Fruit Oil Content Research Articles

Wavelengths Selection Method in Near Infrared Spectra Using Multivariate Analysis for Nondestructive Determination of Oil Content in Palm Oil Fruits

Wavelengths Selection Method in Near Infrared Spectra Using Multivariate Analysis for Nondestructive Determination of Oil Content in Palm Oil Fruits

Non-destructive Evaluation of Oil Content and Carotene in Oil Palm Fresh Fruit Bunches Based on Optical Properties Using Partial Least Square (PLS)

Crude palm oil (CPO) is a raw material for making cooking oil that comes from palm oil, which is greatly influenced by the quality of oil palm fresh fruit bunches (FFB). Oil and carotene content in the FFB influence the quality of palm oil. The oil content is usually determined using a chemical method (Soxhlet extraction) which is time consuming and destructive. This research aimed to predict the oil and carotene content contained in oil palm FFB using partial least square (PLS). In this research, the sample used was the Tenera variety with a maturity of 140-160 day after anthesis (DAA) and 200-220 DAA. The nondestructive method involves recording images using an optical camera, which produces RGB and L*a*b* values. Results showed that PLS predicts the relationship between optical properties and oil and carotene content in palm oil. Non-destructive prediction results using PLS provided consistently correlation of L*a*b* values with estimated oil and carotene content in the FFB. Keywords: Non-destructive, Optical properties, Fresh fruit bunch, Oil palm.

Non-Destructive Prediction of Chemical Content in Palm Oil Fruit Using Near-Infrared Spectroscopy and Artificial Neural Network

Oil and water content are an important quality criteria of crude palm oil (CPO) resulted from palm oil fruit processing. Those contents are usually determined using chemical method in the laboratory. This method is time consuming, long procedure, and destructive. Some efforts had been carried out to determine oil and water content of palm oil fruit non-destructively using some methods including Near-Infrared Spectroscopy (NIRS), but the results had not been satisfied. This research aims to assess Artificial Neural Network (ANN) and NIRS method to predict oil and water content of palm oil fruit’s non-destructively. The samples were palm oil fruits with ten maturity levels harvested from plantation in Bogor. Sample’s reflectance was measured with spectrometer NIR-Flex 500 at wavelength of 1000-2500 nm. After that, oil and water content were determined using chemical method. Some pre-treatments of NIR spectra namely normalization, savitzky-golay first derivative, their combinations, and standard normal variate were applied. Multivariate analysis such as PLS were carried out and the results of Factor Component (FC) were input for ANN model. The result showed the best method to predict oil content was combination savitzky-golay first derivative and normalization pre-treatment using PLS-ANN with 20 FC (R2=0.99; SEC=0,58%, RPD = 29.89; CV = 2.47%). For water content, the best prediction was standard normal variate pre-treatment using PLS-ANN with 20 FC (R2=0.99; SEC=1,07%, RPD=20.68; CV=1,73%). The result shows that developed ANN and NIRS can predict oil and water content of palm oil fruit non-destructively.

Lipidomic Profiling and Pharmacological Activities of Ficus drupacea Oil: Comparative Study Between Conventional vs. Green Solvent.

Ficus drupacea is a medicinal tree found in temperate regions. Various parts of this plant had been used traditionally for the treatment of various ailments such as root powder applied externally for skin infections. Analysis was carried out on the bioactive lipids extracted from Ficus drupacea fruit using both petroleum-based solvent (Hexane) and an environmentally friendly solvent Dimethyl carbonate (DMC). The results showed that DMC extraction yielded a high oil content in Ficus drupacea fruit (6.51 %). When examining the fatty acid composition using GC-FID analysis, Ficus drupacea oil extracted with DMC contained significant proportions of essential fatty acids such as linoleic acid (32.317 %), oleic acid (20.946 %), palmitic acid (25.841 %), etc. Additionally, DMC extraction resulted in higher levels of total phenolics in Ficus drupacea fruit oil compared to hexane. Moreover, DMC extracted oil exhibited stronger antioxidant properties, such as radical scavenging, anti- arthritic, photoprotective activity while displayed similar anti-inflammatory and anti-microbial activity as hexane-extracted oil. In summary, these findings demonstrate that DMC is an efficient and safer alternative to conventional solvent hexane for extracting oils from Ficus drupacea fruit. It is rich in bioactive compounds essential for human nutrition, including polyunsaturated fatty acids, flavonoids, and phenolic compounds, with enhanced biological activities.

Olive-tree physiological response to biotic and abiotic stress fruit yield, oil quality and tolerance to Anthracnose: Doctoral thesis abstract

The olive tree is highly tolerant to water deficit and in humid climate regions, such as Uruguay, the need to irrigation is questioned. However, Uruguay's climate is characterized by high interannual variability, resulting in periods of water deficit. In the event of a water deficit, plants trigger a series of defense mechanisms to maintain cellular homeostasis, including increased antioxidant enzyme activity and cuticle thickening to prevent transpiration. These responses are common during abiotic stress and biotic stress caused by pathogen infections. Anthracnose, caused by the Colletotrichum complex, is a major disease in olive trees, leading to reduced fruit yield and oil quality. Mild drought stress has been found to activate the basal defense response, enhancing plant tolerance to pathogen infections. Therefore, the hypothesis was that exposing olive plants to moderate water deficit during the lipogenesis stage would trigger the basal defense response, increasing fruit tolerance to biotic stress caused by Colletotrichum acutatum. The study also examined whether this response was sustained under moderate water deficit. Results showed that water deficit induced anatomical and biochemical changes in olive fruits, promoting anthracnose tolerance with reduced incidence and severity of C. acutatum infection both in vitro and in vivo. Fruit weight and pulp/pit ratio decreased in response to water deficit, while cuticle thickness and fruit polyphenol content increased. An induction of enzymes related to hydrogen peroxide scavenging were observed, in particular PER and CAT. This enzymatic activity was induced by the pathogen inoculation treatment and was higher in the non-irrigated treatment. Severe water deficit resulted in significant reductions in fruit weight and oil content, but the fruits exhibited enhanced tolerance to anthracnose infection.

Response of Olive Trees (Olea europaea L.) cv. Kalinioti to Nitrogen Fertilizer Application

Nitrogen is the most commonly managed mineral nutrient in olive groves because it is essential for plant growth. The precise management of N fertilization in olive cultivation is still not fully clarified, but it is essential for providing sustainable production. A nitrogen fertilizer experiment with olive trees (cv. Kalinioti) was carried out over a six-year period. Seven levels of nitrogen fertilizer given as ammonium nitrate (control, 1, 2, 3, 4, 5, and 6 kg/tree) were annually applied in order to determine the effect of nitrogen on vegetative growth, fruit set, fruit weight, yield, maturation index, and leaf N, P, and K concentrations. The results indicate that, under these conditions, application of up to 4 kg NH4NO3/tree significantly increased yield to 62.5 kg/tree compared to the control (37.09 kg/tree). The positive effect was attributed to the initial and final fruit set increases (7.63 and 3.73%, respectively at 4 kg NH4NO3/tree). However, the weight of 100 olives (W100 = 331 g) at 4 kg NH4NO3/tree obtained during harvest was considerably lower compared to the control (W100 = 384 g). Higher nitrogen rates decreased yield while increasing overall shoot growth. Nitrogen fertilization did not significantly influence the oil content of olive fruit. Fruit weight, maturation index, and concentration of oil reached maximum levels in the beginning of December, indicating a suitable start to olive harvesting. The concentration of N in olive leaves increased from 1.23% to 2.38% as fertilizer levels increased from 0 to 6 kg NH4NO3. Maximum yield was achieved at a level of 6 kg NH4NO3/tree, which corresponded to 2.01% N in leaves. The results suggest that application of 3 kg NH4NO3/tree can be recommended for table olive production, due to the fact that fruit weight was not decreased, while fertilization with 4 kg NH4NO3/tree was suitable for oil olives.

Effects of summer pruning on the water status and physiology of olive trees and on fruit characteristics and oil quality

An investigation was carried out in 2017 in central Italy, in an adult olive orchard with trees of the cultivar Leccino, spaced 5 × 5 m, trained to a vase and pruned biennially. The aim was to evaluate the effects of summer pruning (i.e. eliminating suckers, in the central part of the canopy, in the non-pruning year), on the water status and physiology of the leaves, on the yield/tree, and on fruit characteristics and oil quality. Unpruned trees were used as the control. During the investigation (July-October), rainfall was low (less than 100 mm) and the orchard was not irrigated. During the summer, the leaves of summer-pruned trees had higher relative water content (RWC) and greater photosynthetic activity than those of control trees. Summer-pruned trees had similar yield, but higher oil content on a dry-weight basis. Oil qualitative parameters (free acidity, peroxide value and spectrophotometric absorbances in the ultra-violet) were similar, whereas the total content of phenolic compounds was higher in control trees. The oils from summer-pruned trees were more herbaceous and fruity, and less bitter and spicy than oils from control trees. The results show that in situations where there is considerable formation of suckers, such as in the case of biennial, triennial or plurennial pruning, summer pruning can contribute to improving tree water status and the physiological condition, favoring photosynthetic activity. This practice also has effects on fruit oil content and oil quality, producing more aromatic and less bitter and spicy oil. Overall, the results indicate that summer pruning can have effects similar to irrigation.

Optimisation of the drying temperature of star anise by low-temperature drying technique combined with microwave

The purpose of this study is to optimise the drying temperature of star anise fruit using the low-temperature drying technique combined with microwaves on a heat pump combined with microwave drying system so that the drying time is shortest and the essential oil is highest. The raw materials used for the research are fresh anise harvested in Van Quan district, Lang Son province in August 2021. Experimentally, the effects of drying temperatures at the levels: 30, 35, 40, 45, 50 and 55oC have been determined on drying time and essential oil content in dried anise fruit (moisture content of anise fruit after drying ≤10%). Research results have determined that the optimal temperature for drying anise fruits using the low-temperature drying technique combined with microwaves is 48.7±1oC, drying time is 530±5 minutes, and the essential oil content in dried star anise fruits reaches 9.9 ml/100 g. These experimental research results have provided a scientific basis for the essential oil content of Lang Son star anise fruit, and technical parameters for drying star anise fruit using low-temperature drying techniques combined with microwaves, helping the production and processing of anise on an industrial scale, increasing the value of goods and serving export purposes.

Exploring fruit lipid diversity in a neglected group of tropical palms: The tribe Phytelepheae

AbstractBackgroundThe palm tribe Phytelepheae (vegetable ivory palms) produces oleaginous fruits traditionally consumed by indigenous and local communities. We therefore analyzed the oil content as well as fatty acid (FA), carotenoid, and tocochromanol composition of fruits collected from 35 palm trees in their natural habitats, namely Phytelephas aequatorialis (Pa, n = 28), Aphandra natalia (An, n = 5), and Ammandra decasperma (Ad, n = 2).ResultsAverage mesocarp oil content was high in Pa and An (ca. 30% dry mass [DM]) but not in Ad (10% DM). However, significant differences in fruit oil content between Pa populations were observed. Further, FA composition varied significantly among species and between Pa populations. The main FAs were oleic (17%–73%), palmitic (17%–41%), linoleic (2%–32%), and stearic (3%–13%) acids. The mesocarp oil of some Pa palms contained a high amount (>20%) of linoleic acid and a low amount of saturated FA (<25%). A high variability of total tocochromanol (89, 122, and 145 mg/kg oil for Pa, An, and Ad, respectively) and total carotenoids (96, 42, and 157 mg/kg for Pa, An, and Ad, respectively) content was also found.ConclusionThe fruits of the neglected Phytelepheae palms may represent a valuable source of lipids, including the essential FA linoleic acid and lipid‐soluble vitamins, and help to diversify dietary lipid sources in Ecuadorian geographical areas where there is a high rate of saturated fat consumption.

Insect pollination and pollinator supplementation enhances fruit weight, quality, and marketability of avocado (Persea americana)

Avocado is a pollinator-dependent crop rich in fiber, monounsaturated oils, vitamins, and minerals, which is seeing an increase in global demand. While some studies have shown that insect pollination improves avocado fruit set, the effects of pollinators on fruit quality and the nutritional profile remain unclear. Furthermore, it remains untested whether a potential pollination deficit can be compensated by the supplementation of farms with extra pollinators. We quantified the contribution of insect pollination on fruit and seed weight, and oil, protein, carbohydrate, and phytochemical (flavonoid and phenolics) contents, and assessed if the supplementation of pollinators on farms can improve fruit parameters. The experiment was conducted in 36 smallholder avocado farms of which 18 farms were supplemented with two Apis mellifera bee hives, while 18 were used as controls. Four manipulative pollination treatments were conducted: hand, open, self- and wind pollination. We observed that avocado fruit weight was significantly higher (213.7 g) for insect pollinated flowers than in case of wind- (107.8 g) or self-pollination (95.1 g).Insect pollination resulted in heavier seeds (29.5 g) as well as higher oil contents, clearly showing that insect pollination was required to reach a high seed yield and quantity of oil. Honey bee supplementation on farms enhanced the avocado fruit weight by 18%, and increased avocado oil content by 3.6%. As the marketability of avocado directly depends on fruit size and oil content, a sustainable management of bee communities may be of key importance for the long-term profitability of avocado agriculture.

Effects of Harvesting Time on Fruit Development Process and Oil Content of Selected Iranian and Foreign Olive Cultivars under Subtropical Conditions.

Climate change and rising global average temperatures across the year may strongly affect olive fruits' development process and their oil yield and quality. There is therefore an urgency to take immediate actions to characterize the wide variability of cultivars in order to identify those with a stable response to high temperatures, particularly in areas like the west of Iran, which is characterized by a warm summer continental climate. The objective of this study is to investigate the process of fruit development and oil accumulation in response to high summer temperature conditions in a set of four Iranian olive cultivars (Shengeh, Roughani, Zard Aliabad, and Dezful) in comparison with four foreign olive cultivars (Konservolia, Sevillana, Manzanilla, and Mission) in seven various harvesting times (20 July, 5 and 20 August, 5 and 20 September, 6 and 21 October). The obtained results evidence a significant positive correlation between fruit dry matter and oil content. High temperatures reduced the oil and dry matter accumulation in the second half of the summer, with severe thermal conditions adversely affecting oil synthesis. Paramount variations were observed among the cultivars regarding oil accumulation, dry matter, and pomological attributes. All of them showed the highest oil content at the last harvest. Among all analyzed varieties, Roughani showed the highest tolerance and adaptive capacity to high temperatures as it accumulated the greatest amount of dry matter as well as oil content in all of the harvesting times, demonstrating a positive correlation between these two traits. Although Shengeh showed the lowest oil content on a dry and fresh weight basis at the first harvesting time, this cultivar generally presented higher fruit development attributes than the other cultivars, highlighting that it benefits from a high temperature.

Influence of Spraying Some Biostimulants on Yield, Fruit Quality, Oil Fruit Content and Nutritional Status of Olive (Olea europaea L.) under Salinity

Salinity currently affects more than 20% of agricultural land and is expected to pose potential challenges to land degradation and agricultural production in the future. It is a leading global abiotic stress that affects general plants and cultivated crops adversely. The utilization of biostimulants can enhance the efficiency of plant nutrition, facilitate the uptake of nutrients, boost crop yield, improve the quality characteristics of fruits and enhance plants’ ability to withstand abiotic stresses. Biostimulants serve as a vital reservoir of macro- and microelements and plant hormones, such as auxins, cytokinins and gibberellins. Therefore, the current study was conducted to examine the effect of the foliar application of some biostimulants on relieving the side effects of salinity on olive trees (Olea europaea) cv. Kalamata. The olive trees were sprayed three times with moringa leaf aqueous extract (MLE) at 2, 4 and 6%, seaweed extract (SWE) at 1000, 2000 and 3000 ppm and their combinations: 2% MLE + 1000 ppm SWE (combination 1), 4% MLE + 2000 ppm SWE (combination 2) and 6% MLE + 3000 ppm SWE (combination 3). The results revealed that the application of biostimulants had a beneficial effect on the overall growth and development of olive trees, surpassing the performance of untreated trees. Spraying MLE and SWE, particularly at concentrations of 6% and 3000 ppm, respectively, significantly enhanced various aspects of olive tree performance. Notably, there were significant increases in leaf chlorophyll content, flower number, fruit set percentages, fruit yields, fruit oil content, fruit firmness, total soluble solid (TSS) percentage and leaf macro- and micronutrients. Furthermore, the combined application of MLE and SWE resulted in a greater effect when compared to using each one individually. In both seasons, combination 3 outperformed the other treatments that were applied.

Elevated fruit nitrogen impairs oil biosynthesis in olive (Olea europaea L.).

Oil in fruits and seeds is an important source of calories and essential fatty acids for humans. This specifically holds true for olive oil, which is appreciated for its superior nutritional value. Most olive orchards are cultivated to produce oil, which are the outcome of fruit yield and oil content. Little information is available on the effect of nitrogen (N) on olive fruit oil content. The response of olive trees to different rates of N was therefore studied in soilless culture (3 years) and commercial field (6 years) experiments. In both experiments, fruit N level and oil biosynthesis were negatively associated. Fruit N increased in response to N fertilization level and was inversely related to fruit load. The negative correlation between fruit N and oil content was more pronounced under high fruit load, indicating sink limitation for carbon. These results agree with those reported for oilseed crops for which a trade-off between oil and protein was proposed as the governing mechanism for the negative response to elevated N levels. Our results suggest that the protein/oil trade-off paradigm cannot explain the noticeable decrease in oil biosynthesis in olives, indicating that additional mechanisms are involved in N-induced inhibition of oil production. This inhibition was not related to the soluble carbohydrate levels in the fruit, which were comparable regardless of N level. These results emphasize the importance of balanced N nutrition in oil-olive cultivation to optimize production with oil content.

Phenological, morphological and physicochemical characteristics of some local olive varieties grown in Mardin (Derik)

This study was carried out between 2016–2017 to identify local olive varieties grown in the Derik district of Mardin province and their distinguishing characteristics. In the study the growing strength of the trees of eight local olive species, pomological characteristics of their leaves, inflorescence, fruit, and seeds, phenological development periods, total oil content, fatty acid composition, and sensory characteristics of their oils were examined. It was found that the “Mavi” variety had the highest values for fruit weight, width, and flesh ratio among the varieties examined. The variety with the highest fruit oil content (30.0%) was “Derik Halhalı”, followed by the “Melkabazi” variety with oil content of 26.0%. The most abundant fatty acid in the oils of local olive varieties was cis-Oleic acid (57.60–73.51%), followed by Palmitic acid (12.90–18.57%), cis-Linoleic acid (7.97–17.76%), and Stearic acid (2.48–3.30%). It has been determined that growing “Derik Halhalı” and “Melkabazi” as oil genotype is suitable, while growing “Zoncuk”, “Mavi”, “Kejik”, “Belluti”, “Hursiki” and “Gulleki” as table genotype is suitable

Effects of Trace Elements on Traits and Functional Active Compounds of Camellia oleifera in Nutrient-Poor Forests

Camellia oleifera is a major woody oilseed species in China, but it is typically cultivated in nutrient-poor soils and may be affected by various trace elements. This study examined how spraying selenium, boron, and zinc trace elements affected the traits and functional active compounds of C. oleifera under nutrient deficiency. The results revealed significant variations in the effects of different trace element combinations on C. oleifera. Optimal concentrations of zinc and selenium are critical for promoting the growth and development of C. oleifera fruit. The transverse diameter of the fruit, the single fruit weight, the number of seeds per fruit, the single fresh seed weight, the oil content in the fruit, and the oil yield per plant of other treatments can be increased by up to 3.07%, 10.57%, 23.66%, 30.23%, 7.94%, and 21.95%, respectively, at most, compared to the control group. Diluting zinc from 1000 to 1500 times and maintaining a selenium concentration from 100 to 200 mg/L has been found to be beneficial for fruit growth. While low concentrations of selenium may promote an increase in fruit transverse diameter, high concentrations of selenium, along with high dilutions of zinc, can have the opposite effect, leading to a reduction in fruit diameter. However, a high concentration of selenium can positively impact the number of seeds per fruit. The most effective combination was found to be a selenium concentration of 0 mg/L, a boron concentration of 4 mg/L, and a zinc dilution of 1500. Interestingly, lower concentrations of selenium and boron, as well as lower dilutions of zinc, were found to increase the oil yield per plant. This suggests that a careful balance of trace elements is required to promote both fruit growth and oil content. The total sterol, squalene, total flavonoid, and polyphenol content of other treatments can be increased by up to 28.81%, 32.07%, 188.04%, and 92.61%, respectively, at most, compared to the control group. Selenium fertilizer and boron fertilizer increased the total sterol content in Camellia oil and had a significant positive correlation at the 0.01 level, but zinc fertilizer had little influence on it. High concentration selenium fertilizer generally increased the squalene, total flavonoid, and polyphenol content in Camellia oil, but boron and zinc fertilizers had little effect on these components. The results suggested that choosing appropriate fertilizer combinations could improve nutrient deficiency in C. oleifera and enhance the functional active compounds of its oil, thereby enhancing its value.

Evaluation of oil accumulation and biodiesel property of Lindera glauca fruits among different germplasms and revelation of high oil producing mechanism for developing biodiesel

BackgroundLindera glauca with rich resource and fruit oil has emerged as novel source of biodiesel in China, but different germplasms show a variation for fruit oil content and FA profile. To develop L. glauca fruit oils as biodiesel, a concurrent exploration of oil content, FA composition, biodiesel yield, fuel property and prediction model construction was conducted on the fruits from 8 plus germplasms to select superior genotype for ideal biodiesel production. Another vital focus was to highlight mechanism that govern the differences in oil content and FA profile of different germplasms. The cross-accessions comparisons associated with oil-synthesized gene transcriptional level and oil accumulative amount led to the identification of potential determinants (enzymes, transporters or transcription factors) and regulatory mechanisms responsible for high-quality oil accumulation.ResultsTo select superior germplasm and unravel regulatory mechanism of high oil production for developing L. glauca fruit oils as biodiesel, 8 plus trees (accession LG01/02/03/04/05/06/07/08) with high-yield fruits were selected to evaluate the differences in oil content, FA profile, biodiesel yield and fuel property, and to construct fuel property prediction model, revealing a variation in the levels of fruit oil (45.12–60.95%), monounsaturated FA (52.43–78.46%) and polyunsaturated FA (17.69–38.73%), and biodiesel yield (80.12–98.71%) across different accessions. Of note, LG06 had a maximum yield of oil (60.95%) and biodiesel (98.71%), and ideal proportions of C18:1 (77.89%), C18:2 (14.16%) and C18:3 (1.55%), indicating that fruit oils from accession LG06 was the most suitable for high-quality biodiesel production. To highlight molecular mechanism that govern such differences in oil content and FA composition of different accessions, the quantitative relationship between oil-synthesized gene transcription and oil accumulative amount were conducted on different accessions to identify some vital determinants (enzymes, transporters or transcription factors) with a model of carbon metabolic regulatory for high-quality oil accumulation by an integrated analysis of our recent transcriptome data and qRT-PCR detection. Our findings may present strategies for developing L. glauca fruit oils as biodiesel feedstock and engineering its oil accumulation.ConclusionsThis is the first report on the cross-accessions evaluations of L. glauca fruit oils to determine ideal accession for producing ideal biodiesel, and the associations of oil accumulative amount with oil-synthesized gene transcription was performed to identify some crucial determinants (enzymes, transporters or transcription factors) with metabolic regulation model established for governing high oil production. Our finding may provide molecular basis for new strategies of developing biodiesel resource and engineering oil accumulation.

Effect of Humic and Salicylic Acids Foliar Application on Vegetative Growth and Fruit Quality of Olive (c.v Sorani and Khadrawi)

This study was carried out on 15 years old trees of two Syrian olives (Olea europaea L.) cultivars Sorani and Khadrawi during 2020-2021 growing season at research orchard, of Horticulture department / College of Agricultural Engineering sciences, University of Sulaimani, Iraqi Kurdistan region. Humic and salicylic acids foliar application with three levels (0, 2000 and 4000 ppm) and (0, 750 and 1500 ppm) were applied respectively (before and after full bloom as well as at fruit set). The parameters annual shoot length, fruit set percentage, fruit weight, fruit volume, oil content in fruit and leaf (nitrogen, phosphorus and potassium) content were studied, and the results showed that cultivar had significant effects on all studied parameters except (fruit weight and fruit volume). Maximum concentration of humic acid (4000ppm) recorded maximum values in all parameters compared to the other concentrations, and also had significant effects on all parameters. Except (fruit volume) all parameters be affected significantly by salicylic acid application.

Sequence characterization and temporal expression analysis of different SADs and FAD2-2 genes in two Iranian olive cultivars

Stearoyl-acyl carrier protein (ACP) desaturases (SADs) and fatty acid desaturases (FADs) are the main genes catalyzing the first and the second desaturation steps throughout the biosynthesis of oleic and linoleic acids, respectively, hence, the major determinants of oil quality and composition. To uncover the molecular mechanisms behind differential oil content and composition in olive fruit, the nucleotide and amino acid sequences of FAD2-2 and three SAD genes were characterized in 'Mari' and 'Shengeh' as two Iranian olive cultivars displaying high contrasting oil composition. In addition, the expression levels of these genes were screened at different time points during fruit development and ripening. Despite detection of a number of nucleotide sequence variations in four characterized genes, the results of amino acid analyses have shown most of them were synonymous and caused no differences at protein level. However, some of the single nucleotide variations caused non cognate amino acid substitution indicating possible conformational changes in the resultant peptide. In particular, regarding OeFAD2-2, a nonsynonymous SNP was detected in 'Shengeh' compared with other olive's FAD2-2 causing an amino acid lysine residue substitution for a glutamic acid, as well as a nonsynonymous substitution in 'Mari' (threonine to serine). The in silico prediction of three-dimensional structure of FAD2-2 revealed these substitutions may lead to structural changes in the final protein structure and function, hence, may contribute to the higher activity of FAD2-2 protein in mesocarp of 'Shengeh' than 'Mari' cultivars. According to results obtained from sequence analysis of oil biosynthesis genes, two Iranian olive cultivars were the most similar and had high sequence differences with international varieties. Results of temporal transcript abundance revealed that OeSAD2 had higher expression in 'Mari' (the high quality oil cultivar) than 'Shengeh' during the critical period of oil biosynthesis. Results of our data corroborates the previous records suggesting that OeSAD2 as the most pronounced isoform of stearoyl-acyl carrier protein desaturases responsible for oleic acid biosynthesis in olive mesocarp. In addition our results also suggest that OeSAD3 may have contributed to the higher oil quality of 'Mari' than 'Shengeh'. Based on our results, OeSAD2 and OeFAD2-2 are suggested as the possible targets for engineering fatty acid composition to help pyramid genes to improve quality and quantity of olive oil and creating high quality olive cultivars.

Fruit Morphology and Fatty Acid Composition of Swida wilsoniana Populations Collected from Different Regions in Southern China

We examined the fruit morphology, oil content, and fatty acids (FAs) of 11 populations of Swida wilsoniana in four provinces in southern China. The fruit oil was extracted by the Soxhlet method, and the FA composition was determined by gas chromatography (GC). The variation in oil content ranged from 16.10 ± 4.94% to 33.08 ± 5.52%, and the major FAs were linoleic acid (44.85 ± 6.70%), oleic acid (29.45 ± 7.63%), palmitic acid (19.59 ± 3.98%), stearic acid (1.95 ± 0.39%), and linolenic acid (0.21 ± 0.07%). The unsaturated FAs accounted for 78.38 ± 3.74%. There was high genetic variation in the oil content and FA composition among the populations. We assessed the relationships between the ecological factors and the FA composition among the populations. The oil content was positively correlated with temperature (r = 0.645, p < 0.05) and negatively correlated with latitude (r = −0.653, p < 0.05). Interestingly, both latitude and temperature were strongly correlated with the unsaturated FAs of the fruits. Principal component analysis (PCA) showed that the populations in different areas could be separated based on oil quality and plant growth. In conclusion, the oil content and FA composition were influenced by geographical area. The findings could help to improve fruit oil quality in future S. wilsoniana breeding programs.

Seedling Selection in Olive Breeding Progenies.

The long juvenile period in olive (Olea europaea L.) delays the evaluation of characters of interest and prolongs the selection of new cultivars in the breeding programs. Therefore, it is important to use accurate selection criteria and appropriate selection pressure to make an effective identification of the superior genotypes and to identify which parents transmit lower juvenile periods to their descendants. In this study, the juvenile period, vigor, fruit fresh weight, and oil content of fruit on a dry weight basis were evaluated in 1568 genotypes from two independent open-pollinated populations; G07, that included 520 genotypes from 25 cultivars and 1 breeding selection and G14, with 1048 genotypes from 13 cultivars. This evaluation was used to test different selection criteria and define optimal selection pressure at the initial stage of an olive breeding program. Wide ranges of variation were obtained for all the characters measured, with higher variability within progenies than between progenies. “Askal” and “Barnea” seem to be the cultivars transmitting the shorter juvenile period to the descendants. In the case of fruit fresh weight and oil content, transgression of variability limits of the parents was observed. Significant correlation was found between mean values of fruit fresh weight of progenies and their parents for G07 (0.59) and G14 (0.95). Selection was made using two selection index formulas (SI1 and SI2). A high coincidence was found between the individuals selected by both formulas and the correspondent selection pressures applied; 15% for SI1, and 14% for SI2. A wide variability in the percentage of selected genotypes was found, from no individuals selected from some progenies to more than 20% of genotypes selected in some others. These results underline the need to explore the wide genetic variability currently hosted in germplasm collections for an optimal choice of parents in olive breeding works.