Diminishing warming effects on plant phenology over time.

Plant phenology, the timing of recurrent biological events, shows key and complex response to climate warming, with consequences for ecosystem functions and services. A key challenge for predicting plant phenology under future climates is to determine whether the phenological changes will persist with more intensive and long-term warming. Here, we conducted a meta-analysis of 103 experimental warming studies around the globe to investigate the responses of four phenophases - leaf-out, first flowering, last flowering, and leaf coloring. We showed that warming advanced leaf-out and flowering but delayed leaf coloring across herbaceous and woody plants. As the magnitude of warming increased, the response of most plant phenophases gradually leveled off for herbaceous plants, while phenology responded in proportion to warming in woody plants. We also found that the experimental effects of warming on plant phenology diminished over time across all phenophases. Specifically, the rate of changes in first flowering for herbaceous species, as well as leaf-out and leaf coloring for woody species, decreased as the experimental duration extended. Together, these results suggest that the real-world impact of global warming on plant phenology will diminish over time as temperatures continue to increase.

Alpine grassland community productivity and diversity differences influence significantly plant sexual reproduction strategies.

Whether and how community structure variation affects plant sexual reproduction is crucial for understanding species' local adaptation and plant community assembly, but remains unrevealed. In Qinghai-Tibetan grassland communities that differed in aboveground biomass (AGB) and species diversity, we found significant influence of AGB on both species' reproductive biomass allocation (RBA) and flowering and fruiting time, but of species diversity only on species' reproductive time. In high-AGB or high-diversity communities, smaller and earlier flowering species generally advanced their reproductive phenology and increased their reproductive allocation for maximizing their reproductive success, whereas larger and later flowering species delayed their reproductive phenology and decreased their reproductive allocation for maximizing their vegetative growth and resource competition. This change in reproductive allocation with the variation in community structures was more pronounced in nonclonal as compared to clonal plant species. Thus, we evidence an important influence of community structure on plant sexual reproduction strategies, and the pattern of the influence depends largely on species biological attributes.

LIKE HETEROCHROMATIN PROTEIN 1 (LHP1) partially inhibits the transcriptional activation of FT by MYB73 and regulates flowering in Arabidopsis.

Polycomb group (PcG) proteins are essential gene repressors in higher eukaryotes. However, how PcG proteins mediate transcriptional regulation of specific genes remains unknown. LIKE HETEROCHROMATIN PROTEIN 1 (LHP1), as a component of Polycomb Repression Complexes (PRC), epigenetically mediates several plant developmental processes together with PcG proteins. We observed physical interaction between MYB73 and LHP1 in vitro and in vivo. Genetic analysis indicated that myb73 mutants showed slightly late flowering, and the lhp1-3 myb73-2 double mutant exhibited delayed flowering and downregulated FT expression compared to lhp1-3. Chromatin immunoprecipitation and yeast one-hybrid assays revealed that MYB73 preferentially binds to the FT promoter. Additionally, our protoplast transient assays demonstrated that MYB73 activates to the FT promoter. Interestingly, the LHP1-MYB73 interaction is necessary to repress the FT promoter, suggesting that the LHP1-MYB73 interaction prevents FT activation by MYB73 in Arabidopsis. Our results show an example in which a chromatin regulator affects transcriptional regulation by negatively regulating a transcription factor through direct interaction.

Knockout of OsWOX13 Moderately Delays Flowering in Rice under Natural Long-Day Conditions.

Plants are sensitive to photoperiods and are also equipped with systems to adjust their flowering time in response to various changes in the environment and developmental hormones. In the present study, previously generated rice OsWOX13 overexpression (OsWOX13-ov) and newly generated OsWOX13 knockout (oswox13-ko) lines constructed via Cas9-CRISPR technology flowered 10 days earlier and 4 to 6 days later than the WT, respectively. qRT‒PCR analyses revealed that OsWOX13 might be involved in drought escape (DE) responses through the b-ZIP TRANSCRIPTION FACTOR 23 (OsbZIP23) signaling pathway during rice flowering via photoperiod signaling genes such as grain number, plant height and heading date (Ghd7), EARLY HEADING DATE 1 (Ehd1), RICE FLOWERING LOCUS T 1 (RFT1), Heading date 3a (Hd3a) and MADS14. Future investigations of OsWOX13 may provide insight into how plants adjust their flowering under stress conditions and how OsWOX13 could be precisely controlled to achieve maximum productivity in rice breeding.

Molecular characterization of PSEUDO RESPONSE REGULATOR family in Rosaceae and function of PbPRR59a and PbPRR59b in flowering regulation.

BACKGROUND: PSEUDO RESPONSE REGULATOR (PRR) genes are essential components of circadian clock, playing vital roles in multiple processes including plant growth, flowering and stress response. Nonetheless, little is known about the evolution and function of PRR family in Rosaceae species. RESULTS: In this study, a total of 43 PRR genes in seven Rosaceae species were identified through comprehensive analysis. The evolutionary relationships were analyzed with phylogenetic tree, duplication events and synteny. PRR genes were classified into three groups (PRR1, PRR5/9, PRR3/7). The expansion of PRR family was mainly derived from dispersed and whole-genome duplication events. Purifying selection was the major force for PRR family evolution. Synteny analysis indicated the existence of multiple orthologous PRR gene pairs between pear and other Rosaceae species. Moreover, the conserved motifs of eight PbPRR proteins supported the phylogenetic relationship. PRR genes showed diverse expression pattern in various tissues of pear (Pyrus bretschneideri). Transcript analysis under 12-h light/ dark cycle and constant light conditions revealed that PRR genes exhibited distinct rhythmic oscillations in pear. PbPRR59a and PbPRR59b highly homologous to AtPRR5 and AtPRR9 were cloned for further functional verification. PbPRR59a and PbPRR59b proteins were localized in the nucleus. The ectopic overexpression of PbPRR59a and PbPRR59b significantly delayed flowering in Arabidopsis transgenic plants by repress the expression of AtGI, AtCO and AtFT under long-day conditions. CONCLUSIONS: These results provide information for exploring the evolution of PRR genes in plants, and contribute to the subsequent functional studies of PRR genes in pear and other Rosaceae species.

First report of anthracnose caused by Colletotrichum fructicola on winter jasmine (Jasminum nudiflorum) in China.

Winter jasmine (Jasminum nudiflorum Lindl.) is a medium-sized, deciduous shrub native to China that has become a popular choice among gardeners and landscapers. In 2020 to 2021, symptoms of anthracnose including brown necrotic spots, enlarged irregular lesions and leaf blight were observed on leaves of 20 winter jasmine shrubs in a public garden (22°34'58'' N; 113°56'23'' E) in Shenzhen, China, and with an estimated disease incidence of 65%. Tissues samples (6 × 6 mm2) surrounding the necrotic spots were surface sterilized with 75% ethanol for 30 s, followed by 2% NaClO for 1 min, then rinsed with sterile water for three times and dried with sterile filter paper. Tissues were placed on potato dextrose agar (PDA) medium and incubated at 25℃. After 3 to 7 d, pure cultures were obtained by transferring hyphal tips to new plates and 32 isolates producing Colletotrichum-like colonies were obtained from 40 tissues (isolation frequency=32/(4×10)=80%). Three representative isolates YCH09, YCH23 and YCH32 were selected for further study. Three selected isolates were identical in morphological characteristics. Colonies on PDA after 5 d at 25℃ were white to gray with cottony mycelia and grayish-white on the underside of the culture. Conidia (n = 60) measured 15.4 ± 1.1 µm (13.0 to 17.1 µm) in length and 5.4 ± 0.3 µm (4.9 to 6.0 µm) in width and were hyaline, single-celled, cylindrical with rounded ends. Appressoria (n = 15) measured 7.1 ± 0.1 µm (5.3 to 8.9 µm) in length and 5.2 ± 0.2 µm (4.1 to 6.2 µm) in width and were brown to dark brown, ovoid. These morphological features were aligned with those of Colletotrichum spp. (Weir et al. 2012). Sequences of five genetic markers of representative isolates YCH09, YCH23 and YCH32 including the rDNA internal transcribed spacer region, chitin synthase, partial actin, ß-tubulin 2 and Apn2-Mat1-2 intergenic spacer and partial mating type (Mat1-2) region were 99.3 to 100% identical to the ex-type isolate of C. fructicola strain ICMP 18581 (Zhang et al., 2020). From the maximum likelihood phylogenetic tree which was constructed based on concatenated sequences, three representative isolates (YCH09, YCH23 and YCH32) were clustered with other isolates of C. fructicola. The above morphological and molecular characteristics suggest that causal agent was C. fructicola. Pathogenicity was tested using a whole-plant assay. Five healthy plants were inoculated by spraying a conidial suspension (1.5×104 conidia/ml; 20 ml per plant) of the isolate YCH23 onto the foliage (Marshall et al., 2023). Three noninoculated control plants were sprayed with sterile water. All plants were placed in a greenhouse at 25±2℃ with approximately 75% relative humidity. Yellow lesions appeared on leaves of inoculated plants as early as 4 days after inoculation (DAI), and irregularly shaped brown spots similar to those observed in the field were formed on 10 DAI. Noninoculated plants remained asymptomatic. Colletotrichum isolates resembling morphological characters of YCH23 were reisolated from all inoculated plants, then identified as C. fructicola by DNA sequence analysis. C. fructicola is a well-known fungus causing anthracnose on more than 63 plant species including agricultural and horticultural plants worldwide (Talhinhas and Baroncelli, 2021). To our knowledge, this is the first report of C. fructicola infecting J. nudiflorum plants in China. Since its potential risk to other horticultural plant species, precautions may be necessary to minimize the spread of this fungi.

First Report of Neofusicoccum yunnanense Causing Leaf Spot on Ivy in Yunnan Province, China.

Ivy (Hedera nepalensis var. sinensis (Tobl.) Rehd) is an evergreen root-climbing vine, widely cultivated in eastern Asia because of its ornamental, environmental, and medicinal value (Wu et al. 2019). In October 2023, the leaf spot symptom of Ivy was observed in the Kunming Botanical Garden in Yunnan Province, China (25.14°N, 102.75°E), and the disease incidence was up to 38% (76 of 200 leaves). Initially, dark-brown or black small spots appeared on the leaves. As the lesions progressed, their center emerged tawny, and the black halos were expanded around the lesions. In severe cases, small spots could link together to form leaf blight even resulting in blade death. In order to obtain pure isolates, 10 diseased leaves were collected and cut into 1 mm × 1 mm pieces, surface disinfected with 75 % ethanol for 30 s, followed by 3% NaClO for 3 min, and finally washed three times with sterilized water. The pieces were placed on the potato dextrose agar (PDA) media, which was incubated at 25°C for 3 days. Individual hyphal tips from the developing fungal colonies were placed on PDA and incubated for 5 to 10 days. Six strains (6 out of 10) were obtained with same colony morphology. Conidia were hyaline, unicellular, nonseptate, ellipsoidal or fusiform, thin walled, externally smooth and ranged from 15.0 to 22.0 (avg. 18.4) µm × 5.0 to 8.0 (avg. 7.2) µm (n=30). Morphological comparison proposed that the present fungi belonged to Neofusicoccum (Zhang et al. 2021). Two isolates (GUCC23-0141 and GUCC23-0142) were selected for multi-gene phylogenetic analyses. The PCR reaction of the internal transcribed spacer region (ITS), translation elongation factor 1-α (EF1-α), and ß-tubulin genes were run using primers ITS1/ ITS4 (White et al. 1990), EF1-728F/ EF1-986R (Carbone and Kohn 1999), and Bt2a/ Bt2b (Glass and Donaldson 1995). The accession numbers of DNA sequences of GUCC23-0141 and GUCC23-0142 are ITS: PP728109 and PP728110; TUB2: PP744490 and PP744491; and TEF1-α: PP744488 and PP744489. BLAST analysis showed 100% identity for ITS and TUB2, and 98.97% for TEF1-α with the Neofusicoccum yunnanense (CSF6142). Phylogenetic analyses also supported that our isolates kept a close relationship to N. yunnanense. Three one-year plants were used for pathogenicity test, two of which were inoculated with PDA plugs containing N. yunnanense and one of which was inoculated with blank PDA plugs and used as control. For each plant, three leaves were selected to conduct the test, whose surfaces were sterilized with 75% alcohol. All the leaves were covered with cotton moistened with sterilized water on top. All plants were placed in a greenhouse with 25℃ and 75% humidity. Few small black spots were observed at the inoculation site after 3 days, which were enlarged gradually after 7 days. However, control plants remained healthy. N. yunnanense was reisolated from the diseased tissues and identified based on morphological and molecular characteristics. On basis of pathogen identification and Koch's test, we proposed the leaf spot of Ivy caused by N. yunnanense. This was the first report about N. yunnanense causing the disease of Ivy. This result provides a theoretical basis for further research into the control of the disease. As an important ornamental plant, we should pay attention to the management of this disease.

Effects of Heat Stress during Anthesis and Grain Filling Stages on Some Physiological and Agronomic Traits in Diverse Wheat Genotypes.

Heat stress represents a significant environmental challenge that adversely impacts the growth, physiology, and productivity of wheat. In order to determine the response to high temperatures of the wheat varieties developed mostly in the Pannonian environmental zone, as well as varietal differences, we subjected seven varieties from Serbia, one from Australia, and one from the UK to thermal stress during anthesis and mid-grain filling and combined stress during both of these periods. The changes in chlorophyll fluorescence and index, leaf temperature, and main agronomic traits of nine winter wheat varieties were investigated under high temperatures. Heat stress negatively affected leaf temperature, chlorophyll fluorescence, and the chlorophyll index during different growth stages. Compared to the control, stress at anthesis, mid-grain filling, and combined stress resulted in yield reductions of 32%, 46%, and 59%, respectively. Single treatment at anthesis had a more severe effect on the number of grains per plant, causing a 38% reduction compared to the control. Moreover, single treatment during mid-grain filling resulted in the greatest decline in grain weight, with a 29% reduction compared to the control. There was a significant varietal variation in heat tolerance, highlighting Avangarda and NS 40s as the most tolerant varieties that should be included in regular breeding programs as valuable sources of heat tolerance. Understanding the genetic and physiological mechanisms of heat tolerance in these promising varieties should be the primary focus of future research and help develop targeted breeding strategies and agronomic practices to mitigate the adverse effects of heat stress on wheat production.

Improvement of Flowering Stage in Japonica Rice Variety Jiahe212 by Using CRISPR/Cas9 System.

The flowering period of rice significantly impacts variety adaptability and yield formation. Properly shortening the reproductive period of rice varieties can expand their ecological range without significant yield reduction. Targeted genome editing, like CRISPR/Cas9, is an ideal tool to fine-tune rice growth stages and boost yield synergistically. In this study, we developed a CRISPR/Cas9-mediated multiplex genome-editing vector containing five genes related to three traits, Hd2, Ghd7, and DTH8 (flowering-stage genes), along with the recessive rice blast resistance gene Pi21 and the aromatic gene BADH2. This vector was introduced into the high-quality japonica rice variety in Zhejiang province, Jiahe212 (JH212), resulting in 34 T0 plants with various effective mutations. Among the 17 mutant T1 lines, several displayed diverse flowering dates, but most exhibited undesirable agronomic traits. Notably, three homozygous mutant lines (JH-C15, JH-C18, and JH-C31) showed slightly earlier flowering dates without significant differences in yield-related traits compared to JH212. Through special Hyg and Cas marker selection of T2 plants, we identified seven, six, and two fragrant glutinous plants devoid of transgenic components. These single plants will serve as sib lines of JH212 and potential resources for breeding applications, including maintenance lines for indica-japonica interspecific three-line hybrid rice. In summary, our research lays the foundation for the creation of short-growth-period CMS (cytoplasmic male sterility, CMS) lines, and also provides materials and a theoretical basis for indica-japonica interspecific hybrid rice breeding with wider adaptability.

Functional Characterization of JcSWEET12 and JcSWEET17a from Physic Nut.

Physic nut (Jatropha curcas L.) has attracted extensive attention because of its fast growth, easy reproduction, tolerance to barren conditions, and high oil content of seeds. SWEET (Sugar Will Eventually be Exported Transporter) family genes contribute to regulating the distribution of carbohydrates in plants and have great potential in improving yield and stress tolerance. In this study, we performed a functional analysis of the homology of these genes from physic nut, JcSWEET12 and JcSWEET17a. Subcellular localization indicated that the JcSWEET12 protein is localized on the plasma membrane and the JcSWEET17a protein on the vacuolar membrane. The overexpression of JcSWEET12 (OE12) and JcSWEET17a (OE17a) in Arabidopsis leads to late and early flowering, respectively, compared to the wild-type plants. The transgenic OE12 seedlings, but not OE17a, exhibit increased salt tolerance. In addition, OE12 plants attain greater plant height and greater shoot dry weight than the wild-type plants at maturity. Together, our results indicate that JcSWEET12 and JcSWEET17a play different roles in the regulation of flowering time and salt stress response, providing a novel genetic resource for future improvement in physic nut and other plants.

First report of Tomato Zonate Spot Virus infecting Belamcanda chinensis in China.

Tomato zonate spot virus (TZSV, Orthotospovirus tomatozonae, genus Orthotospovirus, family Tospoviridae) was first reported to infect tomato (Solanum lycopersicum) in China in 2008 (Dong et al. 2008). Belamcanda chinensis (L.) Redouté is a perennial herbaceous medicinal plant of the family Iridaceae, which is widely distributed in China. Its rhizome contains abundant active components, mainly including flavonoids, and has antibacterial, anticancer, and antioxidative effects. In July 2023, four B. chinensis plants with virus-like symptoms were collected in Fuyuan County, Yunnan Province in China. The diseased leaves showed chlorosis and ringspots (Fig. S1). Spherical virus particles with a diameter of 80-100 nm were observed in the saps of diseased leaves under a transmission electron microscope (Fig. S2). The presence of an orthotospovirus was confirmed by the previously reported method to amplify the partial sequence (312 nt) of L segment (Huang et al. 2018) (Fig. S3). BLASTn analysis showed that the obtained 312-nt sequence was 95.62% nucleotide identity with TZSV tomato-YN isolate (accession no. NC_010491.1). To obtain the complete genome of this isolate, total RNA from symptomatic leaves of two single diseased B. chinensis were extracted using Hipure Universal RNA Mini Kit (Magen Biotech) and subjected to high-throughput sequencing with a NovaPE150 (Illumina, USA) at MAGIGENE (Shenzhen, China). A total of 41,144,571 clean reads were obtained after removing low quality reads. Quality-controlled, qualified reads were assembled into contigs using Megahit v1.1.2 software. Thirteen contigs shared nucleotide identity ranging 86.94%-97.73% with the L, S, and M segments of TZSV using BLASTn searches online (https://blast.ncbi.nlm.nih.gov/Blast.cgi). In addition, no contigs were mapped to other viral (taxid:10239) and viroidal (taxid:12884) sequences in GenBank Databases. The full-length L, M, and S RNA segments of TZSV-Bc isolate was determined tbe 8917 nt (PP314222), 4718 nt (PP314223) and 3213 nt (PP314224), respectively. These segments were validated by RT-PCR, and Sanger sequencing. They shared nucleotide sequence identities of 95.9%, 97.2%, and 93.1% of the L (NC_010491.1), M (NC_010490.1), and S (NC_010489.1) segments, of the TZSV tomato-YN isolate, respectively. Compared to the TZSV tomato-YN isolate, there exists a missing segment with 113 nt in the intergenic region of S RNA and a segment with 199 nt in M RNA. To further confirm the TZSV infection on B. chinensis, three primers pairs Tosp10/ Tosp11， Tosp5/Tosp6, and NSs-F/NSs-R were tested by RT-PCR for TZSV based on the previous report (Dong et al, 2008). The sequences of amplicons shared >99% nucleotide identity with the corresponding TZSV-Bc isolate sequences. Total of 14 B. chinensis samples were detected with the primer pair N-F/N-R (5'-ATGTCTAACGTCCGGAGTTTAACA-3'/ 5'-AAAAGACAGATCATTGCTGCTCTT-3') by One Step RT-PCR, 6 samples (42.85%) showed the positive results. The mechanical inoculation and RT-PCR detection confirmed TZSV-Bc isolate can infect N. bethamiana. So far, tomato zonate spot virus has been detected in different plants including tobacco (N. tabacum) (Huang et al. 2017), sticktight (Bidens pilosa) (Xu et al. 2022), pepper (Capsicum annuum) (Li et al. 2023) in China. To our knowledge, it is the first report of TZSV naturally infecting B. chinensis plants, which enriches information on the host range of TZSV and will be helpful for disease management.

Propagation path of a flowering cherry (Cerasus × yedoensis) cultivar 'Somei-Yoshino' traced by somatic mutations.

In the long history of human relations with flowering cherry trees in Japan, 'Somei-Yoshino' occupies an exceptional position among a variety of flowering trees: it is a self-incompatible interspecific hybrid but has been enthusiastically planted by grafting throughout Japan, due most likely to its flamboyant appearance upon full bloom. Thus, 'Somei-Yoshino' gives us a rare opportunity to trace and investigate the occurrence and distribution of somatic mutations within a single plant species through analysis of the genomes of the clonally propagated trees grown under a variety of geographical and artificial environments. In the studies presented here, a total of 46 samples of 'Somei-Yoshino' trees were collected and their genomes were analyzed. We identified 684 single nucleotide mutations, of which 71 were present in more than two samples. Clustering analysis of the mutations indicated that the 46 samples were classified into eight groups, four of which included 36 of the 46 samples analyzed. Interestingly, all the four tree samples collected in Ueno Park of Tokyo were members of the four groups mentioned above. Based on comparative analysis of their mutations, one of the four trees growing in Ueno Park was concluded to be the closest to the original ancestor. We propose that somatic mutations may be used as tracers to establish the ancestral relationship amongst clonally propagated individuals.

Influence of plant community on Aedes albopictus (Diptera, Culicidae) oviposition behaviour: Insights from a Spanish botanical garden.

Mosquitoes are capable of transmitting pathogens of both medical and veterinary significance. Addressing the nuisance and vector roles of Aedes albopictus through surveillance and control programs is a primary concern for European countries. Botanical gardens provide suitable habitats for the development of Ae. albopictus and represent typical points of entry of invasive species. To assess the oviposition preferences alongside various biotic parameters (plant species community, shade index, and flowering), we conducted a study in a botanical garden of Sóller (Mallorca, Balearic Islands, Spain). A total of 6,368 Ae. albopictus eggs were recorded in 36 ovitraps positioned and revised every 15 days in seven different habitats over six months in 2016. Zero-inflated and generalized linear mixed-effects models were used to analyse Ae. albopictus habitat preferences. The number of eggs increased throughout the sampling period, peaking in September. The oviposition rates showed a patchy distribution, with Ae. albopictus showing preference for oviposition in laurel forest and cropland habitats. A positive effect of large leaves and presence of flowers on the oviposition of Ae. albopictus were also recorded. This study provides valuable information into the behaviour of Ae. albopictus in botanical gardens, which is essential data for informing surveillance and control programs.

H3K36 methyltransferase GhKMT3;1a and GhKMT3;2a promote flowering in upland cotton.

BACKGROUND: The SET domain group (SDG) genes encode histone lysine methyltransferases, which regulate gene transcription by altering chromatin structure and play pivotal roles in plant flowering determination. However, few studies have investigated their role in the regulation of flowering in upland cotton. RESULTS: A total of 86 SDG genes were identified through genome-wide analysis in upland cotton (Gossypium hirsutum). These genes were unevenly distributed across 25 chromosomes. Cluster analysis revealed that the 86 GhSDGs were divided into seven main branches. RNA-seq data and qRT‒PCR analysis revealed that lysine methyltransferase 3 (KMT3) genes were expressed at high levels in stamens, pistils and other floral organs. Using virus-induced gene silencing (VIGS), functional characterization of GhKMT3;1a and GhKMT3;2a revealed that, compared with those of the controls, the GhKMT3;1a- and GhKMT3;2a-silenced plants exhibited later budding and flowering and lower plant heightwere shorter. In addition, the expression of flowering-related genes (GhAP1, GhSOC1 and GhFT) significantly decreased and the expression level of GhSVP significantly increased in the GhKMT3;1a- and GhKMT3;2a-silenced plants compared with the control plants. CONCLUSION: A total of 86 SDG genes were identified in upland cotton, among which GhKMT3;1a and GhKMT3;2a might regulate flowering by affecting the expression of GhAP1, GhSOC1, GhFT and GhSVP. These findings will provide genetic resources for advanced molecular breeding in the future.

First Report of Powdery mildew Caused by Golovinomyces ambrosiae on Verbena × hybrida in the U.S.

Verbena × hybrida, also known as common garden verbena, has an important ornamental value for their wide range of flower colors and for attracting hummingbirds and butterflies. During the winter of 2021-2022 (December through February), more than 50% pot-grown verbena plants showed symptoms of powdery mildew in a field trial at a Syngenta Crop Protection research facility in Vero Beach, FL. Symptoms were characterized by the development of white, superficial mycelium on the adaxial side of leaves which, eventually, progressed to covering the whole surface of leaves, causing leaf discoloration, shoot distortion, and eventual plant death. Morphological characterization was carried out by observing powdery mildew colonies under the microscope. This powdery mildew forms dense patches of white mycelia, mainly on the adaxial leaf surfaces. The mycelium was a mat of hyphae with septa. Conidiophores were erect. The foot cells were straight, followed by one to three short cells bearing short chains of up to four conidia. The conidia were hyaline and ellipsoidal to doliiform in shape. Conidial germination is of the Eudoidium type. The conidia ranged from 25 to 32 µm long by 12 to 16 µm wide. The length to width ratio ranged between 1.6 and 2.3, but most were between 2.0 and 2.2. This is further verification of its identity as Golovinomyces ambrosiae and not Golovinomyces latisporus, because the length to width ratio of the latter species is consistently less than 2.0 (Qiu et al. 2020). Chasmothecia were not observed. Additionally, the ITS, GAPDH, and IGS regions were sequenced using the primer pairs ITS4/ITS5 (White et al. 1990), PMGAPDH1/PMGAPDH3R (Bradshaw et al. 2022a), and IGS-12a/NS1R (Carbone and Kohn 1999), respectively. The ITS region (GenBank number=PP924119) cannot distinguish between G. latisporus and G. ambrosiae and as such aligned 100% with both species on GenBank. However, the GAPDH and IGS regions can be used to distinguish G. ambrosiae from G. latisporus (Bradshaw et al. 2022b). The GAPDH (GenBank number=PP931995) and IGS (GenBank number=PP931996) regions aligned 100% with multiple G. ambrosiae sequences from GenBank including ON360708 and MK452567, respectively. The specimen was deposited in the Larry F. Grand Mycological Herbarium (NCSLG 24479). To confirm pathogenicity, 'Tuscany® Pink Picotee' and 'Quartz XP Violet with Eye' plugs were transplanted to 10-cm diameter pots containing ProMix potting mix and maintained in a greenhouse (± 26 °C). Inoculation was carried out 21 days after transplanting by touching infected leaves onto healthy leaves of 15 disease-free plants of each variety. Fifteen non-inoculated plants of each variety were used as controls. Typical powdery mildew symptoms and signs were first observed ten days after inoculation and the pathogen was more aggressive on 'Tuscany® Pink Picotee'. Symptoms were not observed on non-inoculated plants. The fungus was morphologically identical to the one originally recovered from infected plants in the field. There have been many reports of Golovinomyces spp. affecting Verbena spp. worldwide; however, this is the first report of G. ambrosiae causing powdery mildew on Verbena × hybrida in the U.S. (Braun and Cook, 2012, Choi et al., 2021; Bradshaw et al. 2024). Powdery mildews reduce plant quality and decreases the aesthetics value of infected plants, causing great losses to the ornamental industry. Correct identification of the causal agent is crucial to recommend appropriate control methods, as they may differ according to the pathogen species.

An Overview on MADS Box Members in Plants: A Meta-Review.

Most of the studied MADS box members are linked to flowering and fruit traits. However, higher volumes of studies on type II of the two types so far suggest that the florigenic effect of the gene members could just be the tip of the iceberg. In the current study, we used a systematic approach to obtain a general overview of the MADS box members' cross-trait and multifactor associations, and their pleiotropic potentials, based on a manually curated local reference database. While doing so, we screened for the co-occurrence of terms of interest within the title or abstract of each reference, with a threshold of three hits. The analysis results showed that our approach can retrieve multi-faceted information on the subject of study (MADS box gene members in the current case), which could otherwise have been skewed depending on the authors' expertise and/or volume of the literature reference base. Overall, our study discusses the roles of MADS box members in association with plant organs and trait-linked factors among plant species. Our assessment showed that plants with most of the MADS box member studies included tomato, apple, and rice after Arabidopsis. Furthermore, based on the degree of their multi-trait associations, FLC, SVP, and SOC1 are suggested to have relatively higher pleiotropic potential among others in plant growth, development, and flowering processes. The approach devised in this study is expected to be applicable for a basic understanding of any study subject of interest, regardless of the depth of prior knowledge.

Potato: from functional genomics to genetic improvement.

Potato is the most widely grown non-grain crop and ranks as the third most significant global food crop following rice and wheat. Despite its long history of cultivation over vast areas, slow breeding progress and environmental stress have led to a scarcity of high-yielding potato varieties. Enhancing the quality and yield of potato tubers remains the ultimate objective of potato breeding. However, conventional breeding has faced challenges due to tetrasomic inheritance, high genomic heterozygosity, and inbreeding depression. Recent advancements in molecular biology and functional genomic studies of potato have provided valuable insights into the regulatory network of physiological processes and facilitated trait improvement. In this review, we present a summary of identified factors and genes governing potato growth and development, along with progress in potato genomics and the adoption of new breeding technologies for improvement. Additionally, we explore the opportunities and challenges in potato improvement, offering insights into future avenues for potato research.

Seasonal and vertical patterns of water availability and variability determine plant reproductive phenology.

BACKGROUND AND AIMS: Changing precipitation regimes can influence terrestrial plants and ecosystems. However, plant phenological responses to changing precipitation temporal patterns and the underlying mechanisms are largely unclear. This study was conducted to explore the effects of seasonal precipitation redistribution on plant reproductive phenology in a temperate steppe. METHODS: A field experiment with control (C), advanced (AP) and delayed (DP) growing-season precipitation peaks, and the combination of AP and DP (ADP) were employed. Seven dominant plant species were selected and divided into two functional groups (early- vs. middle-flowering species, shallow- vs. deep-rooted species) to monitor reproductive phenology including budding, flowering, and fruiting date, as well as reproductive duration for four growing seasons from 2015 to 2017, and 2022. KEY RESULTS: The AP, but not DP treatment advanced the phenological (i.e., budding, flowering, and fruiting) dates and lengthened the reproductive duration across the 4 growing seasons and 7 monitored species. In addition, the phenological responses showed divergent patterns among different plant functional groups, which could be attributed to shifts in soil moisture and its variability in different months and soil depths. Moreover, species with lengthened reproductive duration increased phenological overlap with other species, which could have a negative impact on their dominance under the AP treatment. CONCLUSIONS: Our findings reveal that changing precipitation seasonality could have considerable impacts on plant phenology by affecting soil water availability and variability. Incorporating these two factors simultaneously in the phenology models will help us understand the response of plant phenology under intensified changing precipitation scenarios. In addition, the observations of decreased dominance for the species with lengthened reproductive duration suggest that changing reproductive phenology can have a potential to affect community composition in grasslands under global change.