Construction of a strawberry breeding core collection to capture and exploit genetic variation.

BACKGROUND: Genetic diversity is crucial for the success of plant breeding programs and core collections are important resources to capture this diversity. Many core collections have already been constructed by gene banks, whose main goal is to obtain a panel of a limited number of genotypes to simplify management practices and to improve shareability while retaining as much diversity as possible. However, as gene banks have a different composition and goal than plant breeding programs, constructing a core collection for a plant breeding program should consider different aspects. RESULTS: In this study, we present a novel approach for constructing a core collection by integrating both genomic and pedigree information to maximize the representation of the breeding germplasm in a minimum subset of genotypes while accounting for future genetic variation within a strawberry breeding program. Our stepwise approach starts with selecting the most important crossing parents of advanced selections and genotypes included for specific traits, to represent also future genetic variation. We then use pedigree-genomic-based relationship coefficients combined with the 'accession to nearest entry' criterion to complement the core collection and maximize its representativeness of the current breeding program. Combined pedigree-genomic-based relationship coefficients allow for accurate relationship estimation without the need to genotype every individual in the breeding program. CONCLUSIONS: This stepwise construction of a core collection in a strawberry breeding program can be applied in other plant breeding programs to construct core collections for various purposes.

Biochemical characterization for determination of genetic distances among different indigenous chickpea (Cicer arietinum L. ) varieties of North-West Pakistan / Caracterização bioquímica para determinação de distâncias genéticas entre diferentes variedades indígenas de grão-de-bico (Cicer arietinum L. ) do noroeste do Paquistão

Abstract Genetic distances among different chickpea varieties and evaluation of their free amino acid profiles were determined on the basis of Sodium dodecyle sulphate polyacrylamide gels electrophoresis (SDS-PAGE). Total soluble proteins were resolved on 10% SDS Polyacrylamide gel. Low variability in tested varieties was observed. Dendogram based on electrophoretic data clustered the genotypes into 2 groups. The results showed that the average protein content of all the varieties was 26.01% within the range 22.8% for Thal-2006 to 34.06% Sheenghar-2000 of dry seed weight. On the basis of total protein content Bittal-98, Dasht and Sheen Ghar-2000, Karak-3 and CM-98, Paidar -91 and Fakhr-e-Thal, C-44, Balaksar and KK-1showed similar concentrations for protein contents among each other but showed variation from the rest of the varieties. Different proteins were separated on the basis of changes in their molecular weights by means of Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE). Dasht, CM-98, and Sheen Ghar showed 100% similarity. Balaksar and Fakhr-e- Thal, KK-2 and Chattan and KC-98, KK-1 and Lawaghar were 100% similar among each other but showed variation from the rest of the accessions. The overall dendrogram showed high and low level of variation among the accessions. The concentration of free amino acids varied among the 16 chickpea varieties. A significant difference of both essential and non-essential amino acids was found among the chickpea cultivars. The total concentration of essential amino acid was recorded 40.81 g/100 g protein while non-essential was recorded 59.18343 g/100 g protein in the given cultivars. The highest concentration of essential amino acids was found in C-44 followed by KK-2, KK-1 and Fakhr E Tal while the lowest concentration was recorded in Cm-98, Paidar-91 and Sheen Ghar-2000 respectively. Cultivars TAL-2006, Chattan and Karak-3 showed maximum concentration of both essential and endogenous amino acids. In conclusion; for broadening the genetic pools in breeding programs or to search for exotic characters, for instance new disease resistance alleles, accession with low similarity coefficients (Lawaghar and Battal-98) may be utilized. Furthermore the information acquired from this study could be used to device a proficient breeding approach intended at improving nutritional as well as broadening the genetic base of this essential food crop of Pakistan.

Resumo As distâncias genéticas entre as diferentes variedades de grão-de-bico e a avaliação de seus perfis de aminoácidos livres foram determinadas com base na eletroforese em gel de poliacrilamida com dodecil sulfato de sódio (SDS-PAGE). As proteínas solúveis totais foram resolvidas em SDS-PAGE a 10%. Foi observada baixa variabilidade nas variedades testadas. O dendrograma fundamentado em dados eletroforéticos agrupou os genótipos em dois grupos. Os resultados mostraram que o teor médio de proteínas de todas as variedades foi de 26,01%, na faixa de 22,8% para Thal-2006 a 34,06% para Sheenghar-2000 do peso de sementes secas. Com base no conteúdo total de proteínas, Bittal-98, Dasht, Sheen Ghar-2000, Karak-3, CM-98, Paidar-91, Fakhr-e-Thal, C-44, Balaksar e KK-1 apresentaram concentrações semelhantes para o conteúdo de proteínas entre si, mas tiveram variação quanto ao restante das variedades. Diferentes proteínas foram separadas com base nas alterações de seus pesos moleculares por meio de eletroforese em gel de poliacrilamida com dodecil sulfato de sódio (SDS-PAGE). Dasht, CM-98 e Sheen Ghar mostraram 100% de similaridade. Balaksar, Fakhr-e-Thal, KK-2, Chattan e KC-98, KK-1 e Lawaghar foram 100% semelhantes entre si, mas apresentaram variação em relação ao restante dos acessos. O dendrograma geral mostrou alto e baixo nível de variação entre os acessos. A concentração de aminoácidos livres variou entre as 16 variedades de grão-de-bico. Foi encontrada uma diferença significativa entre os aminoácidos essenciais e não essenciais nas cultivares de grão-de-bico. A concentração total de aminoácidos essenciais foi registrada em 40,81 g / 100 g de proteína, enquanto a não essencial foi registrada em 59,18343 g / 100 g de proteína nas cultivares. A maior concentração de aminoácidos essenciais foi encontrada em C-44, seguida de KK-2, KK-1 e Fakhr-e-Thal, enquanto a menor concentração foi registrada em CM-98, Paidar-91 e Sheen Ghar-2000. As cultivares TAL-2006, Chattan e Karak-3 apresentaram concentração máxima de aminoácidos essenciais e endógenos. Em conclusão, para ampliar os pools genéticos em programas de melhoramento ou procurar caracteres exóticos, por exemplo, novos alelos de resistência a doenças, pode ser utilizada a adesão com baixos coeficientes de similaridade (Lawaghar e Battal-98). Além disso, as informações adquiridas neste estudo poderiam ser usadas para criar uma abordagem de criação eficiente, com o objetivo de melhorar a nutrição e ampliar a base genética dessa cultura alimentar essencial do Paquistão.

Biochemical characterization for determination of genetic distances among different indigenous chickpea (Cicer arietinum L.) varieties of North-West Pakistan

Abstract Genetic distances among different chickpea varieties and evaluation of their free amino acid profiles were determined on the basis of Sodium dodecyle sulphate polyacrylamide gels electrophoresis (SDS-PAGE). Total soluble proteins were resolved on 10% SDS Polyacrylamide gel. Low variability in tested varieties was observed. Dendogram based on electrophoretic data clustered the genotypes into 2 groups. The results showed that the average protein content of all the varieties was 26.01% within the range 22.8% for Thal-2006 to 34.06% Sheenghar-2000 of dry seed weight. On the basis of total protein content Bittal-98, Dasht and Sheen Ghar-2000, Karak-3 and CM-98, Paidar -91 and Fakhr-e-Thal, C-44, Balaksar and KK-1showed similar concentrations for protein contents among each other but showed variation from the rest of the varieties. Different proteins were separated on the basis of changes in their molecular weights by means of Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE). Dasht, CM-98, and Sheen Ghar showed 100% similarity. Balaksar and Fakhr-e- Thal, KK-2 and Chattan and KC-98, KK-1 and Lawaghar were 100% similar among each other but showed variation from the rest of the accessions. The overall dendrogram showed high and low level of variation among the accessions. The concentration of free amino acids varied among the 16 chickpea varieties. A significant difference of both essential and non-essential amino acids was found among the chickpea cultivars. The total concentration of essential amino acid was recorded 40.81 g/100 g protein while non-essential was recorded 59.18343 g/100 g protein in the given cultivars. The highest concentration of essential amino acids was found in C-44 followed by KK-2, KK-1 and Fakhr E Tal while the lowest concentration was recorded in Cm-98, Paidar-91 and Sheen Ghar-2000 respectively. Cultivars TAL-2006, Chattan and Karak-3 showed maximum concentration of both essential and endogenous amino acids. In conclusion; for broadening the genetic pools in breeding programs or to search for exotic characters, for instance new disease resistance alleles, accession with low similarity coefficients (Lawaghar and Battal-98) may be utilized. Furthermore the information acquired from this study could be used to device a proficient breeding approach intended at improving nutritional as well as broadening the genetic base of this essential food crop of Pakistan.

Resumo As distâncias genéticas entre as diferentes variedades de grão-de-bico e a avaliação de seus perfis de aminoácidos livres foram determinadas com base na eletroforese em gel de poliacrilamida com dodecil sulfato de sódio (SDS-PAGE). As proteínas solúveis totais foram resolvidas em SDS-PAGE a 10%. Foi observada baixa variabilidade nas variedades testadas. O dendrograma fundamentado em dados eletroforéticos agrupou os genótipos em dois grupos. Os resultados mostraram que o teor médio de proteínas de todas as variedades foi de 26,01%, na faixa de 22,8% para Thal-2006 a 34,06% para Sheenghar-2000 do peso de sementes secas. Com base no conteúdo total de proteínas, Bittal-98, Dasht, Sheen Ghar-2000, Karak-3, CM-98, Paidar-91, Fakhr-e-Thal, C-44, Balaksar e KK-1 apresentaram concentrações semelhantes para o conteúdo de proteínas entre si, mas tiveram variação quanto ao restante das variedades. Diferentes proteínas foram separadas com base nas alterações de seus pesos moleculares por meio de eletroforese em gel de poliacrilamida com dodecil sulfato de sódio (SDS-PAGE). Dasht, CM-98 e Sheen Ghar mostraram 100% de similaridade. Balaksar, Fakhr-e-Thal, KK-2, Chattan e KC-98, KK-1 e Lawaghar foram 100% semelhantes entre si, mas apresentaram variação em relação ao restante dos acessos. O dendrograma geral mostrou alto e baixo nível de variação entre os acessos. A concentração de aminoácidos livres variou entre as 16 variedades de grão-de-bico. Foi encontrada uma diferença significativa entre os aminoácidos essenciais e não essenciais nas cultivares de grão-de-bico. A concentração total de aminoácidos essenciais foi registrada em 40,81 g / 100 g de proteína, enquanto a não essencial foi registrada em 59,18343 g / 100 g de proteína nas cultivares. A maior concentração de aminoácidos essenciais foi encontrada em C-44, seguida de KK-2, KK-1 e Fakhr-e-Thal, enquanto a menor concentração foi registrada em CM-98, Paidar-91 e Sheen Ghar-2000. As cultivares TAL-2006, Chattan e Karak-3 apresentaram concentração máxima de aminoácidos essenciais e endógenos. Em conclusão, para ampliar os pools genéticos em programas de melhoramento ou procurar caracteres exóticos, por exemplo, novos alelos de resistência a doenças, pode ser utilizada a adesão com baixos coeficientes de similaridade (Lawaghar e Battal-98). Além disso, as informações adquiridas neste estudo poderiam ser usadas para criar uma abordagem de criação eficiente, com o objetivo de melhorar a nutrição e ampliar a base genética dessa cultura alimentar essencial do Paquistão.