record the fate of pondberry seeds and seedlings after simulated dispersal in areas with lower and higher understory cover, and (3) calculate the probability of seed survival in the two cover types. The study was conducted in or near the Delta National Forest and the Delta Experimental Forest, MS. Pondberry seed and seedling plots were established at sites with high or low cover. Video cameras with infrared illumination were set up to monitor animal visitors to the plots. Image analysis indicated that swamp rabbits (Sylvilagus aquaticus (Bachman)) and wood rats (Neotoma floridana Ord) cut or ate seedlings, while other animals visited the plots without damaging seedlings. Numerous bird species and mammals visited the seed plots and some were filmed eating seeds. Pondberry seeds exposed in open habitats had a significantly higher survival rate than those exposed in habitats with more herbaceous and woody understory cover. The novelty and quality of the temporal data collected via video monitoring indicate the importance of this method in collecting data that are not otherwise available on endangered and rare species.

Leaf litter affects the survival and predation rates for large and small Pinus seeds in the Qinling Mountains, China

It is generally accepted that leaf litter covers seeds, which may be beneficial for their survival, but it is unclear whether leaf litter contributes in different ways to the survival of plant seeds with contrasting sizes. In this study, we examined the effect of different levels of leaf litter coverage on seed predation and foraging/caching for small-seededPinus tabulaeformisand large-seededPinus armandiiin the Qinling Mountains, China. Our results showed that leaf litter failed to protectP. armandiiseeds from being removed by small rodents, whereas it improved seed survival forP. tabulaeformis.P. tabulaeformiswere eatenin situ, whereas moreP. armandiiseeds were eaten in the high leaf litter coverage plots. Therefore, we propose that leaf litter affects the survival and predation rates for large and smallPinusseeds in the Qinling Mountains, China.

Effects of seed traits on the potential for seed dispersal by fish with contrasting modes of feeding

Summary For aquatic and riparian plants, the important role of fish in seed dispersal is increasingly recognised. While the propensity of seeds to disperse is known to be a function of morphological, physical and chemical traits of the seed, in the case of fish‐mediated seed dispersal (ichthyochory), it is largely unknown how seed traits modulate the potential for seed ingestion and their subsequent survival through the gut. Furthermore, which seed traits are important may vary among fish species. To evaluate the role of both seed and fish traits in ichthyochory, we fed seeds of 19 aquatic and riparian plant species to fish with differing feeding mechanisms. Cyprinus carpio (common carp) has a pharyngeal ‘mill’, which it uses physically to crush hard food, while Oreochromis mossambicus (Mozambique tilapia) has only tiny oral and pharyngeal teeth and instead relies more on chemical digestion. A number of seed traits, including hardness, size and shape, were important determinants of the potential of seeds for ichthyochory. Certain traits (e.g. seed dimensions) were more important during ingestion, whereas other traits were more important for seed survival and subsequent germination (e.g. seed hardness, mucilaginous coat). Compared to controls, germination of retrieved seeds in carp was lower in 10 and higher in two plant species, whereas for tilapia, it was lower in seven and higher in three species. Overlap between these plant species was low, indicating clear difference between the fish studied in their potential for seed dispersal. Carp increased in size during the experiment and concomitant decreases in seed survival and retrieval were found, suggesting that body size and the correlated bite force is an important fish trait in ichthyochory. Overall, seed hardness, size and shape appear crucial for the survival of seeds passing through the guts of carp and tilapia. Beyond this general pattern, a greater complexity of trait‐performance relationships appeared: different seed traits are involved during each of the stages of ichthyochory. Moreover, the importance of seed traits differed between carp and tilapia, with some traits having interactive and contrasting effects in both fish species. Aquatic plants with floating seeds adapted to hydrochorous dispersal were less likely to be dispersed by tilapia than plants with non‐floating seeds, suggesting a dispersal trade‐off between ichthyochory and hydrochory. Thus, depending on their seed characteristics, fish may offer an additional dispersal route to aquatic and riparian plants.

The Influence of Mineral Fertilizers on the Chemical Composition of Verdurous Masses of Forder Crops

This article presents the results of sorghum and pearl millet studies conducted in order to develop the technology of their cultivation as a new forage crops for livestock in arid areas of Kazakhstan. The article presents data on the effect of seeding rates and term of sowing on seeds germination and survival of plants and a crop of verdurous masses of sorghum and pearl millet against the background of watering. The optimal seeding rate and sowing of sorghum and pearl millet in saline soils of rice irrigation systems are determined in terms of the ecological crisis in Aral Sea region, Kazakhstan.

Seed size and number make contrasting predictions on seed survival and dispersal dynamics: A case study from oil tea Camellia oleifera

Seed size and number vary greatly both within and among plant individuals, populations or species. However, we know little about how individual variation in seed size and number relates to seed survival and dispersal dynamics in animal-dispersed plants. Based on the large-seed hypothesis and the predator satiation hypothesis, we developed a synthetic framework and testable predictions for how seed size and number interact to predict seed survival-dispersal patterns at the seed and tree scales, and tested for these effects using rodent-dispersed oil tea, Camellia oleifera. Our results showed that seed size and number varied considerably at both fruit and tree scales, and mean seed size for each fruit was negatively correlated with the number of seeds per fruit. We placed groups of individual-weighed seeds in a way that mimicked seed size and number from individual trees and tracked the fate of these seeds. This showed that seed survival in situ at source trees decreased with increasing seed size, but seed dispersal and the subsequent survival of dispersed seeds increased with larger seed size. In addition, seed survival in situ at source trees increased with larger seed number per tree, but the proportion of dispersed seeds decreased as seed number per tree increased. We demonstrate that individual variation in seed size and number have strong but contrasting effects on seed survival and seed dispersal in oil tea. Moreover, these two factors are not independent in their effects on seed survival at the source tree, but after dispersal, the size of individual seeds may be more important in determining seed survival or further handling by scatterhoarding animals.

Embryogenesis and synthetic seed production in Mondia whitei

An effective plant regeneration system via somatic embryogenesis and synthetic seeds was developed for Mondia whitei, an endangered medicinal plant. Friable embryogenic callus was induced by culturing leaf explants on solid Murashige and Skoog (MS) medium containing various concentrations and combinations of sucrose and plant growth regulators. The highest frequency of somatic embryogenesis (100 %) and production of all developmental stages of somatic embryos were obtained on MS medium with 40 g l−1 sucrose, 8 g l−1 agar, 20 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 μM thidiazuron. This was followed by establishment in MS medium with 20 g l−1 sucrose, 8 g l−1 agar, 0.5 μM meta-topolin riboside (mTR) and 0.25 μM indole-3-acetic acid (IAA). All the embryos germinated and produced healthy plantlets on the same medium. Somatic embryos at the heart, torpedo and cotyledonary-stages were collected from media (EDM) containing MS medium plus 20 g l−1 sucrose, 8 g l−1 agar, 0.5 μM mTR and 0.25 μM IAA. The embryos were encapsulated with liquid MS medium plus different concentrations of sodium alginate (SA) and calcium chloride (CaCl2·2H2O) with a 10 min exposure. A combination of 3 % SA and 100 mM CaCl2·2H2O provided higher survival (95.7 %) and germination (73 %) frequencies of synthetic seeds. Germination frequency of synthetic seeds was 51.6 % after 50 days of storage at 4 °C. Somatic embryos and synthetic seed-developed plantlets were successfully acclimatized in the greenhouse with 90 % survival ex vitro. Application of the protocol provides a relatively simple and rapid system for conservation of natural populations for germplasm conservation. Analysis of bioactive compounds and genetic transformation studies can also be performed.

Effect of dietary probiotic supplement on growth and survival of Indian major carp seeds

Two feeding trials were conducted in triplicates for each treatment for a period of 90 days to delineate the effect of dietary probiotic (Problend) supplementation on growth and survival of Labeo rohita and Catla catla fry. Four isonitrogenous (Crude protein: 29.43±0.6%) diets were prepared utilizing the locally available ingredients to which Problend was added at the rate of 0.5 per cent (T 1 ); 1.0 per cent (T 2 ) and 1.50 per cent (T 3 ). Diet without Problend incorporation served as control (T 0 ). The growth in terms of weight gain (% weight gain) and increment in length was found to be highest in the treatment (T 2 ) followed by the treatments (T 3 and T 1 ), respectively as compared to that of control for both the species of fish. The specific growth rate, food conversion ratio and protein efficiency ratio were observed to be highest in case of the treatment (T 2 ) followed by the treatment (T 3 ) for both the species of fish under study. The highest overall survival percentage was observed in the treatments (T 2 and T 3 ) as compared to treatment (T 1 ) and control (T 0 ). The results thus obtained in the present investigation indicate that incorporation of Problend at the rate of 1 per cent to the basal diet enhances the growth and survival of L. rohita and C. catla fry.

C-2001: Survival of short-lived desiccation tolerant seeds during long-term storage in liquid nitrogen: Implications for the management and conservation of plant germplasm collections

Ex situ seed conservation is a widespread and powerful tool for the preservation of plant genetic resources. However, long-term storage of short-lived seeds is challenging in standard seed bank temperatures (4 and −20 °C), and cryopreservation has been acknowledged as the only effective option for their long-term conservation. However, as seed aging has been demonstrated during cryostorage, the potential and limits of LN storage of short-lived seeds need to be evaluated. We have examined the viability and growth of seeds from species with short-lived seeds stored up to 20 years in CREW’s CryoBioBank®, including Plantago cordata, Populus deltoides, several Salix species, and two species in the genus Betula. We have found survival in short-lived seeds after >14 years of LN storage (−196 °C). P. cordata seeds did not show a significant decrease in germination over this time. However, Salix sp. and P. deltoides accessions tested showed a final germination ranging between 0% and 96% of initial germination. Seeds of P. deltoides stored at 4 and −20 °C did not show any survival after the same storage period. Seed viability in P. deltoides and Salix sp. was overestimated when measured as total germination, rather than normal germination. Furthermore, 38–43% of seedlings from normal seedlings of P. deltoides did not continue normal development during early growth of the young plants. In addition, initial seed quality was correlated with seed longevity. These results suggest that: (1) monitoring of short-lived seeds cryostored as in this study (at 8–10% moisture) should be done at 2–5 year intervals, similar to the recommendation by IPGRI for seeds stored at −18°C, and regeneration should not exceed 10–15 years; (2) in order to minimize loss of seed quality prior to cryostorage, processing of short-lived seeds after harvest must be fast and gentle; (3) based on losses during early seedling growth and development, it is very important not to exceed the time to reach 85% of initial normal germination when planning regeneration of Populus and Salix collections to avoid large genetic erosion.

Bird‐mediated seed dispersal: reduced digestive efficiency in active birds modulates the dispersal capacity of plant seeds

Plant populations in fragmented ecosystems rely largely on internal dispersal by animals. To unravel the mechanisms underlying this mode of dispersal, an increasing number of experimental feeding studies is carried out. However, while physical activity is known to affect vertebrate digestive processes, almost all current knowledge on mechanisms of internal seed dispersal has been obtained from experiments with resting animals. We investigated how physical activity of the mallard Anas platyrhynchos, probably the quantitatively most important biotic dispersal agent in aquatic habitats in the entire Northern Hemisphere, affects gut passage survival and retention time of ingested plant seeds. We fed seeds of nine common wetland plants to mallards trained to subsequently swim for six hours in a flume tank at different swimming speeds (activity levels). We compared gut passage survival and retention times of seeds against a control treatment with mallards resting in a conventional dry cage. Intact gut passage of seeds increased significantly with mallard activity (up to 80% in the fastest swimming treatment compared to the control), identifying reduced digestive efficiency due to increased metabolic rates as a mechanism enhancing the dispersal potential of ingested seeds. Gut passage speed was modestly accelerated (13% on average) by increased mallard activity, an effect partly obscured by the interaction between seed retention time and probability of digestion. Gut passage acceleration will be more pronounced in digestion‐resilient seed species, thereby modulating their dispersal distances. Our findings imply that seed dispersal potential by mallards calculated from previous experiments with resting birds is highly underestimated, while dispersal distances may be overestimated for some plant species. Similar effects of physical activity on digestive efficiency of mammals suggests that endozoochorous dispersal of plant seeds by vertebrates is more effective and plays a quantitatively more important ecological role in both terrestrial and aquatic ecosystems than previously thought.

Specificity of adaptation to a novel host plant by a seed beetle

AbstractAdaptation to one novel host plant may simultaneously improve an insect's performance on other unfamiliar hosts, as a kind of cross‐adaptation. In selection experiments using an Asian population of the seed beetle Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae: Bruchinae), larval survival in lentil seeds increased from about 1 to &gt;90% in fewer than 30 generations, and acceptance of lentil by egg‐laying females increased two‐ to three‐fold. We examined whether rapid adaptation to lentil altered beetle performance on other grain legumes, including hosts more closely related to lentil than to the ancestral host, mung bean. Three replicate, lentil‐adapted lines were compared to the mung‐bean (control) line with respect to both host acceptance (oviposition under no‐choice conditions) and larval performance (survival to adult emergence, development time, and adult mass at emergence). In most experiments, females from the lentil lines laid more eggs on unfamiliar hosts than did females from the mung‐bean line. Greater oviposition on novel hosts could not be explained by variation in potential fecundity, and did not appear to depend on a host's relatedness to lentil. Although survival in lentil remained extremely divergent between the mung‐bean and lentil lines (0 vs. &gt;90%), the lines did not differ in larval performance on two other novel hosts (pea and fava bean) that are much more closely related to lentil than to mung bean. Because larval performance is most likely the limiting factor in the potential colonization of a novel host by C. maculatus, our experiments did not provide strong evidence for cross‐adaptation. The results suggest that adaptation to even a highly marginal host need not lead to a general expansion of an insect's host range.

Impacts of Carpobrotus edulis (L.) N.E.Br. on the germination, establishment and survival of native plants: a clue for assessing its competitive strength.

Does Carpobrotus edulis have an impact on native plants? How do C. edulis’ soil residual effects affect the maintenance of native populations? What is the extent of interspecific competition in its invasion process? In order to answer those questions, we established pure and mixed cultures of native species and C. edulis on soil collected from invaded and native areas of Mediterranean coastal dunes in the Iberian Peninsula. We examined the impact of the invader on the germination, growth and survival of seeds and adult plants of two native plant species (Malcolmia littorea (L.) R.Br, and Scabiosa atropurpurea L.) growing with ramets or seeds of C. edulis. Residual effects of C. edulis on soils affected the germination process and early growth of native plants in different ways, depending on plant species and density. Interspecific competition significantly reduced the germination and early growth of native plants but this result was soil, density, timing and plant species dependent. Also, at any density of adult individuals of C. edulis, established native adult plants were not competitive. Moreover, ramets of C. edulis had a lethal effect on native plants, which died in a short period of time. Even the presence of C. edulis seedlings prevents the recruitment of native species. In conclusion, C. edulis have strong negative impacts on the germination, growth and survival of the native species M. littorea and S. atropurpurea. These impacts were highly depended on the development stages of native and invasive plants. Our findings are crucial for new strategies of biodiversity conservation in coastal habitats.

Evaluation of genetic integrity of tomato seeds during ageing by microsatellite markers

The objective of this project was to evaluate ageing-induced genetic changes during storage of tomato seeds. Seeds of 10 accessions of tomatoes were thus subjected to artificial ageing in chambers conditioned to 55 °C and 72 ± 2% RH for 72 h. Seed survival data were used to estimate probit parameters. Genetic changes during the seed ageing course were evaluated by microsatellite (SSR) analysis using a Direct PCR™ kit., The SSR primer sequences (except SGN-14430) optimized the gene markers for the tomato accessions and are thus recommended for detecting genetic changes during seed storage. Genetic distances were calculated using PAST™ software and percentage genetic integrity was estimated from the genetic distance matrices. Probit analysis showed that P50 estimates was least in accession LOO169 (7 days) and highest in accession 09/044 (64.4 days). Seeds having lower P50 estimates showed lower estimates of genetic integrity. Lowest estimate of average genetic integrity was 99.21% when estimates of genetic distances were compared between 0 and 72 h of artificial ageing. The results showed ageing-induced genetic deterioration during artificial ageing thus suggests possibility of losses in genetic integrity of seeds in storage at a specific physiological (germinability) benchmark. For tomatoes, this study shows that seed germinability benchmark for genetic changes during ageing was approximately 42%. Comparison of tomato seeds stored in the NACGRAB gene bank for 2 years and freshly harvested seeds, validated the artificial seed ageing result and the estimated germination benchmark for declining genetic integrity in tomato seeds.

Effect of Harvesting Time and Storage Duration of Viscum album Seeds on in vitro and ex vitro Germination on the Branch of Prunus mume

Viscum album var. coloratum (mistletoe) is considered as one of the endangered plant species in Korea. Our objective is to restore its population and multiplication of plant by ex situ method. In this research we explored the maximum germination (in vitro) of freshly harvested and stored seeds of mistletoe collected in different time intervals. Ex vitro germination after artificial inoculation on the branches of Prunus mume in different physiological conditions was also monitored. The research revealed that the lately harvested seeds (Feb. and March 2014) were superior over early harvested seeds (Nov. 2013 and Jan. 2014) of mistletoe due to the higher percentage of germination (above 93%). According to the data, it is also revealed that the survival and germination rate of mistletoe seeds decreased with the increase in storage duration. In ex vitro germination, the fluctuated temperature of a glass house in natural condition enhanced (four fold) the rate of germination on the branches of Prunus mume than the constant temperature condition in the glass house.

Modeling and analysis of a density-dependent stochastic integral projection model for a disturbance specialist plant and its seed bank.

In many plant species dormant seeds can persist in the soil for one to several years. The formation of these seed banks is especially important for disturbance specialist plants, as seeds of these species germinate only in disturbed soil. Seed movement caused by disturbances affects the survival and germination probability of seeds in the seed bank, which subsequently affect population dynamics. In this paper, we develop a stochastic integral projection model for a general disturbance specialist plant-seed bank population that takes into account both the frequency and intensity of random disturbances, as well as vertical seed movement and density-dependent seedling establishment. We show that the probability measures associated with the plant-seed bank population converge weakly to a unique measure, independent of initial population. We also show that the population either persists with probability one or goes extinct with probability one, and provides a sharp criteria for this dichotomy. We apply our results to an example motivated by wild sunflower (Helianthus annuus) populations, and explore how the presence or absence of a "storage effect" impacts how a population responds to different disturbance scenarios.

The ecophysiology of seed persistence: a mechanistic view of the journey to germination or demise

Seed persistence is the survival of seeds in the environment once they have reached maturity. Seed persistence allows a species, population or genotype to survive long after the death of parent plants, thus distributing genetic diversity through time. The ability to predict seed persistence accurately is critical to inform long-term weed management and flora rehabilitation programs, as well as to allow a greater understanding of plant community dynamics. Indeed, each of the 420000 seed-bearing plant species has a unique set of seed characteristics that determine its propensity to develop a persistent soil seed bank. The duration of seed persistence varies among species and populations, and depends on the physical and physiological characteristics of seeds and how they are affected by the biotic and abiotic environment. An integrated understanding of the ecophysiological mechanisms of seed persistence is essential if we are to improve our ability to predict how long seeds can survive in soils, both now and under future climatic conditions. In this review we present an holistic overview of the seed, species, climate, soil, and other site factors that contribute mechanistically to seed persistence, incorporating physiological, biochemical and ecological perspectives. We focus on current knowledge of the seed and species traits that influence seed longevity under ex situ controlled storage conditions, and explore how this inherent longevity is moderated by changeable biotic and abiotic conditions in situ, both before and after seeds are dispersed. We argue that the persistence of a given seed population in any environment depends on its resistance to exiting the seed bank via germination or death, and on its exposure to environmental conditions that are conducive to those fates. By synthesising knowledge of how the environment affects seeds to determine when and how they leave the soil seed bank into a resistance-exposure model, we provide a new framework for developing experimental and modelling approaches to predict how long seeds will persist in a range of environments.

Salinidade na água de beber de ovinos e uso dos dejetos em cultivo de plântulas de milho

O objetivo deste estudo foi caracterizar substratos e avaliar a emergência e a sobrevivência de sementes de milho, bem como o crescimento, massa seca da parte aérea e a massa seca da raiz de plântulas cultivadas com substratos (solo e dejetos de ovinos), alimentados com água com diferentes níveis de sólidos dissolvidos totais (SDT)- 640; 3.188; 5.740 e 8.326mgl. O estudo foi desenvolvido em casa de vegetação no setor de produção de mudas da Embrapa Semiárido em Petrolina-PE. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro tratamentos e dez repetições. Os dados foram analisados por meio de contrastes ortogonais e regressão polinomial. Foi verificado efeito (P&lt;0,05) no índice de velocidade de emergência, sendo estimado por regressão que o melhor substrato deva conter até 1811SDT na água de beber dos animais para essa variedade de milho. No entanto, na biomassa da parte aérea e da raiz, o percentual de sobrevivência e altura das plântulas não sofreram modificações (P&gt;0,05).

Pakan suspensi daging kekerangan bagi pertumbuhan benih sidat (Anguilla bicolor)

Abstract The objective of this research was to evaluate the effect of different mussel flesh suspension feed in providing best growth and feed efficiency on eel seeds, Anguilla bicolor. Treatment feed included A (kijing Taiwan Anodonta woodiana Lea)), B (keong mas Pomacea canaliculata), C (kerang darah Anadara granosa) and D (commercial pellet), each with three replications. Elver was reared in plastic container having diameter of 40 cm. Research results showed the best relative growth and feed efficiency were achieved in treatment A with relative growth 64.95% and feed efficiency 4.41, followed by treatment C (relative growth 40.97% and feed efficiency 2.73), Treatment D (relative growth 32.71%% and feed efficiency 2.23), and treatment B (relative growth 31.61% and feed efficiency 2.17). During the experiment, water temperature was 26-28oC and pH 7 which were suitable for growth and survival of eel seeds. As conclusion, the use of suspension food of kijing taiwan mussel resulted in the best relative growth and food efficiency. Keywords: elver, fish feed, mussel, growth, food efficiency