Set Of Seeds Research Articles

Hormonal Response of Gibberellin (Ga3), Grafting and Seasonal Variations on Growth and Yield Parameters on Okra (Abelmoschus Esculentus)

The effect of Gibberellin Hormonal Response and Grafting methods on the Growth and Yield of Okra was investigated, with the aim of inducing variability that could be exploited in the improvement of some quality traits in Okra plants. Gibberellin, grafting and a combination of grafting with Gibberellin) were applied on to the Okra seeds. The seeds of Okra were treated at four different concentrations of Gibberellin (0.1mM, 1.0 mM, 2.0 mM and 0.0 mM as control) after which some of the mutants were grafted using tongue grafting method at seedlings stage. The other set of seeds were not treated with the hormone but were grafted at seedlings stage. The results obtained revealed highly significant difference (P≤ 0.01) in the effects of Gibberellin on survival rates, number of fruits, and fruit weight. Similarly, highly significant differences (P≤0.01) were found between the treatments in Survival rate, except on the number of fruits and fruit weight, where no significant differences exist. More so, significant differences were found in the traits between the seasons except in fruit number. The result showed that Gibberellin and grafting improve important quality traits of Okra. The mutants and grafted Okra could be grown both during the rainy and dry seasons, while 0.1 mM concentration of Gibberellin and grafting improve some important quality traits of Okra that could be utilized for further improvement of Okra. However, the response of Okra to grafting was higher. Based on the findings, the study concluded that, grafting improves some important quality traits of Okra that are of high economic value and possible recommendations that could be made.

Hormonal Response of Gibberellin (Ga3), Grafting and Seasonal Variations on Growth and Yield Parameters on Okra (Abelmoschus Esculentus)

The effect of Gibberellin Hormonal Response and Grafting methods on the Growth and Yield of Okra was investigated, with the aim of inducing variability that could be exploited in the improvement of some quality traits in Okra plants. Gibberellin, grafting and a combination of grafting with Gibberellin) were applied on to the Okra seeds. The seeds of Okra were treated at four different concentrations of Gibberellin (0.1mM, 1.0 mM, 2.0 mM and 0.0 mM as control) after which some of the mutants were grafted using tongue grafting method at seedlings stage. The other set of seeds were not treated with the hormone but were grafted at seedlings stage. The results obtained revealed highly significant difference (P≤ 0.01) in the effects of Gibberellin on survival rates, number of fruits, and fruit weight. Similarly, highly significant differences (P≤0.01) were found between the treatments in Survival rate, except on the number of fruits and fruit weight, where no significant differences exist. More so, significant differences were found in the traits between the seasons except in fruit number. The result showed that Gibberellin and grafting improve important quality traits of Okra. The mutants and grafted Okra could be grown both during the rainy and dry seasons, while 0.1 mM concentration of Gibberellin and grafting improve some important quality traits of Okra that could be utilized for further improvement of Okra. However, the response of Okra to grafting was higher. Based on the findings, the study concluded that, grafting improves some important quality traits of Okra that are of high economic value and possible recommendations that could be made.

Application of a novel approach to modelling the supercritical extraction kinetics of oil from two sets of chia seeds

Application of a novel approach to modelling the supercritical extraction kinetics of oil from two sets of chia seeds

Application of a novel approach to modelling the supercritical extraction kinetics of oil from two sets of chia seeds

The kinetics of the supercritical fluid extraction of edible and discarded chia seeds was studied and modelled for the first time. The total oil was removed at 45 MPa and 60 °C after 240 min. The extraction kinetics was simulated using a dynamic model in gPROMS ModelBuilder environment and the kinetic parameters estimated. Triolein was chosen as a model compound of the chia oil. The agreement between the experimental yields and those calculated by the model was good with deviations in the range (1.2–6.6) %, except at 25 MPa and 60 °C (AARD = 9.5%).

The use of microorganisms as bio-fertilizers in the cultivation of white lupine

AbstractThe agricultural usability of bio-fertilizers, particularly including microbiological seed vaccines meet the recommendations for integrated protection/cultivation applicable in Poland. Combined vaccination seeds with Rhizobium bacteria together with endophitic bacteria from the group of Plant Growth Promoting Rhizobacteria (PGPR), increase the efficiency of biological nitrogen fixation and therefore stimulate the development and yielding of legume crops. This hypothesis was verified in a series of field experiments with white lupine conducted between 2016 and 2018 at Złotniki, Poland. The one-factor experiment consisted of different variants of inoculation including: seeds uninoculated, inoculated with nitragine, nitroflora, Pseudomonas fluorescens strain, Bacillus subtillis strain and seeds co-inoculated with Rhizobium from nitragine or nitroflora + Pseudomonas fluorescens, or + Bacillus subtillis. The experiment showed a positive response of white lupine to all tested seed vaccinations. The highest seed yield was found after seed inoculation with Rhizobium bacteria (from nitragine) and with co-inoculation Rhizobium with Pseudomonas fluorescens. The results indicated that plant height, the development of aboveground parts and roots as well as root nodules and the setting of pods and seeds on the plant increased significantly after seed co-inoculation of Rhizobium derived from the preparation of nitragine with Pseudomonas fluorescens, as compared to the control object without vaccination. A generally positive correlation was found between the number of root nodules, dry mass of nodules and yield, and an especially significant strength of this relationship was found in variant with co-inoculation Rhizobium with Pseudomonas fluorescens.

DIRECT ORGANOGENESIS OF STEVIA REBAUDIANA IN VITRO USING NODAL EXPLANTS

Stevia rebaudiana Bertoni is a medicinal herb belonging to the family ofAsteraceae. It is a natural sweetener plant, which is estimated to be 300 timessweeter than cane sugar. In this study, reliable protocol was developed for directorganogenesis of S. rebaudiana using in vitro derived nodal explants. Seeds werecollected from mother plants and they were surface sterilized. To optimize thesurface sterilization procedure, dark color (fertile seeds) seeds were surfacesterilized using different concentrations and in different exposure time ofcarbendazim and sodium hypochlorite (Clorox). Out of different combinations0.2% carbendazim for 5 minutes, 10% sodium hypochlorite for 10 minutes and70% ethanol each followed by two successive washings in sterile distilled waterwas found to be the best for surface sterilization. Two sets of seeds (fresh, stored)were cultured on MS basal medium supplemented with different concentrations ofGA3 for seed germination. According to the results seed viability was lost withtime and it affected seed germination. Seed germination was not affected by GA3,but seedling height was affected by it. Seeds germinated on MS mediumsupplemented with 3.0 mg/L GA3 showed the highest seedling height after 10days. MS basal medium supplemented with different concentrations of BAP andKin were tested for shoot bud and multiple shoot induction. Out of different mediaMs basal medium supplemented with 2.0 mg/L BAP was found to be the bestmedium for shoot bud and multiple shoot induction within 60 days.

Heat Stress in Legume Seed Setting: Effects, Causes, and Future Prospects.

Grain legumes provide a rich resource of plant nutrition to human diets and are vital for food security and sustainable cropping. Heat stress during flowering has a detrimental effect on legume seed yield, mainly due to irreversible loss of seed number. To start with, we provide an overview of the developmental and physiological basis of controlling seed setting in response to heat stress. It is shown that every single process of seed setting including male and female gametophyte development, fertilization, and early seed/fruit development is sensitive to heat stress, in particular male reproductive development in legume crops is especially susceptible. A series of physiochemical processes including heat shock proteins, antioxidants, metabolites, and hormones centered with sugar starvation are proposed to play a key role in regulating legume seed setting in response to heat stress. The exploration of the molecular mechanisms underlying reproductive heat tolerance is in its infancy. Medicago truncatula, with a small diploid genome, and well-established transformation system and molecular platforms, has become a valuable model for testing gene function that can be applied to advance the physiological and molecular understanding of legume reproductive heat tolerance.

SEED PRODUCTIVITY AND DEVELOPMENT OF PLANTLETS <i>POPULUS × JRTYSCHENSIS</i> CH. Y. YANG

The research explores the seed productivity and plantlets growth in the free pollination of the natural hybrid taxon P. × jrtyschensis. Fruits of P. × jrtyschensis were selected from four plants that grow in the collection ofResearchCenter“EducationalBotanical Garden” ofKemerovoStateUniversity. Four P. nigra model trees, randomly selected from theTomRiverfloodplain population, were applied as a control group. The authors used 30 fruit-bearing amentumsfrom each model. The researchers measured set of fruit (capsule); number of ovules per fruit; number of seeds per fruit; set of seeds.. Laboratory germination was determined by sowing Petri dishes on wet filter paper. The authors found out sowing germination by sowing 100 seeds in a box with soil and drainage. The energy of germination was determined on the second day while germination - on the fifth day. P. × jrtyschensis is characterized by a lower level of seed productivity (15-30%) compared to P. nigra. In terms of laboratory germination of seeds, the descendants of hybrids surpassed many P. nigra models, but their soil germination was 20-30% lower than that of black poplar. The observed variability in reproductive indices of both P. × jrtyschensis and P. nigra is mainly caused by specific features of their genotypes. Plantlets being developed, the authors observed no significant differences among the descendants of P. nigra and hybrids. The researchers highlighted plantlets that can stop growing and even more abnormal plants with one, three or four seeds in P. × jrtyschensis. This may be caused by underdevelopment of hypocotyl or germ root. The authors observed breaches in development of P. nigra just once. They outline high plantlets destruction when sowing hybrids on the first day after germination The share of destructed plants within a month (from the beginning of the experiment) reaches 66,0 %, and in P. nigra it does not exceed 40,0 %.

Effect of Sowing Dates on Fatty Acids and Phytosterols Patterns of Carthamus tinctorius L.

Field experiments were carried out at the Regional Centre of Experimentation in Organic agriculture at Auch (near Toulouse, South west of France). Due to the high potential applications for its oil components such as fatty acids and phytosterols, safflower (Carthamus tinctorius L.) is considered as an emerging crop. Safflower plants, as many other oil crops, are submitted to environmental stresses that modify seed composition. Nevertheless, few reports are available about the effects of environmental conditions on fatty acid and phytosterol compositions in safflower. Different rainfall supplies can be managed by delaying the sowing dates. In this study, fatty acid and phytosterol contents have been evaluated in safflower seeds cultivated at two sowing dates (conventional and late) that led to a differential of rainfall during seed development. At harvest, seeds were used for oil extraction. Fatty acid composition was performed by using GC-FID. A set of seeds was dehulled to separate the almond (embryo) and hull to release the extraction and measurement of sterol contents in the two compartments by GC-FID. A delay of sowing increased the content of all sterol categories but induced a significant decrease in fatty acids. The ratio of saturated to unsaturated fatty acids increased under a delaying sowing. The repartition of phytosterols was ¾ and ¼ of total sterols in the embryo and the hull, respectively. These results could make the use of hull (considered as waste) possible, help breeders to improve safflower oil composition and develop new industrial applications.

Social-Network-Assisted Worker Recruitment in Mobile Crowd Sensing

Worker recruitment is a crucial research problem in Mobile Crowd Sensing (MCS). While previous studies rely on a specified platform with a pre-assumed large user pool, this paper leverages the influence propagation on the social network to assist the MCS worker recruitment. We first select a subset of users on the social network as initial seeds and push MCS tasks to them. Then, influenced users who accept tasks are recruited as workers, and the ultimate goal is to maximize the coverage. Specifically, to select a near-optimal set of seeds, we propose two algorithms, named Basic-Selector and Fast-Selector, respectively. Basic-Selector adopts an iterative greedy process based on the predicted mobility, which has good performance but suffers from inefficiency concerns. To accelerate the selection, Fast-Selector is proposed, which is based on the interdependency of geographical positions among friends. Empirical studies on two real-world datasets verify that Fast-Selector achieves higher coverage than baseline methods under various settings, meanwhile, it is much more efficient than Basic-Selector while only sacrificing a slight fraction of the coverage.

Saliency detection via background prior and foreground seeds

As an image pre-processing technology, saliency detection (DS) can be used in a wide variety of visual tasks. A bottom-up method of DS via background prior and foreground seeds is proposed. To highlight the object and suppress the background noise, two saliency maps are obtained by using the background prior and foreground seeds. First, we use global colour and spatial distance matrices to compute a background saliency map. To evenly emphasize the saliency region, the single-layer cellular automata is used to refine the background-based saliency map. Second, a set of foreground seeds is obtained from the refined background-based saliency map. Then, the foreground-based saliency map is calculated based on the foreground seeds and refined by biased Gaussian filtering. The proposed method could emphasize the foreground target, as well as restrain the background noise. The experiment results show that our method has good ability in saliency detection.

LSSR1 facilitates seed setting rate by promoting fertilization in rice

Seed setting rate is one of the major components that determine rice (Oryza sativa L.) yield. Successful fertilization is necessary for normal seed setting. However, little is known about the molecular mechanisms governing this process. In this study, we report a novel rice gene, LOW SEED SETTING RATE1 (LSSR1), which regulates the seed setting rate by facilitating rice fertilization. LSSR1 encodes a putative GH5 cellulase, which is highly conserved in plants. LSSR1 is predominantly expressed in anthers during the microsporogenesis stage, and its encoded protein contains a signal peptide at the N-terminal, which may be a secretory protein that stores in pollen grains and functions during rice fertilization. To explore the physiological function of LSSR1 in rice, loss-of-function mutants of LSSR1 were created through the CRISPR-Cas9 system, which showed a significant decrease in rice seed setting rate. However, the morphology of the vegetative and reproductive organs appears normal in lssr1 mutant lines. In addition, lssr1 pollen grains could be normally stained by I2-KI solution. Cytological results demonstrate that the blockage of fertilization mostly accounted for the low seed setting rate in lssr1 mutant lines, which was most likely caused by abnormal pollen grain germination, failed pollen tube penetration, and retarded pollen tube elongation. Together, our results suggest that LSSR1 plays an important role in rice fertilization, which in turn is vital for maintaining rice seed setting rate.

Coverage-Based Greybox Fuzzing as Markov Chain

Coverage-based Greybox Fuzzing (CGF) is a random testing approach that requires no program analysis. A new test is generated by slightly mutating a seed input. If the test exercises a new and interesting path, it is added to the set of seeds; otherwise, it is discarded. We observe that most tests exercise the same few “high-frequency” paths and develop strategies to explore significantly more paths with the same number of tests by gravitating towards low-frequency paths. We explain the challenges and opportunities of CGF using a Markov chain model which specifies the probability that fuzzing the seed that exercises path $i$ i generates an input that exercises path $j$ j . Each state (i.e., seed) has an energy that specifies the number of inputs to be generated from that seed. We show that CGF is considerably more efficient if energy is inversely proportional to the density of the stationary distribution and increases monotonically every time that seed is chosen. Energy is controlled with a power schedule. We implemented several schedules by extending AFL. In 24 hours, AFLFast exposes 3 previously unreported CVEs that are not exposed by AFL and exposes 6 previously unreported CVEs 7x faster than AFL. AFLFast produces at least an order of magnitude more unique crashes than AFL. We compared AFLFast to the symbolic executor Klee. In terms of vulnerability detection, AFLFast is significantly more effective than Klee on the same subject programs that were discussed in the original Klee paper. In terms of code coverage, AFLFast only slightly outperforms Klee while a combination of both tools achieves best results by mitigating the individual weaknesses.

Quantifying the Impact of Heat Stress on Pollen Germination, Seed Set, and Grain Filling in Spring Wheat

Exposure to temperatures ≥30°C during flowering and grain filling stages can negatively affect seed set and seed weight in spring wheat (Triticum aestivum L.). The screening of a large set of germplasm under hot wheat growing environments (Indo‐Gangetic Plain in India) led to the identification of promising heat‐tolerant genotypes. The selected set of 28 diverse spring wheat genotypes were exposed to heat stress (34/16°C day/night temperatures) for 10 d during flowering and for 30 d during grain filling to quantify genetic variability in pollen germination, photosynthesis, and yield parameters under controlled‐environment conditions. Pollen grains collected immediately at anthesis (between 0530 and 0630 h) were incubated on liquid in vitro pollen germination media. Averaged across wheat genotypes, a significant reduction in pollen germination (39.9%, P < 0.001) was recorded from plants exposed to heat stress. Heat stress for 10 d during flowering induced significant reduction in seed number (15.4 and 23.0%) and seed weight (32.3 and 34.6%) on main and primary spikes, respectively, compared with the control. Heat stress during grain filling had a more pronounced impact on seed weight (16 and 22%) than seed number (2.7 and 9.3%) in main and primary spikes, respectively. Genotypes KSG025 and KSG1214 with higher seed number, seed weight, and harvest index and appreciable pollen germination under heat stress were identified as candidate donors for simultaneously enhancing flowering and post‐flowering heat tolerance in spring wheat.

Aspects of the population biology, life history and threats to Aloe ortholopha Christian and Milne-Redh.: A serpentine endemic from the northern Great Dyke of Zimbabwe

Background: Aloe ortholopha is a rare endemic confined to serpentine soils of the Great Dyke of Zimbabwe. Its International Union for Conservation of Nature (IUCN) status is listed as Vulnerable; however, its population biology and life history are poorly documented.Objectives: The aim of this article is to provide information on the population biology and life history of A. ortholopha through assessment of its size-class distribution, population size and density, reproductive output and fitness, and threats related to fire and mining.Method: Circumference of A. ortholopha leaf rosette was used to ascertain size-class distribution. Population size and density were determined by enumerating flowering individuals. Per-capita reproductive output was determined as mean number of flowers per plant, fruit set and mean number of seeds per fruit. Fitness was determined from seed germination capacity. Impact of fire and mining were recorded photographically.Results: Determination of size-class distribution of A. ortholopha from three study sites (southern region [SR], central region [CR] and northern region [NR]) revealed a bell-shaped curve dominated by intermediate size classes. Population size (number of flowering individuals) ranged from 36 to 66 per site. This translated to a density of 4.0–7.3 flowering plants per hectare. Per-capita reproductive output, measured as mean number of flowers per plant, was significantly different in SR and CR compared to that in the NR region. Mean number of fruits per plant did not significantly differ across the three regions. Mean seed set per plant in CR and NR was significantly different to that in the SR region. Species fitness, as determined from in vitro germination assays, showed that seeds harvested from fire-damaged capsules have the lowest cumulative germination percentage. It was also observed that leaf rosettes curled up to form a ball that protects the apical centre of plants from fire damage.Conclusion: A. ortholopha occurs in small population clusters of low density. The species has a low per-capita reproductive output characterised by production of many flowers, but with very low percentage fruit and seed set. The species has low fitness as evidenced by nominal recruitment of saplings and juveniles. Conspecific mates are frequently lost owing to fire and mining activities.

Non-vernalization Flowering and Seed Set of Cabbage Induced by Grafting Onto Radish Rootstocks.

Cabbage (Brassica oleracea var. capitata) requires a long-term low-temperature exposure for floral induction, causing a delay in the breeding cycle. The objective of this study is to develop a method to induce flowering in cabbage without low-temperature treatment, using a grafting method. We conducted grafting experiments using two flower-induced Chinese kale cultivars (B. oleracea var. alboglabra) and seven radish cultivars/accessions as rootstocks and investigated the flowering response of grafted cabbage scions without low-temperature treatment. “Watanabe-seiko No.1” cabbage, when grafted onto the two Chinese kale cultivars, did not formed flower buds. Flowering was successfully induced in “Watanabe-seiko No.1” by grafting onto three out of the seven tested radish cultivars, and in “Kinkei No.201” and “Red cabbage” by grafting onto one tested radish cultivar. In “Watanabe-seiko No.1,” the earliest flower bud appearance was observed at 29 days after grafting. Seeds were also obtained from the three cabbage cultivars that flowered by grafting. Gene expression analysis of “Watanabe-seiko No.1” cabbage scions which formed flower buds by grafting, revealed high expression of the homolog of the floral integrator, SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (BoSOC1), at the time of flower bud appearance. However, in the same leaf samples, we observed low expression of two homologs of florigen, FLOWERING LOCUS T (BoFT.C2 and BoFT.C6). In addition, two homologs of the floral repressor FLOWERING LOCUS C (BoFLC3 and BoFLC4), which are known to be down-regulated before flower bud differentiation in the vernalization pathway, were highly expressed, indicating that grafting onto radish induces cabbage flowering independently of the vernalization pathway. The expression level of the radish FT homolog (RsFT) in “Rat’s tail-G2,” which had highly induced flowering in the grafted cabbage scion, was higher than in the other radish cultivars. However, although “Rat’s tail-CH” effectively induced flowering in the cabbage scion, the expression of RsFT was low in this cultivar. In this study, floral induction of non-vernalized cabbage cannot be explained by the expression levels of RsFT in rootstock plants, alone. The flowering of non-vernalized cabbage would be induced by transmissible agents from rootstocks and not by the expression of cabbage FT, BoFT, from the scion itself.

Design and study of seeding devices for small selection seeding machines

In this paper, it is proposed to use a self-propelled pneumatic mini-seeder with replaceable mechanical sowing devices designed and manufactured using computer technologies, advanced software and threedimensional printing for seeds selection. As a result of the research, hightech operating devices for a grain-drill feed with screw and disk-pin continuous seed metering are designed and manufactured. Grain-drill feeds allow sowing of free-flowing and non-free-flowing seeds, when used as seed meters on self-propelled pneumatic mini-seeders for selection sowing of grass seeds. Analysis of laboratory results of and field studies of the proposed grain-drill feeds allowed to determine the qualitative indicators of their performance: at a disk rotation speed of up to 15 rpm a linear dependence of the seed supply on the rotation frequency is provided; in the field studies, the instability of bluegrass seeding did not exceed 8%. The highest performance of the screw is obtained at the angle of choke inclination of 30...35 degrees with the seeding instability indicator of 2.5...3.5%. The developed grain-drill feed will significantly reduce the range of seeders and expand the set of sown seeds of various agricultural plants with one brand of a grain-drill feed.

Effect of chromium on germination in some crops of India.

Industrial development and scientific advancement has contaminated the environment, as a result one of the major pollutants in the environment are heavy metals and their introduction in air, water and agricultural soil. In recent years, chromium has become a major environmental pollutant as it widely used in making alloys, electroplating of stainless steel, production of pigments. Many studies have been carried out on heavy metals to understand their detrimental effects in the ecosystem. In the present study, Chromium was selected to find out its harmful effects on seed germination and seedling growth of Vigna radiata L, Trigonella foenum-graceum L, Oryza sativa L, Sorghum vulgare L and Pennisetum glaucum L. Seeds of the selected plants were grown in petri dishes and treated with varying concentrations of Chromium solution. Each treatment was replicated in a randomised design and observed for 7 days. The developing seedlings were studied for their total rate of germination, seed vigour index, length of radicle, length of plumule and fresh weight compared to a set of seeds germinated using distilled water as control. It was observed that the harmful effects of chromium on all the parameters were directly proportional to the concentration of solution employed, with the inhibition of growth being pronounced from 50 ppm onwards. Based on the response of the plants the toxic effect of chromium was seen in the following order, Trigonella foenum-graceum L>Oryza sativa L>Pennisetum glaucum L>Sorghum vulgare L>Vigna radiata L.

BREEDING CHARACTERISTICS OF PERENNIAL FORMS OF INTERSPECIFIC HYBRIDS OF ALLIUMS

In breeding programs agriculture, interspecies hybridization is an important tool for creating a genetically updated source material in the breeding of varieties. The material consisted of perennial plants of interspecific hybrids of onions BC2(F3-5(A. cepa x A. fistulosum)), BC1(F1-5(A. cepa x A. vavilovii)), F5(A. cepa x A. altaicum) and their inbred offspring. As standard on biometrics and the susceptibility of plants with downy mildew used a variety of onion Odintsovets, as this grade participated in the conduct of the saturating crosses of onion and perennial species A. fistulosum L., A. altaicum Pall. Field experiments were carried out according to the standard technique in conditions of the Moscow region at the experimental base of FSBSI FSVC. Based on the results of the research highlighted in the form of combinations of the cross A. cepa x A. vavilovii and A. cepa x A. fistulosum and A. cepa x A. altaicum interest to breeding in number of leaves, length of leaves, number of seedstalks, the height of the seedstalks, high fertility and relatively high resistance to Peronospora destructor. Forms combination of the cross A. cepa x A. vavilovii was characterized by uniformity the number of seedstalks (5-7 PCs), the height of the seedstalks (96 cm) and resistance to downy mildew (1.0-1.5 score). Forms combination of the cross A. cepa x A. fistulosum stood uniformity by the number of seedstalks (5 PCs), the height of the seedstalks (85-96 cm), resistance to downy mildew (1.0-1.5 score) and a high fertility rate (over 60%). On the basis of the company "regrowth – mass setting of seeds" in each combination of mating types was allocated a separate form, which was distinguished by precocity: BC1(F5(A. cepa x A. vavilovii)) (86 days), BC2(F5(A. cepa x A. fistulosum)) (63 days), I1F5(A. cepa x A. altaicum) (61 days).

Layered fields for natural tessellations on surfaces

Mimicking natural tessellation patterns is a fascinating multi-disciplinary problem. Geometric methods aiming at reproducing such partitions on surface meshes are commonly based on the Voronoi model and its variants, and are often faced with challenging issues such as metric estimation, geometric, topological complications, and most critically, parallelization. In this paper, we introduce an alternate model which may be of value for resolving these issues. We drop the assumption that regions need to be separated by lines. Instead, we regard region boundaries as narrow bands and we model the partition as a set of smooth functions layered over the surface. Given an initial set of seeds or regions, the partition emerges as the solution of a time dependent set of partial differential equations describing concurrently evolving fronts on the surface. Our solution does not require geodesic estimation, elaborate numerical solvers, or complicated bookkeeping data structures. The cost per time-iteration is dominated by the multiplication and addition of two sparse matrices. Extension of our approach in a Lloyd's algorithm fashion can be easily achieved and the extraction of the dual mesh can be conveniently preformed in parallel through matrix algebra. As our approach relies mainly on basic linear algebra kernels, it lends itself to efficient implementation on modern graphics hardware.