Bulb Development Research Articles

Onions Selected for Reduced Symptom Expression of Iris Yellow Spot Have Higher Photosynthetic Rates

Bulb onion (Allium cepa L.) is an economically valuable vegetable crop in the United States. Onion production is threatened by onion thrips, which are the vector for Iris yellow spot virus, which is the causal agent of Iris yellow spot (IYS). New Mexico State University (NMSU) breeding lines 12-236, 12-238, 12-243, and 12-337 have exhibited fewer IYS disease symptoms in the field; however, little is known about the effects of the disease on the photosynthesis rate (Pn). We hypothesized that these NMSU breeding lines would have a higher Pn than IYS-susceptible cultivars Rumba and Stockton Early Yellow. To test this hypothesis, a field study was conducted for 3 years at NMSU, and Pn was measured five times throughout each season at 2-week intervals. During bulb development and maturation, which occurred at 10 and 12 weeks after transplanting, all NMSU breeding lines exhibited a higher Pn when compared with that of an IYS-susceptible cultivar. Pn was highest at the end of the vegetative growth stage and decreased as bulbs approached maturation for all cultivars. Additionally, a high Pn at 10 and 12 weeks after transplanting coincided with high bulb weight at harvest. NMSU breeding lines have increased Pn compared with that of IYS-susceptible cultivars and resulted in larger and more marketable bulbs. These results indicate that maintaining Pn may be related to reduced IYS symptom expression of onion.

LhANS-rr1, LhDFR, and LhMYB114 Regulate Anthocyanin Biosynthesis in Flower Buds of Lilium 'Siberia'.

The bulb formation of Lilium is affected by many physiological and biochemical phenomena, including flower bud differentiation, starch and sucrose accumulation, photoperiod, carbon fixation, plant hormone transduction, etc. The transcriptome analysis of flower buds of Lilium hybrid 'Siberia' at different maturity stages showed that floral bud formation is associated with the accumulation of anthocyanins. The results of HPLC-MS showed that cyanidin is the major anthocyanin found in Lilium 'Siberia'. Transcriptome KEGG enrichment analysis and qRT-PCR validation showed that two genes related to flavonoid biosynthesis (LhANS-rr1 and LhDFR) were significantly up-regulated. The functional analysis of differential genes revealed that LhMYB114 was directly related to anthocyanin accumulation among 19 MYB transcription factors. Furthermore, the qRT-PCR results suggested that their expression patterns were very similar at different developmental stages of the lily bulbs. Virus-induced gene silencing (VIGS) revealed that down-regulation of LhANS-rr1, LhDFR, and LhMYB114 could directly lead to a decrease in anthocyanin accumulation, turning the purple phenotype into a white color. Moreover, this is the first report to reveal that LhMYB114 can regulate anthocyanin accumulation at the mature stage of lily bulbs. The accumulation of anthocyanins is an important sign of lily maturity. Therefore, these findings have laid a solid theoretical foundation for further discussion on lily bulb development in the future.

Transcriptomic and metabolomic analyses provide new insights into the appropriate harvest period in regenerated bulbs of Fritillaria hupehensis.

The bulb of Fritillaria hupehensis, a traditional cough and expectorant medicine, is usually harvested from June to September according to traditional cultivation experience, without practical scientific guidance. Although steroidal alkaloid metabolites have been identified in F. hupehensis, the dynamic changes in their levels during bulb development and their molecular regulatory mechanisms are poorly understood. In this study, integrative analyses of the bulbus phenotype, bioactive chemical investigations, and metabolome and transcriptome profiles were performed to systematically explore the variations in steroidal alkaloid metabolite levels and identify the genes modulating their accumulation and the corresponding regulatory mechanisms. The results showed that weight, size, and total alkaloid content of the regenerated bulbs reached a maximum at IM03 (post-withering stage, early July), whereas peiminine content reached a maximum at IM02 (withering stage, early June). There were no significant differences between IM02 and IM03, indicating that regenerated bulbs could be harvested appropriately in early June or July. Peiminine, peimine, tortifoline, hupehenine, korseveramine, delafrine, hericenone N-oxide, korseveridine, puqiedinone, pingbeinone, puqienine B, puqienine E, pingbeimine A, jervine, and ussuriedine levels were upregulated in IM02 and IM03, compared with IM01 (vigorous growth stage, early April). The Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that the accumulation of steroidal alkaloid metabolites mainly occurred prior to IM02. HMGR1, DXR, CAS1, CYP 90A1, and DET2 may play a positive role in peiminine, peimine, hupehenine, korseveramine, korseveridine, hericenone N-oxide, puqiedinone, delafrine, tortifoline, pingbeinone, puqienine B, puqienine E, pingbeimine A, jervine, and ussuriedine biosynthesis, whereas the downregulation of FPS1, SQE and 17-DHCR may lead to a reduction in peimisine levels. Weighted gene correlation network analysis showed that CYP 74A2-1, CYP 74A2-2, CYP 71A26-1, CYP 71A26-2, and CYP74A were negatively correlated with peiminine and pingbeimine A, whereas CYP R and CYP707A1 were positively correlated. . CYP 74A2-1 and CYP 74A2-2 may play a negative role in peimine and korseveridine biosynthesis, whereas CYP R plays a positive role. In addition, the highly expressed C2H2, HSF, AP2/ERF, HB, GRAS, C3H, NAC, MYB-related transcription factors (TFs), GARP-G2-like TFs, and WRKY may play positive roles in the accumulation of peiminine, peimine, korseveridine, and pingbeimine A. These results provide new insights into scientific harvesting of F. hupehensis.

Nitrogen Nutrition Affect the Growth and Bulb Yield of Garlic (Allium Sativum L.)

Nitrogen (N) is one of the critical nutrients for productivity and quality of cultivated crop species. However, its overused in crop cultivation caused several environmental concerns. Hence its proper use in agriculture is not only pre-requisite for sustainable crop cultivation but also necessary to control environmental pollution. A field trial was designed at experimental area of Department of Horticulture, Sindh Agriculture university Tando Jam, Pakistanto test the response of garlic varietiesto N nutrition in terms of growth and bulb attributed traits during the winter season, 2020-21. The N effect on growth and yield associated traits of two garlic varieties (local white and purple top) were investigated by applying four Nrates that included 0, 50 kg, 100 kg and 150 kg ha-1. The findings of the trial exhibitedthat N application at various rates had substantial positiveimpact on the growth and bulb development of garlic at (P<0.05). The garlic plantation receivedNat maximum rate (150 kg ha-1) resulted tallest plants,better neck thicknesswith more leaves plant-1. The N also positively affected the bulb yield and other yield parameters of garlic.The maximum bulb yield was obtained when plants were nourished with 150 Kg N ha-1that was 381.98 % more than the control. It was noted that increase inN rates was statistically dominant over other doses. The varietal influence on garlic indicated that variety purple top performed better than local white in terms of yield associated traits..These findings provide new insight regarding the significance of N nutrition in improving the growth and bulb yield of garlic genotypes

Assessment of permafrost disturbances caused by two parallel buried warm-oil pipelines: A case study at a high-latitude wetland site in Northeast China

Multiple studies demonstrate that narrow-linear strong disturbances triggered by pipeline engineering activities have resulted in rapid permafrost degradation. However, the extent, duration, and severity of permafrost disturbances induced by two parallel buried warm-oil pipelines remain unclear. Here, we examine the thermal disturbances of the China-Russia crude oil pipelines (CRCOPs I and II) on the surrounding permafrost. Ground temperature measurements on and off the right-of-way of the CRCOPs and an electrical resistivity tomography survey were conducted at a selected high-latitude wetland site in northeastern China. The observations showed that warm oil flow in pipelines dissipated heat to the surrounding soil, resulting in the thawing of underlying permafrost accompanied by the formation and development of thaw bulbs around the pipes. Currently, the thaw bulb of CRCOP-I was about four times as large as that of CRCOP-II, mainly due to the longer 7-year working duration of CRCOP-I. To quantify the permafrost disturbances around the pipeline, a conductive heat transfer model was established. A numerical simulation of the soil thermal regime around the pipeline suggested the initial growth of the thaw bulb was quite fast but gradually slowed with time, of which the shape was modified to ellipse from a semicircle. The existence of CRCOP-II would accelerate the warming of permafrost on the CRCOP-I right-of-way due to the small separation distance between them. We expect that the thaw bulbs of the two pipelines will expand larger than previously estimated due to the adverse effects of pipeline settlement and surface water flow, sparking a wider permafrost disturbance.

Metabolomics and transcriptomics analyses provides insights into S-alk(en)yl cysteine sulfoxides (CSOs) accumulation in onion (Allium cepa)

Primary and secondary metabolites are responsible for the nutritional value of onions. S-Alk(en)ylcysteine sulfoxides (CSOs) are the precursors of onion flavour and medicinal components. The purpose of this study was to investigate the dynamics in metabolites and CSOs biosynthesis during onion bulb expansion by conducting metabolomic and transcriptomic analyses. A total of 633 metabolites were detected in SA1. Lipids, flavonoids and amino acids mainly accumulated in the rapid-expansion stage of onion bulb, whereas alkaloids and phenolic acids accumulated in the late stage of bulb expansion. The concentration of S-methylcysteine sulfoxide (MCSO) was increased in SA1 during onion bulb development, however, there was no significant changes in S-propylcysteine sulfoxide (PeCSO) and S-allylcysteine sulfoxide (ACSO). Candidate genes involving in CSOs biosynthesis were screened by RNA-Seq. Two AcSULTRs and AcCSs, a AcATPS, AcSAT, AcGL, AcGS, AcGGT and AcFMO might play core roles in CSOs biosynthesis. The results offer a theoretical basis for determining the regulation of organosulfur compound synthesis in onion.

Cloning and prokaryotic expression of FcLEA-D29 gene of Fritillaria cirrhosa

Fritillaria cirrhosa, the most valuable source of the precious Chinese medicinal material Fritillariae Cirrhosae Bulbus, suffers from various stresses during growth which influence the yield and quality of the medicinal part. This study aims to explore the genes related to stress resistance in this medicinal species. To be specific, based on the transcriptome data of F. cirrhosa, a gene encoding the late embryogenesis abundant(LEA) protein was obtained, which was named as FcLEA-D29. The gene sequence and protein structure were analyzed with bioinformatics methods and qRT-PCR was used to detect the expression of the gene in different tissues and in response to temperature stress. The low-temperature tolerance of FcLEA-D29 was verified by the prokaryotic expression system. The results showed that FcLEA-D29 contained an open reading frame of 777 bp, encoding 258 amino acids. Multiple sequence alignment revealed that FcLEA-D29 protein belonged to LEA-D29 subfamily of LEA3 family. qRT-PCR results showed that FcLEA-D29 was specifically expressed in bulbs and responded to low temperature. The strain with the recombinant plasmid demonstrated better growth status than the control strain in the instance of low temperature stress, suggesting that FcLEA-D29 may play a role in bulb development and low temperature response of F. cirrhosa. This study laid a basis for further research on the role of FcLEA-D29 in the accumulation of secondary metabolites in F. cirrhosa, especially alkaloids, under low temperature and provided evidence for the low-temperature adaptation of F. cirrhosa.

LoSWEET14, a Sugar Transporter in Lily, Is Regulated by Transcription Factor LoABF2 to Participate in the ABA Signaling Pathway and Enhance Tolerance to Multiple Abiotic Stresses in Tobacco

Sugar transport and distribution plays an important role in lily bulb development and resistance to abiotic stresses. In this study, a member of the Sugar Will Eventually be Exported Transporters (SWEET) gene family, LoSWEET14, from Oriental hybrid lily 'Sorbonne' was identified. LoSWEET14 encodes a protein of 278 amino acids and is capable of transporting sucrose and some types of hexoses. The transcript level of the LoSWEET14 gene was significantly increased under various stress conditions including drought, cold, salt stresses, and abscisic acid (ABA) treatment. Overexpression of LoSWEET14 in tobacco (Nicotiana tabacum) showed that the transgenic lines had larger leaves, accumulated more soluble sugars, and were more resistant to drought, cold, and salt stresses, while becoming more sensitive to ABA compared with wild-type lines. Promoter analysis revealed that multiple stress-related cis-acting elements were found in the promoter of LoSWEET14. According to the distribution of cis-acting elements, different lengths of 5'-deletion fragments were constructed and the LoSWEET14-pro3(-540 bp) was found to be able to drive GUS gene expression in response to abiotic stresses and ABA treatment. Furthermore, a yeast one hybrid (Y1H) assay proved that the AREB/ABF (ABRE-binding protein/ABRE-binding factor) from lilies (LoABF2) could bind to the promoter of LoSWEET14. These findings indicated that LoSWEET14 is induced by LoABF2 to participate in the ABA signaling pathway to promote soluble sugar accumulation in response to multiple abiotic stresses.

Evolutionary Conservation and Transcriptome Analyses Attribute Perenniality and Flowering to Day-Length Responsive Genes in Bulbous Barley (Hordeum bulbosum).

Rapid population growth and dramatic climatic turnovers are challenging global crop production. These challenges are spurring plant breeders to enhance adaptation and sustainability of major crops. One intriguing approach is to turn annual systems into perennial ones, yet long-term classical breeding efforts to induce perenniality have achieved limited success. Here, we report the results of our investigation of the genetic basis of bulb formation in the nonmodel organism Hordeum bulbosum, a perennial species closely related to barley. To identify candidate genes that regulate bulb formation in H. bulbosum, we applied two complementary approaches. First, we explored the evolutionary conservation of expressed genes among annual Poaceae species. Next, we assembled a reference transcriptome for H. bulbosum and conducted a differential expression (DE) analysis before and after stimulating bulb initiation. Low conservation was identified in genes related to perenniality in H. bulbosum compared with other species, including bulb development and sugar accumulation genes. We also inspected these genes using a DE analysis, which enabled identification of additional genes responsible for bulb initiation and flowering regulation. We propose a molecular model for the regulation of bulb formation involving storage organ development and starch biosynthesis genes. The high conservation observed along a major part of the pathway between H. bulbosum and barley suggests a potential for the application of biotechnological techniques to accelerate breeding toward perenniality in barley.

Bulb development in garlic – a review

ABSTRACT Many factors including cold conditioning, temperature, photoperiod, plant population, clove weight, soil nutrients, irrigation, plant growth regulators, and genetic responses influence bulb development in garlic. Garlic produces poor bulbs in warm and short-day conditions but cool and long-days induce flowering. Bulbs exposed before planting from 0° to 10°C for 8 weeks accelerate growth as the low temperatures modify the hormonal balance. Large cloves (>2–4 g) yield heavier bulbs than small (1–2 g) cloves. Plant population has an impact on bulb size: the higher the plant population, the smaller the bulb size. Garlic is sensitive to moisture stress especially during bulb initiation and development. Depending upon cultivar, soil type, and fertility status, NPK fertilisation for enhancement of bulb yield varies from 60–200, 20–75, and 40–166 kg ha−1, respectively. Low-temperature pre-treatment (4°C) increases salicylic acid (SA) concentration in the leaf sheath and enhances bulbing. Injecting garlic plants with gibberellin (GA3) solution increases clove number per bulb. Like onion, flowering and bulb formation in garlic are controlled by different (Flowering Locus T) FT genes. Two antagonistic FT-like genes regulate bulb formation. AsFT1 enhances bulb formation, while AsFT4 prevents AsFT1 up-regulation and inhibits bulbing.

Morphophysiological and productive changes of onion under vitamin application

Studies have been developed to improve cultivation conditions through the introduction of beneficial compounds, among which are vitamins. The present work aimed to investigate the effects of the application of vitamins in the onion crop. For that, five treatments were used, composed of different vitamins (ascorbic acid, thiamine, niacin and pyridoxine), in a concentration of 100 mg L-¹ and a control treatment, with water application, via foliar spray. The characteristics of chlorophyll relative index, number of plant leaves, plant height, fresh leaf mass, leaf dry mass, bulb diameter, bulb mass and bulb yield were evaluated. It was found that the application of ascorbic acid and pyridoxine increased the relative levels of chlorophyll concerning the control treatment and those composed by the application of niacin and thiamine. In addition, for liquid photosynthesis, a superior result was shown when niacin and thiamine were applied, concerning the other treatments. It was concluded that the exogenous application of vitamins alters the physiological and developmental behavior of onion plants, but does not positively affect bulb yield. The increases in photosynthetic activity were not reversed in bulb development, but in the elongation of plant leaves. Finally, the use of the vitamins studied for onion cultivation is not recommended, under conditions similar to those of the present study.

The starch-sugar interconversion mechanism during bulb development of Cardiocrinum giganteum (Wall.) Makino revealed by transcriptome and metabolite analysis

Cardiocrinum giganteum bulbs are rich in starch and natural compounds that benefit health. To better utilize the bulb starch of C. giganteum as an edible resource, understanding of the kinetics of starch and sucrose accumulation as well as the involved metabolic pathways in different developmental stages of the bulbs are required. In this study, we compared the dynamic changes in the transcriptomes and metabolomes of the bulbs over different developmental stages. A total of 43,692 differentially expressed genes and 508 metabolites were identified, which were clustered into nine co-expression clusters based on biological functions. Starch and sucrose metabolic pathways were identified at both the transcriptome and metabolome levels, revealing that activating the pathways of starch synthesis as well as sucrose synthesis and hydrolysis could be main conversion modes in starch-sugar interconversion. The data showed that the starch synthesis genes GBSS, SS3, GBE and ISA were expressed to highest levels at the stage of three-four years of C. giganteum development (c3y-c4y), concomitantly with the highest starch contents in this period. This revealed that the starch from the developing bulbs is optimally harvested at this stage. Meanwhile, sucrose synthesis genes were active and sucrose metabolites were maintained in balance during this stage, providing carbohydrate resources for starch biosynthesis. In the four-five year stage of development (c4y-c5y), the contents of sucrose metabolites increased, starch synthesis slowed down and sucrose hydrolysis genes were activated. Moreover, qRT-PCR analysis showed that the temporal expression patterns of starch and sucrose biosynthesis genes were largely consistent with the RNA-seq results. Taken together, these findings provide important information on the regulatory mechanisms of starch-sugar interconversion during C. giganteum bulb development.

Phenological growth stage of tropical shallot (Allium cepa L. Aggregatum group) planted from seed in lowland area based on the BBCH scale

AbstractShallot (Allium cepa L. Aggregatum group) is an important Allium plant commonly grown in tropical countries, including Indonesia, and it is used as spice for daily cooking, medicine, cosmetics and dietary supplements. Since shallot is predominantly propagated vegetatively by bulbs, it augments pathogen accumulation which influences low seed bulb management as well as productivity. Hence, utilisation of seeds/True Seed Shallot (TSS) emerges an alternative propagation material. However, no information is available on the growth stages of shallot plants from TSS. The phenological growth stages of tropical shallot planted in lowland areas using seeds in accordance with the Biologische Bundesanstalt, Bundessortenamt nd CHemische Industrie (BBCH) scale are first described here. Five introduced TSS cultivars, that is, Tuk Tuk, Lokananta, Sanren, Maserati, Tropix and four landraces TSS cultivars, that is, Bima, Biru Lancor, Pancasona and Trisula, were used as planting materials to develop an extended numerical BBCH scale for the identification of different phenological growth stages of shallot from seed. The study was conducted in lowland areas under tropical conditions of Indonesia. Based on BBCH scale, phenology of tropical shallot from seed in lowland area exhibited five of the 10 principal stages (0–9): germination (stage 0), leaf development (stage 1), formation of lateral shoot/tiller of pseudostem (stage 2), development of bulb (harvestable vegetative part) (stage 4), and senescence (stage 9). The codification of the different growth stages is essential in determination of the correct timing for better crop management, particularly for transplanting, fertilisation, control of weeds, disease and pest, plant growth regulators application and harvest time. As an implication, these BBCH scales could be used in plant breeding activities to shorten the TSS life cycle.

Isolated Congenital Anosmia: Case Report and Literature Review.

Isolated congenital anosmia (ICA) is a rare entity worldwide with poorly understood genetic variation. The diagnosis of ICA is made by exclusion of acquired causes of anosmia. Additionally, magnetic resonance imaging in ICA is essential for diagnosis, as it shows reduced or absent development of olfactory bulbs and shallow olfactory sulci. Here, we present the case of a 21-year-old man who presented to our clinic with complete anosmia since birth. The patient's history was negative for acquired causes of anosmia, and the physical examinations of the ears, nose, throat, head, and neck were all not remarkable. Smell testing revealed complete anosmia. The CT imaging was unremarkable; however, magnetic resonance imaging of the anterior brain and olfactory region showed bilaterally absent olfactory bulbs and olfactory tracts, with a shallow olfactory groove. The patient was then subjected to whole exome sequencing. Bioinformatics analysis was performed on the 37 genes associated with olfactory dysfunction, in which a missense variant was identified in the HS6ST1(NM_004807.3) gene was identified, which insilico tools predicted to be likely pathogenic. The results of this patient's genetic analysis add to the possible genetic culprits reported in ICA cases. Additional genetic analyses are required to validate mutations and understand the heterogeneity of disease representation.

Olfactory Radioanatomical Findings in Patients With Cardiac Arrhythmias, COVID-19, and Healthy Controls.

BackgroundClinical hyposmia and anosmia are commonly seen, most frequently with either post-inflammatory, age-related, or idiopathic causes being most frequent. Actual anatomical abnormalities of the olfactory groove or olfactory bulb are far less common. A recent case report showing a possible link between congenital olfactory bulb agenesis and Wolff-Parkinson-White syndrome suggested that there may be a relationship between cardiac arrhythmia and olfactory bulb development. While Kallmann syndrome (KS) is the classic syndrome involving olfactory bulb agenesis and hypogonadotropic hypogonadism, this case report and a prior report noting isolated hypogonadotropic hypogonadism and the Wolff-Parkinson-White syndrome suggest there may be more rare associations between cardiac arrhythmia and olfactory groove abnormalities.MethodsA retrospective study was conducted to attempt to elucidate whether there may be a link between cardiac arrhythmias and olfactory anatomical abnormalities. The olfactory bulb volume (OBV) and olfactory sulcus depth (OSD) of 44 patients with cardiac arrhythmias were compared to 43 healthy control patients. Additionally, 11 patients with acute COVID-19 were also compared in those groups. Patients were seen between September and December 2020. Available MRI images were utilized.ResultsThe average right and left olfactory bulb volume was 29.42±18.17 mm3 and 25.67±15.29 mm3 for patients with cardiac arrhythmia, 40.79±30.65 mm3 and 38.95±21.87mm3 for healthy controls, and 21.30±15.23 mm3 and 17.75±9.63 mm3 for COVID-19 patients. The average right and left olfactory sulcus depth was 7.68±1.31 mm and 7.47±1.56 mm for patients with cardiac arrhythmia, 10.67±1.53 mm and 10.62±1.67 mm for controls, and 7.91±0.99 mm and 8.02±0.88 mm for COVID-19 patients. The right and left olfactory bulb volume difference versus controls was significant for cardiac arrhythmia patients (p=0.028 and p=0.0038) and for COVID-19 patients (p=0.047 and p=0.0029), and the right and left olfactory sulcus depth difference versus controls was significant for cardiac arrhythmia patients (p<0.0001 and p<0.0001) and for COVID-19 patients (p<0.0001 and p<0.0001). Both COVID-19 and cardiac arrhythmia patients were, on average, significantly older than controls. On multivariate analysis, cardiac arrhythmia or COVID-19 diagnosis did not significantly correlate with smaller olfactory bulb volume, but older age, cardiac arrhythmia diagnosis, and COVID-19 diagnosis did significantly correlate with smaller olfactory sulcus depth. On multivariate analysis, older age was significantly correlated with cardiac arrhythmia diagnosis and COVID-19 diagnosis.ConclusionsOlfactory bulb volume and olfactory sulcus depth in both cardiac arrhythmia and COVID-19 patients appeared significantly smaller than in controls. Cardiac arrhythmia and COVID-19 patients were significantly older than controls. Age, as well as genetic predisposition, may contribute to a difference in the radiographic olfactory anatomical findings in patients with cardiac arrhythmias and COVID-19.

Comparative Neuroanatomical Study of the Main Olfactory Bulb in Domestic and Wild Canids: Dog, Wolf and Red Fox.

Simple SummaryThe study of the morphological, physiological and molecular changes associated with the domestication process has been one of the most interesting unresolved neuroanatomical issues. The olfactory system deserves special attention since both wild and domestic canids are macrosmatic mammals with very high olfactory capacities. Nevertheless, the question remains open as to whether domestication involuted the sense of smell in domestic dogs. Further, there is a lack of comparative morphological information on the olfactory bulb, the first structure integrating olfactory sensory information in the brain. To provide comparative information on the domestication process, we studied the olfactory bulb of dogs and their two most important wild ancestors: the wolf and the fox. The study was carried out by macroscopic dissection and histological and immunohistochemical techniques and has allowed us to verify, first of all, that the three species present olfactory bulbs corresponding to a macrosmatic animal, but that there are noticeable differences not only in size, which was already known, but also in the cellularity and intensity of the immunohistochemical pattern characteristic of each species. These variations point to a reduction of the olfactory system as a consequence of the selection pressure associated with the domestication of animals.The sense of smell plays a fundamental role in mammalian survival. There is a considerable amount of information available on the vomeronasal system of both domestic and wild canids. However, much less information is available on the canid main olfactory system, particularly at the level of the main olfactory bulb. Comparative study of the neuroanatomy of wild and domestic canids provides an excellent model for understanding the effects of selection pressure associated with domestication. A comprehensive histological (hematoxylin–eosin, Nissl, Tolivia and Gallego’s Trichrome stains), lectin (UEA, LEA) and immunohistochemical (Gαo, Gαi2, calretinin, calbindin, olfactory marker protein, glial fibrillary acidic protein, microtubule-associated protein 2) study of the olfactory bulbs of the dog, fox and wolf was performed. Our study found greater macroscopic development of the olfactory bulb in both the wolf and fox compared to the dog. At the microscopic level, all three species show a well-developed pattern of lamination and cellularity typical of a macrosmatic animal. However, greater development of cellularity in the periglomerular and mitral layers of wild canids is characteristic. Likewise, the immunohistochemical study shows comparable results between the three species, but with a noticeably higher expression of markers in wild canids. These results suggest that the reduction in encephalization experienced in dogs due to domestication also corresponds to a lower degree of morphological and neurochemical differentiation of the olfactory bulb.

Development of the mammalian main olfactory bulb.

ABSTRACTThe mammalian main olfactory bulb is a crucial processing centre for the sense of smell. The olfactory bulb forms early during development and is functional from birth. However, the olfactory system continues to mature and change throughout life as a target of constitutive adult neurogenesis. Our Review synthesises current knowledge of prenatal, postnatal and adult olfactory bulb development, focusing on the maturation, morphology, functions and interactions of its diverse constituent glutamatergic and GABAergic cell types. We highlight not only the great advances in the understanding of olfactory bulb development made in recent years, but also the gaps in our present knowledge that most urgently require addressing.

FUZZY MODELING OF SALINITY EFFECTS ON RADISH YIELD UNDER REUSE WATER IRRIGATION

The increase of water usage for food production in recent years has triggered researches on ways to optimize the use of water and to reuse saline water. The present study analyzes the effects of reused saline water in the irrigation of radish culture and the construction of a fuzzy logical mathematic model so that producers may evaluate their production. The experiment, measuring the development of radish bulb at five saline water levels, was developed in a greenhouse in the Botucatu, Campus of the São Paulo State University (UNESP), Botucatu/SP, Brazil. Results showed that salinity caused reduction in fresh and dry matter of the bulb and affected ratings throughout the culture cycle. From the developed fuzzy model, it was possible to verify that the fuzzy modeling helps in the analysis of the experimental data and makes it possible to perform simulations capable of inferring points that were not experimentally determined.

Using Heat as a Tracer to Detect the Development of the Recharge Bulb in Managed Aquifer Recharge Schemes

Managed Aquifer Recharge (MAR), the intentional recharge of aquifers, has surged worldwide in the last 60 years as one of the options to preserve and increase water resources availability. However, estimating the extent of the area impacted by the recharge operations is not an obvious task. In this descriptive study, we monitored the spatiotemporal variation of the groundwater temperature in a phreatic aquifer before and during MAR operations, for 15 days, at the LIFE REWAT pilot infiltration basin using surface water as recharge source. The study was carried out in the winter season, taking advantage of the existing marked difference in temperature between the surface water (cold, between 8 and 13 °C, and in quasi-equilibrium with the air temperature) and the groundwater temperature, ranging between 10 and 18 °C. This difference in heat carried by groundwater was then used as a tracer. Results show that in the experiment the cold infiltrated surface water moved through the aquifer, allowing us to identify the development and extension in two dimensions of the recharge plume resulting from the MAR infiltration basin operations. Forced convection is the dominant heat transport mechanism. Further data, to be gathered at high frequency, and modeling analyses using the heat distribution at different depths are needed to identify the evolution of the recharge bulb in the three-dimensional space.

Changes of starch and sucrose content and related gene expression during the growth and development of Lanzhou lily bulb.

As the main forms of carbohydrates, starch and sucrose play a vital role in the balance and coordination of various carbohydrates. Lanzhou lily is the most popular edible lily in China, mainly distributed in the central region of Gansu. To clarify the relationship between carbohydrate metabolism and bulb development of Lanzhou lily, so as to provide a basis for the promotion of the growth and development in Lanzhou lily and its important economic value, we studied lily bulbs in the squaring stage, flowering stage, half withering stage and withering stage. The plant height, fresh weight of mother and daughter bulbs continued to increase during the whole growth period and fresh weight of stem and leaf began to decrease in the half withering stage. The content of starch, sucrose and total soluble sugar in the lily mother bulb accumulated mostly in the flowering, withering and half withering stages, respectively. Starch, sucrose and total soluble sugar accumulated in the daughter bulb with the highest concentration during the withering stage. In the transcription level, sucrose synthase (SuSy1) and sucrose invertase (INV2) expressed the highest in squaring stage, and the expression was significantly higher in the mother bulb than in the daughter bulb. In flowering stage, the expression levels of soluble starch synthase (SSS1), starch-branching enzyme (SBE) and adenosine diphosphate-glucose pyrophosphorylase (AGP1) genes were higher in the mother bulb than in the daughter bulb. Altogether, our results indicate that starch and sucrose are important for the bulb growth and development of Lanzhou lily.