Clapp Favorite Research Articles

ASSESSMENT FOR RESISTANCE GENES AGAINST PATHOGEN VENTURIA PYRINA ADERH. IN LOCAL, SELECTED AND INTRODUCED VARIETIES OF PEAR CULTIVATED IN AZERBAIJAN

Pear scab (Venturia pyrina Aderh.) is the most perilous fungal disease of the pear plant and from an economic point of view, it causes considerable crop loss in the orchards of our country. Fungicides are mainly used to treat trees to struggle disease. The use of resistant cultivars in production of disease control is most important alternative ways. For this purpose, in our experiment, we found out whether local, selected and introduced pear varieties of Azerbaijan are durable to the pathogen Venturia pyrina Aderh. The seedlings taken for this purpose are thoroughly infected by spraying on 3-5 leaves. The durable of selected pear cultivars to the pathogen Venturia pyrina was basically defined by Chevalier et al. was estimated with a 4-point system and the research results were analysed accordingly. 12% of the plants were scored 1 for the absence of disease symptoms, 29% were scored 2 and 3a for poorly formed spores, but 59% were scored 3b and 4 due to the presence of junior lesions. Among local pear cultivars, Gorkhmazi, Nar, Gov, Ispiya, Cir, Khirda serchebudu, Sini, Uzunbogaz, Boyuk uzunbogaz, selected pear varieties Form3, Form7, introduced pear varieties William, Clapp's favorite and Cure were found to be more infected. Highly durable pear various identified during the study can be used for pear scab introgression in breeding programs.

ASPECTS REGARDING VARIETY/ROOTSTOCK RELATIONSHIP IN SOME SPECIES OF FRUIT SPECIES

Obtaining large and quality productions requires, in addition to agrotechnical measures, the establishment of the most appropriate symbiosis between grafts (varieties) and rootstocks. This variety/rootstock union particularly influences tree growth, production and quality. Knowing the growth of the root system has an important role in choosing the system of use and tillage, in choosing the land. The varieties of nectarine on the frank peach rootstock had different vigor, vigor represented by the height, the diameter of the crown, respectively a lower vigor was recorded in the Marina variety, the other varieties being noted with much greater vigor. Compatibility between nectarine varieties and rootstocks was very good, with no split at the grafting point. Deeply developed roots were found in Costin, Tina and Romamer 2 nectarine varieties. Varieties from the pear species namely Williams red, Clapp's Favorite and Daciana showed average vigor and very good rooting - the same varieties together with the Williams white variety.

DEGREE OF DAMAGE OF PEAR VARIETIES (PYRUS COMMUNIS L.) AND CONTROL ERIOPHYES PYRI PGST. (ACARI: ERIPPHYOIDEA) IN THE FOMIN BOTANICAL GARDEN

In 2018-2020, a study was conducted on the territory of the Academician A.V. Fomin Botanical Garden on the settlement and damage of Eriophyes pyri (Pgst.) pear leaves. The leaves of the studied varieties were selected four times during the growing season, starting from mid-May to early August. All varieties were divided into five groups, depending on the degree of colonization (score) of leaves with mites: I - very low (1 point; <5% are covered with galls), II - low (2-3 points; 5-25% are covered with galls); III - medium (4-5 points; 26-50% are covered with galls), IV - high (6-7 points; 51-85% are covered with galls), V - very high (8-9 points; > 85% are covered with galls). It was found that among the twenty-four varieties of the most damaged (8-9 points) E. pyri were three winter varieties: «Beurré Kyivskaya», «Dekanka winter», «Crymskaya winter» and Willow pear Pyrus salicifolia Pall. Three varieties «Yellow Mlievskaya», «Royal Winte»r, «Tayushchaya» were evaluated in 6-7 points of infestation of pear leaves of E. pyri, and the least damaged (1 point) were four summer varieties – «Williams Rouge Delbara», «Williams summe»r, «Ilyinka», «Clapp's Favorite». All other varieties of Pyrus communis were characterized by a weak or medium degree of E. pyri population. The most significant damage to the leaves of all studied varieties was recorded in late July. The test results of the drugs showed high efficiency of acaricides of biological origin: Fitoverm (DR aversectin C), 5% k.e. and Vertimek (d.r. abamectin), 018 k.e. This will not only inhibit the development of phytophagous, but also save predatory mites. An important problem is the development of parameters necessary for accurate calculation of the sum of effective temperatures at which the spring migration of mites from the buds. This is necessary to accurately determine the time of protective treatments against Eriophyes pyri.

Analysis of metabolite differences in skin between Clapp's Favorite and its mutant Red Clapp's Favorite through non-targeted metabolomics

为了探究西洋梨品种茄梨及其红色芽变红茄梨成熟期果皮代谢产物差异,采用超高效液相色谱-质谱联用技术,对茄梨和红茄梨成熟期果皮进行非靶向代谢组学研究。通过主成分分析和正交偏最小二乘判别分析,构建了多变量统计分析模型,结合模型和变量重要性投影与最大差异倍数值,基于精确质量数、二级碎片以及同位素分布,使用PMDB(Plant Metabolome Database)数据库进行定性,筛选并鉴定出茄梨和红茄梨果皮中显著性变化(P<0.05, VIP(variable importance in project)≥1)的差异代谢物有83种,主要包括酚酸类、黄酮类和氨基酸类物质,涉及类黄酮代谢、氨基酸代谢、苯丙烷类代谢等代谢途径,其中53种物质含量上调,30种物质表达下调。通过KEGG(Kyoto Encyclopedia of Genes and Genomes)数据库进一步对差异代谢物质进行通路富集分析,差异代谢物主要分布在20条代谢途径中,P<0.05的代谢途径有6条,分别是类黄酮生物合成、黄酮和黄酮醇生物合成、苯丙烷生物合成、丁酸酯代谢、苯丙氨酸代谢、酪氨酸代谢。这些差异代谢物的变化可能是导致茄梨和红茄梨果皮色泽不同的原因。该研究从植物代谢组学角度初步揭示了茄梨和红茄梨成熟期果皮的代谢产物差异性。

Transcriptomic and metabolomic analysis provides insights into anthocyanin and procyanidin accumulation in pear

BackgroundPear is one of the most important fruit crops worldwide. Anthocyanins and procyanidins (PAs) are important secondary metabolites that affect the appearance and nutritive quality of pear. However, few studies have focused on the molecular mechanism underlying anthocyanin and PA accumulation in pear.ResultsWe conducted metabolome and transcriptome analyses to identify candidate genes involved in anthocyanin and PA accumulation in young fruits of the pear cultivar ‘Clapp Favorite’ (CF) and its red mutation cultivar ‘Red Clapp Favorite’ (RCF). Gene–metabolite correlation analyses revealed a ‘core set’ of 20 genes that were strongly correlated with 10 anthocyanin and seven PA metabolites. Of these, PcGSTF12 was confirmed to be involved in anthocyanin and PA accumulation by complementation of the tt19–7 Arabidopsis mutant. Interestingly, PcGSTF12 was found to be responsible for the accumulation of procyanidin A3, but not petunidin 3, 5-diglucoside, opposite to the function of AtGSTs in Arabidopsis. Transformation with PcGSTF12 greatly promoted or repressed genes involved in anthocyanin and PA biosynthesis, regulation, and transport. Electrophoretic mobility shift and luciferase reporter assays confirmed positive regulation of PcGSTF12 by PcMYB114.ConclusionThese findings identify a core set of genes for anthocyanin and PA accumulation in pear. Of these, PcGSTF12, was confirmed to be involved in anthocyanin and PA accumulation. Our results also identified an important anthocyanin and PA regulation node comprising two core genes, PcGSTF12 and PcMYB114. These results provide novel insights into anthocyanin and PA accumulation in pear and represent a valuable data set to guide future functional studies and pear breeding.

Comparative analysis of the volatile organic compounds in mature fruits of 12 Occidental pear (Pyrus communis L.) cultivars

Abstract Aroma is an appreciated fruit characteristic, and volatile flavor plays a key role in determining the perception and acceptability of fruit products by consumers. Occidental pear (Pyrus communis) is an aroma-dense fruit, and evaluation of the fruit aroma of different cultivars is meaningful to pear-breeding programs. In this study, we dissected the aroma composition and concentration of mature fruits from 12 Occidental pear cultivars. A total of 335 volatile organic compounds were identified, which were primarily esters, alcohols, alkanes, acids, ketones, terpenes and aldehydes. The concentration of total aroma was highest in ‘Alexandrine Douillard’ (18.73 μg/g), whereas the lowest total concentration was in ‘Bartlett-Max Red’ (0.33 μg/g). The principal aroma biosynthetic pathway of ‘Bartlett-Max Red’, ‘Abate Fetel’ and ‘Butirra Rosata Morettini’ was the fatty acid pathway, whereas the amino acid pathway primarily functioned in ‘Bartlett’, ‘Yubileen Dar’, ‘Doctor Jules Guyot’ and ‘Alexandrine Douillard’. Based on the ABC's of Perfumery System, the 12 pear cultivars were divided into two groups, ‘La france’, ‘Abate Fetel’, ‘Bartlett’, ‘Beurre Bosc’, ‘Alexandrine Douillard’, ‘Doctor Jules Guyot’ and ‘Yubileen Dar’ as the fruit scent type (Group one); and ‘Butirra Rosata Morettini’, ‘beurre Hardy’, ‘Bartlett-Max Red’, ‘Clapp Favorite’ and ‘Red Clapp Favorite’ as the aliphatic scent type (Group two).

Response of prohexadione calcium and paclobutrazol on growth and physio-chemical characteristics of pear cv. Clapp's Favorite

The present investigation was conducted to study the response of growth retardants on pear cv. Clapp's Favorite during the year 2015–2016. The experiment was laid out with thirteen treatments replicated thrice on 12 year-old-trees with uniform vigour and health under uniform cultural practices. The treatment comprises of single spray and double spray of growth retardants (prohexadione calcium @ 100, 200 and 300 ppm and paclobutrazol @ 100, 200 and 300 ppm). The first spray of growth retardants was applied at petal fall stage and second spray was four weeks after first spray. The plants sprayed twice with prohexadione calcium @ 200 ppm (T9S2) recorded minimum annual shoot extension growth (16.92 cm), internodal length (1.82 cm) and leaf area (22.20 cm2) along with increase in fruit set (18.34%) and minimum fruit drop (32.45%). Increased fruit yield (51.24 kg), yield efficiency (4.08) and following year return bloom (24.04%) was noticed in T9S2 treatment. Prohexadione calcium sprayed twice @ 200 ppm (T9S2) also increased fruit weight (82.85 g), TSS (13.21%) and total sugars (10.23%) closely followed by the double spray of prohexadione calcium @ 300 ppm sprayed twice which was also effective in enhancing the fruit firmness (6.15 kg/cm2) followed by treatment T12S2 i.e. paclobutrazol @ 200 ppm double spray (6.07 kg/cm2). Double spray of prohexadione calcium @ 200 ppm was effective in reducing the vegetative characters and increasing yield and fruit quality characters.

The pectin content in different types of fruit crops and their physicochemical characteristics

Currently pectin is widely used in food industry, pharmaceutical industry, medicine, and other industries due to its ability to form gels of different strength, and to having curative and preventive characteristics. Kabardino-Balkaria is one of the regions with industrial amounts of fruits, rich in pectin substances. In order to select the most promising raw materials for commercial production of pectin in the fruit of zoning in the territory of the Republic was determined the content of pectin substances and their physico-chemical parameters in the varieties of apples (Idared, Granny Smith, Florina), pears (Clapp Favorite, Talgar beauty), apricots (Ruddy, Salah), plums (Stanley, Kabardian early). It was established that the greatest number of pectin substances among varieties of apples is allocated in apples in Granny Smith sort, in pears in Clapp Favorite, in plums in Stanley, and in apricots in Salah sort: 1,14, 0,98, 1,03, 0.71% in the raw substance, respectively. It was found that pectin from apples, plums, apricots and pears with the exception of Clapp Favorite is highly etherified. The degree of methoxylation of pectin from apples varies between 70.71–81.85%, plums – from 60.99 to 67.31%, apricots – from 63.72 to 68.25%, from the pear Talgar beauty – 56.0%. Pectin from apples Granny Smith has the highest value of the degree of etherification. A high degree of etherification of pectin in this sort of apples can be recommended as thickening agents in different branches of food industry. Pectin from pears Clapp Favorite has low degree of etherification – 40.7%, that shows the evidence of their possible use in the manufacture of therapeutic and prophylactic purposes. According to the planned program of intensive horticulture in the region, by 2020 the area of Apple orchards will be up to 15 thousand hectares, and the harvest – up to a million tons. Taking that fact and the obtained experimental data into account, we assume that apples are industrially important raw material for the production of pectin.

GROWTH AND YIELDING OF SOME PEAR CULTIVARS GRAFTED ON THREE ROOTSTOCKS

The experiment was carried out in the Experimental Orchard in Dąbrowice, near Skierniewice (Central Poland) in the years 2001-2007. The influence of three rootstocks on tree growth, yield and fruit quality of ten pear cultivars was studied. One-year-old maiden trees grafted on seedlings of Pyrus caucasica were planted at the spacing of 4.0 x 2.50 m, and those on quince clones S1 and MA at the spacing of 4.0 x 1.85 m. After seven years of investigation, Pyrus caucasica seedling induced the highest growth in for all the pear cultivars studied. The tree vigour of ‘Carola’, ‘Clapp's Favorite’ and ‘Packham’s Triumph’ was the strongest. Among the weakest growing trees were those of the cultivars ‘Williams’ and ’Nojabrska’. On both clones of quince, the growth of all trees was clearly weaker than of those on seedlings of Pyrus caucasica. The highest total fruit yields were obtained from the trees grafted on Pyrus caucasica seedlings. Among the trees grafted on the clones of quince, much better yields were produced by the trees grafted on the Polish clone S1. The best yielding trees on Pyrus caucasica seedling were those of the cultivars ‘Nojabrska’ and ‘Bojniczanka’. In the case of both clones of quince, the highest yields were obtained from the trees of the cultivars ‘Conference’, ‘Williams’, and ‘Nojabrska’. In 2007, as in the previous year, after serious spring frosts the best yielding trees were those grafted on Pyrus caucasica seedlings. The highest yields, of more than 20kg per tree, were obtained from the trees of the cultivar ’Bojniczanka’. Pear trees of the Moldavian cultivar ‘Nojabrska’ also produced good yields. All the trees grafted on quince MA yielded on a level similar to that of the trees grafted on quince S1.

Molecular markers derived from RAPD, SCAR, and the conserved 18S rDNA sequences for classification and identification in Pyrus pyrifolia and P. communis.

We generated RAPD, SCAR, and conserved 18S rDNA markers for classifying and identifying cultivars of Pyrus pyrifolia (Japanese pear) and P. communis (European pear). PCR amplification with selected specific primers-LCH327UP and LCH327DOWN-was performed using DNA extracted from 25 P. pyrifolia and P. communis cultivars. The 1,380-bp fragment was amplified from P. communis cvs. Beurre Giffard, Cascade, Conference, Clapp's Favorite, Packhams Triumph, and Winter Nelis. RAPD has only a dominant single band of 1,380-bp, however, SCAR has one or more band of the same size. Amplification involving sequence-specific primer pairs LCH346UP and LCH346DOWN resulted in a loss of polymorphism. The 1,190-bp fragment was amplified from all P. pyrifolia cultivars. The conserved sequences of the 18S rDNA fragment of 25 pear cultivars were amplified and analyzed with 42 restriction enzymes. Compared with P. pyrifolia cultivars, they lacked the restriction enzyme site of KpnI and had one less RsaI site. Cultivar Gamcheonbae had a specific PstI restriction site, while cvs. Mansoo and Conference pear digested with AluI showed a different presentation than other cultivars. For the Okusankichi and Shinil pears TaqI was best marker for identification in P. pyrifolia. These results can be adopted for identifying pear cultivars; to date there is no standard marker for identifying the cultivars of fruit trees in Korean fruit tree breeding programs.

Comparative growth and physiology of selected one-year-old red- and green-fruited European pear cultivars

Red-fruited pear trees are reported to be more difficult to grow, less vigorous and less productive than green-fruited pear trees. This study was undertaken to examine some hypotheses that have been proposed to explain the observed differences in red- vs. green-fruited pear trees. Several growth and gas exchange parameters plus ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, relative total soluble protein, and total chlorophyll were measured on potted, 1-yr-old greenhouse-grown trees of the green-fruited pear cultivars, ‘Bartlett’, ‘d'Anjou’, and ‘Clapp's Favorite’, and their respective red-fruited sports, ‘Red Bartlett’, ‘Red d'Anjou’ and ‘Kalle’. Green-fruited ‘d'Anjou’ trees had double the mean total leaf area of ‘Red d'Anjou’ ( P < 0.05). Specific leaf area of ‘Clapp's Favorite’ was 77% that of ‘Kalle’. The asymptotic maximum net photosynthetic rates ( P max) for red-fruited sports were 69% of those of their green-fruited parents. Stomatal conductance to water vapor of the sports was 78% of that of the parents under light-saturated conditions. Dark respiration of green-fruited ‘d'Anjou’ leaves was 77% of that of ‘Red d'Anjou’ leaves. Intercellular CO 2 concentration was not significantly different between green-fruited parents and red-fruited sports. Although the relative total soluble leaf protein content and total chlorophyll content did not differ significantly between green-fruited parents and red-fruited sports, both characteristics tended to be higher in the parental series, which was consistent with higher net photosynthesis ( P n) in the green-fruited parents than in the red-fruited sports. The ratio of chlorophyll a to chlorophyll b in “Red Bartlett” and ⋚d d'Anjou” was 62% and 54% of that in “Bartlett” and “d'Anjou”, respectively. Rubisco activity in the red-fruited sports was 60% of that in the green-fruited parents. On the basis of these observations, we cannot reject the hypothesis that lower chlorophyll content, particularly chlorophyll a, and lower P n contribute to the reduced vigor in trees of red-fruited sports compared to their green-fruited parents.

Pear rust mite, Epitrimerus pyri (Acari: Eriophyidae) oviposition and nymphal development on Pyrus and non-Pyrus hosts

The ovipositional response of deutogynes of the pear rust mite, Epitrimerus pyri Nalepa, and the rate of development of E. pyri nymphs differed according to the host plant to which mites were exposed. Among the fourteen Pyrus hosts examined, leaves from the Clapp's Favorite cultivar of P. communis elicited the strongest egg-laying response and the fastest rate of nymphal development, whereas egg-laying was least and nymphal development slowest on leaves from P. calleryana. Among the three non-Pyrus hosts, E. pyri oviposited and completed nymphal development on apple and quince leaves, but would not deposit eggs on apricot. Antixenosis appears to be the primary mechanism of resistance, although antibiosis may be operating to a lesser extent. These results are discussed in relation to the resistance of Pyrus to other arthropod pests.

Pears, Pear Psylla Seasonal Control, 1977

Abstract Insecticides were applied with a Myers speed-sprayer in 2 pear blocks containing Bartlett, Bosc, Gorham, and Clapp Favorite cultivars. Treatments were replicated 3 times in ca. 1 acre plots arranged in a randomized complete block design. Early season programs were applied on Apr 11, Apr 27, May 17, June 28, July 22, and Aug 22. Summer programs began at petal fall (May 17) and were then applied on June 3, June 23, July 22, and Aug 2. The check plot received an application of Guthion at PF (May 17) and sprays of Perthane on July 22 and Aug 2. All sprays were dilute (IX) except those at petal fall which were 3X. Nymphs were counted on 10 terminals selected randomly (1 terminal/tree) from each replication. Adults were counted on a 3 ft. square cloth frame held under a vertical branch which was tapped with a rubber hose. Ten such samples were obtained (1/tree) from randomly selected trees in each replication.

Pear, Pear Psylla Seasonal Control, 1976

Abstract Seven seasonal insecticide programs were applied with a Myers speed sprayer to 2 pear blocks containing Bartlett, Bosc, Gorham, and Clapp Favorite cultivars. Each program except that evaluating MO 9087 which was replicated only once, was replicated 3 times. All plots were ca 1 acre and arranged in a randomized complete block design. Sprays were applied on March 29, April 9, April 29, May 24, June 30, July 20 and August 9. All were dilute (IX) except the petal fall spray on May 24 which was applied 3X. Nymphs were sampled on May 17, June 29, and July 26 by putting 10 spurs from each of 4 trees/replication into a Berlese funnel. Adults were sampled by searching for 2 minutes on 4 trees in each plot on August 9 before the final spray application.