Malvaceous Plants Research Articles

Incidence of pink bollworm, Pectinophora gossypiella (Saunders) on various malvaceous plants in North Eastern region of Karnataka, India

Pink bollworm roving survey on Bt-cotton and some malvaceous plants, in and around the cotton field across themajor cotton growing districts of North Eastern region of Karnataka recorded the highest green boll damage in Raichurdistrict (70.79%) followed by Ballari (63.46%) and Yadgir (55.80%) district. Whereas, no incidence of pink bollworm wasrecorded on the malvaceous plants viz., Abutilon indicum (L.), Abutilon hirtum (Lam.) and Abelmoschus ficulneus (L.).

Biology and integrative taxonomy of leaf folder, Helcystogramma hibisci (Stainton, 1859): a pest of musk mallow, Abelmoschus moschatus (L.) Medik.

Abstract The leaf folder, Helcystogramma hibisci (Stainton, 1859) (Lepidoptera: Gelechiidae) is an oligophagous pest of different malvaceous plants. In this study, attempts have been made to study the biology and taxonomy of the insect infesting musk mallow (Abelmoschus moschatus), an aromatic cum medicinal plant in India, following an integrative approach based on external morphology, internal genitalia structures, and molecular taxonomy. In the initial stage, the larva scrapes the tender surface of the leaves, and later, grown-up larvae web the leaves by folding them longitudinally. The entire inner content of the leaves is eaten by the larvae and ultimately the leaves get dry. The identity of the pest species is confirmed through dissecting of the male and female genitalia of the pest species and molecular confirmation (GenBank accession number ON545806). By studying the biology of the insect, the egg incubation period, larval period, and pupal period were determined to be 4.70 ± 0.64, 13.66 ± 0.86, and 6.46 ± 0.61 (male), and 7.60 ± 0.71 days (female), respectively. The average fecundity and adult longevity of males and females were 61.20 ± 11.68 eggs/female, 4.93 ± 1.38 days (male), and 8.06 ± 1.56 days (female), respectively. During their fourth instar, male larvae have dark-colored gonads that are easily visible on the dorsal integument of the abdominal segment distinguishing them from female larvae. Further confirmation of the identification was done by keeping the larvae in separate vials until emergence; larvae with this dark-colored character could be confirmed to be males, while other the larvae developed into female moths. The head capsule width of the larval instars was 0.26 ± 0.02, 0.47 ± 0.04, 0.66 ± 0.03, 0.83 ± 0.06, and 1.13 ± 0.14 mm, respectively. The information is useful for proper identification and management of this pest in such a valuable and popular plant as musk mallow in India. To our best knowledge, this is the first description of this pest species from the Indian region along with molecular confirmation.

Discovery of the Puparia of a Whitefly Species Found on Malvaceae in the Pliocene Rajdanda Formation, Jharkhand, Eastern India

A new genus and species of fossil whitefly, Praealeurolobus indicus gen. et sp. nov., is described and illustrated based on puparia found on leaves of a malvaceous plant from the Pliocene Rajdanda Formation in Eastern India. It is the first record of whitefly puparia on leaves from the Neogene deposits of Asia and the second taxon formally named and described from such adpression fossils. The cephalothorax of some of the puparia has a large, irregularly shaped hole with jagged edges, typical of the emergence holes of parasitoids of modern-day whiteflies and represents the earliest record of parasitism on whiteflies. This finding enriches our knowledge of the fossil record of Aleyrodidae in connection with allied fossils and provides new insight into the ecological interactions of the palaeobiota and taphonomy of fossils preserved in the Pliocene Rajdanda Formation.

Malvaviscus yellow mosaic virus, a divergent begomovirus carrying a nanovirus‐like nonanucleotide and a modified stem‐loop structure

AbstractBegomoviruses (family Geminiviridae) have a circular, ssDNA genome encapsidated in twinned icosahedral particles. Numerous begomoviruses infecting noncultivated malvaceous plants have been described, and evidence suggests that they may have given rise to some of the viruses currently found in crop plants. Here we describe an atypical begomovirus infecting ornamental Turk's hat plants (Malvaviscus arboreus, Malvaceae). Total DNA was extracted, and the viral genome was amplified by rolling‐circle amplification (RCA), cloned and sequenced. Sequence and phylogenetic analyses indicated that the virus corresponds to a new begomovirus phylogenetically related to other malvaceous‐infecting begomoviruses from Brazil, and for which the name malvaviscus yellow mosaic virus (MvYMV) is proposed. M. arboreus plants inoculated with MvYMV infectious clones showed bright yellow mosaic and the virus progeny was identical to the isolate inoculated, thus fulfilling Koch's postulates. Strikingly, MvYMV has a nanovirus/alphasatellite‐like nonanucleotide sequence (5′‐TAGTATTAC‐3′). Moreover, a short sequence located 5′ of the nonanucleotide potentially forms a minor hairpin structure embedded in the major hairpin. Intramolecular interactions involving the sequence of the atypical hairpin structure were predicted and functional analyses were conducted to assess its biological relevance, revealing that the MvYMV Rep protein recognises this unique replication origin but not the typical begomovirus origin. Thus, MvYMV is a begomovirus with an atypical origin of replication and naturally found in noncultivated malvaceous plants.

Molecular and Biological Characterization of a New World Mono-/Bipartite Begomovirus/Deltasatellite Complex Infecting Corchorus siliquosus.

The genus Begomovirus (family Geminiviridae) is the largest genus in the entire virosphere, with more than 400 species recognized. Begomoviruses are single-stranded DNA plant viruses transmitted by whiteflies of the Bemisia tabaci complex and are considered one of the most important groups of emerging plant viruses in tropical and subtropical regions. Several types of DNA satellites have been described to be associated with begomoviruses: betasatellites, alphasatellites, and deltasatellites. Recently, a family of single-stranded DNA satellites associated with begomoviruses has been created, Tolecusatellitidae, including the genera Betasatellite and Deltasatellite. In this work, we analyzed the population of begomoviruses and associated DNA satellites present in Corchorus siliquosus, a malvaceous plant growing wild in Central America, southeastern North America and the Caribbean, collected in Cuba. The genomes of isolates of two New World begomoviruses [(Desmodium leaf distortion virus (DesLDV) and Corchorus yellow vein Cuba virus (CoYVCUV)] and two deltasatellites [tomato yellow leaf distortion deltasatellite 2 (TYLDD2) and Desmodium leaf distortion deltasatellite (DesLDD)] have been cloned and sequenced from plants showing yellow vein symptoms. Isolates of one of the begomoviruses, CoYVCUV, and one of the deltasatellites, DesLDD, represent novel species. Experiments with infectious clones showed the monopartite nature of CoYVCUV and that DesLDD utilizes the bipartite DesLDV as helper virus, but not the monopartite CoYVCUV. Also, CoYVCUV was shown to infect common bean in addition to Nicotiana benthamiana. This is the first time that (i) a monopartite New World begomovirus is found in a host other than tomato and (ii) deltasatellites have been found in C. siliquosus, thus extending the host and helper virus ranges of this recently recognized class of DNA satellites.

English

High quality RNA extraction from field-grown jute plants can be difficult due to the presence of complex polyphenolic, polysaccharide and waxes. But isolation of RNA in high quality is a basic need in plant genetics, genomics, transcriptomics, molecular biology and related physiological investigations. Here, cetyl trimethyl ammonium bromide (CTAB) based modified RNA isolation protocol suitable for isolating high quality total RNA from different parts of field-grown jute plants was reported. Modifications come with two extra wash with extraction buffer, residual polysaccharides precipitation with absolute ethanol and potassium acetate during phenol:chloroform:isoamyl alcohol (PCI), intermediate pelleting with lithium chloride followed by dissolving the pellet in sodium dodecyl sulfate (SDS). The 28S/18S ratio and RIN of isolated RNA were greater than 2.0 and 7.3 to 8.8, respectively reveal RNA to be high purity. The isolated RNA can be used directly for subsequent downstream applications including cDNA library construction, reverse transcription polymerase chain reaction (RT-PCR) and RNA-Seq raw data generation without further purification. Moreover, this study showed that this method could also be successfully applied to other polyphenols and polysaccharides rich malvaceous plants. Key words: RNA isolation, Corchorus, Jute, quantitative polymerase chain reaction with reverse transcription (RT-qPCR), cDNA library construction, next-generation sequencing (NGS) data generation.

PHARMACOLOGICAL STUDY OF AERIAL PARTS OF TWO MALVACEOUS PLANTS.

PHARMACOLOGICAL STUDY OF AERIAL PARTS OF TWO MALVACEOUS PLANTS.

Deciphering the biology of deltasatellites from the New World: maintenance by New World begomoviruses and whitefly transmission.

Deltasatellites are small noncoding DNA satellites associated with begomoviruses. The study presented here has investigated the biology of two deltasatellites found in wild malvaceous plants in the New World (NW). Infectious clones of two NW deltasatellites (from Malvastrum coromandelianum and Sidastrum micranthum) and associated begomoviruses were constructed. Infectivity in Nicotiana benthamiana and their natural malvaceous hosts was assessed. The NW deltasatellites were not able to spread autonomously in planta, whereas they were maintained by the associated bipartite begomovirus. Furthermore, NW deltasatellites were transreplicated by a monopartite NW begomovirus, tomato leaf deformation virus. However, they were not maintained by begomoviruses from the Old World (tomato yellow leaf curl virus, tomato yellow leaf curl Sardinia virus and African cassava mosaic virus) or a curtovirus (beet curly top virus). NW deltasatellites did not affect the symptoms induced by the helper viruses but in some cases reduced their accumulation. Moreover, one NW deltasatellite was shown to be transmitted by the whitefly Bemisia tabaci, the vector of its helper begomoviruses. These results confirm that these molecules are true satellites. The availability of infectious clones and the observation that NW deltasatellites reduced virus accumulation paves the way for further studies of the effect on their helper begomoviruses.

Genetics, realized heritability and possible mechanism of chlorfenapyr resistance in Oxycarenus hyalinipennis (Lygaeidae: Hemiptera)

Dusky cotton bug (DCB), Oxycarenus hyalinipennis (Lygaeidae: Hemiptera) is a serious pest of cotton and other malvaceous plants. Chlorfenapyr, a broad spectrum, N-substituted, halogenated pyrrole insecticide is used extensively to control many insect pests in cotton, including DCB. In this study, we investigated a field strain of DCB to assess its potential to develop resistance to chlorfenapyr. After six generations of continuous selection pressure with chlorfenapyr, DCB had a 7.24-fold and 149.06-fold resistance ratio (RR) at G1 and G6, respectively. The genetic basis of inheritance of chlorfenapyr resistance was also studied by crossing the chlorfenapyr selected (Chlorfenapyr-SEL) and laboratory population (Lab-PK). Results revealed an autosomal and incompletely dominant mode of inheritance for chlorfenapyr resistance in the Chlorfenapyr-SEL population of DCB. The results of the monogenic model test showed chlorfenapyr resistance was controlled by multiple genes. Estimated realized heritability for chlorfenapyr resistance in the tested DCB strain was 0.123. Synergism bioassays with piperonyl butoxide and S, S, S-butyl phosphorotrithioate revealed chlorfenapyr resistance might be due to esterase activity. These results would be useful for devising an effective resistance management strategy against DCB.

Trophic Evolution of Southern Green Stink Bugs (Nezara viridula l.) in Western Part of Romania

Nezara viridula L. (Hemiptera:Pentatomidae) is a relative a invasive species, highly poliphagous, species of solanaceous, legumes, cruciferous, malvaceous, grasses and other plants are affected. Considering that the insect which make the subject of this scientifically paper is a species detected in our country but unregistered and un-localized as a dangerous species we want to bring to attention potential spread and adaptation to new plant species, especially legumes and ornamental plants. Observations were made in Timis county in the western part of Romania (Timis), during the years 2013 and 2014. It was taken under observation by three types of plants (tomato crop, green space and fruit tree plantation). The observations on plants have shown that N. viridula affected all four varieties of tomatoes, especially on fruits, both green and mature stage. In green space only adults and nymphs was observed on follow ornamental plants: Syringa vulgaris , Lonicera japonica, Hibiscus sp. and Magnolia liliiflora . Comparative study between Prunus persica and Prunus persica var. nucipersica made in fruit tree plantation has revealed that insect affected only the last one. N. viridula is a dangerous species for Romania with high expansion potential on new host plant and new surfaces.

High genetic homogeneity points to a single introduction event responsible for invasion of Cotton leaf curl Multan virus and its associated betasatellite into China.

BackgroundCotton leaf curl Multan virus (CLCuMuV) is a Whitefly Transmitted Geminivirus (WTG) endemic to the India subcontinent and is notorious as a causal agent of cotton leaf curl disease (CLCuD), a major constraint to cotton production in south Asia. We found CLCuMuV infecting Hibiscus rosa-sinensis in Guangzhou, China in 2006. The spread and evolution of the invading CLCuMuV were monitored in the following nine years.FindingsCLCuMuV spread rapidly in the last nine years and became established in Southern China. It infects at least five malvaceous plant species, H. rosa-sinensis, H. esculentus, Malvaiscus arboreus, Gossypium hirsutum and H. cannabinus. Complete nucleotide sequences of 34 geographically and/or temporally distinct CLCuMuV isolates were determined and analyzed together with six other publicly available genomes of CLCuMuV occurring in China. The 40 CLCuMuV isolates were found to share > 99 % nucleotide sequence identity with each other. In all cases tested, the CLCuMuVs were associated with a CLCuMuB. The 36 CLCuMuBs (30 sequenced by us) shared > 98 % nucleotide sequence identity.ConclusionThe high genetic homogeneity of CLCuMuV and CLCuMuB in China suggests the establishment of them from a single founder event.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-015-0397-y) contains supplementary material, which is available to authorized users.

Complete nucleotide sequences of two new begomoviruses infecting the wild malvaceous plant Melochia sp. in Brazil.

Wild malvaceous plants are hosts for a large number of begomoviruses (genus Begomovirus, family Geminiviridae) in both the Old World and the New World. Here, we report the complete genome sequences of two new begomoviruses from Melochia sp. plants from Brazil. The cloned bipartite genomes, composed of DNA-A and DNA-B, showed the typical organization of the New World begomoviruses but they were distantly related to the genomes of other begomoviruses. We propose the names Melochia mosaic virus and Melochia yellow mosaic virus for these begomoviruses.

Recombination Among Begomoviruses on Malvaceous Plants Leads to the Evolution of Okra Enation Leaf Curl Virus in Pakistan

AbstractWhitefly transmitted begomoviruses (family Geminiviridae) are the major reason for significant yield losses of dicotyledonous crops in tropics and subtropics. Okra (Abelmoschus esculentus) is one of the important vegetable crops, and leaf curl disease caused by geminiviruses is the most important limiting factor for its production in Pakistan. Here, we report a new species of okra‐infecting begomovirus in south‐eastern region of Pakistan and the name Okra enation leaf curl virus (OELCuV) complex is proposed. This okra enation leaf curl disease complex (OELCuD) in Pakistan is found to be associated with Ageratum conyzoides symptomless alphasatellite (AConSLA). All efforts to clone the betasatellite were unsuccessful. Comprehensive sequence analyses suggest that intermalvaceous recombination between okra and cotton‐infecting begomoviruses resulted in the evolution of the new species. Surprisingly, Bhendi yellow vein mosaic virus (BYVMV) which has not been reported previously from Pakistan is the major parent while Cotton leaf curl Multan virus (CLCuMV) acts as a distant parent of the virus. Comparative recombination analysis also reveals that okra‐infecting begomoviruses from south and north‐western India is causing OELCuD in the Pakistan by recombining with CLCuMV at the Rep (1964–1513 nts). Recombination is common among geminiviruses and recombining of BYVMV and CLCuMV resulted in a new species: OELCuV. To the best of our knowledge, this evolution of a new species of okra‐infecting begomovirus is the first report of intermalvaceous recombination where Rep acts as the target region.

Just spines—mechanical defense of malvaceous pollen against collection by corbiculate bees

Bee-pollinated plants face the dilemma that bees do not only transport pollen grains between flowers as pollen vectors but also collect large amounts of pollen that is withdrawn from pollination. Here, we show that pollen of the common hollyhock, Alcea rosea, is mechanically protected against collection by corbiculate bees. In a laboratory setup, bumblebees did not collect the large, sticky, and spinose pollen grains of A. rosea from artificial flowers unless following manipulation of the spines or the pollenkitt. Following removal of the sticky pollenkitt or bending the spines by vortexing the bumblebees readily collected the pollen. Our results show that the pollen of A. rosea is not bitter-tasting or toxic, but mechanically protected by the spines against being collected by corbiculate bees. Light microscopic (LM)-micrographs indicate that the long spines of malvaceous pollen grains are not covered by pollenkitt suggesting a new mechanism of mechanical defense against collection: pollenkitt-free spines and lipophilic pollenkitt prevent compacting pollen grains into pollen storage organs of corbiculate bees. The experimental data fit to observations at flowers of A. rosea and other malvaceous plants that honeybees and bumblebees are densely dusted with pollen but discard the pollen while packing it into their corbiculae.

A new species of eriophyoid mite, Aceria tripuraensis sp. n.(Acari: Eriophyoidea), on Hibiscus macrophyllus from India.

A new species of Eriophyidae (Acari: Prostigmata: E riophyoidea) mite, Aceria tripuraensis n. sp., is described from the closed bud galls of Hibiscus macrophyllus Roxb. ex Hornem. (Malvaceae) in India. Aceria tripuraensis n. sp. is distinguished by having a prodorsal shield with distinct rounded lobes on the postero-lateral margins and two pairs of submedian lines. The tarsal solenidia with unusual transverse sculptures, are 2.5x longer than the empodia. Twenty Aceria species are now known to inhabit malvaceous plant hosts and those are listed here along with type localities and host plant details. A key to all known species of Aceria recorded from Hibiscus spp. is also provided.

Evaluation of infestation percentage of cotton fields to the spiny bollworm, Earias insulana Boisduval (Lep.: Noctuidae), and its relationship with pheromone traps

Spiny bollworm, Earias insulana Boisduval (Lepidoptera: Noctuidae), is one of the most important pest of malvaceous plants throughout the world, except America. In recent years, this insect has been serious pest for cotton fields in southern regions of Iran, especially Darab region of Fars province. In order to evaluate the performance of sex pheromone in reduction of infestation percentage of the spiny bollworm by mass trapping method, an experiment was carried out during year of 2012 in Darab region in Randomised Completely Block Design with six treatments and four replications. The treatments were: application of the four sex pheromone trap densities at the rates of 16, 20, 24 and 30 traps/h, application of Larvin chemical insecticide at the rate of 1 L/h and control. Percentages of infected bolls and flowers to E. insulana were weekly determined. The application of Larvin insecticide performed as the pest population reached to economic threshold level. Analysis variance of results showed that there are significant differences between time, trap number and time × trap interaction on infestation percentage per hectare. During sampling time, the highest infestation percentage was in control treatment and the lowest one was observed in 30 and 24 traps/h treatments. The peak of infestation percentage was seen in 18th of November. The best efficiency among treatments was observed in pheromone trap. In conclusion, using sex pheromone trap in comparison to application of insecticides can efficiently reduce infestation level of cotton fields.

Population Structure and Genetic Diversity of the Boll Weevil (Coleoptera: Curculionidae) onGossypiumin North America

AbstractAlthough the boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a devastating pest in the United States and Mexico, its population structure and genetic diversity in Mexico on wild and cultivated cotton hosts (genus Gossypium) is poorly understood. Past studies using morphology, host use, and distribution records suggest that A.grandis grandis comprises three forms with host-associated characteristics: the southeastern form (from domesticated Gossypium hirsutum L., southeastern United States and northeastern Mexico), the thurberia form (from Gossypium thurberi Todaro, Arizona and northwestern Mexico), and the Mexican form (from multiple Gossypium species and other malvaceous plant genera in the remainder of Mexico and Central America). However, the phylogenetic relationships, host preferences, and distributions of these forms are not completely understood. An alternative hypothesis of an eastern and western form of the boll weevil is suggested by the suspected phylogeographic range expansion from an ancestral distribution in the tropics northward along both Mexican coasts, culminating in the maximally contrasting phenotypes observed in the northeastern and northwestern arms of the current distribution. In this study, we sequenced one mitochondrial and four nuclear genes to gain insight into the evolutionary relationships among the putative forms and their distributions on wild and domesticated cotton hosts. Using models of evolution, we compared the three-form to the two-form classification and to two alternative classifications that incorporate geography and host use traits. The genetic data at most loci provide stronger support for the two-form than the three-form hypothesis, with an eastern and western group separated by the Sierra Madre Occidental mountain range. They do not support separate taxonomic status for boll weevils developing on G.thurberi.

A novel class of DNA satellites associated with New World begomoviruses

Begomoviruses (family Geminiviridae) are whitefly-transmitted plant DNA viruses that have been shown to be helper viruses for a number of distinct DNA satellites, including betasatellites and alphasatellites. Replication of the satellites interferes to some degree with replication of the helper and in some cases they affect the disease symptoms. To date, betasatellites and related molecules such as the satellite associated with Tomato leaf curl virus (ToLCV-sat), have only been associated with Old World begomoviruses. Here, we report the discovery and characterization of subviral molecules associated with bipartite begomoviruses from the New World, which constitute a novel class of DNA satellites, in two malvaceous plant species. These molecules, in addition to sharing some genetic features with betasatellites and ToLCV-sat, contain nucleotide stretches of begomoviral origin, presumably the remains of recombination events involved in their origin.

Diversity and phylogeography of Begomovirus-associated beta satellites of Okra in India.

BackgroundOkra (Abelmoschus esculentus; family Malvaceae) is grown in temperate as well as subtropical regions of the world, both for human consumption as a vegetable and for industrial uses. Okra yields are affected by the diseases caused by phyopathogenic viruses. India is the largest producer of okra and in this region a major biotic constraint to production are viruses of the genus Begomovirus. Begomoviruses affecting okra across the Old World are associated with specific, symptom modulating satellites (beta satellites). We describe a comprehensive analysis of the diversity of beta satellites associated with okra in India.ResultsThe full-length sequences of 36 beta satellites, isolated from okra exhibiting typical begomovirus symptoms (leaf curl and yellow vein), were determined. The sequences segregated in to four groups. Two groups correspond to the beta satellites Okra leaf curl beta satellite (OLCuB) and Bhendi yellow vein beta satellite (BYVB) that have previously been identified in okra from the sub-continent. One sequence was distinct from all other, previously isolated beta satellites and represents a new species for which we propose the name Bhendi yellow vein India beta satellite (BYVIB). This new beta satellite was nevertheless closely related to BYVB and OLCuB. Most surprising was the identification of Croton yellow vein mosaic beta satellite (CroYVMB) in okra; a beta satellite not previously identified in a malvaceous plant species. The okra beta satellites were shown to have distinct geographic host ranges with BYVB occurring across India whereas OLCuB was only identified in northwestern India. Okra infections with CroYVMB were only identified across the northern and eastern central regions of India. A more detailed analysis of the sequences showed that OLCuB, BYVB and BYVIB share highest identity with respect βC1 gene. βC1 is the only gene encoded by beta satellites, the product of which is the major pathogenicity determinant of begomovirus-beta satellite complexes and is involved in overcoming host defenses based on RNAi.ConclusionThe diversity of beta satellites in okra across the sub-continent is higher than previously realized and is higher than for any other malvaceous plant species so far analyzed. The beta satellites identified in okra show geographic segregation, which has implications for the development and introduction of resistant okra varieties. However, the finding that the βC1 gene of the major okra beta satellites (OLCuB, BYVB and BYVIB) share high sequence identity and provides a possible avenue to achieve a broad spectrum resistance.

The microbial flora of Aphis gossypii: Patterns across host plants and geographical space

The cotton aphid, Aphis gossypii, has a worldwide distribution and causes damage to numerous economically important crops. The bacterial symbionts associated with cotton aphids, sampled mainly from malvaceous and cucurbitaceous plants within Japan and Australia, were characterised using molecular profiling approaches. The goal was to document the aphid symbionts present and determine if patterns of microbial diversity are consistent with the existence of host plant related cryptic species in A. gossypii. The bacterial profiles of the aphids are diverse and reflect local geography more than host plant use.