Papaya Flowers Research Articles

Carica papaya Flower Extracts Possess Antioxidant and 5α-reductase Inhibitory Activities.

Carica papaya has been widely used commercially for skin care due to its therapeutic benefits. The potential of its flower to promote hair growth has been traditionally recognized in other countries but not in the Philippines. In this study, we explored the effect of various extracts of C. papaya flower in the biological activities associated with hair loss, including 5α-reductase inhibition and antioxidation, as well as identified the putative compounds present in the most potent extract. The flowers of C. papaya were macerated separately with ethanol, ethyl acetate, and hexane to obtain their corresponding crude extracts. These extracts were subjected to antioxidant tests via 2,2'-diphenyl-1-picrylhydrazyl (DPPH), and ferric-reducing antioxidant power (FRAP) assays. The total phenolic and flavonoid contents (TPC and TFC) of the crude extracts were determined, as well as the ability of the extracts to inhibit 5α-reductase. The compounds present in the most potent extract were determined using ultraperformance liquid chromatography quadrupole time of flight mass spectrometer (UPLC/MS-QToF). Ethyl acetate extract displayed significantly higher DPPH activity (0.001755 ± 0.00092 ascorbic acid equivalent antioxidant capacity) and 5α-reductase inhibitory activity (115.18 ± 11.61 mg dutasteride/g) compared to ethanol (DPPH: p=0.0121; 5α-reductase: p=0.0016) and hexane (DPPH: p=0.0038; 5α-reductase: p<0.0001) extracts. Similarly, ethyl acetate extract gave the highest FRAP (0.4842 ± 0.0936 mg ascorbic acid/g) activity, TFC (0.0403 mg quercetin/g), and TPC (0.0463 mg gallic acid/g) among the extracts. Forty-nine compounds were annotated in the ethyl acetate extract, with seven (7) putatively identified as fatty acids (9-hydroxy-10,12-pentadecadienoic acid, 9,12,15-octadecatrienoic acid), hydroxyflavone (5-methylkaempferol), alkaloid (allomatrine), dipeptide derivative (aurantiamide acetate), bufotalinin, and 6β-acetoxy-5-epilimonin based on the Traditional Chinese Medicine Library. These results suggest that local C. papaya flowers can be a source of hair growth-promoting agents via their antioxidant and 5α-reductase inhibitory potential.

The cytotoxic activity of lignans and monoterpenoids from the male carica papaya flowers on A549 lung cancer, Hep3B liver cancer, and MCF-7 breast cancer cell lines

Two lignans (lariciresinol (1) and dehydrodiconiferyl alcohol (2)), and four monoterpenoids (vitexoid (3), 6-hydroxy-2,6-dimethyl-2,7-octadienoic acid (4), 6-hydroxy-2,6-dimethyloct-7-enoic acid (5), 2,6-dimethylocta-2,7-diene-1,6-diol (6)) from the male Carica papaya flowers are conducted a cytotoxic activity for lung cancer cells (A549), liver cancer cells (Hep3B), and breast cancer cells (MCF-7). The results, lignan (1), and monoterpenoid (3), (6) exhibited medium cytotoxic activity on these cancer cells with IC50 from 34.73±1.55 to 66.12±5.60 µg/mL. Lignan (2) displayed medium cytotoxic activity on MCF-7, Hep3B with IC50 60.85±4.43, 62.32±5.03 µg/mL, respectively, and weak cytotoxic activity on A549 with IC50 70.99±7.26 µg/mL. Monoterpenoids (4), and (5) showed medium cytotoxic activity on MCF-7 with IC50 54.15±5.89, 67.49±2.41 µg/mL, respectively, and weak cytotoxic activity on A549, and Hep3B with IC50 from 72.25±3.13 to 86.03±7.57 µg/mL. Ellipticine was a positive control.

Potential Use of Papaya Flower Extract (Carica papaya Linn) for Aedes Aegypti Larvicide

Introduction: Temefos as a larvicide to prevent dengue hemorrhagic fever is known to be resistant to Aedes aegypti larvae in several regions in Indonesia. Therefore, alternative larvicides are needed. Papaya plants are one of the alternative solutions as papaya flowers contain secondary metabolite compounds that can kill Aedes aegypti larvae. This study aimed to determine the potential of papaya flower extract to be an Aedes aegypti larvicide.Methods : This study was a true experimental study with a posttest-only control group design, with 6 treatment groups namely 1%, 5%, 10%, 15%, and 20% extract concentrations (Experimental Group) and distilled water (Control Group). The experiment was repeated 4 times with a testing time of 24 hours. A total 600 Aedes aegypti instar larvae III/IV were used. Larvae toxicity was analyzed using Probit Analysis to determine the value of Lethal Concentration (LC) and Lethal Time (LT) and the Kruskall-Wallis test to determine the differences of larval deaths in each experimental group. Results: Results showed that the highest and the lowest average larval mortality was at 20% concentration (25 larvae) and 1% concentration (14.75 larvae), respectively. and values were 4.84% and 10.39%, while values of five concentrations were 115.74, 24.24, 23.41, 25.24, and 16.55 hours and values of five concentrations were 241.95, 29.42, 26.20, 32.24, and 24.48 hours. There was a difference in the number of larval deaths after 24 hours of treatment in the experimental group (p-value = 0.011).Conclusion: Papaya flower extract has the potential to be an Aedes aegypti larvicide with 20% concentration as the optimum dose. However, phytochemical screening needs to be done to determine the dominant papaya flower compounds act as Aedes aegypti larvicides.

Phytochemically enriched male papaya flowers: a better green candidate for silver nanoparticle synthesis and exploring its antibacterial potency

Innovating green pathways for fabricating metal nanoparticles (MNPs) turns into an essential subject to promote sustainability and protect our environment from toxicity. Carica papaya is one of the most common cultivations with enriched phytochemicals. Here in this work, we have used male Carica papaya extract (CPE) from its flowers to synthesize eco-friendly silver nanoparticles (AgNPs). The physicochemical properties of CPE-reduced AgNPs (CPE-AgNPs) were studied by different spectroscopic techniques. The characteristic property of AgNPs has been confirmed by analyzing the surface plasmon resonance (SPR) band of CPE- AgNPs: at around 440 nm. The capping of as-prepared AgNPs mediated by CPE was evaluated based on the vibrational bands of functional groups by Fourier Transform Infra-Red (FTIR) spectrometer. The elemental silver composition present in CPE-AgNPs was evidently seen from the corresponding Energy Dispersive X-ray spectroscopic (EDS) measurements. Studies obtained from Transmission Electron Microscopy (TEM) images of CPE-AgNPs reveals that the majority of the CPE-AgNPs are spheres of 11.10 ± 2.30 nm diameter. The Zeta potential value for CPE-AgNPs prepared using 2 ml of CPE was 65.0 ± 2.1 mV, which ensured better stability, and the sample was selected for further studies. CPE-AgNPs show better antibacterial efficacy against bacterial strains and suggest that they can be used for developing AgNPs based medical devices such as urinary catheters to treat urinary tract infections (UTIs).

THE EFFECT OF MASCULUS IMMERSION AGAINST THE DEATH OF MOSQUITO FLACERS

The transition from the dry season to the rainy season causes mosquito larvae in stagnant water. Researchers are looking for natural larvicidal solutions that are safe and effective with male papaya flowers (masculus). The aim of the study was to determine the effect of masculus immersion water on the death of mosquito larvae in water reservoirs. The location is in Curup Tengah District. Quasi experimental type, Chi-square analysis, calculating odds ratio, Chi square test. Almost all (94.4%) there were 34 dead larvae and a small portion (5.5%) there were 2 live larvae, from 36 Aedes aegypti larvae in 50 ml of masculine immersion water, 1 minute. The results of Chi-square analysis showed that P value = 0.04 &lt; ? 0.05, there was a significant effect between masculine immersion water and Aedes aegypti larvae mortality. Where the value of p value = 0.043, has the effect of masculus immersion water, at odds ratio = 4.10 times. Overall (100%) there were 36 dead larvae and a small portion (0%) there were 0 live larvae, out of 36 Aedes aegypti larvae in the bath 100 ml of masculus soaking water, time under 1 minute. The results of the Chi-square analysis showed that the P value = 0.04 &lt;?0.05, there was a significant effect between the masculine immersion water and the mortality of Aedes aegypti larvae. Where the p value = 0.040, has the effect of masculus soaking water, at odds ratio = 4.00 times. In order for the community to be active in eradicating Aedes aegypti larvae, activities get used to making masculine soaking, pouring it into a water reservoir&#x0D;

Characterization and analysis of the promoter region of monodehydroascorbate reductase 4 (CpMDAR4) in papaya.

Differential spatial and temporal expression patterns due to regulatory cis-elements and two different isoforms are detected among CpMDAR4 alleles in papaya. The aim of this research was to study the effects of cis-element differences between the X, Y and Yh alleles on the expression of CpMDAR4, a potential candidate gene for sex differentiation in papaya, using a transcriptional reporter system in a model species Arabidopsis thaliana. Possible effects of a retrotransposon insertion in the Y and Yh alleles on the transcription and expression of CpMDAR4 alleles in papaya flowers were also examined. When comparing promoters and cis-regulatory elements among genes in the non-recombining region of the sex chromosomes, paired genes exhibited differences. Our results showed that differences in the promoter sequences of the CpMDAR4 alleles drove the expression of a reporter gene to different flower tissues in Arabidopsis. β-glucuronidase staining analysis of T2 and T3 lines for constructs containing 5' deletions of native Y and Yh allele promoters showed the loss of specific expression of the reporter gene in the anthers, confirming the existence and location of cis-regulatory element POLLEN1LELAT52. The expression analysis of CpMDAR4 alleles in papaya flowers also showed that all alleles are actively expressed in different flower tissues, with the existence of a shorter truncated isoform, with unknown function, for the Y and Yh alleles due to an LTR-RT insertion in the Y and Yh chromosomes. The observed expression patterns in Arabidopsis thaliana flowers and the expression patterns of CpMDAR4 alleles in papaya flowers suggest that MDAR4 might have a role on development of reproductive organs in papaya, and that it constitutes an important candidate for sex differentiation.

A review article on

These are well-known health benefits of papaya (Carica papaya Linn.). Ayurveda, for example, recognises papaya's therapeutic value. Herbalists have used it to cure bilious fever, gonorrhoea, eczema, rheumatism and headaches. It took four decades of amazing research to identify a critical nutraceutical compound. It is antibacterial, antipyretic, insecticidal, antimicrobial, and antimolluscan. Leaves have been studied using phytoextraction of heavy metals and phytoremediation of particle pollution. Long-term research on phytoconstituents and leaf composition. Malaria, dengue fever, inflammation, and skin infections are all treated by Carica papaya. C. papaya flowers were first tested for antioxidant and antibacterial properties using TLC and UV spectroscopy. Our tests included TLC and UV-visible spectroscopy. The methanol extract had the most alkaloids, flavonoids, saponins, and tannins. N-hexane had steroids and flavonoids while chloroform had saponins and tannins. In it, there were flavonoids and phenolic compounds.

Phytochemical, Pharmacognostical and Pharmacological Activities of Carica papaya

The nutritional and medicinal benefits of papaya (Carica papaya Linn.) have long been known. Many traditional medical systems, such as Ayurveda, recognise papaya's medicinal potential. Traditional literature has used it to treat fever, swellings, bilious fever, gonorrhoea, eczema, rheumatism, headache, whooping cough, asthma, chickenpox, and bronchitis. A vital nutraceutical agent has been identified after four decades of remarkable research on its biological activity and medical applications. The leaf of Carica papaya Linn. has antibacterial, antipyretic, insecticidal, antimicrobial, and antimolluscan effects. Phytoextraction of heavy metals, phytoremediation of particle pollution, and other modern approaches have been utilised to study leaves. Phytoconstituents and leaf composition have been studied for decades. Carica papaya is used to cure a variety of diseases including malaria, dengue fever, inflammation, and skin infections. The antioxidant and antibacterial activity of C. papaya flowers were first assessed using TLC screening and UV spectroscopy. The extracts were also analysed by TLC and UV-visible spectroscopy. The methanol extract included the greatest alkaloids, flavonoids, saponins, and tannins, according to the screening results. Both chloroform and n-hexane extracts had saponins and tannins, while n-hexane also had steroids and flavonoids. It had flavonoids, tannins, saponins, and phenolic chemicals.

Sex biased expression of hormone related genes at early stage of sex differentiation in papaya flowers

Sex types of papaya are controlled by a pair of nascent sex chromosomes, but molecular genetic mechanisms of sex determination and sex differentiation in papaya are still unclear. We performed comparative analysis of transcriptomic profiles of male and female floral buds at the early development stage before the initiation of reproductive organ primordia at which there is no morphological difference between male and female flowers. A total of 1734 differentially expressed genes (DEGs) were identified, of which 923 showed female-biased expression and 811 showed male-biased expression. Functional annotation revealed that genes related to plant hormone biosynthesis and signaling pathways, especially in abscisic acid and auxin pathways, were overrepresented in the DEGs. Transcription factor binding motifs, such as MYB2, GAMYB, and AP2/EREBP, were enriched in the promoters of the hormone-related DEGs, and transcription factors with those motifs also exhibited differential expression between sex types. Among these DEGs, we also identified 11 genes in the non-recombining region of the papaya sex chromosomes and 9 genes involved in stamen and carpel development. Our results suggested that sex differentiation in papaya may be regulated by multiple layers of regulation and coordination and involved transcriptional, epigenetic, and phytohormone regulation. Hormones, especially ABA and auxin, transcription factors, and genes in the non-recombination region of the sex chromosome could be involved in this process. Our findings may facilitate the elucidation of signal transduction and gene interaction in sex differentiation of unisexual flowers in papaya.

UJI AKTIVITAS EKSTRAK BUNGA PEPAYA JANTAN SEBAGAI ANTIDIARE TERHADAP ESCHERICHIA COLI

The purpose of this study was to study the activity of male papaya flower extract (Carica Papaya L) which was made as an antidiarrheal in order to provide insight and use of male papaya flowers (Carica Papaya L) as a study that discusses male papaya flowers are only used as cooking. This plant has a composition of compounds that contain antibacterial. The research method used was experimental research. The steps that have been carried out are determining the male papaya flower plant, extraction using male papaya flower simplicia powder with 70% ethanol solvent by maceration which is then evaporated on water to get a thick extract. Then make a bacterial suspension by incubating for 1x24 hours at 37 ° C. The results obtained show that the average inhibition zone at a concentration of 40% produces an average diameter of 2.6 cm, at a concentration of 30% produces an average diameter of 2.07 cm, and at a concentration of 20% produces an average diameter of 2.03 cm. The best concentration than the other series at a concentration of 40%.&#x0D; Keywords: Escherichia Coli, Carica Papaya L, Male Papaya Flowers

Optimization of Flavonoids Extraction from Vietnamese Male Papaya (Carica papaya, L.) Flowers by Ultrasound‐Asissted Method and Testing Bioactivities of the Extract

AbstractPapaya (Carica papaya Linn.) is popularly cultivated in most tropical countries such as Malaysia, Vietnam, the West Indies, and throughout Africa. In the present work, an ultrasound‐assisted extraction (UAE) method has been developed for flavonoid extraction from Vietnamese male Carica papaya (C. papaya) flowers. Various influential operating parameters such as extraction time, ultrasonic power, solvent–to–material ratio, and extraction temperature on the flavonoid content were examined to optimize the extraction process. The result showed that under optimum extraction conditions including extraction time of 33 min, ultrasonic power of 240 W, solvent–to–material ratio of 27 : 1 mL/g, and extraction temperature of 46 , the flavonoid content obtained was of 10.648±0.228 mg QE/g, which was found to be higher than that obtained by hot water extraction, enzyme‐assisted extraction, and ultrasound‐assisted enzymatic extraction methods. Therefore, UAE could be considered as the most efficient extraction method for flavonoids from Vietnamese male C. papaya flowers. In addition, the extract obtained under optimum conditions was tested bioactivities to prove the medicinal uses of flavonoids extracted from Vietnamese male C. papaya flowers with the half‐maximal inhibitory concentration values for antioxidant effect and anticancer effect against Hep‐G2 cell lines at 179.69 0.03 and 56.63 1.25 μg/mL, respectively.

Antioxidant, antibacterial activity, and phytochemical characterization of Carica papaya flowers

BackgroundCarica papaya is an eminent medicinal plant used all over the world to treat several diseases like malaria, dengue, inflammation, and skin infections. In this study, preliminary phytochemical screening for C. papaya flowers was carried out using different methods as TLC screening and UV-spectroscopy along with evaluation of antioxidant and antibacterial activities. Methods were also developed for TLC and UV-visible spectroscopic analysis of the extracts.ResultsResults of phytochemical screening revealed that the methanol extract contains alkaloids, flavonoids, saponins, and tannins as major components. Saponins and tannins were present in chloroform and n-hexane extracts; however, steroids and flavonoids were additionally found in n-hexane extract. Flavonoids, saponins, and tannins were present in aqueous extract of papaya flower. TLC and UV-visible spectroscopy also confirmed the presence of phenolics and flavonoids in different plant extracts. The total phenolic content (0.76 ± 0.04 mg GAE/g dry weight) and total flavonoid content (1.53 ± 0.10 mg QE/g dry weight) were the highest in the n-hexane extract of the flower. Antioxidant activity using DPPH free radical scavenging assay was the highest in n-hexane extract (64.07%). Antibacterial screening was carried out using well diffusion method against two pathogens Gram-negative bacteria Escherichia coli and Gram-positive bacteria Bacillus subtilis. The antibacterial assays of the extracts displayed the highest activity in methanolic extract against both E. coli (4.00 ± 0.08) and B. subtilis (01.00 ± 0.05).ConclusionThis is the first report for the presence of alkaloids and saponins in C. papaya flowers. Also, it is the first report for determination of total phenolics and total flavonoids in C. papaya flowers. Methanolic extract displayed considerable antibacterial activity against E. coli and B. subtilis. The antioxidant and antibacterial properties of phytochemical extracts make them attractive alternative complementary medicines. More chemical investigation for chemical constituents is important for further drug development programs.Graphical abstract

Phytochemical study of the ethyl acetate extract of male Carica papaya flowers from Quang Nam – Da Nang

AbstractMale Carica papaya flowers, one of natural materials, have many pharmacology activities including anticancer. We report herein the isolation and structural elucidation of known compounds. Eight flavonoids, kaempferol (1), kaempferol 3‐O‐α‐L‐rhamnopyranoside (2), kaempferol 3‐O‐β‐D‐glucopyranoside (3), kaempferol 3‐O‐α‐L‐arabinopyranoside (4), quercetin (5), quercitrin (6), quercetin 3‐O‐β‐D‐galactopyranoside (7) and myricitrin (8) were isolated from the ethyl acetate extract of male Carica papaya flowers. Their structures were determined by NMR, MS spectra and by comparing with the reported data.

Auxin regulation involved in gynoecium morphogenesis of papaya flowers

The morphogenesis of gynoecium is crucial for propagation and productivity of fruit crops. For trioecious papaya (Carica papaya), highly differentiated morphology of gynoecium in flowers of different sex types is controlled by gene networks and influenced by environmental factors, but the regulatory mechanism in gynoecium morphogenesis is unclear. Gynodioecious and dioecious papaya varieties were used for analysis of differentially expressed genes followed by experiments using auxin and an auxin transporter inhibitor. We first compared differential gene expression in functional and rudimentary gynoecium at early stage of their development and detected significant difference in phytohormone modulating and transduction processes, particularly auxin. Enhanced auxin signal transduction in rudimentary gynoecium was observed. To determine the role auxin plays in the papaya gynoecium, auxin transport inhibitor (N-1-Naphthylphthalamic acid, NPA) and synthetic auxin analogs with different concentrations gradient were sprayed to the trunk apex of male and female plants of dioecious papaya. Weakening of auxin transport by 10 mg/L NPA treatment resulted in female fertility restoration in male flowers, while female flowers did not show changes. NPA treatment with higher concentration (30 and 50 mg/L) caused deformed flowers in both male and female plants. We hypothesize that the occurrence of rudimentary gynoecium patterning might associate with auxin homeostasis alteration. Proper auxin concentration and auxin homeostasis might be crucial for functional gynoecium morphogenesis in papaya flowers. These results will lead to further investigation on the auxin homeostasis and gynoecium morphogenesis in papaya.

Karakter Morfologi dan Sitologi Bunga Pepaya Merah Delima

The papaya plant has three types of flowering, male flowers, female flowers, and perfect flower (hermaphrodite). The difference in interest affects the shape of the resulting fruit. This study aimed to characterize morphology and cytology of papaya flowers. The study was conducted in Tropical Fruit Research Institute at Solok and Laboratory of SPT at the Biology Department of the Faculty of Mathematics and Natural Sciences, Andalas University, Padang, West Sumatra. The research material uses papaya flowers Merah Delima variety from KP. Aripan Balitbu Troipka. The results showed the male flowers of male plants were smaller than the male flowers of the perfect plant. The difference of hermaphrodite flower of pentandria with hermaphrodite elongata flower, among others, the number of stamens, the length of the stem and the size of the ovary. Hermaphrodite pentandria has a number of stamens 5 while elongata has stamens 10

Transcriptome analysis provides insights into the delayed sticky disease symptoms in Carica papaya.

Global gene expression analysis indicates host stress responses, mainly those mediated by SA, associated to the tolerance to sticky disease symptoms at pre-flowering stage in Carica papaya. Carica papaya plants develop the papaya sticky disease (PSD) as a result of the combined infection of papaya meleira virus (PMeV) and papaya meleira virus 2 (PMeV2), or PMeV complex. PSD symptoms appear only after C. papaya flowers. To understand the mechanisms involved in this phenomenon, the global gene expression patterns of PMeV complex-infected C. papaya at pre-and post-flowering stages were assessed by RNA-Seq.The result was 633 and 88 differentially expressed genes at pre- and post-flowering stages, respectively. At pre-flowering stage, genes related to stress and transport were up-regulated while metabolism-related genes were down-regulated. It was observed that induction of several salicylic acid (SA)-activated genes, including PR1, PR2, PR5, WRKY transcription factors, ROS and callose genes, suggesting SA signaling involvement in the delayed symptoms. In fact, pre-flowering C. papaya treated with exogenous SA showed a tendency to decrease the PMeV and PMeV2 loads when compared to control plants. However, pre-flowering C. papaya also accumulated transcripts encoding a NPR1-inhibitor (NPR1-I/NIM1-I) candidate, genes coding for UDP-glucosyltransferases (UGTs) and several genes involved with ethylene pathway, known to be negative regulators of SA signaling. At post-flowering, when PSD symptoms appeared, the down-regulation of PR-1 encoding gene and the induction of BSMT1 and JA metabolism-related genes were observed. Hence, SA signaling likely operates at the pre-flowering stage of PMeV complex-infected C. papaya inhibiting the development of PSD symptoms, but the induction of its negative regulators prevents the full-scale and long-lasting tolerance.

Development, Survival, and Fecundity of Amblypelta lutescens lutescens (Hemiptera: Coreidae) on Distinct Phenological Stages of Different Fruit-Crop Host Plants.

The banana-spotting bug, Amblypelta lutescens lutescens Distant (Hemiptera: Coreidae), is native to Australia and a major polyphagous pest of many tropical and subtropical horticultural crops in the east and north of the country. Different plant structures (flowers, vegetative flush, and different sized fruit) of avocado, lime, and papaya crops and green bean pods (a known suitable host) were evaluated for their suitability as hosts for A. l. lutescens Neonate to imago survivorship, the time taken to complete neonate to imago development, preovipositional period, and fecundity were assessed for each crop. Of all the different phenological stages of the plants investigated, A. l. lutescens could complete development to imago on vegetative flush of papaya and lime, papaya flowers, and green bean pods but on no other structures tested. There was higher survivorship to the second instar when neonates fed on green bean pods or flowers or vegetative flush of avocado, lime, or papaya crops than when neonates fed on small, medium, or large fruit of these crops. Insects that developed to the imago on green bean pods were significantly heavier than insects that developed on papaya flowers or papaya vegetative flush. The mean preoviposition period was shorter, and adult females more fecund, if they completed immature development and then fed as adults on papaya vegetative flush or green beans rather than papaya flowers. The data indicate that avocado is not a suitable host for A. l. lutescens, suggesting that adult populations that cause significant pest damage to the fruit of this crop originate elsewhere.

Distance and quality of natural habitat influence hawkmoth pollination of cultivated papaya

Crop pollination by wild pollinators is an ecosystem service of immense value to modern agriculture. Pollination by wild insects is under-researched in the tropics, where many crops may require or benefit from wild pollinators. Papaya is a dioecious tree crop widely cultivated throughout the tropics. In East Africa, papaya is an important component of rural smallholder farming systems. Traditional agricultural systems are currently under stress due to landscape degradation. These trends are of special concern with respect to pollination services provided by wild insects. Investigation of the role of hawkmoths as pollinators of papaya on subsistence farms in Kenya was conducted over a period of 3 years. Hawkmoths were the most abundant and reliable visitors to both ‘female’ pistillate and ‘male’ staminate papaya flowers. Hawkmoths accounted for >95% of legitimate visits and xenogamous pollination of papaya flowers. Hippotion celerio, Nephele comma and Agrius convolvuli were the main pollinators. Sites in two districts with similar climates and natural vegetation, but different levels of habitat degradation were chosen for comparison of pollinators and pollination services. Hawkmoth abundance and visitation rates declined sharply with increasing distance of natural habitat patches from the crop. Fruit set was also reduced at sites with high levels of disturbance/poor agricultural practices. Natural habitat containing larval food plants and other nectar resources for hawkmoths therefore supports adjacent cultivated papaya with pollination services. Understanding the links between wild biodiversity, in this case pollinating hawkmoths, and agricultural productivity can help bridge the gap between agricultural development and biodiversity conservation.

The in vitro Antibacterial Activity of Methanol and Ethanol Extracts of Carica papaya Flowers and Mangifera indica Leaves

The in vitro Antibacterial Activity of Methanol and Ethanol Extracts of Carica papaya Flowers and Mangifera indica Leaves

Progress in backcrossing between Carica papaya × Vasconcellea quercifolia intergeneric hybrids and C. papaya

Papaya is a major tropical fruit crop worldwide, however, all genotypes are susceptible to Papaya ringspot virus type P (PRSV-P). Protocols have been developed to produce large numbers of intergeneric hybrids between Carica papaya L. and Vasconcellea quercifolia, which is PRSV-P resistant. Although pollen fertility of these hybrids was low, backcross populations were produced in both Australia and the Philippines when papaya flowers were pollinated with pollen from 11 hybrid plants that had been identified as having some pollen fertility and were PRSV-P resistant. Plantlets were produced after embryo rescue and culture in vitro. Second backcross generations (BC2) were easier to produce than first backcross (BC1) generations as pollen fertility was &gt;80% in male BC1 plants. Variation in time to PRSV-P symptom expression and severity of virus symptoms in the backcross generations was observed in both countries. Commercially acceptable fruit were produced in the BC2 generation. The results demonstrate that efforts in wide hybridisation to transfer PRSV-P resistance to C. papaya, are better directed towards crosses between C. papaya and V. quercifolia than with other Vasconcellea species.