The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
João Bosco Dos Santos - One of the best experts on this subject based on the ideXlab platform.
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Increasing the resistance of common bean to white mold through Recurrent Selection
Scientia Agricola, 2016Co-Authors: Monik Evelin Leite, Juliana Andrade Dias, Danuza Araujo De Souza, Filipe Couto Alves, Lucas Rezende Pinheiro, João Bosco Dos SantosAbstract:White mold, caused by Sclerotinea sclerotiorum (Lib.) de Bary is one of the most important diseases of the common bean (Phaseolus vulgaris L.) worldwide. Physiological resistance and traits related to disease avoidance such as architecture contribute to field resistance. The aim of this study was to verify the efficiency of Recurrent Selection in physiological resistance to white mold, “Carioca” grain type and upright habit in common bean. Thirteen common bean lines with partial resistance to white mold were intercrossed by means of a circulant diallel table, and seven Recurrent Selection cycles were obtained. Of these cycles, progenies of the S0:1, S0:2 and S0:3 generations of cycles III, IV, V and VI were evaluated. The best (8 to 10) progenies of the seven cycles were also evaluated, in two experiments, one in the greenhouse and one in the field. Lattice and/or randomized block experimental designs were used. The traits evaluated were: resistance to white mold by the straw test method, growth habit and grain type. The most resistant progenies were selected based on the average score of resistance to white mold. Subsequently, they were evaluated with regard to grain type and growth habit. Recurrent Selection allowed for genetic progress of about 11 % per year for white mold resistance and about 15 % per year for the plant architecture. There was no gain among cycles for grain type. Progeny Selection and Recurrent Selection were efficient for obtaining progenies with a high level of resistance to white mold with “Carioca” grain type and upright habit.
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Reaction of common bean progenies to white mold derived from Recurrent Selection
Ciencia Rural, 2014Co-Authors: Danuza Araujo De Souza, Monik Evelin Leite, Juliana Andrade Dias, Fernanda Aparecida Castro Pereira, João Bosco Dos SantosAbstract:This study was realized with the objective of verifying the resistance to white mold of common bean progenies derived from Recurrent Selection for resistance to angular leaf spot. The plant material used was obtained from a program of Recurrent Selection, which was started by crossing seven lines with carioca grain type with ten sources of resistance to angular leaf spot according to the partial diallel scheme. To evaluate the resistance to white mold, it was verified the reaction of 17 parents plus 35 selected progenies, to oxalic acid. Huge heterogeneity among the parents was observed, showing that some of them have resistance alleles to white mold, and thus, there is a possibility of recombine these alleles through the Recurrent Selection and obtaining progenies with high levels of resistance. Even in initial cycles, some progenies exhibited resistance to white mold similar to the one of cultivar 'G-122', which presents good level of resistance to this disease. This leads to infer that the original population already had some level of physiological resistance for the reaction to absorption of oxalic acid, and also for resistance to angular leaf spot. Thus, among the selected progenies for resistance to angular leaf spot, grain type and high yield, at least four progenies have resistance to white mold similar to the source of resistance 'G-122'.
Kendall R. Lamkey - One of the best experts on this subject based on the ideXlab platform.
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population genetic diversity in a maize reciprocal Recurrent Selection program
Crop Science, 2005Co-Authors: Lori L Hinze, Stephen Kresovich, Jason D Nason, Kendall R. LamkeyAbstract:The genetic structures of the Iowa Corn Borer Synthetic #1 (CB) and Iowa Stiff Stalk Synthetic (SS) maize (Zea mays L.) populations are important because these populations serve as the model for development of modern commercial hybrids. In 1949, CB and SS were used to start a reciprocal Recurrent Selection (RRS) breeding program at Iowa State University. This study was conducted to analyze more thoroughly the genetic diversity within this RRS program and illustrate how the RRS program has changed over time at the molecular level. The progress of this program was measured by analyzing the variation at 86 SSR loci among 28 progenitor lines and 30 plants sampled from each of seven cycles (Cycle 0, Cycle 1, Cycle 3, Cycle 6, Cycle 9, Cycle 12, and Cycle 15) in each population. The progenitors of these populations show a high amount of variation on the basis of expected heterozygosity (0.557). As the RRS program proceeded, this variation decreased (Cycle 15,0.245). In total, a larger amount of genetic variation was found among plants within cycles (66%) than among cycles (13%) or between populations (21%). The repartitioning of variation from within populations (96% in progenitors) to between populations (58% in Cycle 15) over time is consistent with theoretical expectations of divergence between the populations. By sampling intermediate time points, we gained a comprehensive genetic view of CB and SS permitting evaluation of the molecular-level changes occurring as a result of reciprocal Recurrent Selection.
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responses to seven methods of Recurrent Selection in the bs11 maize population
Crop Science, 1998Co-Authors: Roger A Weyhrich, Kendall R. Lamkey, Arnel R. HallauerAbstract:methods include these three phases, they vary in types of progenies evaluated (i.e., inbred, full-sib, half-sib, Recurrent Selection methods have been effectively used by maize etc.); number of progenies evaluated; number of se(Zea mays L.) breeders to improve the performance of maize populations for quantitatively inherited traits. Although theoretical compari- lected families (i.e., 5, 10, 20, 30, etc.); parental control; sons of such methods can be easily made, direct comparisons of the and the type of progenies intermated. It is this flexibility efficiencies of methods are time consuming and laborious. Because in the different types of methods and different parameof these limitations, empirical data comparing multiple Recurrent se- ters that has led to the utilization of a wide range of lection methods in the same base population are lacking for maize. Recurrent Selection methods for population improveOur study was designed to compare the response to Selection for ment with an equally wide range of responses. Even seven different methods (six intra- and one inter-population) in the with the diversity of Recurrent Selection methods, two BS11 maize population. A minimum of four cycles of Selection were goals remain common throughout, increasing the mean conducted for each of the following methods: mass, modified ear-toperformance of the population and maintaining the gerow, half-sib with inbred tester, full-sib, S1-progeny, S2-progeny, and netic variability in the population to facilitate long-term reciprocal full-sib Selection. Selections for all programs except mass and reciprocal full-sib were based on an index composed of grain Selection. The focus of our study was to improve the yield, grain moisture, stalk lodging, and root lodging. Each trait in mean performance of a single population with respect the Selection index was weighted according to its heritability. The to four important agronomic traits via seven different populations per se, populations selfed, and testcrosses of the popula- Recurrent Selection methods. tions to the Cycle 0 population and to inbred B79 were evaluated in Grain yield has historically been the most important our study. Response to Selection was measured for grain yield, grain trait and the trait most frequently used for Selection moisture, stalk lodging, and root lodging along with other agronomic in maize population improvement. Recurrent Selection traits. All Selection methods were successful in significantly improving methods have not been widely adopted by maize breedthe population per se performance for grain yield. S2-progeny Selection ers, although they have been effective for increasing
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Responses to Reciprocal Recurrent Selection in BSSS and BSCB1 Maize Populations
Crop Science, 1993Co-Authors: Vichien Keeratinijakal, Kendall R. LamkeyAbstract:Improvement of germplasm as a parental source for developing inbreds has been an important part of most maize (Zea mays L.) breeding programs. Reciprocal Recurrent Selection is a cyclical breeding procedure designed to improve the interpopulation cross of two base populations. The objective of this study was to evaluate the direct and indirect responses of 11 cycles of reciprocal Recurrent Selection in the BSSS(R) (Iowa Stiff Stalk Synthetic) and BSCB1(R) (Iowa Corn Borer Synthethic no. 1) maize populations (.)
C O Gardner - One of the best experts on this subject based on the ideXlab platform.
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Recurrent Selection for population variety and hybrid improvement in tropical maize
Advances in Agronomy, 1992Co-Authors: S Pandey, C O GardnerAbstract:Publisher Summary The objectives of this chapter is to discuss tropical maize germplasm and environments in which maize is grown, provide information on Recurrent Selection systems, and how they are applied by the breeder; review maize population improvement work in national programs in tropical regions, highlight Recurrent Selection work of the international center for maize, and wheat improvement; and relate population improvement work to hybrid programs for the tropics. It is recognized that maize production practices in the tropics are generally poor. Improved production practices are bound to contribute more to increased yields initially, but as production practices improve, greater breeding effort is required to increase yields and adapt materials to improved practices. Yield potential of tropical maize should be increased by improving grain production efficiency, measured in time and space. Selection for desirable morphological traits, higher harvest index, reduced ASI, increased efficiency of nutrient uptake and utilization, improved stress tolerances, and superior quality traits should all be emphasized in the tropics.
Bhalang Suriharn - One of the best experts on this subject based on the ideXlab platform.
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Recurrent Selection method for improvement of lutein and zeaxanthin in orange waxy corn populations
Australian Journal of Crop Science, 2019Co-Authors: Watanyoo Khamkoh, Danupol Ketthaisong, Khomsorn Lomthaisong, Kamol Lertrat, Bhalang SuriharnAbstract:The information on the responses to simple Recurrent Selection for yield and total carotenoid content in orange waxy corn is lacking. The objectives were to evaluate the responses to simple Recurrent Selection for two cycles for yield and carotenoids of orange waxy corn population and to investigate the correlations between color parameter with carotenoids in waxy corn kernels. Parental sources of germplasm with differences in kernel colors and levels of disease resistance were used for generation of a base population of orange waxy corn. A simple Recurrent Selection for superior phenotypes was practiced on this population for two Selection cycles. Cycle 0 (C0), C1 and C2 were evaluated for two locations in 2016. The cycles showed significant differences for most traits except for plant height. The locations contributed to large portions of total variation in total yield, whereas Selection cycle contributed to large portions of total variations in lutein, zeaxanthin, beta-carotene and total carotenoid content and color parameter (ho), indicating that Selection for carotenoids would be possible. Simple Recurrent Selection for two cycles increased total yield and husked ear weight of 23.2% and 15.0%, respectively. Simple Recurrent Selection for two cycles also increased lutein, zeaxanthin, beta-carotene and total carotenoid content with increasing percentages ranging from 18.5 to 196.6%. The results indicated that population improvement by simple Recurrent Selection could be useful in increasing these traits. Color parameter at immature stage and dry stage was negatively and significantly correlated with lutein, zeaxanthin, beta-carotene and total carotenoid content, indicating that color parameter can be used as an indirect Selection criterion for these traits.
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Recurrent Selection method for improvement of lutein and zeaxanthin in orange waxy corn populations
APRIL 2019, 2019Co-Authors: Watanyoo Khamkoh, Danupol Ketthaisong, Khomsorn Lomthaisong, Kamol Lertrat, Bhalang SuriharnAbstract:The information on the responses to simple Recurrent Selection for yield and total carotenoid content in orange waxy corn is lacking. The objectives were to evaluate the responses to simple Recurrent Selection for two cycles for yield and carotenoids of orange waxy corn population and to investigate the correlations between color parameter with carotenoids in waxy corn kernels. Parental sources of germplasm with differences in kernel colors and levels of disease resistance were used for generation of a base population of orange waxy corn. A simple Recurrent Selection for superior phenotypes was practiced on this population for two Selection cycles. Cycle 0 (C0), C1 and C2 were evaluated for two locations in 2016. The cycles showed significant differences for most traits except for plant height. The locations contributed to large portions of total variation in total yield, whereas Selection cycle contributed to large portions of total variations in lutein, zeaxanthin, β-carotene and total carotenoid content and color parameter (ho), indicating that Selection for carotenoids would be possible. Simple Recurrent Selection for two cycles increased total yield and husked ear weight of 23.2% and 15.0%, respectively. Simple Recurrent Selection for two cycles also increased lutein, zeaxanthin, β-carotene and total carotenoid content with increasing percentages ranging from 18.5 to 196.6%. The results indicated that population improvement by simple Recurrent Selection could be useful in increasing these traits. Color parameter at immature stage and dry stage was negatively and significantly correlated with lutein, zeaxanthin, β-carotene and total carotenoid content, indicating that color parameter can be used as an indirect Selection criterion for these traits.
Freddy Mora - One of the best experts on this subject based on the ideXlab platform.
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Heterozygosity following half-sib Recurrent Selection in popcorn using isoenzyme markers
Electronic Journal of Biotechnology, 2008Co-Authors: Liz Kazmirczak Pereira, Carlos Alberto Scapim, Claudete Aparecida Mangolin, Maria De Fatima Pires Da Silva Machado, Cleso Antonio Patto Pacheco, Freddy MoraAbstract:DOI: 10.2225/vol11-issue1-fulltext-2 RESEARCH ARTICLE Heterozygosity following half-sib Recurrent Selection in popcorn using isoenzyme marker
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Heterozygosity following half-sib Recurrent Selection in popcorn using isoenzyme markers
Electronic Journal of Biotechnology, 2008Co-Authors: Liz Kazmirczak Pereira, Carlos Alberto Scapim, Claudete Aparecida Mangolin, Maria De Fátima Pires Da Silva Machado, Cleso Antônio Patto Pacheco, Freddy MoraAbstract:Isozyme biochemical marker may be useful tool for genomic analysis of maize populations undergoing Recurrent Selection. Thus, isozymes markers was utilized for assess the changes in the genetic variability and distance in a Brazilian composite population of popcorn following four cycles of Recurrent Selection for yield. One hundred and ninety-six half-sib families were evaluated from each cycle and the ten highest-yielding families (5.2%) were recombined to produce the next cycle. Isozyme analysis considered 80 seedlings per cycle. Simple linear regression equations were estimated among the allele frequencies in each locus in function of the Selection cycles, the genetic distances among the cycles and the average heterozygosity per locus for each cycle. Regression analysis did not reveal any common trend for changes in allele frequencies presumably due to Selection. The estimates of the number of polymorphic locus, of the mean of allele per locus and the mean heterozygosity did not reveal any reduction in variability. It was concluded that four Selection cycles did not cause relevant changes in the variability or genetic distance among the Selection cycles of CMS-43 popcorn population. Isozymes markers analysis showed that the number of recombined half-sib families in Recurrent Selection was suitable.