In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam （Ruditapes philippinarum）, crosses between two full-sib families including self and reciprocal cross...In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam （Ruditapes philippinarum）, crosses between two full-sib families including self and reciprocal crosses were carried out. The effects of heterosis, combining ability and interaction on the growth of shell length were estimated. The results showed that the growth of hybrid larvae was intermediate between parents on days 6 and 9. Heterosis on shell length was observed, which varied at juvenile stage. The cross of ♂A×♀B （Hp varied between 10.41% and 68.27%） displayed larger heterosis than ♂A×♀B （Hp varied between 1.89% and 32.33%） did, suggesting that ♂A×♀B was an ideal hatchery method of improving the growth performance of Manila clam. The variances of general combining ability （GCA）, special combining ability （SCA） and interaction （I） were significant in shell length （P〈 0.05）, indicating that both additive and non-additive genetic factors were important contributors to the growth of larvae and juveniles. The GCA for shell length of ♂A×♀B was higher than that of ♂A×♀B at both larval and juvenile stages. This con- firmed that the cross between ♂A and ♀B showed great growth in shell length. In summary, the growth of Manila clam seeds could be improved by hybridizing selected parents from large numbers of full-sib families.展开更多
Five varieties of durum wheat were crossed in full diallel fashion through 2010/2011 growing season. The five parents and their 20 F1 progenies were grown in 2011/2012 at the farm of faculty of agricultural and forest...Five varieties of durum wheat were crossed in full diallel fashion through 2010/2011 growing season. The five parents and their 20 F1 progenies were grown in 2011/2012 at the farm of faculty of agricultural and forestry, Duhok university, Iraq, using randomize complete block design with three replications to estimate heterosis, heritability and some genetic parameters for yield and its components. The results showed highly significant difference among genotypes for all studied traits. The parent Um Raby-5 had a positive general combining ability effect for most traits including grain yield. The crosses （Kokorete71× LD - 357E）, （Crezo × Um Rahy-5）, （Cimeto×Um Raby-5）, （Cimeto×crezo） and （Cimeto × Kokorete 71） exhibited significant desirable specific combining ability effect for most traits. The dominance was greater than additive almost traits. Heritability inbroad sense was high but heritability in narrow sense was low. The expected genetic advance as percent of traits mean was low for all traits. Most crosses showed significant positive heterosis for most traits and two crosses, （Crezo Cimeto） and （Cimeto Urn Raby-5） had the highest positive heterosis for the most studied traits including grain yield.展开更多
基金supported by the earmarked fund for Modern Agro-industry Technology Research System (CARS-48)grants from the ‘863’ Project of China (2012AA10AA400)
文摘In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam （Ruditapes philippinarum）, crosses between two full-sib families including self and reciprocal crosses were carried out. The effects of heterosis, combining ability and interaction on the growth of shell length were estimated. The results showed that the growth of hybrid larvae was intermediate between parents on days 6 and 9. Heterosis on shell length was observed, which varied at juvenile stage. The cross of ♂A×♀B （Hp varied between 10.41% and 68.27%） displayed larger heterosis than ♂A×♀B （Hp varied between 1.89% and 32.33%） did, suggesting that ♂A×♀B was an ideal hatchery method of improving the growth performance of Manila clam. The variances of general combining ability （GCA）, special combining ability （SCA） and interaction （I） were significant in shell length （P〈 0.05）, indicating that both additive and non-additive genetic factors were important contributors to the growth of larvae and juveniles. The GCA for shell length of ♂A×♀B was higher than that of ♂A×♀B at both larval and juvenile stages. This con- firmed that the cross between ♂A and ♀B showed great growth in shell length. In summary, the growth of Manila clam seeds could be improved by hybridizing selected parents from large numbers of full-sib families.
文摘Five varieties of durum wheat were crossed in full diallel fashion through 2010/2011 growing season. The five parents and their 20 F1 progenies were grown in 2011/2012 at the farm of faculty of agricultural and forestry, Duhok university, Iraq, using randomize complete block design with three replications to estimate heterosis, heritability and some genetic parameters for yield and its components. The results showed highly significant difference among genotypes for all studied traits. The parent Um Raby-5 had a positive general combining ability effect for most traits including grain yield. The crosses （Kokorete71× LD - 357E）, （Crezo × Um Rahy-5）, （Cimeto×Um Raby-5）, （Cimeto×crezo） and （Cimeto × Kokorete 71） exhibited significant desirable specific combining ability effect for most traits. The dominance was greater than additive almost traits. Heritability inbroad sense was high but heritability in narrow sense was low. The expected genetic advance as percent of traits mean was low for all traits. Most crosses showed significant positive heterosis for most traits and two crosses, （Crezo Cimeto） and （Cimeto Urn Raby-5） had the highest positive heterosis for the most studied traits including grain yield.
