The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
Michael T. Clegg - One of the best experts on this subject based on the ideXlab platform.
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Assessing the Genetic Determination of Valuable Avocado Traits Using Microsatellite (SSR) Markers and Quantitative Trait Locus (QTL) Analysis
2015Co-Authors: Michael T. Clegg, Vanessa E.t.m. Ashworth, Haofeng ChenAbstract:Avocado breeding is challenged by the inability to perform controlled pollination, the long juvenility period of the trees (4–7 years) and their considerable size. Because of these difficulties, varietal improvement has long relied on multi-year field trials during which large numbers of Seedlings are grown to maturity and screened for desirable (phenotypic) characteristics. Inferior trees are culled as their deficiencies become apparent, leaving only the most promising genotypes. Clearly, the time, land resource, and labor costs associated with growing trees to the appropriate stage of development are huge. This financial burden is further compounded by conventional breeding approaches that use open-pollination, which results in a complete re-shuffling of genes—good and bad—in the hope of coming across a superior Seedling. This approach happened to work well for Rudolph Hass who discovered such a Chance Seedling in his back yard, but Mr. Hass was a very lucky man indeed. The use of molecular markers as surrogates for tangible traits reduces the screening task by between 1–2 orders of magnitude: Markers can be detected in DNA from young Seedlings, eliminating the need to grow large numbers of trees to maturity, thu
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Assessing the Genetic Determination of Valuable Avocado Traits Using Microsatellite (SSR) Markers and Quantitative Trait Locus (QTL) Analysis
2007Co-Authors: Michael T. Clegg, Vanessa E.t.m. AshworthAbstract:Avocado breeding is challenged by the inability to perform controlled pollination, the long juvenility period of the trees (4–7 years) and their considerable size. Because of these difficulties, varietal improvement has long relied on multi-year field trials during which large numbers of Seedlings are grown to maturity and screened for desirable (phenotypic) characteristics. Inferior trees are culled as their deficiencies become apparent, leaving only the most promising genotypes. Clearly, the time, land resource, and labor costs associated with growing trees to the appropriate stage of development are huge. This financial burden is further compounded by conventional breeding approaches that use open-pollination, which results in a complete reshuffling of genes—good and bad—in the hope of coming across a superior Seedling. This approach happened to work well for Rudolph Hass who discovered such a Chance Seedling in his back yard, but Mr. Hass was a very lucky man indeed.
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Enhancement of Avocado Productivity. Plant Improvement: Selection and Evaluation of Improved Varieties and Rootstocks
2004Co-Authors: Mary Lu Arpaia, Eric Focht, M. Crowley, Loretta Bates, W. Manor, Kent Fjeld, Jim Sievert, G. Douhan, D. Crowley, Michael T. CleggAbstract:Since the commercial introduction of avocados to California approximately 100 years ago, growers, enthusiasts and researchers have been searching for the “perfect” avocado. The annals of the California Avocado Society catalogue the many descriptions of new selections of avocado. The 2 most successful commercial cultivars, ‘Fuerte’ and ‘Hass’ were both Chance Seedlings. The ‘Fuerte’ variety originated as a dooryard Seedling in Atlixco, State of Puebla, Mexico. The original tree was discovered by Carl Schmidt and was subsequently introduced into California. For many years, the ‘Fuerte’ was the preeminent California variety and was only replaced by ‘Hass’ as the leading California variety until the large scale industry expansion in the late 1970s. The ‘Hass’ originated as a Chance Seedling in La Habra Heights, California. The variety was originally planted in 1926 and subsequently patented in 1935 by Rudolph Hass. The search for improved rootstocks began in earnest after the discovery of avocado root rot (Phytophthora cinnamomi Rands) and the need for resistant rootstocks became critical. It was only with the commercial introduction of the clonal rootstock method in the late 1970s that it became possible to vegetatively reproduce clonal rootstock material and therefore introduce improved rootstocks. This technique was first described by Frolich and Platt in 1971 and commercialized by W. H. Brokaw in 1977 with the first planting of Hass, Pinkerton and Bacon on clonal Duke 7 rootstock. Today, the majority of new generation avocado trees planted in California are on clonal rootstocks. The California grower has an increasing selection of rootstocks to choose from and we are beginning to better understand the environmental adaptation and influence of the rootstock on the scion’s productivity and growth habits.
Alejandra Salvador - One of the best experts on this subject based on the ideXlab platform.
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Volatile metabolite profiling reveals the changes in the volatile compounds of new spontaneously generated loquat cultivars.
Food research international (Ottawa Ont.), 2017Co-Authors: Cristina Besada, Gerardo Sánchez, R. Gil, Antonio Granell, Alejandra SalvadorAbstract:Abstract In recent years, the advantageous traits of three new loquat cultivars have drawn the attention of breeders and growers. All three have spontaneously arisen from the ‘Algerie’ cultivar: the new ‘Xirlero’ cultivar is a bud mutant of ‘Algerie’, while ‘Amadeo’ and ‘Raul’ arose as Chance Seedlings. Following a non-targeted approach based on HS-SPME-GC–MS, the volatile compounds profile of the fruits from the new cultivars were obtained and compared to the original ‘Algerie’ cultivar. Carboxylic acids clearly dominated the volatile profile of all the loquat cultivars, but esters, aldehydes, ketones and alcohols were also predominant compounds. Interestingly when the bud mutant event did not lead to marked changes in the volatile compounds complement, pronounced changes in the volatile composition of Chance Seedling-generated cultivars ‘Amadeo’ and ‘Raul’ were observed. ‘Amadeo’ fruits showed lower levels of 2-methyl butanoic acid and much higher levels of methylhexanoate, methylbutanoate and 2-hydroxy-5-methylacetophenone. The ‘Raul’ cultivar also had a distinctive volatile profile characterised by high levels of C6-aldehydes, (E)-2-hexanal, 2-hexenal, (Z)-3-hexenal and hexanal, and several carotenoid-derived volatiles; e.g. 2-pentene-1,4-dione 1-(1,2,2-trimethylcyclopentyl), (S)-dihydroactinidiolide, isodurene, cis-geranyl acetone, β-damascenone, β-ionone, α-ionone and 3,4-dehydro-β-ionone. These changes in volatiles were associated with a more intense flavour in cultivars ‘Amadeo’ and ‘Raul’, according to the sensory evaluation of the flavour intensity carried out by a semi-trained panel. A metabolomic correlation network analysis provided insights as to how volatiles were regulated, and revealed that the compounds modified in ‘Amadeo’ were uncoupled from the rest of the volatilome, while the volatiles modified in ‘Raul’ changed according to specific groups. To conclude, this work provides a holistic view of how the loquat volatilome was affected, and this information was integrated with the physical-chemical-sensory attributes to understand the changes that occur in the new cultivars.
Gholam Hossein Davarynejad - One of the best experts on this subject based on the ideXlab platform.
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Investigation of Antioxidant Capacity and Some Bioactive Compounds of Iranian Pistachio (Pistachio vera L.) Cultivars
2016Co-Authors: Gholam Hossein Davarynejad, Peter Tamas NagyAbstract:Edible nuts have an increasing role in human diet. Pistachio is a popular but less known kind of edible nut nevertheless it is rich in health benefiting nutrients, minerals, antioxidants and vitamins. Therefore, this study attempts to determine the antioxidants capacity, total phenolics and amount of some major elements (nitrogen, potassium, calcium and phosphorus), present in the most important Iranian pistachio nut, to enhance the health benefits, and use in breeding programs. For this reason eleven pistachio cultivars (‘Akbary’, ‘Ahmad Aghaii’, ‘Daneshmandi’, ‘Kalle Ghoochi 1’, ‘Kalle Ghoochi 2’, ‘Garmeh’, ‘Ohadi 1’, ‘Ohadi 2’, ‘Sefid’, ‘Momtaz’, and Chance Seedling tree (“None-grafted”) as control) which are grown in commercial orchards of Fayzabad (Khorasan-e-Razavi) were analyzed for determination of some major elements, antioxidants capacity and total phenolics contents. The results showed that the amounts of the nutrients in 100 g kernel were within the following ranges: N 2.5-4.1 g, P 355.9-546.6 mg, K 573.6-994.9 mg and Ca 61.5-134.5 mg. Total phenolics content varied from 5.3-9.9 mg gallic acid equivalents in g fresh weight. The results also showed that the capacity of antioxidant ranged from 1.6-3.7 (mg ascorbic acid equivalents in g fresh weight). Weak correlation was observed between total phenolic content and total antioxidant capacity (r2=0.3824). The result demonstrates that there is adequate variation in major elements, antioxidants capacity and total phenolics contents within pistachio cultivars and hence there is potential for improvement towards enhancing these health
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Identification and Quantification of Heavy Metals Concentrations in Pistacia
Notulae Scientia Biologicae, 2013Co-Authors: Gholam Hossein Davarynejad, Mehdi Zarei, Péter T. NagyAbstract:The levels of heavy metals are very important in pistachio nuts, because the edible nuts have an important and increasing role in human nutrition. Pistachio is one of the native nuts of Iran which contains high genetic resources, but there is insufficient information regarding nutritional properties and other elements like heavy metals. The objective of the present study was to investigate and compare heavy metals contents in the kernels of various pistachio samples including; ‘Daneshmandi’, ‘Sephid’, ‘Garmeh’, ‘Momtaz’, ‘Ahmad Aghaei’, ‘Badami Zarand’, Pistacia atlantica Desf. (‘Baneh’), Pistacia vera ‘Sarakhs’ and Chance Seedling as ‘Non-grafted 1’, ‘Non-grafted 2’ and ‘Non-grafted 3’. Inductively coupled plasma emission spectrophotometer (ICP) was used for the determination of aluminium, chromium, nickel, copper, strontium, arsenic, cadmium and cobalt concentrations in pistachio kernels. This study showed that there were significant differences among the samples in all measured heavy metals except the arsenic, cadmium and cobalt. The content of aluminium varied from 3.22 to 9.59 (mg kg-1 of dry matter) and chromium concentration from 0.60 to 1.86 (mg kg-1 of dry matter). The nickel content of examined pistachio samples was found between 0.43 and 3.63 (mg kg-1 of dry matter) and copper ranged from 3.20 to 12.33 (mg kg-1 of dry matter). The strontium content was observed between 4.96 and 24.93 (mg kg-1 of dry matter). The contents of arsenic, cadmium and cobalt not reported, because their amounts were lower than the detection limit of the applied measuring method (ICP). These data demonstrated that the concentrations of heavy metals in pistachios varied by cultivar.
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Identification and Quantification of Heavy Metals Concentrations in <i>Pistacia</i>
University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 2013Co-Authors: Gholam Hossein Davarynejad, Mehdi Zarei, Peter Tamas NagyAbstract:The levels of heavy metals are very important in pistachio nuts, because the edible nuts have an important and increasing role in human nutrition. Pistachio is one of the native nuts of Iran which contains high genetic resources, but there is insufficient information regarding nutritional properties and other elements like heavy metals. The objective of the present study was to investigate and compare heavy metals contents in the kernels of various pistachio samples including; ‘Daneshmandi’, ‘Sephid’, ‘Garmeh’, ‘Momtaz’, ‘Ahmad Aghaei’, ‘Badami Zarand’, Pistacia atlantica Desf. (‘Baneh’), Pistacia vera ‘Sarakhs’ and Chance Seedling as ‘Non-grafted 1’, ‘Non-grafted 2’ and ‘Non-grafted 3’. Inductively coupled plasma emission spectrophotometer (ICP) was used for the determination of aluminium, chromium, nickel, copper, strontium, arsenic, cadmium and cobalt concentrations in pistachio kernels. This study showed that there were significant differences among the samples in all measured heavy metals except the arsenic, cadmium and cobalt. The content of aluminium varied from 3.22 to 9.59 (mg kg-1 of dry matter) and chromium concentration from 0.60 to 1.86 (mg kg-1 of dry matter). The nickel content of examined pistachio samples was found between 0.43 and 3.63 (mg kg-1 of dry matter) and copper ranged from 3.20 to 12.33 (mg kg-1 of dry matter). The strontium content was observed between 4.96 and 24.93 (mg kg-1 of dry matter). The contents of arsenic, cadmium and cobalt not reported, because their amounts were lower than the detection limit of the applied measuring method (ICP). These data demonstrated that the concentrations of heavy metals in pistachios varied by cultivar
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Investigation of Antioxidant Capacity and Some Bioactive Compounds of Iranian Pistachio (Pistachio vera L.) Cultivars
Notulae Scientia Biologicae, 2012Co-Authors: Gholam Hossein Davarynejad, Éva Stefanovits-bÁnyai, Peter Tamas NagyAbstract:Edible nuts have an increasing role in human diet. Pistachio is a popular but less known kind of edible nut nevertheless it is rich in health benefiting nutrients, minerals, antioxidants and vitamins. Therefore, this study attempts to determine the antioxidants capacity, total phenolics and amount of some major elements (nitrogen, potassium, calcium and phosphorus), present in the most important Iranian pistachio nut, to enhance the health benefits, and use in breeding programs. For this reason eleven pistachio cultivars (‘Akbary’, ‘Ahmad Aghaii’, ‘Daneshmandi’, ‘Kalle Ghoochi 1’, ‘Kalle Ghoochi 2’, ‘Garmeh’, ‘Ohadi 1’, ‘Ohadi 2’, ‘Sefid’, ‘Momtaz’, and Chance Seedling tree ("None-grafted") as control) which are grown in commercial orchards of Fayzabad (Khorasan-e-Razavi) were analyzed for determination of some major elements, antioxidants capacity and total phenolics contents. The results showed that the amounts of the nutrients in 100 g kernel were within the following ranges: N 2.5-4.1 g, P 355.9-546.6 mg, K 573.6-994.9 mg and Ca 61.5-134.5 mg. Total phenolics content varied from 5.3-9.9 mg gallic acid equivalents in g fresh weight. The results also showed that the capacity of antioxidant ranged from 1.6-3.7 (mg ascorbic acid equivalents in g fresh weight). Weak correlation was observed between total phenolic content and total antioxidant capacity (r2=0.3824). The result demonstrates that there is adequate variation in major elements, antioxidants capacity and total phenolics contents within pistachio cultivars and hence there is potential for improvement towards enhancing these health-promoting photochemical in this nuts.
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Concentration of Some Major Elements in the Kernel of pistacia atlantica desf., p. Vera Variety “sarakhs”, “badami zarand” and Cultivated Pistachio in Iran
2012Co-Authors: Gholam Hossein Davarynejad, T. Nagy Peter, E. DavarynejadAbstract:Edible nuts have an increasing role in human diet. Pistachio is popular but less known kind of edible nut nevertheless it is rich in health benefiting nutrients, minerals, antioxidants and vitamins. This research focused on the concentration of nitrogen (N), phosphorus (P), potassium (K) and calcium (Ca), all of which play a key role in the healthy human nutrition and lifestyle in the kernels of various cultivars and several samples, including "Ahmedaghaii", "Akbari"( 2 different phenotypes), "Sefid", "Momtaz" "Kallehghuchi " ( 3 different phenotype), "Ohadi ( 3 different phenotypes), "Garmeh" "Daneshmandi", and "Badami zarand" which are most important commercially cultivated pistachio in Iran, also wild pistachios such as Pistacia atlantica, Sub sp. mutica Desf. (Baneh), P. vera variety "Sarakhs" and Chance Seedling as "Non-grafted trees. The amounts of the nutrient elements as well as protein content in 100 g kernel were eliminated. Protein content for examined cultivars varied form 13.75-28.13 gr/100gr, as well as N: 2.2-4.5 gr/100gr, P: 350-550 mg/100gr, K: 500-1100 mg/100gr and Ca: 40-135 mg/100gr. The results revealed wide variation in mineral content among different species and cultivars. In addition to, the results provided important data on the concentration of some major elements, emphasizing that pistachio kernel can be used as a good source of major elements as huge quantity of kernels produced and disposed in pistachio processing terminals.
Vanessa E.t.m. Ashworth - One of the best experts on this subject based on the ideXlab platform.
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Assessing the Genetic Determination of Valuable Avocado Traits Using Microsatellite (SSR) Markers and Quantitative Trait Locus (QTL) Analysis
2015Co-Authors: Michael T. Clegg, Vanessa E.t.m. Ashworth, Haofeng ChenAbstract:Avocado breeding is challenged by the inability to perform controlled pollination, the long juvenility period of the trees (4–7 years) and their considerable size. Because of these difficulties, varietal improvement has long relied on multi-year field trials during which large numbers of Seedlings are grown to maturity and screened for desirable (phenotypic) characteristics. Inferior trees are culled as their deficiencies become apparent, leaving only the most promising genotypes. Clearly, the time, land resource, and labor costs associated with growing trees to the appropriate stage of development are huge. This financial burden is further compounded by conventional breeding approaches that use open-pollination, which results in a complete re-shuffling of genes—good and bad—in the hope of coming across a superior Seedling. This approach happened to work well for Rudolph Hass who discovered such a Chance Seedling in his back yard, but Mr. Hass was a very lucky man indeed. The use of molecular markers as surrogates for tangible traits reduces the screening task by between 1–2 orders of magnitude: Markers can be detected in DNA from young Seedlings, eliminating the need to grow large numbers of trees to maturity, thu
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Assessing the Genetic Determination of Valuable Avocado Traits Using Microsatellite (SSR) Markers and Quantitative Trait Locus (QTL) Analysis
2007Co-Authors: Michael T. Clegg, Vanessa E.t.m. AshworthAbstract:Avocado breeding is challenged by the inability to perform controlled pollination, the long juvenility period of the trees (4–7 years) and their considerable size. Because of these difficulties, varietal improvement has long relied on multi-year field trials during which large numbers of Seedlings are grown to maturity and screened for desirable (phenotypic) characteristics. Inferior trees are culled as their deficiencies become apparent, leaving only the most promising genotypes. Clearly, the time, land resource, and labor costs associated with growing trees to the appropriate stage of development are huge. This financial burden is further compounded by conventional breeding approaches that use open-pollination, which results in a complete reshuffling of genes—good and bad—in the hope of coming across a superior Seedling. This approach happened to work well for Rudolph Hass who discovered such a Chance Seedling in his back yard, but Mr. Hass was a very lucky man indeed.
Cristina Besada - One of the best experts on this subject based on the ideXlab platform.
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Volatile metabolite profiling reveals the changes in the volatile compounds of new spontaneously generated loquat cultivars.
Food research international (Ottawa Ont.), 2017Co-Authors: Cristina Besada, Gerardo Sánchez, R. Gil, Antonio Granell, Alejandra SalvadorAbstract:Abstract In recent years, the advantageous traits of three new loquat cultivars have drawn the attention of breeders and growers. All three have spontaneously arisen from the ‘Algerie’ cultivar: the new ‘Xirlero’ cultivar is a bud mutant of ‘Algerie’, while ‘Amadeo’ and ‘Raul’ arose as Chance Seedlings. Following a non-targeted approach based on HS-SPME-GC–MS, the volatile compounds profile of the fruits from the new cultivars were obtained and compared to the original ‘Algerie’ cultivar. Carboxylic acids clearly dominated the volatile profile of all the loquat cultivars, but esters, aldehydes, ketones and alcohols were also predominant compounds. Interestingly when the bud mutant event did not lead to marked changes in the volatile compounds complement, pronounced changes in the volatile composition of Chance Seedling-generated cultivars ‘Amadeo’ and ‘Raul’ were observed. ‘Amadeo’ fruits showed lower levels of 2-methyl butanoic acid and much higher levels of methylhexanoate, methylbutanoate and 2-hydroxy-5-methylacetophenone. The ‘Raul’ cultivar also had a distinctive volatile profile characterised by high levels of C6-aldehydes, (E)-2-hexanal, 2-hexenal, (Z)-3-hexenal and hexanal, and several carotenoid-derived volatiles; e.g. 2-pentene-1,4-dione 1-(1,2,2-trimethylcyclopentyl), (S)-dihydroactinidiolide, isodurene, cis-geranyl acetone, β-damascenone, β-ionone, α-ionone and 3,4-dehydro-β-ionone. These changes in volatiles were associated with a more intense flavour in cultivars ‘Amadeo’ and ‘Raul’, according to the sensory evaluation of the flavour intensity carried out by a semi-trained panel. A metabolomic correlation network analysis provided insights as to how volatiles were regulated, and revealed that the compounds modified in ‘Amadeo’ were uncoupled from the rest of the volatilome, while the volatiles modified in ‘Raul’ changed according to specific groups. To conclude, this work provides a holistic view of how the loquat volatilome was affected, and this information was integrated with the physical-chemical-sensory attributes to understand the changes that occur in the new cultivars.