Chinese semi-winter rapeseed,genetically differing from winter and spring rapeseed,has been considered to possess strong potential as parent in winter and spring rapeseed hybrid breeding programs. However,no detailed ...Chinese semi-winter rapeseed,genetically differing from winter and spring rapeseed,has been considered to possess strong potential as parent in winter and spring rapeseed hybrid breeding programs. However,no detailed researches have been documented whether winter and spring rapeseed lines have potential for Chinese semiwinter rapeseed hybrid breeding. The objectives of this study are to estimate the potential of winter and spring rapeseed for semi-winter rapeseed hybrid breeding,and to investigate the association of general combining ability(GCA) with adaptation of parental lines by combining with the data in our previous studies. Four winter and four spring male sterile lines were crossed with 14 Chinese semi-winter rapeseed lines to develop 112 hybrids,which were evaluated together with their parents for seed yield under three environments in China. The exotic parental lines were not adapted to local environment as demonstrated by late flowering,low seed weight and poor seed yield per se. However,the hybrids,especially derived from winter rapeseed exhibited strong heterosis for seed yield,indicating that winter rapeseed germplasm has a great potential for rapeseed hybrid breeding in China. Our data suggested a strong association of GCA with their adaptation ability of parental lines,since high to middle correlations were found for local parental lines and low correlations for exotic parental lines under spring,winter and semi-winter eco-growth environments. The hybrid breeding program using exotic germplasm in rapeseed was discussed.展开更多
Hybrid speciation is increasingly recognized as a mechanism for novel evolutionary trajectories. However, we know very little about the ecology of a contact zone that has arisen in sympatry. This study examines the fo...Hybrid speciation is increasingly recognized as a mechanism for novel evolutionary trajectories. However, we know very little about the ecology of a contact zone that has arisen in sympatry. This study examines the foraging behavior and fitness of two species of Darwin＇s tree finches （Camarhynchus parvulus, C pauper） and hybrid offspring on Floreana Island. Previous study showed that the percentage of hybrids in the tree finch population increased from 19% in 2005 to 41% in 2010, and their body and beak size increased by -5% （parental phenotype did not change）. In 2005-2006, all three tree finch groups （two paren- tal species and hybrid birds） used the same foraging substrate, technique, and height. By 2010-2013, the small tree finch C. par- vulus had changed its foraging technique and the medium tree finch C. pauper had changed its foraging height. Both parental species had higher body condition when foraging at （divergent） mean foraging heights per species but hybrid birds did not. We discuss the implications of conserving forest to facilitate vertical niche expansion and the role of hybridization for genetic persis- tence [Current Zoology 61 （1）： 181-190, 2015].展开更多
基金Forschungs-und Entwicklungsfonds RapsGrants from the Fundamental Research Funds for the Central Universities to Qian wei+1 种基金National Natural Science Foundation of China(No.31171585)Chongqing Science&Technology Commission(No.201180001)
文摘Chinese semi-winter rapeseed,genetically differing from winter and spring rapeseed,has been considered to possess strong potential as parent in winter and spring rapeseed hybrid breeding programs. However,no detailed researches have been documented whether winter and spring rapeseed lines have potential for Chinese semiwinter rapeseed hybrid breeding. The objectives of this study are to estimate the potential of winter and spring rapeseed for semi-winter rapeseed hybrid breeding,and to investigate the association of general combining ability(GCA) with adaptation of parental lines by combining with the data in our previous studies. Four winter and four spring male sterile lines were crossed with 14 Chinese semi-winter rapeseed lines to develop 112 hybrids,which were evaluated together with their parents for seed yield under three environments in China. The exotic parental lines were not adapted to local environment as demonstrated by late flowering,low seed weight and poor seed yield per se. However,the hybrids,especially derived from winter rapeseed exhibited strong heterosis for seed yield,indicating that winter rapeseed germplasm has a great potential for rapeseed hybrid breeding in China. Our data suggested a strong association of GCA with their adaptation ability of parental lines,since high to middle correlations were found for local parental lines and low correlations for exotic parental lines under spring,winter and semi-winter eco-growth environments. The hybrid breeding program using exotic germplasm in rapeseed was discussed.
文摘Hybrid speciation is increasingly recognized as a mechanism for novel evolutionary trajectories. However, we know very little about the ecology of a contact zone that has arisen in sympatry. This study examines the foraging behavior and fitness of two species of Darwin＇s tree finches （Camarhynchus parvulus, C pauper） and hybrid offspring on Floreana Island. Previous study showed that the percentage of hybrids in the tree finch population increased from 19% in 2005 to 41% in 2010, and their body and beak size increased by -5% （parental phenotype did not change）. In 2005-2006, all three tree finch groups （two paren- tal species and hybrid birds） used the same foraging substrate, technique, and height. By 2010-2013, the small tree finch C. par- vulus had changed its foraging technique and the medium tree finch C. pauper had changed its foraging height. Both parental species had higher body condition when foraging at （divergent） mean foraging heights per species but hybrid birds did not. We discuss the implications of conserving forest to facilitate vertical niche expansion and the role of hybridization for genetic persis- tence [Current Zoology 61 （1）： 181-190, 2015].
