Bud Production Research Articles

Principles and Significance of Nitrogen Management for Blackberry Production

Blackberry cultivation presents significant opportunities for fruit growers in subtropical regions, where nitrogen (N) is identified as a crucial macronutrient for optimal production. Given the variability in climate and soil conditions, determining the ideal N fertilizer amount can be complex. Effective blackberry cultivation requires careful attention to the principles of nutrient stewardship, including the selection of appropriate N sources, application rates, timing, and placement. Recommended N rates generally range from 25–45 kg/ha in the first year and 45–70 kg/ha in subsequent years, with adjustments based on plant type and regional conditions. The choice of fertilizer, particularly NH4+, is beneficial for blackberry plants, which thrive in acidic soils and show improved biomass and chlorophyll levels with this form of N. Research on N-cycling reveals its importance in supporting new plant growth, such as primocane development. However, improper N management, either excessive or insufficient, can negatively impact flower bud production and, consequently, fruit setting and yield. By using databases such as Google Scholar, Scopus, and Web of Science, this review synthesizes existing research on the role of N in blackberry cultivation, emphasizing the importance of precise fertilization practices tailored to regional climate and soil conditions. By highlighting variations in recommended N amounts and underscoring the principles of nutrient stewardship, this review aims to guide growers in achieving sustainable and high-quality blackberry production.

Endophytic Fungi Inoculation Reduces Ramulosis Severity in Gossypium hirsutum Plants.

Biotic stress in cotton plants caused by the phytopathogenic fungus Colletotrichum gossypii var. cephalosporioides triggers symptoms of ramulosis, a disease characterized by necrotic spots on young leaves, followed by death of the affected branch's apical meristem, plant growth paralysis, and stimulation of lateral bud production. Severe cases of ramulosis can cause up to 85% yield losses in cotton plantations. Currently, this disease is controlled exclusively by using fungicides. However, few studies have focused on biological alternatives for mitigating the effects of contamination by C. gossypii var. cephalosporioides on cotton plants. Thus, the hypothesis raised is that endophytic fungi isolated from an Arecaceae species (Butia purpurascens), endemic to the Cerrado biome, have the potential to reduce physiological damage caused by ramulosis, decreasing its severity in these plants. This hypothesis was tested using plants grown from seeds contaminated with the pathogen and inoculated with strains of Gibberella moniliformis (BP10EF), Hamigera insecticola (BP33EF), Codinaeopsis sp. (BP328EF), G. moniliformis (BP335EF), and Aspergillus sp. (BP340EF). C. gossypii var. cephalosporioides is a leaf pathogen; thus, the evaluations were focused on leaf parameters: gas exchange, chlorophyll a fluorescence, and oxidative metabolism. The hypothesis that inoculation with endophytic strains can mitigate physiological and photochemical damage caused by ramulosis in cotton was confirmed, as the fungi improved plant growth and stomatal index and density, increased net photosynthetic rate (A) and carboxylation efficiency (A/Ci), and decreased photochemical stress (ABS/RC and DI0/RC) and oxidative stress by reducing enzyme activity (CAT, SOD, and APX) and the synthesis of malondialdehyde (MDA). Control plants developed leaves with a low adaxial stomatal index and density to reduce colonization of leaf tissues by C. gossypii var. cephalosporioides due to the absence of fungal antagonism. The Codinaeopsis sp. strain BP328EF can efficiently inhibit C. gossypii var. cephalosporioides in vitro (81.11% relative inhibition), improve gas exchange parameters, reduce photochemical stress of chlorophyll-a, and decrease lipid peroxidation in attacked leaves. Thus, BP328EF should be further evaluated for its potential effect as a biological alternative for enhancing the resistance of G. hirsutum plants and minimizing yield losses caused by C. gossypii var. cephalosporioides.

Divergent reproductive responses of Caatinga dry forest plants to leaf-cutting ant herbivory

Herbivory is one of the key processes shaping life history traits linked to plant fitness and the leaf-cutting ants are amongst the most voracious and polyphagous herbivores of the Neotropics. They extensively harvest aboveground plant parts to grow their symbiotic fungus, including vegetative and reproductive tissues. Although leaf-cutting ant herbivory is expected to reduce plant reproductive success, the potentially different outputs of damage to vegetative and reproductive parts are still poorly known. This study investigates the influence of Atta opaciceps herbivory on the reproductive success of three plant species native to the Caatinga dry forest: Croton argyrophylloides (Euphorbiaceae), Cenostigma pyramidale, and Indigofera suffruticosa (Leguminosae). We selected 10 adult and active nests of A. opaciceps based on the presence of individuals of the three focal plant species in their vicinity. For each colony, we marked four individuals of each plant species (totaling 12 individuals per colony), which were then subjected to one of four herbivory treatments: (1) ant herbivory on both reproductive and vegetative parts, (2) manually simulated herbivory on the reproductive parts alone, (3) ant herbivory exclusively on vegetative parts, and (4) no herbivory. From January to April 2020, we monitored all 120 individuals, recording the number of inflorescences, flower buds, flowers, fruits, and the proportion of flowers maturing into fruits (fruit set, as a proxy of reproductive success). Results revealed variations in reproductive structure production and divergent responses to leaf-cutting ant herbivory among our focal species. In terms of inflorescence, flower bud production, and fruit set C. argyrophylloides showed reduced numbers when subjected to higher levels of total herbivory (reproductive and vegetative parts), but increased inflorescence and flower bud production when plants suffered only leaf damage. Cenostigma pyramidale individuals under partial herbivory displayed lower flower bud numbers than protected ones. In contrast, I. suffruticosa displayed conflicting results, with fully exposed plants producing more inflorescences than partially exposed counterparts and more flowers than leaf-damaged and protected individuals. Despite the varied effects on different plant parts across all three study species, the overall reproductive success (i.e. fruit set) of only one species (C. argyrophylloides) was significantly reduced by leaf-cutting ant herbivory. The resilience of the two other plant species to leaf-cutting ant pressure may be attributed to compensatory mechanisms, shedding light on the intricate interplay between herbivores and plants in the Caatinga dry forest. As leaf-cutting ants proliferate in response to anthropogenic disturbances, the patterns described in this study may become more pronounced, potentially affecting the organization of plant communities in the Caatinga dry forest.

Production of quality planting material in commercial banana cvs. Rasthali (Silk, AAB) and Neypoovan (Neypoovan, AB) through farmer-friendly macropropagation technique and their field evaluation

Macropropagation is a low cost farmer friendly alternative to tissue culture propagation to cater to the farmers’ need for quality planting material at an affordable cost. Attempts were made to study the effect of age and hot water treatment on macropropagation of cvs. Rasthali (AAB, Silk) and Neypoovan (AB, Neypoovan) in pot and bed methods. Age of the sucker, hot water treatment and propagation method played a vital role on shoot bud production in both the test cultivars. In cv. Rasthali, bed method produced maximum number of plants (50.5) in five months old suckers subjected to hot water treatment in 42.2 days but the same treatment produced only 24.7 plants under pot method. In cv. Neypoovan, five months old suckers subjected to hot water treatment resulted in 23.3 and 16.7 plants in bed and pot methods respectively. Therefore, five months old suckers with hot water treatment under bed method are more appropriate for macropropagation purpose in banana. Results of field evaluation indicated that macropropagated bananas were at par with control in respect of all plant parameters like plant height, bunch weight and fruit parameters like total soluble sugar (TSS) and acidity.

Myrtaceae flowering strategies in a gallery forest, Chapada Diamantina, Brazil

Abstract Tropical plants exhibit virtually all known phenological responses, which can range from near-continuous to brief events, and from complete synchrony to complete asynchrony. This wide variety of phenological patterns is related to high tropical biodiversity and complex interactions with diverse abiotic and biotic factors, such as plant-pollinator interactions. Changes in these factors will therefore influence plant phenology, and differences in those phenological responses can impact reproductive success and plant fitness. We report here interspecific variations in the reproductive ecology (flowering phenology, floral biology, reproductive systems, and pollination) of 10 Myrtaceae species in a gallery forest in northeastern, Brazil. We evaluated flowering patterns and strategies, considering the frequency and duration of each phenophase from monthly observations, using the semi-quantitative Fournier scale. We also analyzed floral biology, recorded floral visitors, conducted pollination experiments (autonomous self-pollination, hand self-pollination, hand cross-pollination, and natural/open pollination), and calculated sefl-incompatibility (SII) and autogamy (AI) indices. Most species exhibited synchronous and annual flowering lasting between 1 and 5 months, with a “pulsed bang” strategy (i.e., mass flowering concentrated within just a few days, with intervals). These patterns were repeated among congeneric species, except in Myrcia, in which half of the species accompanied were classified as having a “pulsed bang” and the other half a “big bang” strategy. The flowering strategies appeared to be associated with distinct patterns of inflorescence development, bud production, flowering duration, and the timing of flowering in individual plants. Bee species were considered pollinators. Most species studied were self-incompatible and allogamous. In general, the species produced large quantities of flowers during short temporal intervals, favoring crosses between individuals having precise synchrony.

Management practices of Cereus jamacaru DC in the Caatinga dry forest differentially affect its reproductive phenology, fruit set and nectar availability

The management of plants and landscapes can affect the reproductive cycle of species through changes in morphology, temporal distribution of resources, and productivity, with ecological implications. In this study, we investigated the influence of management practices on the reproductive phenology and nectar availability of Cereus jamacaru DC, a columnar cactus native to Brazil managed by local people in the Caatinga dry forest. Our results reveal that the traditional management practices alter the quantitative and spatiotemporal distribution of resources (flowers, fruits, and nectar) of individuals of C. jamacaru in the studied Caatinga. All populations exhibited annual patterns of flowering and fruiting. However, individuals of the ex situ managed population showed a distinct temporal distribution pattern of flowering, with flower buds and flowers more regularly distributed throughout the reproductive period, compared to individuals of the in situ and unmanaged populations. Management practices differentially affected the production of flower buds, flowers, and fruits with a positive effect on fruit set in the in situ managed population. In addition, individuals of managed populations presented anticipation in the average date of the emission peaks of flower buds and ripe fruits. Individuals from the in situ managed population had available a greater volume of nectar with a higher sugar concentration per flower (twice as high) compared to the ex situ managed population and unmanaged population. The management practices seem to provide advantageous conditions for individuals of C. jamacaru since they allow higher availability of resources (flowers, nectar, and fruits) for a longer period in the Caatinga dry forest. Thus, management practices can prolong the temporal distribution of flowers and fruits, providing more resources for specialized pollinators (Sphingids) and dispersers (birds, reptiles), which are groups vulnerable to anthropic disturbances and climate changes in the Caatinga dry forest. These practices ultimately contribute to the maintenance of key ecological interactions of other species dependent on these vectors, benefiting the whole plant and animal community in the Caatinga dry forest.

Lateral bud induction and establishment of regeneration system of cassia mimosoides L.

To establish an efficient plant regeneration system of Cassia mimosoides, the 10-day-old seedlings were used as explants for inducing lateral buds. Results showed that the addition of BA and NAA for different ratios on the basis of 1/2 MS could effectively induce the production of lateral buds. By adding different additional elements, it was found that the growth of lateral buds was longer and stronger on the medium of 1/2 MS + 3.0 mg/l BA + 0.1 mg/l NAA + 4.0 mg/l Gln or 1/2 MS + 3.0 mg/l BA + 0.1 mg/l NAA + 1.0 mg/l AgNO3. Meanwhile, cutting with the lateral buds of tissue culture seedling, the rooting rate could reach 77.8% when 1/2 MS medium contained 0.2 mg/l NAA, although the root length was shorter. When the regenerated strong seedlings were transplanted into the soil, the survival rate was over 75%. Therefore, the best medium for lateral bud induction using 10-day-old seedlings as explants in C. mimosoides was 1/2 MS + 3.0 mg/l BA + 0.1 mg/l NAA. The growth of lateral buds can be promoted by the appropriate concentration of Gln and AgNO3, and the best rooting medium was 1/2 MS contained 0.2 mg/l NAA. Bangladesh J. Bot. 52(2): 515-521, 2023 (June) Special

Lateral bud induction and establishment of regeneration system of cassia mimosoides L.

To establish an efficient plant regeneration system of Cassia mimosoides, the 10-day-old seedlings were used as explants for inducing lateral buds. Results showed that the addition of BA and NAA for different ratios on the basis of 1/2 MS could effectively induce the production of lateral buds. By adding different additional elements, it was found that the growth of lateral buds was longer and stronger on the medium of 1/2 MS + 3.0 mg/l BA + 0.1 mg/l NAA + 4.0 mg/l Gln or 1/2 MS + 3.0 mg/l BA + 0.1 mg/l NAA + 1.0 mg/l AgNO3. Meanwhile, cutting with the lateral buds of tissue culture seedling, the rooting rate could reach 77.8% when 1/2 MS medium contained 0.2 mg/l NAA, although the root length was shorter. When the regenerated strong seedlings were transplanted into the soil, the survival rate was over 75%. Therefore, the best medium for lateral bud induction using 10-day-old seedlings as explants in C. mimosoides was 1/2 MS + 3.0 mg/l BA + 0.1 mg/l NAA. The growth of lateral buds can be promoted by the appropriate concentration of Gln and AgNO3, and the best rooting medium was 1/2 MS contained 0.2 mg/l NAA. Bangladesh J. Bot. 52(2): 515-521, 2023 (June) Special

A Global Perspective of the Functional Trait Responses of Graminoids to the Seasonality of Fire

In fire-prone ecosystems, plant resilience to recurrent fires depends on certain fire-adaptive traits. However, how key functional and reproductive traits of graminoids respond to varying burning seasons is poorly understood. This meta-analysis, therefore, unpacks global perspectives on how resprouting, growth, reproductive, and productivity traits of graminoids (grasses and sedges) respond to different burning seasons. We recorded 569 observations from 80 experimental studies comparing graminoid plant trait responses in unburned vs. burned treatments over different seasons of burn. Weighted log response ratios and 95% confidence intervals (95%CI) were analyzed for each plant trait using random effects models and compared across burning seasons. Summer (0.35 (95%CI = 0.25 to 0.46)) and autumn burns (0.24 (95%CI = 0.16 to 0.31)) increased above-ground biomass m−2, while biomass plant−1 was increased only by spring burns (0.27 (95%CI = 0.22 to 0.32)). Bud production plant−1 and tiller−1 were reduced significantly by fire, especially spring, summer, and autumn burns. The shoot height (0.29 (95%CI = 0.17 to 0.41)), leaf length (0.15 (95%CI = 0.11 to 0.20)), and specific leaf area (0.08 (95%CI = 0.06 to 0.09)) increased only under summer burns, while flowering was enhanced by spring (0.19 (95%CI = 0.00 to 0.38)) and autumn burns [0.34 (95%CI = 0.02 to 0.66)]. However, seed production m−2 was reduced by spring and summer burns and the opposite was true for seed production plant−1. Overall, herbaceous plant trait responses to fire varied by the season of burn, disagreeing with the general principle that early spring burning is the best practice. We suggest that a decision on the season of burn should be informed by the objective of burning.

Shoot growth pattern and return bloom of six olive varieties in response to cultivation practices stimulating or limiting the vegetative growth in young trees

Olive trees show a very marked alternate bearing behavior. Generally, this behavior is regulated by the balance between growth of vegetative and reproductive organs. A high fruit load can negatively affect the elongation of 1-year-old mixed shoots and lead to decreased production of new potential reproductive buds in the following year. Applied nutrients and water availability can also affect new shoot growth, yet, the best period for vegetative growth and bud induction is unclear. In this study we investigated growth pattern of the vegetative portion of 1-year-old mixed shoots (year n) and the return bloom in the following year (n + 1) in six olive cultivars under “strong” and “weak” vegetative growth practices. Results found that in the following year the number of inflorescences on 1-year-old mixed shoots was affected as a consequence of the different level of vegetative growth. In addition to the greater vegetative growth of 1-year-old mixed shoots, the number of sylleptic shoots also seemed to be influenced by cultivation practices. Moreover, sylleptic shoots had more inflorescences per bud than the 1-year-old shoots. The nodes of the 1-year-old mixed shoots that grew during June and July produced the majority of inflorescences per bud compared to the nodes that grew during spring and late summer.

Fire reduces Russian olive seed germination and seedling survival with increasing fuel load

Elaeagnus angustifolia (Russian olive) is an invasive tree common within riparian areas in the western United States. Control methods can be expensive and regular monitoring is necessary to control stump and root sprouts, and newly established seedlings. Studies have assessed scarification and cold treatment effects on germination and establishment of Russian olive seeds. However, fire effects on seeds and newly emerged seedlings have not been documented. Russian olive seeds were subjected to fire at three fuel loads (1,500, 3,000, and 4,500 kg/ha) and a non‐burned control. With no fire, 40% of seeds germinated and fire at any of the three fuel loads reduced germination. Germination was reduced to one‐fifth of the non‐burned level with fire at the 1,500 kg/ha fuel load and did not differ from 0% at the 4,500 kg/ha−1 fuel load. The probability of at least one seed germinating from 50‐seed lots decreased as all measures of temperature and time–temperature increased. Fire killed all but one of the 250 seedlings tested, indicating Russian olive seedlings at 10 weeks old or younger were highly susceptible to fire‐induced mortality. However, some seedlings did not die immediately following fire and produced new axillary buds. Although all but one seedling died, bud production after fire was interpreted as an indicator of potential resistance to fire. Our results indicate that fire does not enhance Russian olive seed germination and is deleterious to seed viability. Fire could potentially kill most Russian olive seedlings that are less than 1 year old.

Spatio-temporal analysis of strawberry architecture: insights into the control of branching and inflorescence complexity.

Plant architecture plays a major role in flowering and therefore in crop yield. Attempts to visualize and analyse strawberry plant architecture have been few to date. Here, we developed open-source software combining two- and three-dimensional representations of plant development over time along with statistical methods to explore the variability in spatio-temporal development of plant architecture in cultivated strawberry. We applied this software to six seasonal strawberry varieties whose plants were exhaustively described monthly at the node scale. Results showed that the architectural pattern of the strawberry plant is characterized by a decrease of the module complexity between the zeroth-order module (primary crown) and higher-order modules (lateral branch crowns and extension crowns). Furthermore, for each variety, we could identify traits with a central role in determining yield, such as date of appearance and number of branches. By modeling the spatial organization of axillary meristem fate on the zeroth-order module using a hidden hybrid Markov/semi-Markov mathematical model, we further identified three zones with different probabilities of production of branch crowns, dormant buds, or stolons. This open-source software will be of value to the scientific community and breeders in studying the influence of environmental and genetic cues on strawberry architecture and yield.

Reciprocal regulation of flower induction by ELF3α and ELF3β generated via alternative promoter usage.

Flowering is critical for sexual reproduction and fruit production. Several pear (Pyrus sp.) varieties produce few flower buds, but the underlying mechanisms are unknown. The circadian clock regulator EARLY FLOWERING3 (ELF3) serves as a scaffold protein in the evening complex that controls flowering. Here, we report that the absence of a 58-bp sequence in the 2nd intron of PbELF3 is genetically associated with the production of fewer flower buds in pear. From rapid amplification of cDNA ends sequencing results, we identified a short, previously unknown transcript from the PbELF3 locus, which we termed PbELF3β, whose transcript level was significantly lower in pear cultivars that lacked the 58-bp region. The heterologous expression of PbELF3β in Arabidopsis (Arabidopsis thaliana) accelerated flowering, whereas the heterologous expression of the full-length transcript PbELF3α caused late flowering. Notably, ELF3β was functionally conserved in other plants. Deletion of the 2nd intron reduced AtELF3β expression and caused delayed flowering time in Arabidopsis. AtELF3β physically interacted with AtELF3α, disrupting the formation of the evening complex and consequently releasing its repression of flower induction genes such as GIGANTEA (GI). AtELF3β had no effect in the absence of AtELF3α, supporting the idea that AtELF3β promotes flower induction by blocking AtELF3α function. Our findings show that alternative promoter usage at the ELF3 locus allows plants to fine-tune flower induction.

Construction of SNP fingerprint and population genetic analysis of honeysuckle germplasm resources in China

The flower buds of Lonicera japonica Thunb. are widely used in Chinese medicine for their anti-inflammatory properties, and they have played an important role in the fight against SARS COVID-19 and other major epidemics. However, due to the lack of scientific and accurate variety identification methods and national unified standards, scattered and non-standardized management in flower bud production has led to mixed varieties that have caused significant difficulties in the cataloging and preservation of germplasm resources and the identification, promotion, and application of new L. japonica varieties. In this study, we evaluated the population structure, genetic relationships, and genetic fingerprints of 39 germplasm resources of Lonicera in China using simplified genome sequencing technology. A total of 13,143,268 single nucleotide polymorphisms (SNPs) were identified. Thirty-nine samples of Lonicera were divided into four subgroups, and the population structure and genetic relationships among existing Lonicera germplasm resources were determined using principal component analysis, population structure analysis, and phylogenetic tree analysis. Through several stringent selection criteria, 15 additional streamlined, high-quality DNA fingerprints were filtered out of the validated 50 SNP loci and verified as being able to effectively identify the 39 Lonicera varieties. To our knowledge, this is the first comprehensive study measuring the diversity and population structure of a large collection of Lonicera varieties in China. These results have greatly broadened our understanding of the diversity, phylogeny, and population structure of Lonicera. The results may enhance the future analysis of genetic diversity, species identification, property rights disputes, and molecular breeding by providing a scientific basis and reference data for these efforts.

Microzooplankton as a food source for the scyphozoan <i>Aurelia coerulea</i>: growth and feeding responses of the polyp stage in field assemblages

To evaluate the growth and feeding responses of the polyp stage of the moon jellyfish Aurelia coerulea to natural microzooplankton assemblages, bud production among A. coerulea polyps was monitored in field bottle incubation experiments using fractionated field seawater (<200-µm fraction) in summer. During this incubation period, feeding rates were measured twice by examining changes in the abundance of various microzooplankton taxa over two days. The number of buds increased with incubation period, reaching a mean of 5.8–9.3 buds per polyp after 16 days, at which point the carbon content of the new buds and the mother polyp was estimated to be 1.3–2.5 times higher than the carbon content of the initial polyp. Using these carbon content estimates, I calculated specific growth rates of 0.1–0.2 d−1 during the first 10 days. The results of the present feeding experiments suggest that polyps utilize diverse groups of microzooplankton and achieve relatively high carbon ingestion rates from ciliates, dinoflagellates, molluscs, and copepod nauplii. Total microzooplankton ingestion rates were estimated to be 4.05 and 3.27 µgC polyp−1 d−1 in the two experiments, respectively. These findings show that natural microzooplankton assemblages play a role as prey of polyps and can promote asexual reproduction of polyps under natural summer conditions.

Influences of Various Factors on Inducing Adventitious Shoot Regeneration From Stem Explants of Cassia Mimosoides Linn.

In the present study, an efficient plant regeneration method was established in Cassia mimosoides by using stem explants. Low regeneration frequency with poor quality advantageous shoot buds were obtained when the explants were grown only Kinetin (KN) or thidiazeuron (TDZ) enriched media. For improving the regeneration efficiency and production of good quality adventitious buds, Cu2+, Mg2+, Fe2+ and Ag+ were supplemented in the regeneration medium at different concentrations. The highest (63.96%) adventitious bud regeneration rate, the maximum number of buds (5.39) per explant and the longest regenerated buds (3.49 cm) were obtained by adding 26 mg/l Ag+ in the regeneration medium. In order to improve the rooting in shoot buds, diethyl aminoethyl hexanoate (DA-6) at different concentrations was added into rooting medium. The optimal rooting was obtained by supplementing 0.6 mg/l DA-6. The highest rooting rate (90.23%), the highest number of roots per bud (6.08) and the longest roots (4.26 cm) were developed within 20 days of culture in this medium. By applying this method culture cycle for obtaining complete regenerated plantlets was significantly shortened (in 60 days), Additional culture for proliferation and elongation of regenerated adventitious buds was not needed. Therefore, the method established in the present study was helpful to improve the efficiency of plant regeneration from stem explants in C. mimosoides. Besides the establishment of this culture method could lay a foundation for the future large-scale cultivation and genetic transformation of C. mimosoides. Bangladesh J. Bot. 51(4): 873-882, 2022 (December) Special

Reproductive and vegetative phenology of the micro endemic Stachytarpheta cassiae (Verbenaceae)

Abstract The flora of the Brazilian rupestrian grasslands represents a hotspot of species richness and endemisms. Stachytarpheta cassiae (Verbenaceae), is a micro endemic species, from which nothing is known. Here, we quantified the activity and intensity of vegetative and reproductive phenophases throughout 12 months and tested for their seasonality and their relationship with local climatic variables. Both vegetative and reproductive phenophases were continuous. No seasonality was observed in the vegetative phenophases and none of them was influenced by climatic variables. Only flower buds and mature fruits’ intensities showed seasonality in February (rainy season) and July (dry season), respectively. Accordingly, increased temperature and humidity combined explained increased production of flower buds whereas decreased rainfall explained increased mature fruits. Higher intensity in flower buds may respond to similar climatic conditions as other species in the community. However, S. cassiae is much different as it continues producing flowers continuously. Higher intensity of mature fruits in the dry season is expected as their seeds are abiotically dispersed. Due to constant flower and leaf production, S. cassia may be a key species for the conservation of many vertebrate and invertebrate species and for maintaining the biogeochemical functioning of the impoverished soils of the rupestrian grasslands.

Lessons from a tropical deciduous shrub species: leaf fall can play a more important role than rain in leaf budding

In the Cerrado, the sequential chaining of phenological events during the dry season is a pattern observed in many plant species. In this season, many plants completely lose their leaves, and soon after deciduous, there is an expressive production of leaf buds. In this study, we investigated the effect of irrigation and early defoliation on the triggering of leaf budding of the deciduous species Peixotoa tomentosa A.Juss. in the dry season of a seasonal environment with water restrictions. Therefore, we set up an experiment with three groups of plants: control (n = 15), irrigation treatment (n = 15), and removal treatment (n = 15), and after the complete deciduousness of the plants, we carried out phenological monitoring of the development of leaf buds in these plants. From July to August 2022, the leaf budding phenology of the 45 individuals was evaluated twice a week. To test whether there is a difference in the number of leaf buds between treatments, we built generalized linear mixed models (GLMMs). Plants in the removal treatment had a statistically higher number of leaf buds produced than the plants in the irrigation and control groups (P &amp;lt; 0.05). However, the control group and the irrigation treatment did not differ from each other (P &amp;gt; 0.05). We showed that early defoliation influenced the triggering of leaf buds in P. tomentosa, increasing the production of young leaves in their individuals in a seasonal environment with water restrictions. Irrigation was not able to break the dormancy of leaf buds. Our findings contribute to a better understanding of the triggering of vegetative phenophases in deciduous Cerrado plants, showing that leaf fall may play a more important role than rain in the production of leaf buds in the dry season.

Disinfection procedure for stem cuttings and in vitro production of axillary buds for the Persian lime sanitation

The research work covered the in vitro establishment of Persian lime nodal segments using a twig disinfection protocol, and their culture on Murashige and Skoog (MS) culture media supplemented with antibiotics (Estrepto-Ler® and Rifampicin) and fungicide (Chlorothalonil). The axillary buds production was performed cultured the nodal segments without contamination signs on MS culture media enriched with two cytokinins (6-BAP and Kinetin) at different concentrations. Results showed that 52 % of the nodal segments did not show signs of in vitro contamination when the twig submerged in 20% chlorine for 15 min during disinfection process and nodal segments were grown in MS culture medium supplemented with 2 mg L-1 of Rifampicin and fungicide Chlorothalonil. Interestingly, MS culture medium enriched with 6-BAP (0.5 mg L-1) + Kinetin (0.5 mg L-1) turned out to be the best combination to achieve that 78 % of nodal segments promoted 1 to 2 axillary buds.

Vegetative propagation of Epimedium elatum C. Morren and Decne.

Epimedium L. is a celebrated medicinal genus of Chinese pharmacopoeia comprising of sixty two species, with only one species, Epimedium elatum C. Morren and Decne., in Indian subcontinent. The species is endemic to Kashmir Himalaya and grows wild as undergrowth in forests. It is a slow-growing and slow-reproducing medicinal herb, with a huge potential for being exploited for therapeutic uses, thereby necessitating its conservation, cultivation and propagation. In this context, the present work has been undertaken to develop its propagation protocol. In spring, rhizomes were divided into different sizes on the basis of the number of buds and fresh mass; planted in 10 cm pots and then evaluated for survival, growth, production and multiplication. Similarly, the divisions were made in different seasons to study the seasonal effect. Single bud divisions, with or without roots, were also made to study the effect of IBA on rooting. Rhizome divisions of larger size produced plants with the best growth characteristics and propagation potential. Plants produced from the rhizome divisions of small size didn’t flower, but showed high bud production efficiency. Rhizome divisions of spring significantly produced plants of bigger size, with better growth characteristics, than plants produced from divisions of summer and autumn. When treated with different concentrations of IBA, single-bud divisions without roots, rooted successfully; however, rooting and survival rate was significantly higher at IBA concentration of 800 ppm as compared to other two IBA concentrations. The present study indicates that small size divisions can be used in nurseries to produce more plants from a smaller number of mother stock, while large size divisions can be used to produce and cultivate mature plants. Though division of Epimedium elatum rhizomes can be undertaken at any time of the growing season, spring is the best season.