Fruit Shape Index Research Articles

Phenotypic Trait Analysis of Tomato (Solanum lysopersicum) Genotypes in Qatar and Indian Agro-climatic Conditions

Background: The study included four genotypes of tomato (EC620378, EC620380, EC620383, EC620534) which were cultivated to find out their similarities and differences based on phenotypic traits when they were grown under different soil zones of Doha (Qatar) and Meerut (India) to find out that which of the genotypes can be cultivated better in Qatar and India. Methods: The experiment was laid out in Randomized Complete Block Design (RBCD) with two replications. Statistical analysis for variation in quantitative characteristics among genotypes was done by collecting data in 15 qualitative and quantitative traits. Data showed great variation for almost all the traits. The principal component analysis involved plant height and days to marketable maturity as the most discriminating trait that accounted for greater variability in genotypes in both zones, and they should be considered in tomato improvement programs. The correlation analysis showed that fruit yield per plant was positively and significantly correlated with number of fruits per plant and fruit width. Present findings suggest that the identified superior genotypes may be utilized by different farms to further improve their breeding and cultivation strategies. Result: In Indian soil zone, genotype EC620534 performed extremely well in terms of maximum yield per plant. Similarly, in Qatar soil zone, EC620534 and EC620380 performed well. The phenotypic coefficient of variation (PCV) was higher than its corresponding genotypic counterpart (GCV) for all characters studied showing environmental influence. High broad-sense heritability were recorded for days to marketable maturity, fruit shape index and fruit weight in both agro-climatic zones, they were associated with low genetic advance indicating non-additive gene action and environmental influence, hence, heterosis breeding is recommended.

Wild pear (Pyrus pyraster (L.) Burgsd.) fruit and seed morphology depending on fruit size

The current study aims to evaluate the effects of fruit size of wild pear (Pyrus pyraster (L.) Burgsd.) on morphological fruit and seed traits. Wild pear fruit was collected from 10 trees in the area of Žumberačko gorje in the fall of 2022. The fruit was randomly collected from the ground and divided into three groups according to their weight (small (<10 g), medium (10 – 15 g) and large (>15 g)). Fruit size had a significant effect on the following morphological traits: fruit weight, fruit length, fruit width, the number of filled seeds, the weight of fresh seeds per fruit, the weight of 1 fresh seed and the weight of air-died seed, while no significant difference was found for fruit shape index, the number of empty seeds, the weight of 1 air dried seed and the share of seed dry matter. For all the aforementioned traits where the difference was significant, large fruit had significantly highest values, while in most cases (with the exception of the weight of 1 fresh seed), medium fruit had significantly higher values than small fruit. Comparing the correlation coefficients between different fruit size groups, it is evident that higher fruit size traits had a significant effect on the number of filled seeds in medium and large wild pear fruit only. In addition, it is visible that fruit weight and width, and not fruit length, had of the largest impact on the number of filled seeds. The principal component analysis revealed 3 significant principal components with eigenvalues greater than 1, which explained 75.88% of the total variability. It was shown that large fruit distinguish themselves from small and partly between medium by F1 axis. F1 was mainly influenced by fruit weight, fruit length, fruit width, the number of filled seeds, the weight of fresh seeds per fruit and the weight of air-dried seed per fruit. Based on the results obtained from this study, it can be concluded that for nursery production of wild pear seedlings bigger fruit should be used due to the higher number of filled seeds.

Correlation between Pulp Weight and Physio-Biochemical Traits of Mango (Mangifera indica L.) Germplasms

Aim: The present study was conducted to evaluate the relationship between pulp weight and various physio-biochemical attributes among 30 diverse mango (Mangifera indica L.) germplasms under the Tarai region of Uttarakhand. Place and Duration of Study: This investigation was carried out at Horticulture Research Centre, GB Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, during the years 2021 and 2022. Methodology: The selected 30 germplasms included two commercially grown cultivars and 28 primary germplasms sourced from different eco-geographical locations of Uttar Pradesh and Uttarakhand states of India. Pulp weight, physical characteristics (fruit shape index, pulp/stone ratio) and biochemical parameters (Brix/Acid ratio and pH) were measured for each germplasm and statistically laid out in completely randomized design (CRD), and their relationships were analyzed using simple linear regression and Pearson’s correlation coefficients. Results: The maximum values recorded among the studied germplasms were 300.73 g for pulp weight (PMGC-19), 2.41 for fruit shape index (PMSS-31), 0.309 for pulp/stone ratio (PMGC-71), 140.87 for Brix/Acid ratio (PMGC-96) and 5.87 for pH (PMGC-96). Among the physical attributes, pulp weight exhibited a moderate positive correlation with fruit shape index (r = 0.419), indicating that fruits with a higher shape index tend to have increased pulp weight. Whereas, a moderate negative correlation was observed between pulp weight and pulp/stone ratio (r = -0.457), suggesting that as the pulp/stone ratio increases, pulp weight decreases. However, biochemical attributes such as Brix/Acid ratio and pH showed no significant correlation with pulp weight (r = 0.005 and r = 0.018, respectively), indicating an independent influence of these parameters on pulp characteristics. Conclusion: These findings provide important insights into the complex relationships between pulp weight and other physio-biochemical traits in mango, some traits for breeding programs aimed to improving fruit quality and pulp content and identified superior and promising germplasms for cultivation as well as potential parental genotypes in mango improvement programs.

Bio-fortification with selenium (Se) improves quality and nutrient profile in citrus fruit

Selenium (Se) is an essential nutrient for the human body. Humans can enhance Se absorption by consuming horticultural plants, particularly fruits. Therefore, there is need for Se biofortification in fruits to meet the human demand for Se. The objective of this study was to determine the optimal Se application rate, application stage and method, and to assess their impacts on improving both the quality and nutrient profile of a sweet orange cultivar 'Hongjiangcheng' (Citrus sinensis (L.) Osbeck). 'Hongjiangcheng’ is a notable variety of mandarin orange, acclaimed for its large size, thin and smooth skin, orange-red flesh, tender and juicy texture, balanced sweetness and acidityand distinctive flavor. A field experiment was conducted at the Qiaotou Town Test Base in Chengmai County, Hainan Province, China. Biofortification of Se was done through foliar and soil application methods. Treatments were: Control (C) with no application of Se, foliar application of 25 (SeF1), 50 (SeF2), 100 (SeF3) and 200 (SeF4) mg/L and soil application of 100 mg/L (SeS1) as well as a combination of 100 mg/L Se in soil along with 50 mg/L Se on leaves (SeS1F2). At start of the experiment, 189 healthy, four-year-old citrus trees of similar size and normal growth were selected. The trees were divided into three groups of 63 each. Each group received the aforementioned treatments at the young fruit, expanding fruit and premature fruit stages. The Se was applied once during each stage before 9:00 am on sunny days. Treatments were arranged in a randomized complete block design with 9 biological replicates (7 treatments × 9 replicates = 63 citrus trees/ application stage). Foliar application of Se at rate of 200 mg/L (SeF4) enhanced total Se content in leaves by 105, 34 and 69 % at young fruit, expanding fruit and premature fruit stages compared to control (p≤0.05). Respective increments in fruits were 264, 22 and 21 %. The total Se content in leaves were 32 and 40 % higher in the SeF4 (foliar) compared to SeS1 and SeS1F2 (soil) treatments across all development stages (p≤0.05), respectively. The respective increments in fruits total Se content were 16 and 52 %. Only at the young fruit stage, the organic Se content in fruits was significantly higher in the SeF4 compared to soil application treatments (p≤0.05). Single fruit weight was enhanced by 16.61, 13.69 and 4.36 g by foliar than soil application at young fruit, expanding fruit and premature fruit stages, respectively. It was significantly higher (155.53 vs. 113.13 g) after application of SeF4 treatment at young fruit stage relative to all other treatments (p≤0.05). The application of SeF4 at the young fruit stage resulted in an increased seed rate (97 %), total soluble solids (28 %) and solid-to-acid ratio (75 %), while titratable acid decreased by 26 % compared to the control. Interestingly, Se application had non-significant effects on the fruit shape index, peel rate and residue rate across all stages (p>0.05). Additionally, a positive correlation was observed between fruit Se content and several quality indices like total soluble solids, solid acid ratio, fruit shape index and fruit weight at young fruit stage (p≤0.05). It is concluded that foliar application of Se at 200 mg/L (SeF4) during young fruit stage improved citrus Se content, its fruit weight and quality indices establishing these fruits as a valuable source of Se-rich food for human consumption.

Morphological, histological and transcriptomic mechanisms underlying different fruit shapes in Capsicum spp.

Pepper (Capsicum spp.) has a long domestication history and has accumulated diverse fruit shape variations. The illustration of the mechanisms underlying different fruit shape is not only important for clarifying the regulation of pepper fruit development but also critical for fully understanding the plant organ morphogenesis. Thus, in this study, morphological, histological and transcriptional investigations have been performed on pepper accessions bearing fruits with five types of shapes. From the results it can be presumed that pepper fruit shape was determined during the developmental processes before and after anthesis, and the anthesis was a critical developmental stage for fruit shape determination. Ovary shape index variations of the studied accessions were mainly due to cell number alterations, while, fruit shape index variations were mainly attributed to the cell division and cell expansion variations. As to the ovary wall thickness and pericarp thickness, they were regulated by both cell division in the abaxial-adaxial direction and cell expansion in the proximal-distal and medio-lateral directions. Transcriptional analysis discovered that the OFP-TRM and IQD-CaM pathways may be involved in the regulation of the slender fruit shape and the largest ovary wall cell number in the blocky-shaped accession can be attributed to the higher expression of CYP735A1, which may lead to an increased cytokinin level. Genes related to development, cell proliferation/division, cytoskeleton, and cell wall may also contribute to the regulation of helical growth in pepper. The insights gained from this study are valuable for further investigations into pepper fruit shape development.

MORPHOLOGICAL AND YIELD-RELATED POMOLOGICAL CHARACTERIZATION OF INTRODUCED OLIVE (OLEA EUROPEA) CULTIVARS IN RAINFED AREA OF POTHOWAR PUNJAB

This study aims at pomological characterizing of 09 olive cultivars planted in the field area of Barani Agricultural Research Institute (BARI), Chakwal to estimate genetic variability in Ottobratica, Hamdi, FS-17, Gerboi, Arbequina, Persia, Nabali, Koroneiki and Earlik. Following pomological traits: fruit and stone weight (g), fruit and stone size (cm), fruit and stone shape index (length/width) and flesh to stone ratio were studied. Data for studied traits were collected in 2019 according to the International olive council descriptor. A significant genetic difference was noticed in the morphological characteristics of both fruit and stone. Different pomological characters were expressed by each cultivar. A wide range of variation was noticed in fruit weight (1.33-5.57g), stone weight (0.20-0.63g) and flesh/stone ratio (0.90-4.96). Based on their fruit shape, studied cultivars were classified into two groups i.e., ovoid and elongate. However, no significant difference was recorded for the stone shape, as all the studied cultivars had the same elongated stone shape. Concerning the fruit size, high fruit size (4-6g) was observed in FS-17, Hamdi, Earlik and Persia whereas Koroneiki, Nabali and Gerboi had the smallest ones (>2g). Based on our results, Earlik, Hamdi and FS-17 are suggested to be more appropriate for table olive production. Thus, an evaluation of genetic diversity through this study can help in the varietal development of olive for table and oil purposes.

Phenotypic Diversity and Seed Germination of Elaeagnus angustifolia L. in Relation to the Geographical Environment in Gansu Province, China

Elaeagnus angustifolia L. is a highly adaptable urban ornamental plant, playing a key role in dry land and saline-alkali protective forests. The diverse geographical and climatic conditions in Gansu Province have resulted in variations in its distribution and growth. This study assesses the phenotypic diversity of fruits and seeds, and the seed germination characteristics of 82 E. angustifolia plants from nine populations in Gansu Province, exploring their relationship with geographical and climatic factors. We measured 12 phenotypic traits and five germination indices. This study included germination tests under standard conditions, statistical analysis of phenotypic differences, and Pearson and Spearman correlation analyses to examine relationships between traits and geo-climatic factors. Principal component and cluster analyses were also performed to identify key traits and classify populations. The findings were as follows: (1) Significant differences were observed in phenotypic traits and germination characteristics among populations. Single fruit weight showed the highest variation (27.56%), while seed transverse diameter had the lowest (8.76%). The Lanzhou population exhibited the greatest variability (14.27%), while Linze had the lowest (6.29%). (2) A gradient change pattern in traits was observed, primarily influenced by longitude and a combination of geographical and climatic factors. Seed germination was positively correlated with altitude, annual precipitation, and relative humidity, but negatively affected by latitude and traits such as fruit weight. (3) Principal component analysis identified germination rate, germination index, seed shape index, and fruit shape index as primary factors, contributing 27.4%, 20.6%, and 19.9% to the variation, respectively. Cluster analysis grouped the 82 plants into four clusters, not strictly based on geographical distance, suggesting influence from factors such as genotype or environmental conditions. In conclusion, this study lays a foundation for understanding the genetic mechanisms behind the phenotypic diversity and germination characteristics of E. angustifolia. It offers insights into how geo-climatic factors influence these traits, providing valuable information for the species’ conservation, cultivation, and management.

Multivariate Analysis and Optimization Scheme of the Relationship between Leaf Nutrients and Fruit Quality in ‘Bingtang’ Sweet Orange Orchards

Citrus trees require a balanced and adequate supply of macronutrient and micronutrient elements for high yield and fruit quality. Foliar nutrient analysis has been widely used in fruit-tree nutrient diagnosis and fertilization calculation. However, there is no information on ways to produce optimal fruit quality in sweet oranges. In the present study, fruit and leaf samples were collected from 120 ‘Bingtang’ sweet orange [Citrus sinensis (L.) Osbeck] orchards during four consecutive years (2019–2022). Parameters of leaf nutrition and fruit quality were analyzed based on these samples. Diagnostic results based on leaf classification standards indicated that the most deficient elements were Ca, Mg, and B, followed by N and Zn. Fruit quality, determined by single fruit weight (SFW), fruit shape index (FSI), total soluble solids (TSS), titratable acidity (TA), vitamin C (Vc), and maturation index (MI = TSS/TA) during fruit maturation, exhibited inconsistent responses to leaf mineral nutrition concentrations. The leaf-nutrient optimum values for high quality of the ‘Bingtang’ sweet orange fruit were ranges of 2.41–4.92% N, 0.10–0.28% P, 1.30–2.11% K, 2.99% Ca, 0.26–0.41% Mg, 340–640 mg/kg S, 89.65–127.46 mg/kg Fe, 13.48–51.93 mg/kg Mn, 2.60–13.84 mg/kg Cu, 15.59–51.48 mg/kg Zn, and 53.95 mg/kg for B. These results suggest the leaf-nutrient optimum values for diagnosis can be used not only to identify the nutrient constraints but also to provide guidance for the establishment of fertilization regimes in citrus cultivation.

An ultra-dense linkage map identified quantitative trait loci corresponding to fruit quality- and size-related traits in red goji berry.

Goji berries are a small-fruited shrub with industrial importance whose fruit considered beneficial in both fresh and dried forms. Current germplasms of goji berries include small fruits with a short shelf life, less sweet and bitter taste, and a lack of appropriate genetic information. This study aimed to employ whole genome resequencing to generate an ultra-dense bin linkage map and to elucidate the genetic basis of goji fruit quality and size using quantitative trait loci (QTL) mapping analysis in a cross-pollinated hybrid population. To achieve this goal, human sensory tests were carried out to determine the bitter taste (BT) and sweet taste (ST), and to quantify the soluble solid content (SSC), fruit firmness (FF), and fruit size-related traits of fresh goji fruits over three or four years. The results revealed that the goji bin linkage map based on resequencing spanned a total length of 966.42 cM and an average bin interval of 0.03 cM. Subsequent variant calling and ordering resulted in 3,058 bins containing 35,331 polymorphic markers across 12 chromosomes. A total of 99 QTLs, with individual loci in different environments explaining a phenotypic variance of 1.21-16.95% were identified for the studied traits. Ten major effects, including colocalized QTLs corresponding to different traits, were identified on chromosomes 1, 3, 5, 6, 7, and 8, with a maximum Logarithm of Odds (LOD) of 29.25 and 16.95% of explained phenotypic variance (PVE). In addition, four stable loci, one for FF, one for fruit weight (FW), and two for fruit shape index (FSI), were mainly mapped on chromosomes 5, 6, and 7, elucidating 2.10-16.95% PVE. These findings offer valuable insights into the genetic architecture of goji fruit traits along with identified specific loci and markers to further improve and develop sweeter, less bitter and larger fruited goji berry cultivars with extended shelf life.

Genetic Diversity and Response of Melon Accessions toMonosporascus cannonballus

ABSTRACTMelon holds significant economic importance for Brazilian agribusiness. It exhibits high polymorphism and genetic variability, yet knowledge regarding its genetic diversity and response to root diseases remains limited. Therefore, this study aimed to assess the genetic diversity and response of melon plant accessions to Monosporascus cannonballus. Two trials were conducted involving 29 melon accessions and a commercial hybrid of the yellow melon plant, Natal RZ. In the first trial, the accessions and the commercial hybrid were grown in the field under a randomised complete block design with three replications. They were evaluated for fruit‐related descriptors: number of fruits per plant (NFP), average fruit weight, shape index, pulp thickness, pulp firmness (PF) and total soluble solids (TSS). Standardised Euclidean distances were calculated on the basis of the results, and the accessions were grouped using the UPGMA method. In the second trial, the melon plant accessions and commercial hybrid were cultivated in a greenhouse under a completely randomised design with 12 replications. For inoculation, wheat grains infested with M. cannonballus isolate CMM‐2429 were used. Evaluations were conducted 60 days after transplanting, assessing the incidence and severity of the disease, and biometric variables. The study revealed genetic variability among the evaluated accessions for fruit descriptors and response to M. cannonballus. Most divergent accessions were A16, A53, NZR, A28, A51 and A44, with divergence primarily observed in NFP, PF and TSS. Promising accessions for breeding programmes aimed at resistance to M. cannonballus included A01, A04, A25, A27 (moderately resistant) and A26 (highly resistant to the pathogen).

Diversity analysis of panicle traits in Chinese prickly ash germplasm resources and their influence on its systematic classification

This study aimed to reveal the diversity and variation in panicle traits of the Chinese prickly ash and clarify their influence on the its systematic classification to provide a theoretical basis and technical support for the efficient utilization of Chinese prickly ash germplasm resources and breeding. Sixteen panicle traits were identified from 35 Chinese prickly ash germplasm resources from 2021 to 2022. The diversity of these panicle traits and their role in the plant’s systematic classification were studied using variance, correlation, cluster, and principal component analyses. Cluster analysis showed that the 35 Chinese prickly ash germplasm resources could be divided into two groups with Euclidean distances of 25. Further analysis showed that yield traits such as panicle length, panicle width, primary branching, grain number per panicle, and grain weight per panicle were significantly positively correlated with grain chlorophyll content, while grain anthocyanin content was negatively correlated with both panicle (panicle length, panicle width, panicle length to width ratio, primary branching, grain number per panicle, and grain weight per panicle) and grain characteristics (single grain weight, thousand-grain weight, grain length, grain width and fruit shape index). In conclusion, Chinese prickly ash germplasms have diverse panicle traits. Z. armatum has dark green grains, long and wide panicles, a long conical shape, many primary branches, high grain weight, and high grain number per panicle. In contrast, Z. bungeanum has bright red seeds, a panicle width larger than its length, short and conical panicles, a small number of primary branches, and low grain weight per panicle and number of grains per panicle. Overall, Z. armatum had a significant yield advantage over Z. bungeanum.

Differential responses of summer pruning timing on growth, quality and yield of low chill peach

Abstract Summer pruning is an important horticultural operation that is performed to manipulate tree response so as to make it better manageable without a reduction in yield and fruit quality. But the timing is also an important factor in performing this event. Keeping in view the above facts, the present investigation was carried out to elucidate the ‘differential response of summer pruning timing on cropping behavior in low-chill peach cvs. Florida Prince and Shan-i-Punjab’. The experiment was carried out at the experimental orchard of the Department of Fruit Science, College of Horticulture and Forestry, Neri, Hamirpur (HP) during the years 2018–2019 and 2019–2020. There are six treatments in the experiment, each with four replications. T1: no pruning; T2: 25% summer pruning on July 10th + winter pruning (WP); T3: 25% summer pruning on July 20th +WP; T4: 25% summer pruning on July 30th +WP; T5: 25% summer pruning on August 10th +WP); and T6: standard winter pruning (SWP). According to the study’s findings, combining 25% summer pruning on July 10th with winter pruning resulted in the greatest improvement in terms of vegetative, flowering or blooming, and qualitative parameters, namely fruit weight, fruit shape index, total soluble solid, and sugar content. However, Florida Prince showed positive enhancement of various characteristics and performed better than Shan-i-Punjab.

Changes in Quality of Carya illinoinensis at Different Harvest Periods.

In order to determine the appropriate harvesting period of Carya illinoinensis planted in Nanjing city of China, this study analyzed the phenotypic characteristics and inclusions, including single fruit quality, fruit transverse and vertical diameter, kernel rate, water content, color, respiratory strength, crude fat, soluble sugar, soluble protein, and total phenols, of two cultivars 'Pawnee' and 'Wichita' during September and October, respectively. Results showed that the respiration intensity and IAD values of pecan fruits decreased as the harvest date was delayed. 'Pawnee' fruits exhibited the highest seed kernel fullness, ∆E value, fruit transverse diameter, shape index, kernel yield, crude fat, and total phenolic content in late September and early October, while the quality of 'Wichita' fruits reached its peak in late October. The appropriate harvest period is conducive to the material accumulation of Carya illinoinensis, which is of great practical significance for improving the commodity value of pecans. The optimal harvesting period for 'Pawnee' in Nanjing is from the end of September to the beginning of October, and the optimal harvesting period for 'Wichita' is from mid- to late-October to the end of October.

QTL mapping of fruit quality traits in tetraploid kiwiberry (Actinidia arguta)

Fruit quality traits play an important role in consumption of kiwiberry (Actinidia arguta). The genetic basis of fruit quality traits in this woody, perennial and dioecious fruit crop remains largely unknown. This study aimed to identify the underlying genetic basis of fruit quality traits in A. arguta, using a single nucleotide polymorphism (SNP) genetic linkage map previously developed in a tetraploid F1 population of ‘Ruby-3’ × ‘KuiLv-M’. The F1 population was phenotyped over three years (2020–2022) for fruit quality traits, including skin color, flesh color, fruit weight, fruit diameter, total soluble solids, fruit longitudinal diameter and fruit shape index. A total of nine QTLs were detected for five traits, explaining 10%–32% of the trait variation. For fruit color, the support interval of a major QTL on LG9 contained an MYB transcription factor MYB110, which was previously demonstrated to control color regulation in kiwifruit, thus suggesting that the MYB110 is the candidate gene for fruit color in kiwiberry. The linked marker for fruit color was validated in an F1 population and 25 kiwiberry cultivars. In conclusion, the knowledge obtained through the QTL mapping is applicable to improve the efficiency and cost-effectiveness in kiwiberry breeding.

Physicochemical Quality Properties of Peach (Prunus Persica L.) Varieties at Holeta, Ethiopia

Holeta has different peach fruit varieties that can be used for various purposes. However, their fruit quality characteristics were not fully identified. Studies have indicated that the physicochemical qualities of peach fruits are influenced by a number of factors, with the varietal factor being one of the most important. Limited information regarding the factors that affect these qualities is available in the country, specifically at Holeta. Therefore, this study was initiated to evaluate the physicochemical quality properties of peach fruit varieties. Their physical quality traits, such as fruit length, fruit diameter, fruit shape index, and average fruit weight, as well as chemical quality parameters, such as TSS, specific gravity, TA, ripening index, ascorbic acid content, and pH, were evaluated. The results revealed that both physical and chemical quality parameters were significantly affected by varietal factors. Among, the Bonny Gold variety had the longest fruit length, and Florida down had the largest fruit diameter. As far as average fruit weight is concerned, 88-18 W had the heaviest weight with 111.98 g, while Transvalia had the highest TSS and specific gravity. However, the Summersun and 9A-35C varieties had the highest TA and ripening index, respectively. Thus, the physicochemical quality properties of the fruit were highly altered with peach varieties.

Fruiting Characteristics and Molecular-Assisted Identification of Korla Fragrant Pear Bud Mutation Materials

Korla fragrant pear is a high-quality local pear variety native to Xinjiang, China. Currently, the low fruit-setting rate and low calyx shedding rate problems in Korla fragrant pears have been highlighted, which seriously affect the fruit yield and quality. It is of great significance to research the fruiting characteristics and molecular-assisted identification of Korla fragrant pear bud mutation materials for enriching the germplasm resources of Korla fragrant pear. In this research, a natural pollination group (YB) of Korla fragrant pear bud mutation materials and a natural pollination group (CK) of Korla fragrant pears were established. On the fruiting characteristics, the fruit-setting rate and calyx-removal rate of the two groups were investigated. In terms of fruit quality, the fruit shape index, fruit specific gravity, soluble solids content, sugar:acid ratio, soluble sugar content, and other indicators were measured. For the anatomical structure of the calyx tube, the detachment cells were observed. The formation time of the two groups of detached cells was compared. In the GBS simplified genome sequencing, a phylogenetic tree was constructed based on the obtained SNP sites. A principal component analysis, population genetic structure analysis, and genetic diversity index analysis were carried out. In the aspect of SSR molecular marker identification, the SSR types were counted. Polyacrylamide gel electrophoresis was performed. The results demonstrate the following: (1) the fruit-setting rate (30.87%) and calyx-removal rate (68.11%) in the YB group were significantly higher than those in the CK group (19.37%) and the calyx-removal rate (55.18%). (2) There was no significant difference in fruit quality indexes, such as average fruit weight (127.10–130.00 g) and soluble sugar content (9.47–9.56%) between the two groups. (3) Abscission-layer cells were observed at 2, 4, 6, 8, and 10 h after calyx tube discoloration in the YB group and at 48, 72, and 96 h after calyx tube discoloration in the CK group. (4) The genetic background of the YB group and the CK group was similar at the GBS level, but there were differences at the DNA level. This research finally shows that Korla fragrant pear bud mutation material is a good germplasm resource. This germplasm resource can promote the structural optimization of Korla fragrant pear varieties and the healthy development of the industry.

Genetic diversity and population structure of a modified three-way tomato hybrids for determining fruit size traits

The assessment of genetic diversity and genetic structure of crops has a vital impact on the plant breeding program, including the characterization, use and conservation of genetic material. The genetic diversity and genetic structure of a set of 94 F3 tomato hybrids were assessed with 25 polymorphic SNP markers of quantitative trait loci (QTLs) underlying fruit size in tomatoes using Sequenom Mass ARRAY system. A total of 50 alleles were amplified and the average polymorphic information content (PIC) was 0.2220. Nei's genetic distance ranged from 0 to 0.62. Therefore, single nucleotide sequence (SNP) markers detected a significantly high degree of polymorphism in tomato hybrids. Cluster analysis using the unweighted pair group method with arithmetic mean methods (UPMA) indicated that the tomato hybrids studied are grouped into four main groups, which is to some extent consistent with the size, shape and number of locules of the tomatoes studied. Analysis of population structure with SNP markers revealed three subpopulations. Association mapping using 25 SNP markers detected 9 markers with a significant association with mean fruit weight, fruit length, fruit diameter, number of locules, and fruit shape index. The nine markers detected in this study are recommended for the tomato fruit size improvement breeding program.

Identification and Comprehensive Analysis of OFP Genes for Fruit Shape Influence in Mango.

OVATE family proteins (OFPs) are a class of plant-specific proteins with a conserved OVATE domain that play fundamental roles in fruit development and plant growth. Mango (Mangifera indica L.) is an economically important subtropical fruit tree characterized by a diverse array of fruit shapes and sizes. Despite extensive research on OFPs across various species, there remains a scarcity of information regarding OFPs in mango. Here, we have successfully identified 25 OFP genes (MiOFPs) in mango, each of which exhibits the conserved OVATE domains. The MiOFP gene exhibit a range of 2-6 motifs, with all genes containing both motif 1 and motif 2. Phylogenetic analysis on 97 OFPs (including 18 AtOFPs, 24 SlOFPs, 25 MiOFPs, and 30 OsOFPs) indicated that MiOFPs could be divided into three main clades: clade I, II, and III. Comparative morphological analysis identified significant variations in fruit longitudinal diameter, fruit transverse diameter, and fruit shape index between two distinct shaped mango cultivars ('Hongxiangya' and 'Jingpingmang') at DAP5, DAP7, and DAP10 stages. The subsequent examination of paraffin sections revealed distinct patterns of cell elongation. The majority of MiOFP genes exhibited predominantly expressed in developing organs, specifically flowers and immature fruits, while displaying distinct expression patterns. RNA-Seq analysis revealed significant disparities in the expression levels of several OFP genes, including MiOFP5, MiOFP11, MiOFP21, MiOFP22, MiOFP23, and MiOFP25, between the two mango cultivars. These findings suggest that these six genes may play a crucial role for fruit shape in mango, especially the MiOFP22. The findings of this study have established a basis for future investigations into MiOFPs in mango, offering a solid foundation for further research in this field.

Evaluation of the Pollination Efficiency of Apple Trees by Osmia excavata Alfken (Hymenoptera: Megachilidae).

The mason bee Osmia excavata Alfken is an apple pollinating insect widely distributed in northern China, in order to effectively utilize the mason bee and improve the pollination rate of apples, there is a need to evaluate the pollination efficiency of the bees. This study evaluated the pollination efficiency of the mason bee on apple orchards in Jinan and Yantai, Shandong Province, China. The study compared natural pollination areas and pollination areas with different release densities of O. excavata in terms of the effects of bee density, timing of pollination, and distance effects on fruit set rate, fruit shape index, fruit shape skewness, fruit soluble solids content, and fruit firmness. The optimal release density of bees was 6000 cocoons per hectare, resulting in the highest fruit setting rate of apple lateral flowers. From 07:00 to 14:00 was the best time for bee pollination. The optimal distance of hives from apple trees for pollination by O. excavata was 60m. Single fruit weight was significantly higher and fruit unsymmetrical rate, partial slope and hardness were all significantly lower at the release densities of 6000 or 12000 cocoons per hectare compared with 3000 cocoons per hectare or under natural pollination conditions. There was no significant difference in the content of soluble solids under different release densities. Thus, the radius of 60m from the hive was the effective pollination range and 6000 cocoons per hectare of mason bees could ensure the fruit quality of apple.

Improving mangoes' productivity and crop water productivity by 24-epibrassinosteroids and hydrogen peroxide under deficit irrigation

In nature, plants are frequently subjected to a wide range of abiotic stresses that drastically reduce crop productivity. Deficit in irrigation is one of the main factors of abiotic stresses that affect agricultural productivity. Nevertheless, not much research has been done on how to use water with brassinosteroids (Br) and hydrogen peroxide (H2O2)in deficit water conditions in order to reach comparatively good values of mango tree growth, productivity, and fruit quality as well as crop water productivity (WPC). A split-plot experiment in a complete randomized block system design study with 3 regulated deficit irrigation levels i.e. 100% IR (Irrigation requirement), 80% IR, and 60% IR was implemented in 2022 and 2023, each irrigation regime was combined with the foliar application of distilled water (control), 1 mg/L Br, 10 mM H2O2, 1 mg/L Br + 10 mM H2O2. Foliar treatments were applied at 3 different phenological stages: flower bud induction and differentiation, full bloom, and beginning of fruit set. The results showed that fruit shape index and acidity significantly improved as irrigation volume increased, however, the proportion of fruit mineral content and fruit chemical characteristics was inversely correlated with the volume of water. Meanwhile, moderate regular deficit irrigation (80% IR) achieved marked increases in leaf minerals and total chlorophyll content, fruit quality, yield, and water use efficiency. Drought stress (60% IR) significantly decreased fruit set, fruit retention, yield traits, and fruit physical and chemical properties, at the same time, significant improvements in the content of stress indicators (proline, total phenols, and carotenoids) were observed compared with control. All treatments with Br and H2O2 alone or in combination under drought stress had a pronounced effect in this regard. Overall, foliar spray of 1 mg/L Br+10 mM H2O2 was the most powerful treatment that emended the unpropitious effect of water stress.