Transcriptome analysis and identification of genes associated with floral transition and fruit development in rabbiteye blueberry (Vaccinium ashei)

Flowering and fruit set are important traits affecting fruit quality and yield in rabbiteye blueberry (Vaccinium ashei). Intense efforts have been made to elucidate the influence of vernalization and phytohormones on flowering, but the molecular mechanisms of flowering and fruit set remain unclear. To unravel these mechanisms, we performed transcriptome analysis to explore blueberry transcripts from flowering to early fruit stage. We divided flowering and fruit set into flower bud (S2), initial flower (S3), bloom flower (S4), pad fruit (S5), and cup fruit (S6) based on phenotype and identified 1,344, 69, 658, and 189 unique differentially expressed genes (DEGs) in comparisons of S3/S2, S4/S3, S5/S4, and S6/S5, respectively. There were obviously more DEGs in S3/S2 and S5/S4 than in S4/S3, and S6/S5, suggesting that S3/S2 and S5/S4 represent major transitions from buds to fruit in blueberry. GO and KEGG enrichment analysis indicated these DEGs were mostly enriched in phytohormone biosynthesis and signaling, transporter proteins, photosynthesis, anthocyanins biosynthesis, disease resistance protein and transcription factor categories, in addition, transcript levels of phytohormones and transporters changed greatly throughout the flowering and fruit set process. Gibberellic acid and jasmonic acid mainly acted on the early stage of flowering development like expression of the florigen gene FT, while the expression of auxin response factor genes increased almost throughout the process from bud to fruit development. Transporter proteins were mainly associated with minerals during the early flowering development stage and sugars during the early fruit stage. At the early fruit stage, anthocyanins started to accumulate, and the fruit was susceptible to diseases such as fungal infection. Expression of the transcription factor MYB86 was up-regulated during initial fruit development, which may promote anthocyanin accumulation. These results will aid future studies exploring the molecular mechanism underlying flowering and fruit set of rabbiteye blueberry.

Dissipation Kinetics of Deltamethrin 10 EC in Capsicum (Capsicum Annum var. Frutescens) and Cropped Soil Under Field and Polyhouse Conditions

The dissipation behavior of deltamethrin 10 EC (Decis®) in capsicum (Capsicum annuum var. frutescens) grown in polyhouse and open field was investigated. Two sprays of deltamethrin 10 EC @ 15 and 30g a.i./ha (150 ml/ha -recommended and 300 ml/ha- double the recommended dose), respectively were applied at 10 days intervals, initiating at button sized fruit stage. Fruit samples were collected at 0, 1, 3, 5, 7, 10, 15, 20, 25 days after second spray and the soil samples were collected at final harvest for residue analyses. Modified QuEChERS multi-residue analysis showed initial residues of 0.976 and 1.161 mg/kg recorded at 15 and 30 g a.i./ha doses, respectively in polyhouse. The residues persisted upto 7th and 10th day, reaching below quantification limit (BQL) by 10th and 15th day, respectively at both the doses. In open field, the initial deposits recorded were 0.607 and 1.924 mg/kg reaching BQL on 5th and 7th day, respectively @ 15 and 30 g.a.i./ha. The comparative results showed that half life (syn. Dissipation time 50- DT50) for deltamethrin in capsicum fruits varied from 2.05–2.45 days in polyhouse. The corresponding values in open field were 1.51–1.86 days suggesting that dissipation of deltamethrin residues took longer time in controlled conditions than open field. The soil samples analysed at harvest contained no residues. The insecticide degradation followed the first order kinetics. Since, the insecticide is not recommended under capsicum in India; the data may help to fix maximum residue limit (MRL) and pre harvest interval (PHI).

Transcriptome and metabolome analyses reveal pathways associated with fruit color in plum (Prunus salicina Lindl.)

Background In order to reveal the mechanism of fruit color changes in plum, two common plum cultivars Changli84 (Ch84, red fruit) and Dahuangganhe (D, yellow fruit) in Northeast China were selected as plant materials. Transcriptome sequencing and metabonomic analyzing were performed at three different developmental stages: young fruit stage, colour-change stage, and maturation stage. Results “Flavonoid biosynthesis” was significantly enriched in the KEGG analysis. Some DEGs in “Flavonoid biosynthesis” pathway had an opposite trend between the two cultivars, such as CHS , DFR and FLS . Also, transcriptional control of MBW (MYB–bHLH–WD) protein complexes showed a close relationship with plum fruit color, especially the expression of MYBs and bHLHs . In the current study, procyanidin B1 and B2 had the highest level at young fruit stage in Ch84 and the content of procyanidin B2 decreased sharply at the color change stage. Conversely, the content of cyanidin increased with the growth of fruit and reached the peak at the maturation stage. Conclusion The content of procyanidin B1 and B2 in plums at young fruit stage might be the leading factors of the matured fruit color. At the maturation stage, the cyanidin produced by procyanidins keeps the color of the fruit red. Correspondingly, genes in “flavonoid biosynthesis” pathway play critical roles in regulating the accumulation of anthocyanin in plum.

Phenotyping Brown Rot Susceptibility in Stone Fruit: A Literature Review with Emphasis on Peach

Plant disease phenotyping methodologies can vary considerably among testers and often suffer from shortcomings in their procedures and applications. This has been an important challenge in resistance breeding to brown rot, one of the most severe pre-and postharvest stone fruit diseases caused by Monilinia spp. Literature about methodologies for evaluating stone fruit susceptibility to brown rot is abundant but displays significant variations across the described approaches, limiting the ability to compare results from different studies. This is despite the fact that authors largely agree on the main factors influencing brown rot development, such as Monilinia inocula, environmental conditions, cultivars, fruit stage, and management practices. The present review first discusses ways to control or at least account for major factors affecting brown rot phenotyping studies. The second section describes in detail the different steps of fruit infection assays, comparing different protocols available in the literature with the objective of highlighting best practices and further improvement of phenotyping for brown rot susceptibility. Finally, experimental results from multi-year evaluation trials are also reported, highlighting year-to-year variability and exploring correlations of evaluation outcomes among years and assay types, suggesting that choice of phenotyping methodology must be carefully considered in breeding programs.

Performing sequential harvests based on berry sugar accumulation (mg/berry) to obtain specific wine sensory profiles

This study aimed to investigate the possible existence of reproducible aromatic red wine styles, focusing on fresh fruit aromas and mature fruit aromas (i.e., with dark, jammy fruit characteristics) and taking into account both vintage and vineyard.The study was performed on Australian Shiraz and Cabernet‑Sauvignon from three different meso-climate areas and two consecutive vintages. Sequential harvests were carried out based on the plateau of the physiological indicator berry sugar accumulation (mg/berry) in order to obtain fresh fruit and mature fruit wine sensory profiles. There was a predictable aromatic sequence during grape ripening at each of these two distinct maturity stages regardless of grape genotype (variety) and environment (vineyard and vintage). The post-plateau period of berry sugar accumulation was found to be crucial for the evolution of wine aromatic profiles. During this period, wine aromatic and phenolic maturity were uncoupled from technological maturity (i.e., berry sugar concentration). Dimethyl sulfide was found to be the most relevant wine aromatic marker for differentiating the fresh fruit and mature fruit stages irrespective of the variety. Specific cultivar markers with potential sensory contribution were also identified; for example, (Z)‐3‐hexenol, a possible contributor to the aromatic freshness of Shiraz wines from the fresh fruit stage. The evolution of terpenoids appeared to be separate from the dynamics of berry ripening post plateau of fruit sugar accumulation. On the other hand, ester composition was significantly altered during the same ripening period in Shiraz and Cabernet‑Sauvignon wines with a marked grape genotype effect. The results showed that yeast metabolism was also affected by berry ripening evolution from the plateau of berry sugar accumulation onwards.

Title: Transcriptome and metabolome analyses reveal pathways associated with fruit color in plum (Prunus salicina Lindl.)

Background In order to reveal the mechanism of fruit color changes in plum, two common plum cultivars Changli84 (Ch84, red fruit) and Dahuangganhe (D, yellow fruit) in Northeast China were selected as plant materials. Transcriptome sequencing and metabonomic analyzing were performed at three different developmental stages: young fruit stage, colour-change stage, and maturation stage. Results “Flavonoid biosynthesis” was significantly enriched in the KEGG analysis. Some DEGs in “Flavonoid biosynthesis” pathway had an opposite trend between the two cultivars, such as CHS, DFR and FLS. In the current study, procyanidin B1 and B2 had the highest level at young fruit stage in Ch84 and the content of procyanidin B2 decreased sharply at the color change stage. Conversely, the content of cyanidin increased with the growth of fruit and reached the peak at the maturation stage. Conclusion The content of procyanidin B1 and B2 in plums at young fruit stage might be the leading factors of the matured fruit color. At the maturation stage, the cyanidin produced by procyanidins keeps the color of the fruit red. Correspondingly, genes in “flavonoid biosynthesis” pathway play critical roles in regulating the accumulation of anthocyanin in plum.

Floral and reproductive biology of Matisia cordata (fam: malvaceae)

In Colombia there is a large diversity of promising fruit trees, one of them is Matisia cordata. Sapoti species is appreciated by the consumers, although it is produced in small volumes by traditional productors. The objective of this research is to describe the floral and reproductive biology of sapoti, including floral visitors that act as biotic pollination agents. The study was conducted in two farms, between February/2016 and July/2017. In the first farm, floral buds were marked to follow the stages until fruit formation, pollination mechanism was studied, and floral visitors were collected for identification. In the second farm, flowers were marked to measure the floral nectar production. The duration from floral bud to ripe fruit was 269 days, the 2.7% of the flowers reached the fruit stage. Twenty-five floral visitors were registered, seven of which contacted the sexual whorls, specially Meliponini bees, hummingbirds and bats from Artibeus and Glossophaga genus. M. cordata is a prevalently allogamous species, it attracts diurnal and nocturnal animals, which can contribute to the pollination process. The flowers produced 1.6 ml of nectar with a sugar content from 6.2 to 11 °Brix. The sapoti flowers constitute an abundant and valuable resource for animals from the region.

Association of biochemical constituents with anthracnose resistance in chilli

Colletotrichum species is considered as amajor fungal pathogen that can cause economic damage in commercial chilli production because of its ability to infect fruits both at pre- and post-harvest stages. Results obtained from the Fourier transform near-infrared spectrophotometer in chilli genotypes indicated that, there is a significant difference among the chilli genotypes for both quantitative and qualitative traits. Furthermore, capsaicin and oleoresin contents have a significant linear relationship with resistance to anthracnose at red fruit stage. Incidentally, chilli genotypes that are moderately resistant to anthracnose were significantly superior in capsaicin and oleoresin contents and fruit yield. Hence, capsaicin and oleoresin content can be used as an indirect method to predict anthracnose resistance in chilli breeding.

A blueberry MIR156a–SPL12 module coordinates the accumulation of chlorophylls and anthocyanins during fruit ripening

Color change is an important event during fruit maturation in blueberry, usually depending on chlorophyll degradation and anthocyanin accumulation. MicroRNA156 (miR156)–SPL modules are an important group of regulatory hubs involved in the regulation of anthocyanin biosynthesis. However, little is known regarding their roles in blueberry or in chlorophyll metabolism during color change. In this study, a MIR156 gene (VcMIR156a) was experimentally identified in blueberry (Vaccinium corymbosum). Overexpression of VcMIR156a in tomato (Solanum lycopersicum) enhanced anthocyanin biosynthesis and chlorophyll degradation in the stem by altering pigment-associated gene expression. Further investigation indicated that the VcSPL12 transcript could be targeted by miR156, and showed the reverse accumulation patterns during blueberry fruit development and maturation. Noticeably, VcSPL12 was highly expressed at green fruit stages, while VcMIR156a transcripts mainly accumulated at the white fruit stage when expression of VcSPL12 was dramatically decreased, implying that VcMIR156a–VcSPL12 is a key regulatory hub during fruit coloration. Moreover, VcSPL12 decreased the expression of several anthocyanin biosynthetic and regulatory genes, and a yeast two-hybrid assay indicated that VcSPL12 interacted with VcMYBPA1. Intriguingly, expression of VcSPL12 significantly enhanced chlorophyll accumulation and altered the expression of several chlorophyll-associated genes. Additionally, the chloroplast ultrastructure was altered by the expression of VcMIR156a and VcSPL12. These findings provide a novel insight into the functional roles of miR156–SPLs in plants, especially in blueberry fruit coloration.