Rose Leaf Research Articles

Optimized Convolutional Neural Network Architecture for High-Accuracy Classification of Rose Leaf Diseases

Optimized Convolutional Neural Network Architecture for High-Accuracy Classification of Rose Leaf Diseases

Unveiling Lathyrus aphaca L. as a Newly Identified Host for Begomovirus Infection: A Comprehensive Study.

The Begomovirus genus of the family Geminiviridae comprises the largest group of geminiviruses. Begomoviruses are transmitted by the whitefly complex (Bemisia tabaci) and infect dicotyledonous plants in tropical and subtropical regions. The list of begomoviruses is continuously increasing as a result of improvements in the methods for identification, especially from weed plants, which are considered a source of new viruses and reservoirs of economically important viruses but are often neglected during diversity studies. Lathyrus aphaca L. weed plants (yellow-flowered pea) with varicose veins and discoloration of the leaves were found. Amplified genomic DNA through rolling circular amplification was subjected to PCR analysis for the detection of the viral genome and associated DNA-satellites (alphasatellites and betasatellites). A full-length sequence (2.8 kb) of a monopartite begomovirus clone was determined; however, we could not find any associated DNA satellites. The amplified full-length clone of Rose leaf curl virus (RoLCuV) reserved all the characteristics and features of an Old World (OW) monopartite begomovirus. Furthermore, it is the first time it has been reported from a new weed host, yellow-flowered pea. Rolling circle amplification and polymerase chain reaction analysis of associated DNA satellites, alphasatellite, and betasatellite, were frequently accomplished but unable to amplify from the begomovirus-infected samples, indicating the presence of only monopartite Old World begomovirus. It is observed that RoLCuV has the capability to infect different hosts individually without the assistance of any DNA satellite component. Recombination in viruses is also a source of begomovirus infection in different hosts.

Identity of Kalanchoe ‘Fang’ and K. ‘Rose Leaf’, two cultivars derived from K. ×edwardii (Crassulaceae subfam. Kalanchooideae), with notes on aspects of interspecific hybridisation in the genus

The nothospecies name Kalanchoe ×edwardii (Crassulaceae subfam. Kalanchooideae) was published for the hybrid between the arborescent K. beharensis and the shrubby K. tomentosa, two Malagasy species. Two well-known cultivars, K. ×edwardii ‘Fang’ and K. ×edwardii ‘Rose Leaf’, or simply K. ‘Fang’ and K. ‘Rose Leaf’, have been selected and named from K. ×edwardii. To facilitate distinguishing between these two cultivars, differences between them are tabulated and discussed. A general discussion of aspects of interspecific hybridisation in Kalanchoe is provided.

Rose leaf curl betasatellite

This datasheet on Rose leaf curl betasatellite covers Identity, Hosts/Species Affected, Further Information.

Allelopathic Efficiency of Plant Extracts to Control Cyanobacteria in Hydroponic Culture

Cyanobacteria rapidly form harmful algal blooms (HABs) that cause serious nutritional imbalances in crop production via hydroponics. Allelopathic extracts from plants can be applied as a solution for ecologically sustainable control of algal blooms. In this study, the effects of 11 aqueous extracts of 10 allelopathic plants in controlling Microcystis aeruginosa were evaluated. Among the extracts, walnut husk and rose leaf extracts exhibited high inhibitory levels for efficient control of algae. High inhibitory levels were achieved owing to large amounts of water-soluble tannins, especially tannic acid. The effective extracts were applied to a hydroponic system cultivated on leafy perilla vegetables. Although the severe doses (IC90) did not guarantee complete algal control due to partial algal regrowth, walnut husk and rose leaf extracts only exerted strong persistent effects on algae control. Persistent algae inhibition contributed to the increase in perilla growth and leaf quality. Rose leaf was potentially a more useful resource for controlling algae in a hydroponic system because the application of rose leaf extract efficiently controlled the algae and was less toxic to perilla growth. In contrast, the treatment of walnut husk extract also controlled algae but inhibited perilla growth with pale green leaves.

A Hybrid Deep Learning and Optimized Machine Learning Approach for Rose Leaf Disease Classification

Analysis of the symptoms of rose leaves can identify up to 15 different diseases. This research aims to develop Convolutional Neural Network models for classifying the diseases on rose leaves using hybrid deep learning techniques with Support Vector Machine (SVM). The developed models were based on the VGG16 architecture and early or late fusion techniques were applied to concatenate the output from a fully connected layer. The results showed that the developed models based on early fusion performed better than the developed models on either late fusion or VGG16 alone. In addition, it was found that the models using the SVM classifier had better efficiency in classifying the diseases appearing on rose leaves than the models using the softmax function classifier. In particular, a hybrid deep learning model based on early fusion and SVM, which applied the categorical hinge loss function, yielded a validation accuracy of 88.33% and a validation loss of 0.0679, which were higher than the ones of the other models. Moreover, this model was evaluated by 10-fold cross-validation with 90.26% accuracy, 90.59% precision, 92.44% recall, and 91.50% F1-score for disease classification on rose leaves.

First report of Rose leaf rosette-associated virus infecting rose (Rosa spp.) in California, USA.

Rose leaf rosette-associated virus (RLRaV) is a member of genus Closterovirus, family Closteroviridae. The virus was first discovered in China in 2015 from a mixed infected wild rose (Rosa multiflora Thunb.) showing small leaf rosettes on branches, dieback and severe decline symptoms (He et al. 2015). In 2013, a rose plant (cv. Roses Are Red) was introduced to Foundation Plant Services (FPS, UC-Davis) rose collection. The plant was originated from a private rose breeder collection located in California. In 2019, total nucleic acids (TNA) were isolated from leaf tissues of one asymptomatic plant (Roses Are Red plant) using MagMax Plant RNA Isolation Kit (Thermo Fisher Scientific, USA). Extracted TNA were screened by reverse-transcription quantitative PCR (RT-qPCR) for six common viruses infecting roses, including prunus necrotic ringspot virus (PNRSV), apple mosaic virus (ApMV), rose spring dwarf associated virus (RSDaV), rose yellow vein virus (RYVV), rose rosette virus (RRV), and blackberry chlorotic ringspot virus (BCRV); however, the results were negative. Therefore, the sample was subjected to high throughput sequencing (HTS). Briefly, TNA was depleted of rRNA and advanced for cDNA library preparation using TruSeq Stranded Total RNA kit (Illumina, USA). HTS was performed on Illumina NextSeq 500 platform. The raw reads were trimmed, de novo assembled, and subsequently were annotated using tBLASTx algorithm (Al Rwahnih et al. 2018). HTS generated 23.6 million 75 nucleotide (nt) single-end raw data reads. De novo assembly generated a contig (16,528 nts) resembling RLRaV reference sequence (KJ748003) with 74% identity at the nucleotide level. Putative coat protein and heat shock protein 70-like protein were identified based on >90% identity with RLRaV genes. To confirm HTS results, RT-PCR was performed using two primer sets, 1) Clo-F4916 (5'-GGTGTTCCAACGCTATCGTG-3') and Clo-R5215 (5'- TGTCCTCAAACCGCCTACAT-3') targeting nucleotide sequences of putative polyprotein 1a, and 2) Clo-F10006 (5'-GATTCCGCGGACGAATTAAT-3') and Clo-R10311 (5'-GGTAACCGAAAGGTAAAGTATTC-3') targeting nucleotide sequences of putative protein p25. The RLRaV amplicons with expected size of 300 nt were confirmed using bidirectional Sanger sequencing. The near-complete sequence of the new RLRaV isolate was deposited in GenBank under accession number MW056181. In addition, HTS analysis showed that RLRaV was in mixed infection with two mycoviruses (rose cryptic virus with 8,267 mapped reads and rose partitivirus with 7,283 mapped readss). To our knowledge, this is the first report of RLRaV affecting roses in California. Further research is needed to determine the prevalence of RLRaV in California as well as evaluation of RLRaV effect on rose performance.

Design and Implementation of an Efficient Rose Leaf Disease Detection using K Nearest Neighbours

Plants are prone to different diseases caused by multiple reasons like environmental conditions, light, bacteria, and fungus. These diseases always have some physical characteristics on the leaves, stems, and fruit, such as changes in natural appearance, spot, size, etc. Due to similar patterns, distinguishing and identifying category of plant disease is the most challenging task. Therefore, efficient and flawless mechanisms should be discovered earlier so that accurate identification and prevention can be performed to avoid several losses of the entire plant. Therefore, an automated identification system can be a key factor in preventing loss in the cultivation and maintaining high quality of agriculture products. This paper introduces modeling of rose plant leaf disease classification technique using feature extraction process and supervised learning mechanism. The outcome of the proposed study justifies the scope of the proposed system in terms of accuracy towards the classification of different kind of rose plant disease.

Color and stability of anthocyanins in strawberry nectars containing various co-pigment sources and sweeteners

Effects of various co-pigment sources [gallic acid (GA) and the extracts of rose leaf (RLE), cherry stem (CSE), pomegranate rind (PRE) and sour cherry stem (SCSE)] on anthocyanins and colour in strawberry nectars (SNs), sweetened with sucrose (SNS), maltose syrup (SNM) and honey (SNH), were investigated during storage at 20 °C. Honey elicited the highest stabilities of anthocyanins, hyperchromic and bathochromic effects in SNs containing all co-pigment sources, except for PRE. PRE co-pigments were composed of mainly tannins which could interact with SNs proteins and honey proline. As a result of these interactions, PRE co-pigments could not show significant contribution to protection of SN anthocyanins and colour. Among co-pigment sources, SCSE caused the highest stabilities of anthocyanins, hyperchromic effect and colour density, regardless of sweetener used. Interactions between SCSE phenolic acids, and pelargonidin-3-glucoside and pelargonidin-3-rutinoside resulted in the most stable co-pigmentation effect. Thus, SCSE should be preferred in beverages containing pelargonidin-based anthocyanins.

First record of Pestalotia macrotricha as acusal of Rose leaf spot disease in Basrah and its integrated control

This study was conducted in the laboratories of the Plant Protection Department / college of Agriculture / University of Basra during the period from 2015-2016. The survey results showed that Rose leaf spot diseases spread in all the nurseries surveyed, but the highest incidence rate and disease severity were recorded in Khurh nurseries ( 62.3% and 53.3%) respectively, and the lowest incidence and disease severity in Zubair nurseries( 21.6% and 23.3%) respectively . Isolation results showed the presence of fungus Diplocarpon rosa with the fungus Pestalotia macrotricha from most infected leave samples. The pathogenicity testing results showed the ability of the fungus P. macrotricha to cause leaf spot. In addition the results of pesticide testing showed that pesticide Dazim and Revous Top were the most inhibitory of the growth of fungus Pestalotia macrotricha were the percent of inhibition was 100% compared to 55% of the pesticide Hunter. The results also showed the ability of the Chaetomium globosum and Psedomonas fluorescens bacteria in inhibition the growth of Pestalotia macrotricha. The results also showed that the plant extract (Quercetin), which derived from a number of plants such as onions and apples, was most effective in inhibition of the growth of P. macrotricha compared with Silibnin extract which was extracted from Sylibum marianum.

Pathogen Identification and Fungicides Screening of Kushui Rose Leaf Spot Disease

Leaf spot disease pathogen of kushui rose was isolated, purified, morphologically identified and screened for appropriate fungicides through tissue isolation, microscopic observation and growth rate methods. Results showed that the pathogen causing leaf spot disease was Alternaria sp., and for the 7 tested fungicides, difenoconazole and tebuconazole had the best inhibitory effect, the EC50 values were 0.0017 and 0.0041 μg/mL, respectively, followed by zineb, triadimefon, chlorothalonil and thiophanate-methyl, successively, with the EC50 values at 0.0157, 0.0422, 0.5160 and 0.87 μg/mL, respectively, while carbendazim had the worst inhibitory effect with the EC50 value at 1.3089 μg/mL.

First report of a begomovirus and associated betasatellite in Rosa indica and in India

The complete genome sequences of a begomovirus and associated betasatellite was obtained by the rolling circle amplification from rose (Rosa indica) exhibiting dwarfing, leaf distortion and leaf curling symptoms from Rajasthan, India. The sequence of the begomovirus was determined to be 2,741 bp and showed the typical genome arrangement of an monopartite Old World begomovirus. The sequence showed the highest nucleotide sequence identity (98 %) to an isolate of Rose leaf curl virus (RoLCuV), confirming it as an isolate of RoLCuV. The sequence of the rose begomovirus associated betasatellite (1,349 bp) displayed greater than 97 % nucleotide sequence identity to Digera leaf curl betasatellite. Our analysis also demonstrated that recombination events shaped the evolutionary history of RoLCuV. To our knowledge, this is the first report of RoLCuV associated with betasatellite infecting rose in India.

A betasatellite-dependent begomovirus infects ornamental rose: characterization of begomovirus infecting rose in Pakistan.

The Begomovirus genus of the family Geminiviridae comprises the largest group of geminiviruses. The list of begomoviruses is continuously increasing as a result of improvement in the methods for identification. Ornamental rose plants (Rosa chinensis) with highly stunted growth and leaf curling were found in Faisalabad, Pakistan. Plants were analyzed for begomovirus infection, through rolling circle amplification and PCR methods. Based on complete genome sequence homologies with other begomoviruses, a new begomovirus species infecting the rose plants was discovered. In this paper, we propose a new species name, Rose leaf curl virus (RoLCuV), for the virus. RoLCuV showed close identity (83 %) with Tomato leaf curl Pakistan virus, while associated betasatellite showed 96 % identity with Digera arvensis yellow vein betasatellite (DiAYVB), justifying a new isolate for the betasatellite. Recombination analysis of newly identified begomovirus revealed it as a recombinant of tomato leaf curl Pakistan virus from its coat protein region. The infectious molecules for virus/satellite were prepared and inoculated through Agrobacterium tumefaciens to N. benthamiana plants. RoLCuV alone was unable to induce any level of symptoms on N. benthamiana plants, but co-inoculation with cognate betasatellite produced infection symptoms. Further investigation to understand the trans-replication ability of betasatellites revealed their flexibility to interact with Rose leaf curl virus.

Influence of Basal Medium and Hormones on Callus Induction and its Organogenesis from In Vitro Culture of Rose Leaf Segments

Influence of culture media and hormone concentrations on plant regeneration from rose (Rosa hybrida L. cv. Raktagandha) leaf segments were investigated. Leaves were excised from healthy, well-grown and mature plants. Leaf segments (4-5 mm long) were sectioned and cultured on Murashige and Skoog (1962) medium containing different concentration of growth hormones. Callus formation was most prolific (97.09%) on MS medium containing MS basal salts + 0.5 mg·L-1 BAP + 2.0 mg·L-1 2,4-D. maximum (56.67%) organogenesis or shoot differentiation was achieved on MS modified medium supplemented with 1.0 mg L-1 BAP + 0.1 mg·L-1 NAA + 10.0 mg·L-1 Adenine Sulphate. The highest percentage (93.73%) of in-vitro rooting was observed in half-strength MS basal medium containing 0.5 mg·L-1 IBA. Rooted plants were transferred in to sterilized potting mixture and grown in a greenhouse.

Effects of Dark and TDZ on Callus Formation of Rose Leaf Explants

Effects of Dark and TDZ on Callus Formation of Rose Leaf Explants

A Coupled Model of Photosynthesis, Stomatal Conductance and Transpiration for a Rose Leaf (Rosa hybrida L.)

The following three models were combined to predict simultaneously photosynthesis, stomatal conductance, transpiration and leaf temperature of a rose leaf: the biochemical model of photosynthesis of Farquhar, von Caemmerer and Berry (1980, Planta 149: 78-90), the stomatal conductance model of Ball, Woodrow and Berry (In: Biggens J, ed. Progress in photosynthesis research. The Netherlands: Martinus Nijhoff Publishers), and an energy balance model. The photosynthetic parameters: maximum carboxylation rate, potential rate of electron transport and rate of triose phosphate utilization, and their temperature dependence were determined using gas exchange data of fully expanded, young, sunlit leaves. The stomatal conductance model was calibrated independently. Prediction of net photosynthesis by the coupled model agreed well with the validation data, but the model tended to underestimate rates of stomatal conductance and transpiration. The coupled model developed in this study can be used to assist growers making environmental control decisions in glasshouse production.

Rose leaf structure in relation to different stages of micropropagation

The Mme Isaac Pereire rose was investigated in an attempt to establish how micropropagated roses might best be weaned into normal growth conditions. Leaves of in vitro grown plants, weaned plants and the stock plant were studied, using light microscopy and different scanning and transmission electron microscopical techniques. Features that varied in the different growing conditions were leaf size and thickness, amount of wax, thickness of cuticle and external epidermal cell wall, number and aperture of the stomata, size of the epidermal cells, number of layers of the palisade cells, and size of the chloroplasts in the mesophyll. The rose in the present study had wax on the in vitro cultured plants; this wax was of similar ultrastructural appearance to that of the stock plant, even though in smaller quantities. Weaned plants had an intermediate amount of wax. The cuticle was thin, ranging from 0.04 μm on plants growing in vitro to 0.3-0.6 μm on weaned plants and stock plants. Stomata were always wide-open on leaves taken from cultures with a relative humidity of 100%. After four weeks in a humidity lowered to 85% stomata had closed.

Rose leaf elasticity changes in response to mycorrhizal colonization and drought acclimation

Tissue elasticity can affect plant response to drought, in terms of turgor maintenance and water uptake from drying soils. The purpose of this study was to determine the effect of mycorrhizal colonization and drought acclimation on rose (Rosa hybrida L. cv. Samantha) leaf elasticity. Bulk elasticity was characterized by the pressurevolume method using plots of the elastic modulus as a function of leaf turgor pressure, total water potential and relative water content. The treatments, arranged in a 2 × 3 factorial design, included acclimated and unacclimated plants, and either Glomus irararadices Schenck and Smith, Glomus deserticola Trappe, Bloss and Menge, or a non‐mycorrhizal control. Plants with root mycorrhizal colonization showed reduced leaf elasticity (i.e. higher elastic moduli) over a broad range of leaf waler potential and water content. Both mycorrbizal colonization and acclimation facilitated the maintenance of positive values of turgor and elasticity at lower leaf water potential and water content than in controls. Mycorrhizal infections may aid plants in acclimating to water deficits through effects on leaf tissue elasticity.

Effect of Daylength on the Growth and Flowering of Roses (Rosa hybrida)1

Abstract Four greenhouse rose cultivars were grown under 9, 12, and 16-hr daylengths from September to May during 1969-70 and 1970-71. Flower production was generally increased significantly under the 16-hr daylength, particularly during January and February. At this day length, rose stems flowered again more quickly, but with the same number of nodes present as in the other treatments. The internode between the 2 uppermost 5-leaflet leaves was significantly longer on plants grown at 16 and 12 hr than the 9-hr daylengths. Flower fresh and dry wt increased as the daylengths increased from 9 to 16 hr and the percentages of blind stems were found to decrease. Rose leaf and flower petal size were unchanged by the daylength.