Pear Varieties Research Articles

Effect of parent selection and crosses of Pyrus ussuriensis on the early-bearing ability of F1 progenies

In order to investigate the effect of combinations of different pear varieties and their descendants and other cultivated pear varieties on the early fruiting of F1 generation, the individual plant Numbers of F1 generation of 17 hybrid combinations were investigated. The results showed that: 17 combinations of 1175 hybrid seedlings, 15 combinations of fruit age in 6∼8 years, 8 years of birth there are two combinations of Hanxiangli×Jinxiangshui, Dacili× Eli1 did not blossom. Among the flowering combinations, there were differences among different maternal combinations. The flowering plant rate of the combination with Dacili as the parent was the highest, which was 12.14%.Hanxiangli was the second 9.42%.Jinxiangshui was the lowest 6.43%.There were significant differences in the number of flowering plants in the offspring population in different combinations of maternal parent and paternal parent, indicating that parental parent had a significant influence on the age of bearing fruit in the hybrid population. There was a big difference in the age of the first fruit in F1 generation in the combination of pear varieties in other cultivation systems. However, the progeny of the parent and parent groups of Pyrus ussuriensis had a lower flowering individual plant, and the combination of Pyrus ussuriensis×Pyrus ussuriensis was zero. It can be seen that the seed sex of Pyrus ussuriensis has a great influence on the early and late fruit age of offspring.

Osmotic dehydration of apple and pear slices: color and chemical characteristics

Abstract Osmotic dehydration is the pre-treatment method of preservation the fruits and vegetables to increase their shelf life. This method consists of immersing fruits and vegetables in concentrated solutions of salt or sugar. The effect of osmotic dehydration was investigated on the color and chemical characteristics of dehydrated fruits (apple and pear) in fructose osmotic solutions. Difference in CIE-LAB, chroma - C* and hue angle H* were performed with a Chroma Meter CR-400/410. Apple (Malus domestica ‘Jonathan’) and sweet autumn pear variety (Pyrus comunis) were osmotically dehydrated in three aqueous solution of fructose (40, 60 and 80%), during 3 h of process at temperatures of 20 °C, with fruit/osmotic agent ratio of 2:1. Water loss and solids gain showed significant differences depending on the concentration of the osmotic agent and process time. The use of highly concentrated osmotic solutions induced losses of phenolic content (TPC) and ascorbic acid in the sliced apples and pears. Fructose concentration and osmosis time induce significant increase of a* and b* colorimetric parameters but did not affect the lightness (L*) of pear slices.

Evaluation of certain pomological and phenological traits of selected asian pear varieties growing in Middle European conditions

The cultivation and breeding of new pear tree varieties have great potential, especially with the changing climate. The introduction of genetic resources and varieties from regions with a high genetic diversity can have a positive effect on the cultivation of pear trees in our region. In this experiment, a total of 23 Asian pear varieties originating from Japan and China were assessed. Based on the values obtained, the varieties were sorted, and suitable varieties for the conditions of the Czech Republic were selected. The early-maturing varieties that proved to be promising were ‘Shinseiki’ and ‘Zao Su Li’ due to their refreshing juiciness, plasticity and ease of cultivation. generally low demand. The ‘Shinseiki’ bears medium- to small-sized fruits (103 g on average). The size of the fruits of the evaluated cultivar ‘Zao Su Li’ can reach very large sizes (255 g on average). The medium-maturity varieties suitable for the conditions of the Czech Republic were ‘Hosui’ and ‘Dangshansu Li’ (ripening on the September 11–19 on average) and another interesting variety, ‘Kirgizkaja zimnaja’. Other suitable medium-maturity varieties are ‘Nijisseiki’, ‘Sha Li’ and ‘Pung Su’. Of the assessed late-maturing varieties, the promising ones were ‘Ya Li’ and ‘Mut Chen’, especially due to their relatively high storability under cold storage.

Forage nutritional differences within the genus Opuntia

The objective of this study is to evaluate the bromatological composition, carbohydrate fractionation, in vitro digestibility and gas production of varieties of forage cactus of the genus Opuntia, associated with different phenological phases. The experiment was conducted in a completely randomized design in a 5 × 3 factorial arrangement consisting of five forage cactus varieties of the genus Opuntia ((IPA-20 (Opuntia ficus-indica Mill), Gigante (Opuntia ficus-indica Mill), Erect Prickly Pear (EPP) (Opuntia stricta Haw), African Prickly Pear (APP) (Opuntia undulata) and F-08 (Opuntia atropes Rose)). and three phenological phases (young, intermediate and mature). The concentrations of neutral detergent fiber and the C ratio of carbohydrates were lower in the Erect Prickly Pear (EPP) variety, in this same variety, a higher proportion of pectin was observed along with the giant variety and higher in vitro digestibility, with similar digestibility for the African Prickly Pear (APP) and F-08. The concentration of total carbohydrates was higher in the IPA-20 variety since the gas production adjusted by the bicompartmental model was higher for APP. Was observed in all varieties greater concentration of neutral detergent fiber and the C fraction of the carbohydrates in the mature cladodes. In vitro digestibility of mature phase was also superior in all varieties except APP. The Erect Prickly Pear and African Prickly Pear varieties present best nutritional value for feeding ruminants and mature phase is the least relevant.

Physicochemical evaluation of the fruit pulp of Opuntia spp growing in the Mediterranean area under hard climate conditions

AbstractBarbary fig called prickly pear is a plant belonging to family Cactaceae growing under hard climate conditions. A spiny variety of prickly pear named “Drbana” (Opuntia megacantha) and two non-spiny varieties named “Akria” and “Mlez” (Opuntia ficus-indica) growing in the Rhamna region (Morocco) were studied in terms of physicochemical characteristics. The physicochemical characterization (humidity, water activity, pH, total titratable acidity, Brix, and ash content) and the biochemical characterization (total carotenoid content, betalain content, total polyphenolic content, and ascorbic acid content) of the fruit pulp of prickly pear were performed according to the previously reported methods. The finding of physicochemical characterization of all studied varieties showed that the fruit pulp also contained an interesting bioactive compound classes in humidity, water activity, pH, total titratable acidity, Brix, and ash content. Regarding the biochemical characterization, the obtained finding showed the fruit pulp also contained an interesting bioactive compound classes particularly the total betalains, polyphenols, carotenoids, and ascorbic acids. Based on the obtained results in the current research work, we can affirm that the fruits of all studied varieties meet the requirement for being exploited in food, cosmetic, and pharmaceutical industries.

Comparison of Pomological and Chemical Properties of Autochthonous Pear Varieties with Standard Pear Varieties

Indigenous fruit varieties are the wealth and natural resource of every country. Their importance is reflected, in addition to economic and biological, through the growing consumer interest in consuming fruits produced without the use of chemicals. Proper and accurate identification and preservation of valuable assortment has resulted in studies of the physicochemical and pomological properties of the fruits of ten pear varieties and their comparison with standard varieties. The usable value of pear fruits is multiple. It is used for liqueurs, vinegar, fruit salads, jams, jam, as dried fruit. The aim of the study is to determine the pomological and chemical properties of indigenous pear varieties and their comparison with standard pear varieties grown in northern Bosnia. The size of the fruit was quite different in the tested varieties and ranged from very small to extremely large fruits with the content of total acids slightly lower than the standard varieties. The research was supported by the Federal Ministry of Education and Science as part of a scientific research project entitled "Investigation of phenological and pomological characteristics of indigenous pear varieties in north-eastern Bosnia".

Pearprocess: A new phenotypic tool for stone cell trait evaluation in pear fruit

The content of stone cells is an important factor for pear breeding as a high content indicates severely reduced fruit quality in terms of fruit taste. Although the frozen-HCl method is currently a common method used to evaluate stone cell content in pears, it is limited in incomplete separation of stone cell and pulp and is time consuming and complicated. Computer-aided research is a promising strategy in modern scientific research for phenotypic data collection and is increasingly used in studying crops. Thus far, we lack a quantitative tool that can effectively determine stone cell content in pear fruit. We developed a program, Pearprocess, based on an imaging protocol using computer vision and image processing algorithms applied to digital images. Using photos of hand-cut sections of pear fruit stained with phloroglucin-HCl (Wiesner's reagent), Pearprocess can extract and analyze image-based data to quantify the stone cell-related traits measured in this study: number, size, area and density of stone cell. We quantified these traits for 395 pear accessions by Pearprocess and revealed large variation in different pear varieties and species. The number of stone cells varied greatly from value of 138 to 2 866, the density of stone cells ranged from 0.0019 to 0.0632 cm2 cm−2, the distribution of stone cell area ranged from 0.06 to 2.02 cm2 and the stone cell size was between 2e-4 and 1e-3 cm2. Moreover, trait data were correlated with fruit taste data. We found that stone cell density is likely the most important factor affecting the taste of pear fruit. In summary, Pearprocess is a new cost-effective web-application for semi-automated quantification of two-dimensional phenotypic traits from digital imagery using an easy imaging protocol. This simpler, feasible and accurate method to evaluate stone cell traits of fruit is a promising new tool for use in evaluating future germplasms for crop breeding programs.

Peculiarities of growth and development of pear varieties in the central black earth region

In I. V. Michurin Federal Scientific Center a unique genetic collection of pears, numbering more than 300 genotypes was created. As a result of the study of the peculiarities of growth and development of various pear varieties the influence of the growth force, crown diameter and other parameters on yield has been revealed. Based on the conducted research, forms with restrained growth were identified: Pamayty Yakovleva, Augustovskaya Rosa, Smuglyanka, Hera, Allegro, Pervomaiskaya.

Peculiarities of the phytosanitary state of pome fruits in industrial horticulture

Data were obtained on the basis of the results of research carried out on the territory of the educational and experimental farm of the Timiryazev State Agrarian University, in Moscow during 2018-2019. As a result of the surveys, the most dangerous diseases and pests of pome crops on the territory of this farm were established. The most resistant apple and pear varieties to major diseases have been identified. Peculiarities of development of alternariosis on pear are described, the harmfulness of the disease on pear and apple seedlings is noted. A possible role in the transfer of alternariosis infection from garden-protective plantations and weed vegetation to fruit trees was noted. A possible role has been established in the transport of septoriosis, powdery dew infection from dicotyledonous weeds plants. The peculiarities of the spread of infection under the influence of wind direction are noted. The results and peculiarities of the application of various methods of scaring birds in the orchard are presented. As a result of route surveys the most harmful weed plants have been identified. The possibility of using herbicides of different mechanism of action in fruit gardens for weed control has been studied. High efficiency and relative safety of application of herbicides of contact action in nursery fields, operational orchards and for control of piglets on fruit trees are shown. Recommendations are given for the use of soil and systemic herbicides of soil in seedlings beds, the first and second fields of the nursery, as well as in the process of production of large-scale planting material and operational orchards of fruit crops. The safety of the herbicides in question is established when used in accordance with the recommended methods of use.

Digestive Stability and Bioaccessibility of Antioxidants in Prickly Pear Fruits from the Canary Islands: Healthy Foods and Ingredients.

Although prickly pear fruits have become an important part of the Canary diet, their native varieties are yet to be characterized in terms of betalains and phenolic compounds. To exert potential health benefits, these antioxidants must be released from the food matrix and be stable in the gastrointestinal tract. Our aim was to characterize the betalain and phenolic profile of four prickly pear varieties from the Canary Islands (Spain) and determine their digestive stability and bioaccessibility via in vitro gastrointestinal digestion. Digestive studies were performed considering the (i) importance of the edible fraction (pulps) and (ii) potential of fruit peels as by-products to obtain healthy ingredients. Betalains and phenolic profiles were analyzed by HPLC-DAD-ESI/MS and HPLC-DAD-MS/QTOF. Pulps in Colorada and Fresa varieties presented high indicaxanthin and betanin content, respectively. Despite low pH in the gastric phase, betalains were stable to reach the intestinal phase, although indicaxanthin presented a higher bioaccessibility. Blanco Buenavista peels contained a distinct flavonoid profile including a new isorhamnetin-hexosyl-rhamnoside. Phenolic compounds were abundant and highly bioaccessible in fruit peels. These findings suggest that prickly pear pulps are rich in bioaccessible betalains; and that their peels could be proposed as potential by-products to obtain sustainable healthy ingredients.

Histone Acetylation at the Promoter for the Transcription Factor PuWRKY31 Affects Sucrose Accumulation in Pear Fruit.

Sugar content is an important trait of fleshy fruit, and elevating Suc levels is a major goal in horticultural crop breeding. Here, we examined the sugar content in two varieties of the Ussurian pear (Pyrus ussuriensis), 'Nanguo' (NG) and its bud sport (BNG), and we found that Suc content was higher in BNG fruit than in NG fruit. We compared the transcriptomes of the two varieties using RNA sequencing and identified a SWEET (Sugars Will Eventually be Exported Transporter) gene, PuSWEET15, expressed at higher levels in BNG fruit. Heterologous expression of PuSWEET15 in a SUSY7/ura yeast (Saccharomyces cerevisiae) strain showed that PuSWEET15 is an active Suc transporter. Overexpression of PuSWEET15 in NG pear fruit increased Suc content, while silencing of PuSWEET15 in BNG fruit decreased Suc content. The WRKY transcription factor PuWRKY31 was also expressed more highly in BNG fruit than in NG fruit, and we found that PuWRKY31 bound to the PuSWEET15 promoter and induced its transcription. The histone acetylation level of the PuWRKY31 promoter was higher in BNG fruit, suggesting a mechanism by which Suc levels can be elevated.

Genome size and chromosome ploidy identification in pear germplasm represented by Asian pears - Local pear varieties

Pear (Pyrus) germplasm resources in Xinjiang were rich, most of which were diploid. Including dozens of varieties such as Pyrus bretschneideri Rehd. (P-br), Pyrus pyrifolia Nakai. (P-py), Pyrus ussuriensis Maxim. (P-us), Pyrus communis L. (P-co), Pyrus betulifolia Bunge. (P-be), Pyrus sinkiangensis Yü. (P-si). The P-si was mainly distributed in Shanshan, Turpan, Korla, Aksu and other places. The genetic background of the main varietieswas not completely clear.The genome size and chromosome ploidy of main pear varieties in Xinjiang were identified by flow cytometry (FCM) and the traditional chromosome pressing method. The results showed that, the genome size of P-xj was 566.54 ± 125.17 Mb, slightly larger than that of the introduced varieties, with a 2C values of 1.16 ± 0.26 pg and a ploidy value (DI) of 1.1 ± 0.24. Twenty-four P-xj were diploid with 34 chromosome numbers. The genome sizes of introduced P-br, P-py, P-us, P-be, and P-co were 485.44 ± 10.05∼567.94 ± 44.40 Mb, and the 2C values was 0.99 ± 0.02∼1.16 ± 0.10 pg. The DI was 0.9 ± 0.06∼1.0 ± 0.09, the FCM detection indicated that they were diploid; the number of chromosomes was 34.There were differences in genome size between pear with the same ploidy. The genome size of all diploid pear was 480.95 ± 16.24∼599.14 ± 38.36 Mb, the 2C values was 0.98 ± 0.03 pg ∼1.23 ± 0.08 pg, and the DI was 0.9 ± 0.00∼1.2 ± 0.06. A total of 5 polyploid materials were found in this study: ‘Yilikamut’, ‘Kotoamut’, ‘Aiwenqieke’, ‘Heisuanli’ and ‘Sha01′, it can provide materials for the innovation and utilization of pear germplasm resources. The results of this study can provide technical support for Pyrus plant on ploidy breeding and omics study, and also a reference for other plants.

An Analysis on Some Reciprocal Pear Hybridization Combinations in Terms of Transferring Resistance to Fire Blight

Since it has a wide variety, pear can be grown in all temperate zones and high-altitude areas of tropical and subtropical climates of the Earth. On the other hand, most of the cultured pear varieties are susceptible to fire blight caused by Erwinia amylovora, and their susceptibility is threatening pear cultivation. The lack of a certain solution to fire blight, the harmful effects of the chemicals on environment and human health and the increasing demand for organic products, give priority to breeding new resistant rootstocks and varieties in control of the disease. Due to the polygenic nature of fire blight resistance and the complexity of its mechanism, controlled hybridization is generally used in breeding programs. In order to determine the effect of the parents for the transmission of fire blight resistance, hybridizations are also carried out reciprocally. In the study which was carried out for this aim, susceptibility levels of the F1 hybrids, obtained from the reciprocal combinations of fire blight resistant ’Kieffer’ and the susceptible ’Williams’, ’Santa Maria’ and ’Akca’ cultivars, were evaluated. While ’Kieffer’ x ’Santa Maria’ was found the most resistant combination to fire blight, ’Akca’ x ’Williams’ was found as the most susceptible one. In addition, it has been determined that F1 hybrids obtained from ’Kieffer’ x ’Santa Maria’ and ’Akca’ x ’Williams’ hybridization combinations and their reciprocals are different in terms of disease resistance, while there was no difference in resistance in F1 hybrids of ‘Williams’ x ’Santa Maria’ combination and its reciprocal combination.

Dissipation behavior, residue distribution and risk assessment of three fungicides in pears

Fungicides are often applied to pears before they are kept in storage facilities. The scientific application of pesticides can reduce unnecessary exposure, which in turn could benefit both humans and the environment. We investigated dissipation behavior and residue distribution, and conducted risk assessments for prochloraz, pyraclostrobin, and tebuconazole in pears stored under different conditions using ultra-performance liquid chromatography (UPLC). The recoveries of the three fungicides ranged from 76.5% to 114.5%, and the coefficients of variation were 1.0%-8.5%. The half-life (t1/2 ) ranges for degradation of the three fungicides in Dangshan Su pear peel were 8.8-13.9 days after storage at 25 °C and 99.0-346.6 days after storage at 2 °C. Among the three fungicides, tebuconazole had the lowest residue concentration in pear pulp (maximum of 0.226 mg·kg-1 ) and the longest half-life (≥ 231.0 days). Accordingly, among these fungicides, tebuconazole is the most suitable for the preservation of Dangshan Su pears during storage. Finally, we analyzed samples of six pear varieties from markets in China and found that the residue concentrations of the three fungicides in pear pulp and fruit met Chinese standards. The results provide a scientific basis for rationalizing the use of prochloraz, pyraclostrobin, and tebuconazole, and improving the safety of pears for eating. © 2019 Society of Chemical Industry.

Distinct features of adaptive and productive potential of prospective pear varieties

The goal of the research is to identify the most productive and environmentally sustainable varieties of pear in the conditions of the Central Black Earth region of Russia. The research was carried out from 2015 to 2017 in the Oryol Oblast on leached black earth. The average humus content in the arable layer was 6.0–6.5%, phosphorus – 21–27 mg/100g, potassium – 12–15 mg/100 g. Soil acidity was 5.7–6.1. The thickness of the humus horizon was 40–75 cm. The degree of saturation of the bases was within 91%. Climate in the region is moderate-continental, heat is sufficient for the normal growth and development of fruit plants. The trees were planted in 2004; the scheme of planting was 6x4 m. The stock was seedlings of common pear. Accounting was conducted using the “Program and method of studying fruit, berry and nut crop varieties” (Oryol, 1999). The varieties Pamiati Yakovleva and Annushka are characterized by a restrained growth force – 3.5–3.8 m. In the natural climatic conditions of the Oryol Oblast, the Annushka and Velesa varieties are considered hardy, the Rossoshanskaya krupnaya and Svetlyanka – medium-hardy. Varieties Annushka and Velesa are quite resistant to the pathogens of scab, brown and white spotting – the average score for damage to fruits and leaves did not exceed 1.5. On average, for 3 years the yield of the Rossoshanskaya krupnaya pear variety was at the level of the zoned control variety Pamiati Yakovleva. Yields were 112.2 and 108.3 centners per hectare, respectively. The yield of the Annushka variety was 7.5 centners per hectare, or 6.7% higher than that of the control variety.

Physico-chemical, nutritional and functional characterization of Pathernakh pear (Pyrus pyrifolia L.) from Himachal Pradesh of India

The present study was conducted to evaluate the physico-chemical, nutritional and functional properties of pathernakh pear grown in Himachal Pradesh. The physical properties (weight, length, width and colour), chemical and nutritional properties of the pathernakh pear including moisture, ash, total sugar, reducing sugar and minerals of pathernakh pear were studied. Moreover, the pear variety was characterized for functional components with respect to total phenols, ascorbic acid and fiber analysis. The results indicated that the fruit is a good supplier of sugars, minerals, ascorbic acid and polyphenols. The edible portion of the fruit possess a high level of fiber content. Additionally, textural properties in terms of firmness of the fruit were also studied. The overall results concluded that pathernakh pear could be best for consumption owing to superior nutritional and functional properties that has many health benefits.

The Correlation between Cellular Features and Gene Expression in ‘Korla’ Fragrant Pear

‘Korla’ fragrant pear (Pyrus sinkiangensis T.T. Yu) variety has shown severe coarse skin in recent years. The intrinsic quality of its coarse fruit shows an increase in the number of stone cells and poor taste. In this study, stone cells and the cell wall of coarse pear (CP) and normal pear (NP) during various development stages were compared using paraffin-sectioning and transmission electron microscopy (TEM), and the relationships between lignin-related genes and stone cell formation and cell wall thickening were also analyzed. Our results show that giant stone cells are formed and distributed in the core of pear, whereas many of these crack 60 days after flowering (DAF). The period of stone cell fragmentation occurs later in CP fruits than in NP fruits. Parenchyma cell wall development in CP and NP fruits varies from 120 DAF to maturity. The parenchyma cell wall of CP fruits thickens, whereas that of NP fruits is thinner during the same period. The expression pattern of five genes (Pp4CL1-l, PpHCT-l, Pp4CL2-l, PpPOD4, and PpPOD25) coincides with changes in stone cell content in the pulp. Correlation analysis demonstrates a significant correlation between stone cell content and the expression level of the five genes (ρ < 0.05). In addition, the expression of those five genes and PpCCR1 genes in CP fruits significantly increases during maturation and is highly correlated with the thickness of the parenchyma cell wall. The aim of this work is to provide insights into the mechanism of stone cell and parenchyma cell wall development in pear fruits and identify important candidate genes to regulate the quality of fruit texture using bioengineering methods.

АЛЬТЕРНАРИОЗ СЕМЕЧКОВЫХ КУЛЬТУР

The research was carried out on the premises of the experimental study farm of Russian State Agrarian University – Moscow Timiryazev Agricultural Academy in Moscow in 2018–2019. Over two years, the authors collected and microscoped samples of affected plants of different families to determine the causative agents of fungal diseases. The identification of the fungi species of the Alternaria genus was carried out by morphological features of conidia and the habitus of sporulation. It was found that the damage of apple and pear trees is caused by two non-specialized fungus species of Alternaria tenuissima and Alternaria infectoria. It was found that 73% of 110 apple varieties and 47.2% of 53 pear varieties studied were affected to varying degrees by the fungi of the Alternaria genus. The paper describes apple varieties that have been damaged by Alternaria. There has been detected a high malware of Alternaria blight on the young seedlings of pome crops. The species of A. tenuissima and A. infectoria pathogens have been determined to affect dicotyledonous weed plants widely distributed in fruit gardens, as well as a number of garden-protective and ornamental crops. Also, their possible role as infection reservoirs and vectors for fruit crops has been established. The authors considered grade vulnerability to Alternaria blight lesion of different pome and stone fruit varieties. The most Alternaria blight-resistant varieties of pome crops have been identified. The authors have stated the relationship between the degree of Alternaria blight progression and factors such as pest damage and the location of plantings. They also describe some differences in the manifestation of Alternaria blight symptoms on apple and pear trees during the initial period of disease progression. As a result of the studies, recommendations are given on the implementation of protective measures aimed at reducing the spread of Alternaria blight of pome crops in fruit gardens.

РЕЗУЛЬТАТЫ КОЛЛЕКЦИОННОГО ИЗУЧЕНИЯ МОЛДАВСКИХ СОРТОВ И ФОРМ ГРУШИ В НИКИТСКОМ БОТАНИЧЕСКОМ САДУ

РЕЗУЛЬТАТЫ КОЛЛЕКЦИОННОГО ИЗУЧЕНИЯ МОЛДАВСКИХ СОРТОВ И ФОРМ ГРУШИ В НИКИТСКОМ БОТАНИЧЕСКОМ САДУ

ОЦЕНКА КАЧЕСТВА ПЛОДОВ СОРТОВ ГРУШИ В ПРЕДГОРНОЙ ЗОНЕ СЕВЕРО-ЗАПАДНОГО КАВКАЗА

ОЦЕНКА КАЧЕСТВА ПЛОДОВ СОРТОВ ГРУШИ В ПРЕДГОРНОЙ ЗОНЕ СЕВЕРО-ЗАПАДНОГО КАВКАЗА