Fruit Plants Research Articles

Optimasi Ukuran Pot dan Dosis Pupuk pada Budidaya Melon (Cucumis melo L)

This research aimed to determine the optimum pot size and fertilizer dosage for melon (Cucumis melo L) cultivation based on productivity. The experiment used a Completely Randomized Design (CRD) arranged factorially with 2 factors and two replicates. The first factor was the dose of compost fertilizer (D) which consists of 1500 g (D1), 1500 g+10 g NPK (D2), 2000 g (D3), and 2000 g+10 g NPK (D4), and the second factor was the pot size or volume of growth media (N) consisting of 5 liters (N1), 10 liters (N2), and 20 liters (N3). The results showed that fertilizer dosage had no effect on all parameters, while pot size had an effect on fresh fruit weight, plant height, fruit circumference, stem diameter and water productivity, but had no effect on sweetness level, number of leaves and root weight. If seen from fruit weight and water productivity, the N2 treatment factor is the best treatment factor. Therefore; the D1N2 treatment combination could be chosen as the optimum treatment because it produced fruit weights of 1434.58-1532.36 g and an average water productivity of 39.07kg/m3. Keywords: Compost Dose, Melon Cultivation, Pot Size, Water Productivity.

Using Trichoderma asperellum to Antagonize Lasiodiplodia theobromae Causing Stem-End Rot Disease on Pomelo (Citrus maxima).

Stem-end rot disease has been causing damage to the production of pomelos in Vietnam. The cur-rent study aimed to (i) isolate fungal pathogens causing pomelo stem-end rot disease (PSERD) and (ii) discover Trichoderma spp. that had an antagonistic ability against pathogens under in vitro conditions. Fungi causing PSERD were isolated from pomelo fruits with symptoms of stem-end rot disease and collected from pomelo farms in Ben Tre province, Vietnam. Moreover, 50 fungal strains of Trichoderma spp. also originated from soils of these pomelo farms in Ben Tre province and were dual-tested with the fungal pathogen on the PDA medium. The results demonstrated that 11 pathogenic fungi causing PSERD were isolated from the fruit and showed mycelial growth of roughly 5.33-8.77 cm diameter at 72 h after inoculation. The two fungi that exhibited the fast-est growth, namely, S-P06 and S-P07, were selected. ITS sequencing of the S-P06 and S-P07 fungi resulted in Lasiodiplodia theobromae. All the 50 Trichoderma spp. strains were allowed to antago-nize against the S-P06 and S-P07 strains under in vitro conditions. The greatest antagonistic effi-ciency was found in Trichoderma spp. T-SP19 at 85.4-86.2% and T-SP32 at 84.7-85.4%. The two antagonists were identified as Trichoderma asperellum T-SP19 and T-SP32. The selected strains of Trichoderma asperellum were potent as a biological control for fruit plants.

Effects of the age of raised beds on the physicochemical characteristics of fruit orchard soil in the Vietnamese Mekong Delta.

To grow fruit plants, farmers in the Vietnamese Mekong Delta (VMD) must use raised bed constructions to avoid waterlogging during the rainy season. This study aimed to evaluate the effects of the age of the raised beds on the soil physicochemical properties of longan orchards located in the VMD. Two raised bed systems were evaluated: a young bed constructed 10 years ago and an old bed constructed 42 years ago. Soil samples were collected from five different soil layers (0-20, 20-40, 40-60, 60-80, and 80-100 cm) with four replicates per layer. Soil samples were tested for pH, electrical conductivity (EC), available phosphorus (AP), total nitrogen (TN), soil organic matter (SOM), exchangeable cations (Ca2+, K+, Mg2+, and Na+), cation exchange capacity (CEC), bulk density (BD), soil porosity, available water-holding capacity (AWC), particle composition (sand, silt, and clay), and size. The soil pH was approximately 1.0 units lower in the old bed compared to the young bed at depths of 0-20 and 20-40 cm. The BD was higher in the old bed (0.15 g cm-3) than in the young bed at a soil depth of 0.4 m. SOM, AP, exchangeable cations (Ca2+, Na+, and Mg2+), AWC, and soil porosity were significantly lower in both the topsoil (0-20 cm) and subsoil (20-40 cm) layers in the old bed than in the young bed. In particular, the SOM, AP, AWC, and soil porosity contents in the old bed decreased by 18%, 20%, 15%, and 17%, respectively, compared with those in the young bed at soil depths of 0-40 cm. Therefore, cultivating raised bed soil for a longer period significantly reduced the soil exchangeable cations, porosity, and fertility of the surface and subsurface soils. Based on these results, farmers should use soil conservation practices, such as cover crops, rice straw mulching, and soil amendments in their orchards to mitigate topsoil degradation.

The Patterns of Agroforestry and Its Contribution to the Community Income

Farmers choose an agroforestry pattern to fulfill various objectives, including obtaining their income. The diversity of fruit plants chosen by the Nanga Menterap village community as a component of the agroforestry system has the potential to contribute significantly as a source of community income. This research aimed to describe the agroforestry patterns and calculate the contribution of agroforestry patterns to the income of the people of Nanga Menterap Village, West Kalimantan Province, Indonesia. The research used a survey method by census. Data collection techniques included observation, questionnaires, and interviews with the Nanga Menterap Village community with agroforestry land. The agroforestry pattern in Nanga Menterap Village can be classified into two types: the agrisilvicultural and the agrosilvopastural. Farmers in Nanga Menterap Village apply a random mixture planting form in which crops and trees are planted irregularly. The agroforestry plants combined in the forestry component include durian (Durio zibethinus), aren (Arenga pinnata), tengkawang (Shorea stenoptera), mango (Mangifera indica), jackfruit (Artocarpus heterophyllus), and petai (Parkia speciosa). The agricultural component includes chili (Capsicum annuum), cocoa (Theobroma cacao), corn (Zea mays), coconut (Cocos nucifera), coffee (Coffea robusta), banana (Musa sp.), cassava (Manihot esculenta), long bean (Vigna unguiculata), ginger (Zingiber officinale), turmeric (Curcuma longa Linn. syn. Curcuma domestica Val.), eggplant (Solanum melongena), and tomatoes (Solanum lycopersicum), while the types of livestock such as pigs, domestic chickens, cows, and goats. The contribution of agroforestry to community income in Nanga Menterap Village is 82.74%. From these contributions, the agroforestry system is the right choice for the community and government to manage land. The governments should be able to facilitate and determine specific and targeted activity programs to improve the cultivation capabilities and welfare of farmers. Keywords: agroforestry, community, contribution, income

An Overview of the Increasing Ornamental Plant Business in Indonesia Post-COVID-19 Pandemic as a Result of Social Media and Its Future Perspective

The ornamental plant is one of the important horticultural commodities in Indonesia, but its development differs from that of other horticultural commodities, such as vegetable and fruit plants. The COVID-19 pandemic, which has been ongoing since early 2020, apart from having an impact on health, has also positively impacted the ornamental plant business in Indonesia. Home confinement caused certain physiological problems that could be solved by indoor gardening activity, leading to an increase in the demand for ornamental plants, especially for leafy ornamental plants. This review provides a comprehensive overview of the growth of the ornamental production business in Indonesia in terms of psychological needs and the power of social media. There was an increase in ornamental prices due to the impact of the COVID-19 pandemic in Indonesia. Consumer preferences and behaviors were also altered by the pandemic, as indicated by consumers’ new motivations, perceptions, learning, and belief systems regarding ornamental plants. The government has launched several strategies to gain domestic competitiveness and maintain its sustainability in the environment. Digital transformation has been applied by ornamental plant businesses in Indonesia. The digital marketing of ornamental plants relies on social media concepts such as entertainment, customization, interactions, electronic word of mouth (EWOM), and trendiness.

Resident Hymenopteran Parasitoids with Potential Drosophilid Associations in Andean North Patagonia: Implications for the Biological Control of the Spotted Wing Drosophila.

The spotted wing drosophila, Drosophila suzukii Matsumura, is native to Southeast Asia and has become a serious pest of soft-skinned fruits worldwide. Several control methods are being tested worldwide as part of an integrated pest management approach. Biological control is a promising alternative tactic that can be used to manage D. suzukii populations, especially in unmanaged areas. This study aimed at exploring the diversity of resident hymenopteran parasitoids of drosophilids in northwestern Patagonia, where D. suzukii is considered an important pest. The survey also aimed to investigate possible associations between parasitoids and D. suzukii in several crops and non-crop fruits, and to determine D. suzukii fruits infestation levels. Fourteen sites with mainly berry crops were sampled biweekly using cider vinegar traps and collecting fresh fruits from a variety of crop and non-crop fruit plants. We identified five species of hymenopteran parasitoids, obtained from the baited traps, that have the potential to associate with D. suzukii: Leptopilina heterotoma Thomson, Ganaspis brasiliensis Ihering, Hexacola hexatoma Hartig (Figitidae), Pachycrepoideus vindemmiae Rondani (Pteromalidae), and Spalangia endius Walker (Spalangiidae). Leptopilina heterotoma is reported for the first time in Argentina. High numbers of D. suzukii adults were recovered from baited traps and field-collected fruits. However, no parasitoid emerged from D. suzukii pupae recovered from fruits, nor were any dead parasitoids recorded inside D. suzukii pupae. Overall infestation levels of D. suzukii on field-collected fruits did not differ significantly between species/varieties. The results are discussed with emphasis on the possible functionality and perspectives of using these species as biological control agents.

Application of the KNN method to check soil compatibility using a microcontroller for android-based banyuwangi citrus fruit plants

Application of the KNN method to check soil compatibility using a microcontroller for android-based banyuwangi citrus fruit plants

Growth of leaf cutting of malay apple (Syzygium malaccense (L.) Merr & Perry) with coconut water treatmen

Malay apple (Syzygium malaccense (L.) Merr & Perry) is a fruit plant in the Myrtaceae family, which has high economic value and nutritional content. The aim of this study was to determine the growth response of guava leaf cuttings to treatment with coconut water concentrations. The research design used was a randomized block design with 5 treatment levels and 5 replications. The treatment consisted of 5 levels namely control, water immersion, 25% coconut water, 50% coconut water, and 75% coconut water. Coconut water treatment was given to cuttings by soaking for 2 hours. Furthermore, leaf cuttings are planted in polybags that have been doused with water and then given a plastic cover. Parameters observed included the percentage of live cuttings, the percentage of formed roots, the percentage of shoots formed, the percentage of petiole damage, the percentage of petiole swelling and the percentage of petiole callus formation, the percentage of damaged leaves, and the symptoms of leaf damage. The results showed that the control treatment, water immersion and coconut water treatment showed the percentage of live cuttings was 100%, the leaf cuttings had not yet formed roots and shoots. Coconut water treatment reduced the percentage of petiole and leaf blade damage, increased the percentage of petiole swelling and increased callus formation, but was not able to stimulate root and shoot formation. Treatment of 75% coconut water showed the lowest percentage of damage to leaf cuttings with the highest percentage of swelling and callus formation.

Evaluating the potential of Distribution of Relaxation Times analysis for plant agriculture

The analysis of a Distribution of Relaxation Times (DRT) has proven to be extremely effective for the study of electrochemical power sources. Biological systems are non-inductive, making them very suitable candidates for DRT analysis, as demonstrated by recent research. In this work, we conduct the first evaluation of DRT analysis in agricultural applications. We revisit published equivalent electrical circuit parameter data to evaluate the potential of DRT analysis for various plant electrochemical impedance spectroscopy applications. We investigate the advantages and limitations of adopting this emerging analysis method as an impedance modelling strategy for the electrochemical characterisation of plants. We illustrate its promise by comparing it with the standard methods using simulations and measurements published in the literature on fruit ripening, plant stress, and post-harvest processing of agricultural products. This study highlights the potential of DRT analysis as an effective modelling strategy for impedimetric system characterisation in agriculture, with promising advantages over standard techniques.

Genome-wide identification of the heat shock transcription factor gene family in two kiwifruit species.

High temperatures have a significant impact on plant growth and metabolism. In recent years, the fruit industry has faced a serious threat due to high-temperature stress on fruit plants caused by global warming. In the present study, we explored the molecular regulatory mechanisms that contribute to high-temperature tolerance in kiwifruit. A total of 36 Hsf genes were identified in the A. chinensis (Ac) genome, while 41 Hsf genes were found in the A. eriantha (Ae) genome. Phylogenetic analysis revealed the clustering of kiwifruit Hsfs into three distinct groups (groups A, B, and C). Synteny analysis indicated that the expansion of the Hsf gene family in the Ac and Ae genomes was primarily driven by whole genome duplication (WGD). Analysis of the gene expression profiles revealed a close relationship between the expression levels of Hsf genes and various plant tissues and stress treatments throughout fruit ripening. Subcellular localization analysis demonstrated that GFP-AcHsfA2a/AcHsfA7b and AcHsfA2a/AcHsfA7b -GFP were localized in the nucleus, while GFP-AcHsfA2a was also observed in the cytoplasm of Arabidopsis protoplasts. The results of real-time quantitative polymerase chain reaction (RT-qPCR) and dual-luciferase reporter assay revealed that the majority of Hsf genes, especially AcHsfA2a, were expressed under high-temperature conditions. In conclusion, our findings establish a theoretical foundation for analyzing the potential role of Hsfs in high-temperature stress tolerance in kiwifruit. This study also offers valuable information to aid plant breeders in the development of heat-stress-resistant plant materials.

A new disease of kumquat (Fortunella margarita) caused by Colletotrichum karsti: twig and branch dieback

Citrus fruit crops are important in many countries. Anthracnose, post bloom fruit drop, fruit stem-end rot, twig and branch dieback and gummosis, caused by Colletotrichum spp., are diseases that seriously threaten citrus production. Surveys of kumquat (Fortunella margarita) orchards were conducted in Eastern Sicily, Southern Italy, during 2022-23. Fungi isolated from twig and branch dieback of F. margarita were identified as Colletotrichum karsti through multi-locus (gapdh, tub2 and act) phylogeny. Pathogenicity and aggressiveness on detached apple fruit and kumquat plants were confirmed for a selection of representative isolates, although with different levels of disease incidence observed. This is the most comprehensive study on identification of C. karsti as the causal agent of twig and branch dieback of kumquat.

Effect of adjuvants on physicochemical properties of lime sulfur on flower/paraffin and application on flower thinning.

Adjuvants can effectively enhance the utilization rate of pesticides, but the application of adjuvants in plant growth regulators is rarely studied. This work explored the effects of adjuvants dioctyl sulfosuccinate sodium salt (AOT) and methyl oleate (MO) on lime sulfur (LS), especially the drop behavior on flower and paraffin surface. The results showed that the addition of AOT and AOT+MO can significantly reduce the static and dynamic surface tension of LS from 72mN/m to 28mN/m and 32mN/m respectively, and increase the spreading factor from 0.18 to 1.83 and 3.10 respectively, reduce the bounce factor from 2.72 to 0.37 and 0.27 respectively. The fluorescence tracer test showed that the addition of adjuvants could promote the spreading and permeation of droplets. The field test results revealed that the flower thinning rate of adjuvant and non-adjuvant were 80.55% and 54.4% respectively, and the flower thinning effect of adding adjuvant was the same as that of artificial which the flower thinning rate was 84.77%. The quality of apples treated with adjuvants was similar to that treated with artificial, and the weight of single fruit increased by 24.08% compared with CK (spray water). The application of tank-mixture adjuvant could reduce the dosage of LS for thinning agent application, improve apple's quality, and decrease labor cost and improve the economic benefits of fruit planting and the environmental benefits of plant growth regulators.

Multi-omic characterisation as a tool to improve knowledge, valorisation and conservation of wild fruit genetic resources: the case of Arbutus unedo L.

The valorisation and conservation of plant genetic resources (PGRs) and wild fruit PGRs are critical to ensure the maintenance of genetic and cultural heritage and to promote new perspectives on resource use. New strategies to characterize PGRs are needed, and the omics approach can provide information that is still largely unknown. The Strawberry tree (Arbutus unedo L.) is an underutilized, drought and fire-resistant species distributed in the Mediterranean area and its berries have large ethnobotanical use. Although their phenolic profile and antioxidant capacity are known, they are not well characterised, particularly from a proteomic perspective. The aim of this work is the characterisation of two ecotypes of A. unedo (Campania and Sicily) from a molecular viewpoint to valorise and encourage the preservation of this wild fruit. Samples were collected from two different geographical areas to assess whether different geographical conditions could influence the characteristics of leaves and fruits at the three stages of ripening (green, veraison, red). Proteomic analysis identified 904 proteins, of which 122 showed significance along the ripening. Some of these differentially abundant proteins, such as chalcone synthase, show a marked increase during ripening. The protein functional classes with the highest representation are involved in protein and amino acid metabolism, glycolysis and in secondary metabolism. From a proteomic perspective, there are no differences between the fruits from the two regions compared by the ripening stage. However, the pedoclimatic metabolic imprinting allowed the observation of good diversity in the metabolomic profiles between the two ecotypes, especially for anthocyanins, 4 times more abundant in the Sicilian veraisoned fruit than in the Campania one, and catechins, with double the abundance in the Campania ecotype compared to the Sicilian ecotype in the green phase, but more abundant (3x) in the Sicilian veraisoned fruit. Phenolic compounds show a 20% greater abundance in the Campania green arbutus fruit than in the Sicilian one, values that then equalise as ripening progresses. Multi-omic characterisation enhanced the knowledge on a wild fruit plant species which shows specific adaptations and responses to the environment to be considered when addressing the issue of local agrobiodiversity.

First Report of Passiflora latent virus in Passion fruit (Passiflora edulis) in China.

Passion fruit (Passilora edulis, family Passifloraceae.) is an economically important fruit crop in many tropical and subtropical regions worldwide. It is widely planting in southern China, and in greenhouses throughout the country. In Mar 2022, symptoms of a viral-like infection were observed on the leaves of passion fruit plants in a 3-hectare greenhouse complex in Hohhot, China. Chlorotic lesions were observed on leaves of two vines of passion fruit and symptomatic leaves developed chlorotic spots, followed by systemic leaf chlorosis and necrosis. Dark ringed spots emerged on the surface of matured fruits (Figure 1). To confirm infectivity, mechanical transmission of the virus was performed by grinding leaves from two symptomatic passion fruit vines in 0.1M phosphate buffer pH 7, and the resulting two samples were each used to rub-inoculate carborundum-dusted leaves of three healthy passion fruit seedlings. Newly emerging leaves of inoculated plants developed mild mosaic symptoms 30-days after inoculation. Three samples from each of the two original symptomatic plants and two samples from each inoculated seedling tested positive using a Passiflora latent virus (PLV) ELISA Kit (Creative Diagnostics, USA). To further confirm the virus identity, total RNA from leaf samples from one of the original greenhouse symptomatic plants and one of the inoculated seedlings were extracted using an TaKaRa MiniBEST Viral RNA Extraction Kit (Takara, Japan). The two RNA samples were subjected to reverse transcription-polymerase chain reaction (RT-PCR) tests with virus specific primers PLV-F (5'-ACACAAAACTGCGTGTTGGA-3') and PLV-R (5'-CAAGACCCACCTACCTCAGTGTG-3') (Cho et al., 2020). RT-PCR products of the expected 571 bp were obtained from both the original greenhouse sample and inoculated seedling. Amplicons were cloned into the pGEM-T Easy Vector, and two clones per sample were Sanger sequenced bidirectionally (Sangon Biotech, China), and the sequence of one clone from one of the original symptomatic sample was uploaded to NCBI (GenBank OP320922.1). This accession had 98% nucleotide sequence identity with a PLV isolate from Korea (GenBank: LC556232.1). RNA extracts from two asymptomatic samples tested negative for PLV with both ELISA and RT-PCR tests. We also tested the original symptomatic sample for common occurring passion fruit viruses, including passion fruit woodiness virus (PWV), cucumber mosaic virus (CMV), east asian passiflora virus (EAPV), telosma mosaic virus (TeMV), papaya leaf curl Guangdong virus (PaLCuGdV), and the RT-PCR results were negative for those viruses. However, based on the systemic leaf chlorosis and necrosis symptoms, we cannot preclude a mixed infestation of other viruses. PLV affects fruit quality and has high potential to reduce market value. To our knowledge, this is the first report of PLV in China, which could provide a reference basis to PLV identification, prevention and control. Acknowledgments This research was carried out with the support of Inner Mongolia Normal University High-level Talents Scientific Research Startup Project (Grant no. 2020YJRC010). Supplementary material Figure 1. Mottle, leaf distortion, puckering symptoms on old leaf (A), mild puckering symptom on young leaf (B), and ring-striped spots symptoms on fruit (C) of the PLV infected passion fruit plant in China.

Effect of Naphthalene Acetic Acid (NAA) on Blossom Drop in Chili (Capsicum frutescens)

Chili (Capsicum frutescens) is a significant cash crop in Bangladesh. It is very popular spices and the demand of chili is increasing day by day. To investigate the influence of Naphthalene Acetic Acid (NAA) on bloom drops in Chili cv. BARI Morich-3 from November 2020 to April 2021. These types demonstrated the optimal dosages of NAA as a foliar spray in reducing blossom drop with the application of five different concentrations of NAA at 0, 10, 20, 30, and 40 ppm, respectively. It was determined that 10ppm NAA performed the best, and it takes the fewest days (43.33) to first flowering, the fewest days (50) to 50% blooming, the fewest days (48.44) to first fruiting, and the fewest days (60.11) to 50% fruiting. It also reduces the number of bud drops (12.39), flowers drops (13.89), fruits drops (12.11), and increases the number of fruits plant-1 (41.61) and fruit plant-1 weight (70.94) when followed by 20 ppm, 30 ppm, 40 ppm, and 0 ppm NAA. For the parameter plant height 10ppm NAA was found to be optimum. The highest average plant height (72.61cm) was observed from 20ppm NAA. This result defines that NAA @10ppm is very beneficial for reducing blossom drop and increasing the growth and yield of chili.

Gadolinium vacancy induced photoluminescence enhancement of Cr3+-doped Gd3-xGa5O12 near-infrared garnet phosphors for plant cultivation

Near-infrared (NIR) phosphors have increased in popularity owing to their unique optical properties and have been widely used in phosphor converted light emitting diodes (pc-LEDs) for plant cultivation in recent years. However, their low luminous intensity and poor thermal stability restrict their application in high-powder LEDs. In this study, a series of Gd3-xGa5O12:Cr3+ phosphors was successfully prepared by reducing the Gd3+ content to introduce gadolinium vacancies into the lattice. The structural stability of Gd3-xGa5O12:Cr3+ was confirmed using X ray diffraction and transmission electron microscopy. The emission intensity was improved by introducing Gd3+ vacancies into the lattice and the emission intensity of the optimized Gd2.9Ga5O12:Cr3+ was 135% higher than that of Gd3Ga5O12:Cr3+. At high temperatures, the emission spectra were broadened and shifted toward the NIR direction and maintained 84.6% of the luminescence intensity at 423 K compared with that at room temperature. The bandgap structures of Gd3Ga5O12 with and without vacancies were determined via density functional theory to explain the improvement in luminescence. Finally, an NIR-LED device was fabricated and applied to the cultivation of dragon fruit plants. The results showed that the growth rate and fruit set rate of dragon fruit were greatly improved by irradiation with NIR light source. This technique of creating vacancies in the lattice provides a new approach to enhance the luminescence properties of NIR phosphors for plant cultivation.

Assessing the Potential for an Agro-GeoHydroPark in Gedangrejo: An Integrated Geological and Agricultural Study

This study aimed to evaluate the potential of Gedangrejo, located in the Karangmojo district, Gunung Kidul regency, Yogyakarta Special Region, Indonesia, for agro-geohydropark development. Employing a comprehensive geological analysis, which included assessing geomorphological, lithological, and geological structures alongside hydrogeological conditions, the study also focused on the evaluation of water sources and agricultural potential. Gedangrejo, which falls within the Baturagung subzone of the Southern Mountains zone, presents a unique amalgamation of undulating plains, hills, karst hills, and alluvium deposits with formations belonging to Semilir, Oyo, and Wonosari. Geological structures constituted by joints and faults, including three horizontal faults with a Northeast-Southwest orientation, were noted. The hydrogeology uncovered two aquifer systems, with the Semilir fissured inter-grain aquifer controlling the Baturagung Embung. In terms of agricultural viability, the area exhibits fertile land capable of supporting ornamental and fruit plants, presenting potential for fruit-picking tourism. Therefore, findings suggest that the Gedangrejo region holds substantial potential for development as an agro-geohydropark, implying a sustainable economic upliftment of the local community through the prudent utilization of natural resources and local wisdom.

Apple Fruitlet Abscission Prediction. II. Characteristics of Fruitlets Predicted to Persist or Abscise by Reflectance Spectroscopy Models

Apple (Malus ×domestica L. Borkh.) growers need tools to predict the efficacy of chemical thinners that are applied to induce fruitlet abscission to aid in crop load management decisions. Recently, reflectance spectroscopy-based models to predict fruitlet abscission rates were developed. Using spectroscopy, persisting fruitlets had lower reflectance in the red-light (∼600 nm) and near infrared (∼950 nm) regions than abscising fruitlets. The goal of this study was to better understand how reflectance models distinguished between fruitlets that ultimately persisted or abscised. Individual models for the difference and ratio of each combination of wavelengths were developed to identify key wavelengths for abscission prediction from reflectance models. Accuracy for wavelength difference and ratio models was improved for all model prediction dates when reflectance (R) from R640–675 was subtracted from or divided by R675–696. This spectra region indicates differences in chlorophyll content between persisting and abscising fruitlets. Calculation of the chlorophyll concentration index (R522–579:R640–700) from nondestructively measured spectra supported this result. Chlorophyll concentration index was higher for fruitlets that ultimately persisted than abscised fruitlets (P < 0.01) for all measurement dates –1 to 9 days after thinner (DAT) in both years, except –1 DAT in 2021 (P = 0.468). Plant water index (R950–970:R890–900) was lower for persisting than abscising fruitlets for 3 to 9 DAT in 2021 (P < 0.001) and on –1 (P < 0.01) and 9 DAT (P < 0.001) in 2022. The relationship of fruit size and plant pigment (anthocyanins or chlorophyll) content in fruitlets to reflectance spectra between persisting and abscising fruitlets was also followed. Fruitlet persistence or abscission was predicted from developed models for destructively sampled fruitlets using measured reflectance spectra. Whole-fruit chlorophyll content was numerically higher in fruitlets predicted to persist than abscise for all collection dates. Higher total chlorophyll was correlated to a larger fruit size in persisting than abscising fruitlets. This higher chlorophyll content led to a lower reflectance of red light and was a key factor in model development. These results indicate that chlorophyll and water content can distinguish physiological parameters between persisting and abscising fruitlets.

Miracle Fruit Pulp Transcriptomes Identify Genetic Variants in Support of Discovery Research and Breeding

Miracle fruit (Synsepalum dulcificum) is the botanical source of miraculin, a natural, noncaloric sweetener. Miracle fruit plants have a bush-like architecture and produce multiple flushes of attractive red berries each year. The berries consist of a large seed, opaque pulp, and brilliant red peel. The pulp of the fruit contains a glycoprotein, miraculin, that binds to the tongue’s sweet receptors and induces a conformational change in response to acidic stimuli. Thus, a strong sweet sensation is imparted in the absence of sugars. The miracle fruit plant is becoming increasingly popular because of its taste-modifying properties, but the species lacks many of the breeding tools common to other crops. We report miracle fruit pulp transcriptomes from ‘Sangria’, ‘Vermilion’, ‘Flame’, and ‘Cherry’ morphotypes. A consensus transcriptome included 91,856 transcripts. Reads mapping to the miraculin gene had the highest representation in individual miracle fruit pulp transcriptomes. Other abundant transcripts primarily included Gene Ontology categories representing cellular components, nucleus and nucleic acid binding, and protein modification. The transcriptomes were used to design real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) primers for actin, elongation factor 1α, and the miraculin gene. Analysis by qRT-PCR indicated that miracle fruit pulp and peel tissues had the highest abundance of miraculin transcripts, although other tissues such as leaf, root, and flower also had detectable levels of the target sequence. Overall, these results will support discovery research for miracle fruit and the eventual breeding of this species.

GROWTH PERORMANCE OF TAMARIND (Tamarindus indica L.) SEEDLINGS TO DIFFERENT LEVELS OF SALINITY AND SODICITY

Agroforestry is a viable land-use option of salt affected soils which ensure the remunerative use of this valuable resource. A two years pot study was carried out to evaluate salinity tolerance of tamarind fruit plant against different levels of salinity and sodicity. Treatments included were: T1 = ECe, 1.17 dS m-1 + SAR, 10.87, T2 = ECe, 6 dS m-1 + SAR, 25, T3 = ECe, 6 dS m-1 + SAR, 35, T4 = ECe, 6 dS m-1 + SAR, 45, T5 = ECe, 8 dS m-1 + SAR, 25, T6 = ECe, 8 dS m-1 + SAR, 35, T7 = ECe, 8 dS m-1 + SAR, 45, T8 = ECe, 10 dS m-1 + SAR, 25, T9 = ECe, 10 dS m-1 + SAR, 35, T10 = ECe, 10 dS m-1 + SAR, 45. Results revealed that no plant was survived at higher level of salinity (10 dS m-1) and sodicity (SAR 45) and complete cessation and mortality was observed in this treatment. Data of survived plants at the end of study showed that salinity and sodicity arrested the growth variables of tamarind seedlings and increasing levels of salinity-sodicity led a reduction of 3.52% to 82.47% in plant height, 1.53% to 84.61% in stem girth, 5.63% to 88.26% in number of leaves and 7.44 to 90.77 in number of branches over control (non-stress) treatment. Therefore, it was concluded that tamarind seedling can withstand and survive at salinity and sodicity level of 10 dS m-1 and SAR 35.