Budding Rate Research Articles

Frost risk assessment based on the frost-induced injury rate of tea buds: A case study of the Yuezhou Longjing tea production area, China

The tea tree (Camellia sinensis [L.] O. Kuntze) is a perennial cash crop, whose tender shoots and young leaves are used in tea production. Tea tree buds that have burst but have not yet been plucked may be damaged by frost, resulting in severe economic losses. And frost disasters in spring bring a serious threat to tea production in China. However, the impacts of frost disasters on tea production are not well evaluated. To address this gap, we quantified temporal and spatial changes of frost risk in the Yuezhou Longjing tea production area, which is China’s largest site of green tea production. Accordingly, we developed a new frost risk index based on the percentage of frost-damaged tea buds in relation to all tea buds and its probability. The results showed that elevation was the main factor associated with frost risk. Applying the Mann Kendall test, the effects of elevation on the tea frost risk in plain areas (50–250 m) and hilly areas (251–450 m) were determined. In plain areas, the frost risks and trends for the percentage of all frost-damaged tea buds did not change significantly with elevation. In hilly areas, the frost risks increased significantly with the increasing of elevations. However, the temporal change of percentage of frost-damaged tea buds decreased significantly, and this change showed a significant decreasing trend with increasing elevation in hilly areas. This trend is conducive to tea production in the hills, which are the main Longjing tea production areas. Our findings provide a better understanding of frost risk in tea production and could offer valuable references for frost risk prevention in tea production.

Effects of Saccharomyces cerevisiae quorum sensing signal molecules on ethanol production in bioethanol fermentation process

In this study, the concentrations of Saccharomyces cerevisiae quorum sensing signal molecules (QSMs) were determined, not to mention the exploration of the effects of exogenous S. cerevisiae QSMs on the sole fermentation of S. cerevisiae and co-fermentation of S. cerevisiae and Lactobacillus plantarum. The results showed that the concentrations of three signal molecules (2-phenylethanol (2-PE), tyrosol and tryptophan) produced by S. cerevisiae increased with a higher bacteria density, which tends to become stable up to 118.02, 32.05 and 1.93 mg/L respectively when cultivating for 144 h. Among the three signaling molecules, only 2-PE promoted the ethanol production capacity of S. cerevisiae. The ethanol concentration of the sole fermentation of S. cerevisiae loaded with 120 mg/L 2-PE reached 3.2 g/L in 9 h, which was 58.7% higher than that of the group without 2-PE addition. Moreover, 2-PE reduced the negative impact of L. plantarum on S. cerevisiae. Within 12 h of the co-fermentation of L. plantarum and S. cerevisiae, the ethanol concentration in the co-fermentation group loaded with 2-PE reached 5.6 g/L, similar to that in the group fermenting with sole S. cerevisiae, and the yeast budding rate was also restored to 28.51%. qRT-PCR results of S. cerevisiae which was in sole fermentation with 2-PE addition for 9 h showed that the relative expression levels of ethanol dehydrogenase gene ADH1 in S. cerevisiae decreased by 25% and the relative expression levels of MLS1, CIT2, IDH1,CIT1 decreased by 26%, 30%, 22%,18%, respectively, meant that the glyoxylic and tricarboxylic acid cycles were greatly inhibited, which promotes the accumulation of ethanol. The results of this study provide basic data for using QSMs more than antibiotics in the the prevention of contamination during the industrialized bioethanol production.

Far-Red-Light-Induced Morphology Changes, Phytohormone, and Transcriptome Reprogramming of Chinese Kale (Brassica alboglabra Bailey)

With far-red-light supplementation (3 W·m-2, and 6 W·m-2), the flower budding rate, plant height, internode length, plant display, and stem diameter of Chinese kale were largely elevated, as well as the leaf morphology such as leaf length, leaf width, petiole length, and leaf area. Consequently, the fresh weight and dry weight of the edible parts of Chinese kale were markedly increased. The photosynthetic traits were enhanced, and the mineral elements were accumulated. To further explore the mechanism that far-red light simultaneously promoted the vegetative growth and reproductive growth of Chinese kale, this study used RNA sequencing to gain a global perspective on the transcriptional regulation, combining it with an analysis of composition and content of phytohormones. A total of 1409 differentially expressed genes were identified, involved mainly in pathways related to photosynthesis, plant circadian rhythm, plant hormone biosynthesis, and signal transduction. The gibberellins GA9, GA19, and GA20 and the auxin ME-IAA were strongly accumulated under far-red light. However, the contents of the gibberellins GA4 and GA24, the cytokinins IP and cZ, and the jasmonate JA were significantly reduced by far-red light. The results indicated that the supplementary far-red light can be a useful tool to regulate the vegetative architecture, elevate the density of cultivation, enhance the photosynthesis, increase the mineral accumulation, accelerate the growth, and obtain a significantly higher yield of Chinese kale.

Effects of β-alanine on intestinal development and immune performance of weaned piglets.

Beta-alanine is an important amino acid involved in several metabolic reactions in the body. The study aimed to investigate the effect of β-alanine supplementation on intestinal development and the immune performance of weaned piglets. Thirty-two 21-day-old healthy weaned piglets (half female and half male; Duroc×Landrace×Yorkshire) with an initial body weight of 8.11±0.21kg were randomly divided into 4 groups with 8 replicates of 1 pig each. The control group was fed a basal diet and the three experimental treatment groups were fed diets supplemented with 300, 600 and 1,200mg/kg β-alanine, respectively. The trial lasted 28 days and the diets fed were divided into 2 phases: the late lactation period (day 1 to 14) and the nursery period (day 15 to 28), during which the weaned piglets had free access to food and water. The regulatory effects of β-alanine were further investigated invitro using organoids obtained from the jejunum of piglets. Invivo, the addition of β-alanine to the diet had no significant effect on the growth performance of weaned piglets (P>0.05), but significantly reduced serum levels of immunoglobulin G (IgG) (P<0.01), immunoglobulin M (IgM) (P=0.005), and complement 3 (C3) (P=0.017). The serum interleukin- 6 (IL-6) levels (P<0.01) were significantly reduced in the 1,200mg/kg treatment group. The addition of β-alanine increased ileal villus height, with the most significant effect at a concentration of 300mg/kg (P=0.041). The addition of 600mg/kg β-alanine significantly up-regulated the expression of superoxide dismutase (SOD) activity (P=0.020) and the zonula occludens-1 (ZO-1) gene (P=0.049) in the jejunum. Diets supplemented with 300mg/kg β-alanine significantly increased the number of Ki67 positive cells in the jejunal crypts (P<0.01). Invitro, β-alanine increased the organoid budding rates (P=0.001) and the budding height of the crypt significantly (P=0.004). In conclusion, β-alanine can improve intestinal morphology and barrier function, reduce inflammatory responses and alleviate the adverse effects of weaning stress on piglet intestinal health.

Establishment of a Highly Efficient In Vitro Propagation System of Diospyros lotus

Persimmon (Diospyros) is an economically important tree widely cultivated for woody grain production in China, and Diospyros lotus is mainly used as the grafting stock of persimmon. However, the breeding of stress-resistant rootstocks of D. lotus using molecular means has yet to be achieved; in particular, an efficient blade-regeneration system has not been perfected to date. This study examined the effects of different plant-growth regulators and concentrations on the primary culture of stems with buds, the induction of leaf callus, the differentiation of adventitious shoots, and rooting culture of D. lotus. The optimal formula for inducing axillary buds from stems with buds was 1/2 Murashige and Skoog (MS) medium containing 2.0 mg/L 6-benzylaminopurine (6-BA) and 0.5 mg/L naphthaleneacetic acid (NAA), in which the induction rate of axillary buds approached 67.1%. The best medium formula for leaf callus induction was 1/2 MS medium containing 2.0 mg/L 6-BA and 0.5 mg/L NAA. Then callus was transferred to 1/2 MS medium containing 2.0 mg/L 6-(γ,γ-dimethylallylamino)purine (2iP), 2.0 mg/L thidizuron (TDZ), and 40 g/L sucrose to induce adventitious shoots after dark culture for 48 h, resulting in 7.9 shoots per explant and a 75.2% induction frequency of adventitious shoots. In addition, it was difficult to induce adventitious shoots from callus after six times of continuous transfer and differentiation. The adventitious shoots were transferred to 1/2 MS medium containing 2.0 mg/L zeatin (ZT) and 2.0 mg/L 2iP for proliferation culture, in which the multiplication coefficient approached 7.6. The adventitious shoots after multiplication were inoculated into 1/2 MS + 1.0 mg/L IBA + 0.5 mg/L NAA medium, the rooting rate was 70.2%, and the average number of heels was 9.6. Thus, studies in this area are expected to facilitate rapid and excellent growth, as well as theoretical support for factory saplings’ care and molecular breeding.

Brassinosteroid Biosynthetic Gene CmDWF4 Regulates Bud Outgrowth in Chrysanthemum morifolium

Brassinosteroids (BRs), a class of steroid phytohormones, play a critical role in plant growth and development. The <i>DWF4</i> gene encodes a cytochrome P450 enzyme (CYP90B1), which is considered a rate-limiting enzyme in BR biosynthesis. Here, we identified a homologous gene of <i>DWF4</i> in chrysanthemum, <i>CmDWF4</i>. This gene was predicted to encode 491 amino acid residues with a molecular weight of 56.2 kDa and an isoelectric point (pI) of 9.10. Overexpression of <i>CmDWF4</i> in chrysanthemum was found to significantly increase growth rate, number, and length of lateral buds. Transcriptome analysis showed that multiple xyloglucan endotransglycosylase/hydrolase (XTH) family encoding genes associated with cell wall modification were up-regulated in <i>CmDWF4</i>-overexpressing lines. qRT-PCR assay confirmed the up-regulation of <i>CmXTH6</i>, <i>CmXTH23</i>, and <i>CmXTH28</i> in <i>CmDWF4</i>-overexpression line. Overall, this work establishes a mechanism by which BR biosynthetic gene <i>CmDWF4</i> promotes lateral bud outgrowth in chrysanthemum, possibly through regulating cell elongation and expansion.

Appropriate Condition for Cluster Buds Induction of &lt;i&gt;Cremastra appendiculata&lt;/i&gt;

To screen for suitable conditions for cluster bud induction of Cremastra appendiculata .&nbsp;The aseptic germination protocorms&nbsp;of C. appendiculata &nbsp;seeds were used as explant materials to explore the effects of different basic media, types of plant growth regulators, anti-browning agents&nbsp;and their concentrations&nbsp;on the induction of cluster buds&nbsp;of C. appendiculata .&nbsp;The results showed that: 1/4MS medium was the suitable basic medium for cluster buds growing; when the concentration of plant growth regulator TDZ was 2.0 mg/L and the concentration of IAA was 0.2 mg/L, the induction rates of cluster bud were higher which are 72.58% and 55.63% respectively; when the anti-browning agent was PVP and its concentration is 2&nbsp;000 mg/L, the induction rate of cluster buds was higher which is 79.90%. The suitable conditions for C. appendiculata cluster buds induction are: 1/4MS + TDZ 2.0 mg/L+ IAA 0.1 mg/L+ PVP 2&nbsp;000 mg/L, and the induction rate can reach 81.16%. This&nbsp;provided&nbsp;a basis for establishing a rapid propagation technology system of &nbsp;C. appendiculata &nbsp;and realizing its&nbsp;large-scale artificial cultivation.

Изучение влияния способа защиты места окулировки на приживаемость и развитие привоя сладкого апельсина (citrus sinensis l.)

Citrus fruits are the world’s leading fruit crops. To meet the growing demand and increase the area under these crops, it is necessary to produce high quality planting material. The main method of producing seedlings of cultivated citrus varieties is budding. When using this technique, it is necessary to ensure reliable protection of the joint of the components. There is a lack of information on this issue in the literature. The present study was conducted in the suburb of Jalalabad, Nangarhar, Afghanistan, at a modern nursery. The first experiment (Citrus sinensis L.) included the following variants: 1. binding the scions with polyethylene tape without covering the buds; 2. binding the scions with polyethylene tape covering the buds; 3. binding the scions with polyethylene tape without covering the buds + painting the binding with white paint; 4. binding the scions with polyethylene tape covering the buds + painting the binding with white paint; 5. binding the scions with the innovative adhesive tape “Buddy Tape” covering the buds; 6. binding the scions with the innovative adhesive tape “Buddy Tape” without covering the buds + painting the binding with white paint. The second experiment involved three options for limequat (Citrus Aurantiifolia x Citrus Japonica): 1. binding the scions with polyethylene tape without covering the buds; 2. binding the scions with polyethylene tape covering the buds; 3. binding the scions with the innovative adhesive tape “Buddy Tape” covering the buds. The study results showed that the binding materials, the method of binding and the use of painting had a significant impact on the survival of scions, the budding time of the scions, the development of shoots and leaf surface on the scion component. In the experiment with sweet orange, the maximum survival rate (91.64%) was observed when binding the scions with the innovative adhesive tape “Buddy Tape” covering the buds, and the minimum rate (77.52%) was noted when binding the scions with polyethylene tape without covering the buds + painting the binding with white paint. The studies showed that the binding materials of the limequat scions had a significant effect on the budding time, the number of leaves on the shoot, the length of the shoot and the survival rate of the scion buds. The minimum budding time was found when binding the scions with the innovative adhesive tape “Buddy Tape” covering the buds, while the maximum budding time was noted when binding the scions with polyethylene tape covering the buds. The maximum survival rate was observed when binding the scions with the innovative adhesive tape “Buddy Tape” covering the buds, and the minimum one was when binding the scions with polyethylene tape covering the buds.

Effect of light quality of long-day treatments on flowering in &lt;i&gt;Delphinium&lt;/i&gt;

The effects of light quality on the flowering need to be investigated for the efficient use of light-emitting diodes (LEDs) in cut flower production because of the environmentally friendly features of LEDs. Assuming long-day treatments in cut flower production, we used Delphinium species, popular long-day plants, and treated the plants at night with relatively weak light to investigate the effects of light quality. We used reproductive experimental conditions with phytotrons and long-day treatments, mainly monochromatic light, to establish an experimental system to elucidate physiological and molecular mechanisms in the near future. Before investigating the effect of monochromatic light, we first performed a long-day treatment with a widely used white LED. A similar effect to the incandescent lamp on bolting was observed, suggesting the possibility that red or blue light, but not far-red light, are adequate to promote flowering from the spectra of both light sources. Next, long-day treatments were performed with LEDs emitting monochromatic blue, red, and far-red light. In the model plant Arabidopsis thaliana, flowering is well known to be promoted by far-red and blue light and inhibited by red light. However, long-day treatment with red light for Delphinium effectively promoted flowering. Treatment with far-red light, which shows an opposite flowering response to red light in A. thaliana, also promoted the flowering of Delphinium. As for blue light, the flower budding rate of D. grandiflorum reached 100%, and that of D. elatum was lower. Compared to far-red and blue lights, long-day treatment with red light did not negatively impact cut flower quality, including cut flower length and number of florets. Our results on light quality impact on flowering response will contribute to technology for regulating Delphinium flowering and potentially also lead to the elucidation of the mechanism of unique flowering promotion by red light.

Effects of low temperature on flowering and the expression of related genes in Loropetalum chinense var. rubrum.

Loropetalum chinense var. rubrum blooms 2-3 times a year, among which the autumn flowering period has great potential for exploitation, but the number of flowers in the autumn flowering period is much smaller than that in the spring flowering period. Using 'Hei Zhenzhu' and 'Xiangnong Xiangyun' as experimental materials, the winter growth environment of L. chinense var. rubrum in Changsha, Hunan Province was simulated by setting a low temperature of 6-10°C in an artificial climate chamber to investigate the effect of winter low temperature on the flowering traits and related gene expression of L. chinense var. rubrum. The results showed that after 45 days of low temperature culture and a subsequent period of 25°C greenhouse culture, flower buds and flowers started to appear on days 24 and 33 of 25°C greenhouse culture for 'Hei Zhenzhu', and flower buds and flowers started to appear on days 21 and 33 of 25°C greenhouse culture for 'Xiangnong Xiangyun'. The absolute growth rate of buds showed a 'Up-Down' pattern during the 7-28 days of low temperature culture; the chlorophyll fluorescence decay rate (Rfd) of both materials showed a 'Down-Up-Down' pattern during this period. The non-photochemical quenching coefficient (NPQ) showed the same trend as Rfd, and the photochemical quenching coefficient (QP) fluctuated above and below 0.05. The expression of AP1 and FT similar genes of L. chinense var. rubrum gradually increased after the beginning of low temperature culture, reaching the highest expression on day 14 and day 28, respectively, and the expression of both in the experimental group was higher than that in the control group. The expressions of FLC, SVP and TFL1 similar genes all decreased gradually with low temperature culture, among which the expressions of FLC similar genes and TFL1 similar genes in the experimental group were extremely significantly lower than those in the control group; in the experimental group, the expressions of GA3 similar genes were all extremely significantly higher than those in the control group, and the expressions all increased with the increase of low temperature culture time. We found that the high expression of gibberellin genes may play an important role in the process of low temperature promotion of L. chinense var. rubrum flowering, and in the future, it may be possible to regulate L. chinense var. rubrum flowering by simply spraying exogenous gibberellin instead of the promotion effect of low temperature.

Transgenerational effects and temperature variation alter life history traits of the moon jellyfish

Understanding the life history strategy of organisms is key to predicting their population dynamics. The population of scyphozoan jellyfish has displayed an increasing trend in recent decades, yet its life history strategy is not fully understood. To interpret the reproduction strategy of scyphozoan jellyfish from an evolutionary ecology perspective, we dissected 10 asexual generations of Aurelia coerulea polyps to investigate the relationships between transgenerational effects on their budding reproduction and strobilation. Our results reveal that a polyp’s average budding reproduction rate declined 32.82% through asexual generations within the experimental time. Furthermore, a longer culture duration counteracted the transgenerational effects on budding rates and strobilation afterward. Thus, this effort provides insight into the necessity of sexual reproduction in organisms involving a metagenic life cycle, i.e., to renew the asexual reproduction ability of a population. Besides this, we suggest taking note that it is necessary to know the “asexual age” of polyps when performing experimental studies and mathematical modeling to explore their population dynamics. Our results also present a valuable data set to interpret the evolution of the scyphozoan jellyfish’s life history strategy under multifactorial environments.

In vitro propagation and improving accumulation of coumarin in Lycium barbarum, a rare plant in the flora of Egypt

BackgroundThe conservation of natural populations of plants is very important for maintaining biological diversity. Lycium barbarum (goji berries) is classified as a very rare plant in the Egyptian flora. Goji berry is a fruit commonly known as ‘super-fruit,’ due to its beneficial constituents and medicinal properties. The aim of this study was to determine the influence of media formula added with various cytokinins on axillary bud induction of L. barbarum from shoot tip. An additional objective of this study was to investigate the effect of 2,4-D, TDZ, zeatin, IBA and NAA on growth and development of the plant through different stages. The present study also aims to improve coumarin accumulation as one of the most active constituents in the plant.ResultsSterilized shoot tips of L. barbarum were cultured without growth regulators on different media formulas: Murashige and Skoog basal medium (MS medium), Gamborg’s medium (B5 medium) and Woody plant medium (WP medium). MS medium gave the best shoot induction. The maximum multiplication rate of shoots was recorded on MS medium supplemented with 225.24 µM 6-benzyl amino purine (BAP). The best callus induction rate from in vitro derived young leaves was obtained on MS medium with 552.60 µM thidiazuron (TDZ). At 176.20 µM TDZ, the maximum shoot proliferation ability was obtained through organogenesis from the callus. MS medium with 220.25 µM TDZ produced the highest number (15 buds) and forming rate (96%) of adventitious buds through direct organogenesis. On MS medium with 304.86 µM naphthalene acetic acid (NAA), 100% rooting was obtained. Almost 95% of the in vitro-generated plantlets were successfully acclimatized. Furthermore, suspension culture containing MS medium with 552.60 µM TDZ and cinnamic acid at a concentration of 763 μM increased coumarin synthesis (1.95-fold), compared to control.ConclusionThe in vitro regeneration of plants via leaf-mediated shoot organogenesis protocol presented in this study is well suited for L. barbarum propagation and produced large quantities of identical planting materials for desert revegetation and pharmaceutical industries. A very effective indirect regeneration method via callus culture provides a potential for this ethnomedicinal plant to be improved by genetic transformation procedures, in addition to mass propagation of elite plants. The cell suspension culture medium with 763 µM cinnamic acid had the highest coumarin accumulation.

UVA-Radiation Exposure of Different Durations Promoted the Growth, Phytochemicals and Glucosinolate Biosynthesis of Chinese Kale.

Ultraviolet-A (UVA) (315–400 nm) is an essential environmental signal that regulates plant development and affects phytochemicals biosynthesis, including glucosinolate biosynthesis. The effects of different UVA (380 ± 10 nm, 40 μmol/m2/s) exposure durations, including 0 h/d (UV0), 6 h/d (UV6) and 12 h/d (UV12), on the growth and phytochemicals of Chinese kale (Brassica alboglabra) under white 250 μmol/m2/s LEDs were investigated. UVA exposure of different durations influenced the growth and phytochemicals biosynthesis of Chinese kale. Prolonging UVA irradiation throughout the growth cycle positively affected the growth and the development of Chinese kale, with evident increases in the dry weights of shoots and roots, plant height, stem diameter, specific leaf weight and flower budding rate. The application of UVA increased the soluble sugar content, whereas higher flavonoid content and antioxidant capacity (FRAP) and lower nitrate content were only observed in Chinese kale exposed to UV6 treatment. Besides, the qPCR assay showed that supplemental UVA-radiation exposure up-regulated the gene expressions of UVR8, transcription factors genes and genes related to the glucosinolate biosynthesis pathway, thereby promoting the accumulation of glucosinolates. Therefore, supplemental UVA-radiation exposure for 12 h/d was more conducive to plant growth, while supplemental UVA-radiation exposure for 6 h/d was better for phytochemical biosynthesis in Chinese kale in an artificial-light plant factory.

A YOLOv3-based computer vision system for identification of tea buds and the picking point

Famous tea industry which need to harvest tea buds has great economic benefits. However, the harvesting is time-consuming and labor-intensive, especially with the shortage of labor currently, an intelligent tea bud picking robot is urgently needed. The vision system is a precursor to the development of a tea bud picking robot. To resolve such issues, we applied robotics and deep learning technologies to develop a computer vision system for intelligent picking of tea buds. The system was designed to recognize tea buds and extract their picking points. A method for locating the picking points was proposed based on a combination of YOLO-v3 algorithm, semantic segmentation algorithm, skeleton extraction and minimum bounding rectangle. An intelligent tea end-effector based on Personal Computer and microcontroller collaborative control was designed to solve the picking problem like complex shading and easy breakage. Thus, the picking rate of the overall system was improved. Based on Openmv smart camera embedded mobilenet_v2 algorithm as the visual model of the classification device, so that the quality of tea buds was preliminatively classified. Finally, the effects of different shooting angles and shooting methods as well as the accuracy of target detection and semantic segmentation algorithms on the extraction of tea bud picking points were investigated. The results show that the average accuracy of YOLO-v3 for identification of tea buds is 71.96% and the average horizontal positioning error of the robotic arm is 2.4 mm. Also, the average depth positioning error is 4.2 mm and the accuracy of tea bud picking point extraction is 83%. After the test, the successful picking rate of tea buds is 80% by this computer vision system of robot. The results of this study is potential to develop a machine-based tea picking system for industry and would contribute to the development of precision agriculture.

Mechanisms of phosphatidylserine influence on viral production: A computational model of Ebola virus matrix protein assembly

Ebola virus (EBOV) infections continue to pose a global public health threat, with high mortality rates and sporadic outbreaks in Central and Western Africa. A quantitative understanding of the key processes driving EBOV assembly and budding could provide valuable insights to inform drug development. Here, we use a computational model to evaluate EBOV matrix assembly. Our model focuses on the assembly kinetics of VP40, the matrix protein in EBOV, and its interaction with phosphatidylserine (PS) in the host cell membrane. It has been shown that mammalian cells transfected with VP40-expressing plasmids are capable of producing virus-like particles (VLPs) that closely resemble EBOV virions. Previous studies have also shown that PS levels in the host cell membrane affects VP40 association with the plasma membrane inner leaflet and that lower membrane PS levels result in lower VLP production. Our computational findings indicate that PS may also have a direct influence on VP40 VLP assembly and budding, where a higher PS level will result in a higher VLP budding rate and filament dissociation rate. Our results further suggest that the assembly of VP40 filaments follow the nucleation-elongation theory, where initialization and oligomerization of VP40 are two distinct steps in the assembly process. Our findings advance the current understanding of VP40 VLP formation by identifying new possible mechanisms of PS influence on VP40 assembly. We propose that these mechanisms could inform treatment strategies targeting PS alone or in combination with other VP40 assembly steps.

LEUKOCYTE PROFILE, MICRONUCLEUS AND ERYTHROCITARY NUCLEAR PROTRUSIONS IN SPARROWS (Centronyx bairdii and Ammodramus savannarum) OF THE CHIHUAHUENSE DESERT DURING THE WINTER

The populations of Baird’s (Centronyx bairdii) and grasshopper (Ammodramus savannarum) sparrows are decreasing as a consequence of the loss of their natural habitat and the indiscriminate use of agrochemicals in farming areas bordering their breeding habitat. Although these two species have been studied from an ecological perspective, there is no research on the presence of abnormalities in their leukocyte and erythrocytes counts, both of them health biomarkers. The objective of this work was to determine the spontaneous rate of polychromatic erythrocytes (PCE), micronucleated erythrocytes (MNE), and nuclear buds (NBs), as well as the leucocyte differential and the heterophil/lymphocyte ratio (H:L), in order to establish the health status of these sparrow species that live in Cuchillas de la Zarca, Durango, Mexico. With this aim, we captured 20 organisms of each species with mist nets. We carried two blood smears per individual which we analysed under the microscope (100x). There were no statistically significant differences among species regarding the frequencies of the various biomarkers, which had similar values to those established for other healthy bird species. Therefore, there is no evidence of genomic instability, nor of genotoxic or cytotoxic effects. Likewise, we detected no alterations in the immune system, based on the leukocyte differential and the H:L ratio evaluation. This is the first study that establishes reference values for these biomarkers among these particular species of sparrows.

In vitro clonal propagation of Billbergia zebrina (Bromeliaceae) and analysis of anatomy and physiology of regenerated plantlets

Abstract During in vitro multiplication of horticulture plant species, synthetic cytokinins such as 6-benzylaminopurine (BA) can affect the microshoot formation. Murashige and Skoog culture medium (MS) can also act as a morphogenetic response modulator. The aim was to analyze the effects of BA and a gradient of MS salts on the morphophysiological status of Billbergia zebrina microshoots. Plantlets were cultured with a gradient of MS salts (50%, 100%, 150%, or 200%) supplemented with two BA levels (0 or 13 μM). After 50 days of culture, stomatal parameters, contents of photosynthetic pigments, and chlorophyll fluorescence were assessed. Plantlets cultured in all media without BA presented a low budding rate. In contrast, plantlets cultured with BA showed 100% budding. With 13 μM BA, the leaves presented bigger stomata and wider opening. Plantlets cultured with BA had lower contents of photosynthetic pigments. MS treatments without BA supplementation did not show any change in the pigments’ ratios. Plantlets cultured with BA had lower activity of the water-splitting complex and signs of photoinhibition damage. This resulted in the reduced performance of the photosynthetic apparatus. BA exposure can ensure the inducement of adventitious microshoots. BA at the tested concentration can induce morphophysiological disorders, irrespective of MS salt concentration.

Phenology and fruit set of peach trees cultivated in Dois Vizinhos, Paraná State, Brazil

Understanding the dormancy phases and dynamics of commercial cultivars in the regions where they are grown allows for the implementation of different cultural practices and aids in the understanding of the temperature requirements for collaboration with genetic improvement programs. The objective of this study was to determine the budding, flowering, and fruit set rates of peach trees cultivated in the municipality of Dois Vizinhos, Southwestern Paraná, Brazil. The present work was developed using the collection of peach trees in the fruit growing sector of the Universidade Tecnológica Federal do Paraná. Sixteen peach cultivars were evaluated: Rubimel, Leonense, Coral, Marli, Charme, Riograndense, Douradão, Chimarrita, Granada, BR-1, Bonão, and Eldorado (all planted in 2009), as well as Regalo, Kampai, Fascínio, and Zilli (planted in 2014). The experimental design was completely randomized with four replications of one plant each, in a 16 × 2 bifactorial arrangement (cultivars × year/harvest). Phenology evaluations were performed weekly by counting open (anthesis) and sprouted flower buds, and the fruit set rate was measured just before fruit thinning. Flowering (%), budding (%), and fruit set (%) rates were calculated. It was found that the year/harvest 2016 promoted the highest rates of sprouting and fruit set. The Bonão cultivar showed greater flowering intensity and regularity in the crop years evaluated (2016 and 2017). Coral and Kampai present fruit sets with greater intensities and regularities when compared to the other cultivars evaluated under the climatic condition of the municipality of Dois Vizinhos. The Riograndense cultivar showed greater irregularity in flowering and fruit production.

In Vitro-Propagation of Agave tequilana Weber cv. azul in a Temporary Immersion System

In Mexico, there is a need to produce large quantities of plantlets for the establishment and replanting of blue (cv. azul) agave production areas. Most of these plots are within the origin denomination area (DOT, Spanish acronym) of the distilled product of this plant, known as tequila. The objective of this study was to develop an in vitro-propagation protocol for Agave tequilana Weber cv. azul using segmented stems in both: solid and liquid media. A disinfection and in vitro technique were developed to obtain shoots, through plantlets collected in commercial plots, which attained 100% surface-disinfection and budding rate. At the multiplication stage, the effects of 6-Benzylaminopurine (BA) (0.0, 4.4 and 13.2 μM) and kinetin (0.0, 9.4, 18.8 and 37.6 μM) were evaluated on lateral-shoot production of segmented sagittal stems. These were cultivated on Murashige & Skoog (MS) medium, with the addition of 3.0% sucrose and 8 g L−1 agar. It was observed that BA and kinetin increased the number of shoots per explant, obtaining up to 18 and 26, respectively. Furthermore, it was found that just the sagittal segmentation of explants increased axillary budding. On the other hand, segmented-stem bases were grown in MS liquid medium with 3.0% sucrose, inside a RITA® system, programmed by a 5 min immersion step with a frequency of every 4 h. The effect of Indole−3-Acetic acid (IAA) (0.57, 2.9, 5.7 μM) was evaluated, while maintaining a concentration of BA (13.2 μM). It was observed that the greatest concentration of IAA led to the formation of more than 20 buds per explant. These results offer a new methodology to increase the efficiency of A. tequilana Weber cv. azul-in vitro multiplication by sagittal segmentation of stems and the addition of BA and/or IAA.

Design and experiment of vibration plate type camellia fruit picking machine

In order to solve the problem of high missed rate of camellia fruits and high damage rate of flower buds during vibratory picking, through the study on the biological characteristics of camellia tree, the crown of camellia tree was divided into upper and lower canopy at the maximum canopy diameter. A kind of vibration plate type camellia fruit picking machine was designed. The structure and working principle of the whole machine were described. Through the analysis of the factors of camellia fruit abscission, it is concluded that frequency, amplitude and working time are the main factors affecting the magnitude of inertia force. Through preliminary research and coupling simulation, the horizontal range of each factor is determined: operation time is 5 s, 10 s, 15 s, frequency is 3 Hz, 5 Hz, 7 Hz and amplitude is 50 mm, 60 mm, 70 mm. Orthogonal tests were carried out on the upper and lower canopies successively, and the comprehensive scoring method was used to analyze the orthogonal test results. The results showed that the optimal combination of working parameters for picking camellia in the upper canopy was A3B3C2, that is, the operation time was 15 s, the amplitude was 70 mm and the frequency was 5 Hz. Under this condition, the missed picking rate of camellia fruits was 8.21% and the rate of flower buds damage was 9.12%. The optimal combination of working parameters for picking camellia fruits in the lower canopy was A3B1C3, that is, the operation time was 15 s, the amplitude was 50 mm and the frequency was 7 Hz. Under this condition, the rate of missing picking of camellia fruits was 6.84% and the rate of flower buds damage was 6.92%. Keywords: canopy stratification, structural design, analysis of shedding factors, coupling simulation, orthogonal test DOI: 10.25165/j.ijabe.20221504.6971 Citation: Wu D L, Ding D, Cui B W, Jiang S, Zhao E L, Liu Y Y, et al. Design and experiment of vibration plate type camellia fruit picking machine. Int J Agric & Biol Eng, 2022; 15(4): 130–138.