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In this paper, ‘Lu Feng No. 1’which is mainly cultured longan varieties in Luzhou was chosed as the research object. And we chose some experimental measurements on the basis of the local methods to promote floral bud differentiation. Before flower bud morphological differentiation, taking several regulation measures of spraying growth regulator in different proportions, girdling the primary branches and root pruning with coating the earth, we regularly measured endogenous hormones in terminal bud at flower bud differentiation period by every 1 5 d. When the differentiation finished, we calculated the rate of flower and fruit setting to discuss effects of regulation measures on change of endogenous hormones in terminal bud at flowering stage and flower formation and fruit setting. We analysed all experimental data for researching mechanism of flower formation. The result showed that all of these measures improved flower rate and fruit setting rate in different degrees remarkably. However, the control measures of ethylene regulator combination with appropriate concentrations (150 mg·L-1 and 100 mg·L-1)could improve the number of trees female flowers, female flowers rate and fruit-bearing rate of trees, among which the female flowers rate improved respectively by 32. 57% and 38. 22% than CK, the tip-blunting rate of each treatment was significantly lower than CK, and the tip-blunting rate (18. 58%)of treatment B (100 mg·L-1 ethylene regulator combination)was the minimum, which was 34. 18% lower than CK, and the growth rate of bud axis and tip-blunting rate have significant positive correlation. The different treatments improved the flowering and fruit-bearing status of longan body in different degrees, inhibited flowering reversion occurring effectively, and the effects of the treatment spraying mixed liquor consisted of 150. 00 mg·L-1 mutli-effect triazole an 100. 00 mg·L-1 ethephon and 1.0 mg·L-1 6-benzyl-aminopurine evenly in the crown most excellent. For the hormones in terminal buds, these contents and hormone balance were changed by the different measures. The results were as follows: with higher GA3 and ABA contents in the spindle differentiation stage, then GA3 content and ABA content keeping at a low level in multi-level side inflorescence rapidly-differentiation stage, lower ZT level in the entire morphological differentiation, and that was good for preventing longan flower from reversing and promoting longan bud differentiating. The change of IAA content affection was relatively complex, and its regularity was not strong. Viewing the point of hormones content proportion, smaller ratio of IAA/GA3 in the spindle differentiation stage, the bigger ratio of ZT/ABA before purple inflorescence primordia appearing-period and the lower ratio of ZT/ABA and GA3/ABA in hole morphological differentiation, which were beneficial to longan flowering. The study would provide theoretical basis for Luzhou longan high quality and high yield cultivation. [ABSTRACT FROM AUTHOR]

Mentha × piperita (L.) Huds. of the family Lamiaceae is a very important species for commercial exploitation due to the high content of essential oil. Besides the essential oils, there are also other significant secondary metabolites in peppermint, especially flavonoids and hydroxycinnamic derivatives. In this study, we evaluate the variability of essential oil constituents and of phenolic compounds in the leaves of M. × piperita during the development of inflorescence. Similar studies, dealing with the variation of the essential oils and its composition, have been performed in the past, but no attention was paid to the variation of other secondary metabolites. We examined M. × piperita cv. 'Perpeta', the domestic cultivar. The plants were cultivated in the climatic conditions of south-west Slovakia. The contents of secondary metabolites were investigated in the week periods, from the beginning of inflorescence formation to the end of flowering. The yield and the quality of essential oil have been carried out by distillation and gas chromatography mass spectrometry (GC-MS). The phenolic substances were analysed using spectrophotometric methods according to European Pharmacopoeia. The highest contents of phenolic substances have been found in leaves of plants during the flowering phenophase, the same stage when essential oil of mint also achieves the highest quality. [ABSTRACT FROM AUTHOR]

Current agricultural methodologies are vulnerable to erratic climate and are dependent on cost-intensive fertilization to ensure high yields. Sustainable practices should be pursued to ensure food security. Phaseolus vulgaris L. is one of the most produced legumes worldwide and may be an alternative to reduce the environmental impact of meat production as a reliable source of high-quality protein. Plant growth-promoting rhizobacteria (PGPR) are emerging as a sustainable option to increase agricultural production. To understand the dynamics between plants and microorganisms, the culturable microbiota of bean roots was isolated and identified at distinct stages of plant development (early and late vegetative growth, flowering, and pod) and root compartments (rhizoplane, endosphere, and nodules). Diversity and abundance of bacteria associated with root compartments differed throughout the plant life cycle. Bacterial plant growth promotion (PGP) and protection abilities (indole-3-acetic acid production, siderophore synthesis, and antifungal activity) were assessed and associated with plant phenology, demonstrating that among the bacteria associated with plant roots, several strains had an active role in the response to plant biological needs at each stage. Several strains stood out for their ability to display one or more PGP traits, being excellent candidates for efficient stage-specific biostimulants for application in precision agriculture.

Populations of the same plant species living in different locations but flowering at different times may vary in pollinator availability and floral traits. However, the spatial and temporal links between floral traits and pollination are rarely included in single studies. In this study, three populations of an alpine lousewort, Pedicularis rhinanthoides Schrenk subsp. tibetica (Bonati) Tsoong, were surveyed to detect the variations in floral traits and pollinator activity. We hypothesized that floral divergence was spatio-temporally correlated with pollen limitation (PL) in relation to pollinators. Sampled plants from each population were divided into three groups, according to flowering stage: early, peak, and late. Pollen-supplementation experiments and investigations into pollinators, reproductive success, and floral traits were conducted on the plants from the different flowering stages and across the populations. Our results showed that the extent of PL varies across populations and among flowering stages. Populations in which more pollinators were recorded displayed a lower extent of PL. Furthermore, the temporal differences in PL showed a similar pattern for the three populations; the plants from the peak flowering stage suffered slighter PL than those from the other two stages. Nevertheless, some of the floral traits displayed similar spatial and temporal patterns to the PL, while the others only varied among the populations spatially. The results indicated that the performance of floral traits in a particular spatial-temporal situation shows they are well adapted to the corresponding pollination environment, which might help plants to optimize their reproductive fitness under different abiotic factors.

[Display omitted] • V cmax25 , N a and Chl a of winter wheat and paddy rice exhibited distinguishable seasonality. • The seasonality of leaf N a and Chl a were inconsistent with that of V cmax25. • Differentiating pre- and post-flowering stages significantly improved the estimation of V cmax25 from Chl a. Accurate representation of photosynthetic capacity and its seasonal variations is critical for modeling carbon sequestration of cropland ecosystems through photosynthesis. Previous studies indicated that the maximum carboxylation rate at 25 °C (V cmax25) is the key determinant of photosynthetic capacity and can be mapped according to leaf nitrogen (N) and chlorophyll (Chl) contents. However, whether relationships of V cmax25 with leaf nitrogen and chlorophyll contents in cropland ecosystems change over the whole growing season remain unclear. To address this question, we conducted intensive field campaigns in winter wheat and paddy rice farmlands of Eastern China, with leaf V cmax25 , the maximum electron transport rate at 25 °C (J max25), N, and Chl measured every 7 to 10 days from the tillering stage to maturity. Results showed that V cmax25 and J max25 varied significantly during the growing seasons and maximized at flowering stages. For both winter wheat and paddy rice, Chl a (Chl content at the area unit) showed significantly different relationships with V cmax25 pre- and post- flowering while N a (N content at the area unit) did not. When different empirical models were used for pre- flowering and post- flowering stages, V cmax25 estimated from Chl a was closer to observations (R2 = 0.875, RMSE = 9.479 µmol m−2 s−1) than that estimated from N a (R2 = 0.565, RMSE = 17.718 µmol m−2 s−1). The findings in this study imply that the combination of remotely sensed leaf Chl a content and phenology would improve the mapping of V cmax25 for crops at regional and even global scales. [ABSTRACT FROM AUTHOR]

Opuntia flowers belonging to two species of prickly pear were evaluated at four flowering stages: vegetative, initial flowering, full flowering and post-flowering stage, for possible use as a potential source in the food enrichment. Chemical composition including moisture, ash, protein, fat, soluble sugars, total fibers, mineral amounts and fatty acid profiles of Opuntia ficus-indica and Opuntia stricta flowers were investigated. Functional properties (swelling capacity (SWC), water holding capacity (WHC), water solubility index (WSI) and oil holding capacity (OHC)) were also studied. Results showed that during the maturation of flowers, there is a decrease in protein contents whereas fat contents increase, for both species. High minerals amounts were noticed in Opuntia flowers and they can be considered as an excellent source of minerals. The fatty acids profiles were dominated by the palmitic acid (38–59%). The techno-functional properties (SWC, WSI, WHC and OHC) were found to be important and they can be modulated according to the temperatures. Owing to its chemical profile and functional properties, Opuntia flowers could be used as an ingredient to improve different physical and nutritional properties of foods. [ABSTRACT FROM AUTHOR]

Dracocephalum moldavica L. of the Labiatae family is an annual herbaceous plant. In Iran it is known as Badrashbi and Badrashboo. Recent publications have reported antibacterial and antimicrobial properties of its essential oil, which have a wide usage in industry. In this research, the effects of iron foliar application and different yields' harvest times on the essential oil content and some morphological treats (plant height, branch number, fresh and dry weights, essential oil content and leaf Iron content) were investigated under experimental study in faculty of Agriculture of Urmia University during 2012. A factorial experiment in a randomized complete block design with three replications was used in the present study. Results showed that foliar application of iron had a significant effect on branch number, fresh and dry weight, biomass and oil percentage. Similarly, harvest time had a significant influence on fresh and dry weight, essential oil content, essential oil yield and leaf iron content, but its effect was not significant on stem diameter and branch number. The best harvest time for Dracocephalum moldavica L. was at 100% of flowering and 6 ml/l of iron application showed the best results in all characters measured. [ABSTRACT FROM AUTHOR]

Opuntia ficus-indica f. inermis (cactus pear) flowers have wide application in folk medicine. However, there are few reports focusing on their biological activity and were no reports on their chemical composition. The nutrient composition and hexane extracts of Opuntia flowers at 4 flowering stages and their antibacterial and antifungal activities were investigated. The chemical composition showed considerable amounts of fiber, protein, and minerals. Potassium (K) was the predominant mineral followed by calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), and zinc (Zn). The main compounds in the various hexane extracts were 9.12-octadecadienoic acid (29-44%) and hexadecanoic acid (8.6-32%). The antibacterial activity tests showed that O. inermis hexane extracts have high effectiveness against Escherichia coli and Staphylococcus aureus, making this botanical source a potential contender as a food preservative or food control additive. [ABSTRACT FROM AUTHOR]

Highlights: [•] Flowers of Opuntia microdasys were profiled for hydrophilic and lipophilic compounds. [•] Significant differences were detected according to the flowering stage. [•] The chemical profiles of each flowering were classified in different clusters using PCA. [•] The antioxidant activity levels were coherent with the bioactive compounds contents. [•] These results are useful to select specific flowering stages for functional foods. [Copyright &y& Elsevier]

After a spring frost occurred in second half of March 2008, with temperatures below 0°C for 8 days consecutively and an absolute minimum of -5.5°C, a lot of observations have been made on the sweet cherry flowers damages. In three different orchards “Italian palmetta” trained on grassing ground soil, the percentage of the flowers killed by frost, was detected and recorded considering the different genotypes and flowers height from the ground. Furthermore, in one orchard only it was possible to find relationship between flowering stage and frost damage. The results clearly confirm our previous works about the highest mortality of the flower in the upper part ( > 1.50 m) of the canopy and in the full bloom open flowers. So, in this area, the easiness of agronomic operations, like pruning and, especially, fruit harvest, due to the crown proximity to the ground, is cancelled by the frequency of spring frost.

Radiant frost is a major abiotic stress, particularly at the reproductive stage, in field pea ( Pisum sativum L.) grown in Mediterranean environments. Here, response to frost was studied for flowering stage (FS) organs (buds, flowers and set pods) and pod development stage (PDS) organs (flat, swollen and mature pods) under controlled conditions, with plants exposed to a minimum temperature of -4.8°C for 4 h. This frost treatment adversely affected seed yield through (i) abortion of buds, flowers and set pods (ii) death of pods and (iii) reduction in seed size. FS organs were more sensitive to frost than PDS organs. Genetic variation was observed among 83 accessions collected from 34 countries worldwide for survival of FS buds, flowers and set pods. In 60 of 83 accessions, no buds, flowers or set pods survived the frost treatment. Five accessions: ATC 104 (origin: United Kingdom), ATC 377 (Estonia), ATC 968 (Italy), ATC 3992 (Kazakhstan) and ATC 4204 (China), showed the highest frost tolerance of FS organs and lowest numbers of abnormal seeds. The frost tolerant accessions identified in this study may be useful as parents for breeding field pea varieties that will be less likely to suffer yield loss due to radiant frost during the reproductive stage. [ABSTRACT FROM AUTHOR]

This study was carried out to investigate the morphological characteristics of collected Miscanthus spp. Fourteen accessions of Miscanthus spp. were collected in various localization in Korea, India, Nepal and USA. Collected Miscanthus spp. accessions were investigated their morphological characters, compared with pre-flowering stage and post-flowering stage. Plant height, stem diameter, number of node, tiller number, number of leaf, length of leaf, width of leaf and color of leaf have different characters significantly among the collected accessions. Miscanthus spp. accessions collected in Yangpyeong-gun (MS005), India (MS013), Iowa (MS010), M.×giganteous (MS011) showed comparatively taller height, range of more than 200 cm. There were no significant differences in the collected Miscanthus spp. accessions ranging from 2 to 3 numbers of tillers. Of the total accessions, most of collections showed 1-2 cm as over 65% in width of leaf, but collection Miscanthus spp. accessions in Andeok-myeon (MS002), Seongsan-eup (MS003) and Yangpyeong-gun(MS005) showed over 2 cm in width of leaf. Miscanthus spp. collected in Yangpyeong-gun (MS005) could be used as a bio-energy plant showing up large scale biomass in plant height, length of leaf and width of leaf. [ABSTRACT FROM AUTHOR]

A pot experiment with soybean cultivar Nannong 99-6 was conducted to study its growth and C and N metabolism at seedling and flowering stages under the stress of different duration of waterlogging. Waterlogging inhibited the soybean growth. The plant biomass, leaf area, leaf pigment content, and photosynthesis rate all decreased significantly, and the leaf malonyldialdehyde (MDA) content had a significant increase. The change ranges of the physiological indices increased with increasing waterlogging duration. After the release of the stress, the plants had some recovery. The recovery capability in treatment waterlogging for 10 d was stronger than that in the treatment waterlogging for 20 d. The leaf soluble C and N and key enzymes had different responses to waterlogging. Soluble sugar content and glutamine synthease and sucrose synthease activities all increased, but soluble protein content decreased. The influence of waterlogging on the plant biomass, leaf area, and MDA content was smaller at seedling stage than at flowering stage. It was suggested that the shorter the waterlogging duration was, the lesser damage the soybean plant suffered, and the stronger the recovery capability was. Soybean plant could recover itself after waterlogging for 10 d. [ABSTRACT FROM AUTHOR]

Abstract: The chemical composition of hexane extracts from flowers belonging to two species of prickly pear, Opuntia ficus-indica (L.) Miller and Opuntia stricta (Haw.) Haworth has been studied by gas chromatography–mass spectrometry in four developmental stages of flower: vegetative, initial flowering, full flowering, and post-flowering stages. Remarkable differences were noted between the flowers’ compositions. The main compounds were carboxylic acid (28–97%), terpenes (0.2–57%), esters (0.2–27%), and alcohols (<1.8%). The study of the biological activities showed that extracts were active in vitro towards four bacteria and two fungal strains. It exhibited remarkable activity against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Antioxidant activity of the flowers extracts was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method. Our findings demonstrate the interest of Opuntia flowers extract as a source of bioactive substances and its potential preservative use in food. [Copyright &y& Elsevier]

With 3 figures and 5 tables Abstract To identify quantitative trait loci (QTL) controlling heat tolerance in rice, the progeny of BC1F1 and F2 populations derived from an IR64 × N22 cross were exposed to 38/24°C for 14 days at the flowering stage, and spikelet fertility was assessed. A custom 384-plex Illumina GoldenGate genotyping assay was used to genotype the F2 and selected BC1F1 plants. Four single nucleotide polymorphisms were associated with heat tolerance in the BC1F1 population using selective genotyping and single marker analysis, and four putative QTL were found to be associated with heat tolerance in the F2 population. Two major QTL were located on chromosome 1 (qHTSF1.1) and chromosome 4 (qHTSF4.1). These two major QTL could explain 12.6% (qHTSF1.1) and 17.6% (qHTSF4.1) of the variation in spikelet fertility under high temperature. Tolerant allele of qHTSF1.1 was from the susceptible parent IR64, and that of qHTSF4.1 was from tolerant parent N22. The effect of qHTSF4.1 on chromosome 4 was confirmed in selected BC2F2 progeny from the same IR64 × N22 cross, and the plants with qHTSF4.1 showed significantly higher spikelet fertility than other genotypes. [ABSTRACT FROM AUTHOR]

Yield factors and oil contents of 19 Brassica napus genotypes were investigated under continuous low temperature overcast and rainy weather (CLTORW) from March 2 to March 11, 2010. Results were as below: (1) CLTORW after flowering, RES (ratio of effectual silique) decreased and was 72. 81 % of control, SPS (seeds per silique) was 57. 32% and OC (oil content) was 95. 31 % of control, but WTS (thousand seeds weight) increased to 119. 79% of control. (2) CLTORW during the flowering stage, RES decreased and was 46. 01% of control, SPS was 33. 11% and OC was 96. 71% of control, but WTS increased to 114. 67% of control. (3) The effects of CLTORW on RES and SPS during flowering stage were much more severe than those of CLTORW after flowering stage. (4) Genotypes had different responses to CLTORW. Cluster analysis showed 7 varieties had higher tolerance, such as Xiwang 98 and Zhongyou 821. The cultivar had the same tolerance response to CLTORW both during and after flowering stages. [ABSTRACT FROM AUTHOR]

Artemisinin is an endoperoxide sesquiterpene lactone, and has been proven to be very effective in treating drug resistant cases of malaria, cancer, etc. The compound is obtained from Artemisia species. In the current study, the effects of vegetative and flowering stages on artemisinin production were studied, to determine the proper harvesting time of naturally growing Artemisia species with the highest levels of artemisinin. Eight Artemisia species along with two varieties were selected for this analytical work. The results showed that artemisinin content was high in the leaves of Artemisia indica, A. sieversiana, A. roxburghiana var. roxburghiana, A. roxburghiana var. gratae, and A. parviflora at the flowering stage. The highest artemisinin content was measured in the leaves of A. dracunculus var. dracunculus. Upon comparisons of artemisinin content among the individual plant species, the highest amount of artemisinin was again in A. dracunculus var. dracunculus followed by A. sieversiana when harvested at the flowering stage. In overall comparisons, the plants at the flowering stage showed high levels of artemisinin, which is deemed the optimum harvesting time of Artemisia species in Pakistan for maximum artemisinin content. [ABSTRACT FROM AUTHOR]

Abstract: Two rice genotypes with different drought tolerance, namely Jin 23B (drought tolerant) and Zhenshan 97B (drought sensitive), were used to study the antioxidant enzyme activities, soluble sugar and starch contents in spikelets, pistil water potential and pollen number on a stigma under water-deficit stress at the flowering stage, which were involved in the spikelet sterility. Compared with respective controls, drought stress induced more serious decreases of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities and more significant increase of malonaldehyde (MDA) content in spikekets of Zhenshan 97B than in Jin 23B on 9 and 12 days after water stress (DAWS). The soluble sugar and starch contents increased significantly in spikelets of Jin 23B, but decreased significantly in spikelets of Zhenshan 97B during 9-12 DAWS. The pistil maintained higher water potential in Jin 23B than in Zhenshan 97B during 3-6 DAWS and 9-12 DAWS. In addition, water stress induced more significant decrease in the pollen number on a stigma as well as the percentage of unfilled grains in Zhenshan 97B than in Jin 23B. Thus, it is suggested that water stress induced spikelet sterility by damaging antioxidant enzyme activities, reducing carbohydrate content in spikelets and decreasing pistil water potential at the flowering stage in rice. [ABSTRACT FROM AUTHOR]

Abstract: Flowering time plasticity is a commonly occurring adaptive characteristic of fodder crops, including legumes, in arid and semiarid environments of the Mediterranean regions. Time of flowering is mainly influenced by genotype, temperature and photoperiod. Field experiments were carried out at Foggia (southern Italy) during successive growing seasons (from 8 to 16 growing cycles according to species) to study the relation among air temperature, photoperiod and duration of the morphological development of flowering in eight forage legume species: sulla (Hedysarum coronarium L.), sainfoin (Onobrychis viciifolia Scop.), pea (Pisum sativun L.), berseem clover (Trifolium alexandrinum L.), Persian clover (Trifolium resupinatum L.), faba bean (Vicia faba L.), common vetch (Vicia sativa L.) and hairy vetch (Vicia villosa Roth). Time to reach 10% flowering (EF) and 100% flowering (FF) were recorded. Rate of progress to flowering, defined as the inverse of time from sowing to EF and FF, was related to mean daily temperature, or to both mean daily temperature and mean photoperiod. Using the linear equations, the thermal time requirements (T t) and the base temperature (T b) expressed as heat units were determined by the x-intercept method for both EF and FF stages. Evaluation of flowering time was also based on days after planting (DAP), day of year (DOY) and on a photothermal index (PTI). For all species, a significant negative correlation (P ≥0.01) was found between planting date (PD) and DAP whereas PTI showed a significant negative relationship (P ≥0.05) only for faba bean, pea, berseem clover and common vetch. In sainfoin, sulla and berseem clover, the rate of progress to flowering was affected significantly (P ≥0.05) by both mean temperature and photoperiod. The T t requirements to reach the EF and the FF stage ranged from 871 to 1665°Cday and from 1043 to 1616°Cday, respectively, for the studied species. Both phenological stages considered depended upon accumulated thermal time above a species-specific base temperature. Furthermore, in all legumes the onset of flowering only occurred when dual thresholds of a minimum T t and a minimum photoperiod were reached, which were specific to each species. [Copyright &y& Elsevier]

The objective of this research was to develop a prognosis support system that provides users with predictions of the dates of the beginning and end of flowering stage and the honey potential yield of sunflower (Helianthus annuus L.) crops. It is emphasized that this prognosis is a "poor-structured" problem and it can be solved most advantageously by a tool of "decision support system" type. The prognosis method of the flowering stage is based on "thermal time" (TT) measured in "growing degree-days". The model of calculation of the daily biologically active temperature for TT summations uses a "base temperature" of 6.7 °C and a correction of the average daily temperature. Three TT thresholds are defined: (1) sowing - emergence, (2) emergence - beginning of flowering, and (3) beginning - end of flowering. These TT thresholds and the honey potential yield - the prognosis parameters - are specific to hybrids, maturity class of hybrids (four classes) and to climatic types of crop years (four types). The (re-) calibration of the prognosis parameters is performed by averaging the sunflower crops historical data that are accumulated during system use (in that way a "self-improving" system is obtained). Four estimation methods of different accuracies are used. The prognosis of meteorological data is performed based on the historical data of the years of the given climatic type estimated by user for the prognosis year. The prognoses of the flowering stage and honey potential yield are based on the calibrated parameters, estimated meteorological data for the prognosis year, and sowing data specified by user. [ABSTRACT FROM AUTHOR]

Abstract: The Cd accumulation and biomass characteristics of a newly found Cd-hyperaccumulator Solanum nigrum L. were investigated at the flowering stage and the mature stage. The results showed that the concentration of Cd in the stems and leaves of S. nigrum harvested at the flowering stage was up to 83.1% and 85.5% of that at the mature stage, and the dry-weight sum of the stems and leaves of S. nigrum harvested at the flowering stage was 93.4% of that at its seed maturity. The Cd-removing ratio by the shoots of S. nigrum harvested at the flowering stage was 87.5% of that at the mature stage. It was also found by observing the growth duration of S. nigrum that the frostless period at the experimental site was at least twice as long as the growth duration from the seedling-transplanted phase to the flowering stage of the hyperaccumulator. Therefore, S. nigrum could be transplanted into contaminated soils twice in one year by harvesting the hyperaccumulator at its flowering stage based on climatic conditions of the site and traits of the plant growth. In particular, the extraction efficiency of Cd by harvesting the shoots of S. nigrum at its flowering stage twice in one year could increase 75.0% compared to that of at its single maturity. Thus, the method of multiple harvesting would be very important to increase phytoremediation efficiency in practice. [Copyright &y& Elsevier]

Spearmint ( Mentha spicata L. ) plants were grown in a greenhouse in a nutrient solution containing manganese (Mn) concentrations varying between 9 μM and 15.75 μM until the flowering stage. The rates of chlorophyll and carotenoid contents were similar for treatments up to 13.5 μM, followed by a statistically significant increase onwards. Chlorophyll a and total carotenoids reduced gradually with increasing Mn concentrations, showing statistically significant differences in the last treatment (15.75 μM Mn) Anthocyanin contents increased gradually and steadily with increasing Mn concentrations. Accumulation of Mn in Mentha spicata roots was greater than shoots, indicating significant metal immobilization by the roots. The main conclusion is that Mn accumulation starts to be toxic as concentration of Mn increases. [ABSTRACT FROM AUTHOR]

The color of bracts generally turns yellow or black from green during cereal grain development. However, the impact of these phenotypic changes on photosynthetic physiology during black bract formation remains unclear. Two oat cultivars (Avena sativa L.), 'Triple Crown' and 'Qinghai 444', with yellow and black bracts, respectively, were found to both have green bracts at the heading stage, but started to turn black at the flowering stage and become blackened at the milk stage for 'Qinghai 444'. Their photosynthetic characteristics were analyzed and compared, and the key genes, proteins and regulatory pathways affecting photosynthetic physiology were determined in 'Triple Crown' and 'Qinghai 444' bracts. The results show that the actual PSII photochemical efficiency and PSII electron transfer rate of 'Qinghai 444' bracts had no significant changes at the heading and milk stages but decreased significantly (p < 0.05) at the flowering stage compared with 'Triple Crown'. The chlorophyll content decreased, the LHCII involved in the assembly of supercomplexes in the thylakoid membrane was inhibited, and the expression of Lhcb1 and Lhcb5 was downregulated at the flowering stage. During this critical stage, the expression of Bh4 and C4H was upregulated, and the biosynthetic pathway of p-coumaric acid using tyrosine and phenylalanine as precursors was also enhanced. Moreover, the key upregulated genes (CHS, CHI and F3H) of anthocyanin biosynthesis might complement the impaired PSII activity until recovered at the milk stage. These findings provide a new insight into how photosynthesis alters during the process of oat bract color transition to black. [ABSTRACT FROM AUTHOR]

• Volatiles profiling of Egyptian Rosa damascena Mill. flowers at different stages was presented. • Differences in flowers aroma along with anti-collagenase effect were identified. • Alcohols, esters and oxides were detected at higher levels in expanded flowers. • Ultra-high performance liquid chromatography-mass spectrometry revealed 66 secondary metabolites in Egyptian rose. • Several sphingolipid conjugates and tannins were reported for the first time. Rosa damascena Mill. is well recognized for its value as an ornamental aromatic plant with several folk medicinal uses. As a valuable oil-bearing plant, its aroma profile was extensively studied, albeit differences between unexpanded rose flowers (URF) and expanded rose flowers (EFR) at different levels of blooming is not reported. Rose scent from both stages was determined using headspace solid-phase microextraction (HS-SPME) for the first time for Egyptian rose. A total of 75 volatiles were detected, with alcohols, esters, and oxides as valuable volatile classes at ca. 64 %, 10 % and 2 % respectively in ERF compared to 46 %, 2 %, and 0.4 % in URF. Egyptian rose aroma is considered of high quality being enriched in citronellol, geraniol, and phenylethyl alcohol (rose oil). Total flavonoids, phenolics, and anthocyanins were found more enriched in ERF than URF. Further, comprehensive ultra-high-performance liquid chromatography/photodiode array detector/electrospray ionization-mass spectrometry UHPLC/PDA/ESI-MS revealed 66 secondary metabolites, of which sphingolipid conjugates and tannins are first time to be reported in rose including several novel phenolics viz. , gallic acid-di- O -hexoside, galloyl hexose malic acid I, digalloyl-hexosyl-ellagic acid and levoglucosangallate I. Further, in-vitro anti collagenase assay revealed a strong effect for ERF compared to URF and in correlation to its metabolite fingerprint. The strong fragrant scent of Egyptian rose along with its anti-collagenase effect poses it for incorporation in cosmetics and skincare products. [ABSTRACT FROM AUTHOR]

• The EarSegNet outperformed SegNet and Two-stage method, providing robust results. • The EarSegNet was efficient at segmenting ears of winter wheat. • The encoder structure had no significant influence on the performance. • The EarSegNet had promising potentials for field applications. Fast and accurate segmentation of winter wheat ears from canopy images can significantly promote the field phenotyping of ears by improving efficiency. In this study, a semantic segmentation based method, i.e., EarSegNet, was proposed to perform pixel-wise classification to segment wheat ears from canopy images captured in field conditions. The EarSegNet integrated the encoder-decoder structure and dilated convolution, aiming to further improve the segmentation accuracy and efficiency for the ears of winter wheat. The results showed that the proposed EarSegNet was able to achieve accurate segmentation of wheat ears from canopy images captured at the flowering stage (segmentation quality = 0.7743, F1 score = 87.25%, structural similarity index = 0.8773). In order to validate the proposed method, the performance of the proposed EarSegNet was compared to the widely used segmentation methods, i.e., SegNet, Two-stage method, and Panicle-SEG. Results showed that the proposed EarSegNet outperformed the compared methods, making a robust and efficient tool to segment ears of winter wheat from canopy images captured at the flowering stage. Generalization tests showed that the proposed EarSegNet achieved superior performances to the compared method, suggesting that the EarSegNet had great potentials for field applications. Obtained results showed that the depths of the encoder, i.e., VGG16, had no significant influences on the performance of EarSegNet, however, deepening the VGG16 would improve the performance of the EarSegNet on the evaluation metric of recall. The results showed that the EarSegNet was a promising tool for ears of winter wheat at flowering stage. [ABSTRACT FROM AUTHOR]

Background: Salt stress, a major plant environmental stress, is a critical constraint for rice productivity. Dissecting the genetic loci controlling salt tolerance in rice for improving productivity, especially at the flowering stage, remains challenging. Here, we conducted a genome-wide association study (GWAS) of salt tolerance based on exome sequencing of the Thai rice accessions., Results: Photosynthetic parameters and cell membrane stability under salt stress at the flowering stage; and yield-related traits of 104 Thai rice (Oryza sativa L.) accessions belonging to the indica subspecies were evaluated. The rice accessions were subjected to exome sequencing, resulting in 112,565 single nucleotide polymorphisms (SNPs) called with a minor allele frequency of at least 5%. LD decay analysis of the panel indicates that the average LD for SNPs at 20 kb distance from each other was 0.34 (r 2 ), which decayed to its half value (~ 0.17) at around 80 kb. By GWAS performed using mixed linear model, two hundred loci containing 448 SNPs on exons were identified based on the salt susceptibility index of the net photosynthetic rate at day 6 after salt stress; and the number of panicles, filled grains and unfilled grains per plant. One hundred and forty six genes, which accounted for 73% of the identified loci, co-localized with the previously reported salt quantitative trait loci (QTLs). The top four regions that contained a high number of significant SNPs were found on chromosome 8, 12, 1 and 2. While many are novel, their annotation is consistent with potential involvement in plant salt tolerance and in related agronomic traits. These significant SNPs greatly help narrow down the region within these QTLs where the likely underlying candidate genes can be identified., Conclusions: Insight into the contribution of potential genes controlling salt tolerance from this GWAS provides further understanding of salt tolerance mechanisms of rice at the flowering stage, which can help improve yield productivity under salinity via gene cloning and genomic selection.

With pot experiment, two soybean (Glycine max) varieties, Jindou 21 (drought-tole-rant) and Xudou 22 (drought-sensitive), were used to examine the effects of α-naphthaleneacetic acid (NAA) on carbon metabolism of soybean under drought stress at flowering stage. The results showed that under drought stress, compared to Xudou 22, Jindou 21 had smaller decrease in net photosynthetic rate (P n ), smaller increase in photorespiration rate (P r ) and soluble sugar content of leaves, while a greater increase in the activities of sucrose phosphate synthase (SPS) and sucrose synthetase (SS) (synthesis) of leaves and sucrose content of roots. NAA treatment increased P n and decreased P r under drought stress, and thus obviously alleviated the growth inhibition of drought stress on plants. NAA treatment reduced the activities of starch-degrading enzymes, acid invertase (AI) and SS (cleavage), thereby inhibited the accumulation of soluble sugar induced by drought stress. In addition, NAA treatment increased SPS and SS (synthesis) activities of leaves, sucrose content of roots and shoot-root ratio, indicating that NAA treatment improved the transportation of sucrose from leaf blade to root under drought stress. In conclusion, exogenous NAA could enhance drought tolerance in soybean by regulating carbon metabolism.