Analysis of Pedigree and Trait Evolution of Peanut Varieties Registered in Fujian Province

In order to provide reference for the breeding of new peanut varieties and introduction of peanut cultivars in Fujian Province, the pedigree and trait evolution of 33 peanut varieties registered （certified, identified） during 1949-2011 in Fujian Province were analyzed. Results showed that, 45 parents were used as parents for peanut breeding, and 22 parents were originated from Fujian Province, 24 parents were registered varieties; Shitouqi, Yueyou 92, Shanyou 523, Quanhua No.10 and Quanhua 327 were milestone parents of peanut varieties in Fujian Province, and the phylogenetic relationship of varieties mainly came from Guangdong. Systematic se- lection was the main breeding method during 1951-1980 in Fujian Province, while crossbreeding became the main method of peanut breeding since 1991. With the variety update of peanuts, the yield levels were constantly increasing. The gradual increase of 100-pod weight and 100-kernel weight played an important role in the improvement of peanut yield. Fat content increased slightly with time, while protein content changed in contrast. Plant height was gradually decreased, and anti-lodging and fertilizer-tolerance capacity was improved, which were suitable for close planting. The total number of branches was decreased slightly, while the number of bearing branches barely changed.

Mitochondrial phylogenomics provides insights into the phylogeny and evolution of spiders(Arthropoda:Araneae)

Spiders are among the most varied terrestrial predators,with highly diverse morphology,ecology,and behavior.Morphological and molecular data have greatly contributed to advances in the phylogeny and evolutionary dynamics of spiders.Here,we performed comprehensive mitochondrial phylogenomics analysis on 78 mitochondrial genomes(mitogenomes)representing 29 families;of these,23 species from eight families were newly generated.Mesothelae retained the same gene arrangement as the arthropod ancestor(Limulus polyphemus),while Opisthothelae showed extensive rearrangement,with 12 rearrangement types in transfer RNAs(tRNAs)and control region.Most spider tRNAs were extremely truncated and lacked typical dihydrouridine or TΨC arms,showing high tRNA structural diversity;in particular,trnS1 exhibited anticodon diversity across the phylogeny.The evolutionary rates of mitochondrial genes were potentially associated with gene rearrangement or truncated tRNAs.Both mitogenomic sequences and rearrangements possessed phylogenetic characteristics,providing a robust backbone for spider phylogeny,as previously reported.The monophyly of suborder,infraorder,retrolateral tibial apophysis clade,and families(except for Pisauridae)was separately supported,and high-level relationships were resolved as(Mesothelae,(Mygalomorphae,(Entelegynae,(Synspermiata,Hypochilidae)))).The phylogenetic positions of several families were also resolved(e.g.,Eresidae,Oecobiidae and Titanoecidae).Two reconstructions of ancestral web type obtained almost identical results,indicating that the common ancestor of spiders likely foraged using a silk-lined burrow.This study,the largest mitochondrial phylogenomics analysis of spiders to date,highlights the usefulness of mitogenomic data not only for providing efficient phylogenetic signals for spider phylogeny,but also for characterizing trait diversification in spider evolution.

Ecological predictors of extinction risks of endemic mammals of China

In this brief report, we analyzed ecological correlates of risk of extinction for mammals endemic to China using phylogenetic eigenvector methods to control for the effect of phylogenetic inertia. Extinction risks were based on the International Union for Conservation of Nature （IUCN） Red List and ecological explanatory attributes that include range size and climatic variables. When the effect of phylogenetic inertia were controlled, climate became the best predictor for quantifying and evaluating extinction risks of endemic mammals in China, accounting for 13% of the total variation. Range size seems to play a trivial role, explaining -1% of total variation; however, when non-phylogenetic variation partitioning analysis was done, the role of range size then explained 7.4% of total variation. Consequently, phylogenetic inertia plays a substantial role in increasing the explanatory power of range size on the extinction risks of mammals endemic to China. Limitations of the present study are discussed, with a focus on under-represented sampling of endemic mammalian species.

Genetically Based Trait Differentiation but Lack of Trade-offs between Stress Tolerance and Performance in Introduced Canada Thistle

Trade-offs between performance and tolerance of abiotic and biotic stress have been proposed to explain both the success of invasive species and frequently observed size differences between native and introduced populations.Canada thistle seeds collected from across the introduced North American and the native European range were grown in benign and stressful conditions(nutrient stress,shading,simulated herbivory,drought,and mowing),to evaluate whether native and introduced individuals differ in performance or stress tolerance.An additional experiment assessed the strength of maternal effects by comparing plants derived from field-collected seeds with those derived from clones grown in the glasshouse.Introduced populations tended to be larger in size,but no trade-off of stress tolerance with performance was detected;introduced populations had either superior performance or equivalent trait values and survivorship in the treatment common gardens.We also detected evidence of parallel latitudinal clines of some traits in both the native and introduced ranges and associations with climate variables in some treatments,consistent with recent climate adaptation within the introduced range.Our results are consistent with rapid adaptation of introduced populations,but,contrary to predictions,the evolution of invasive traits did not come at the cost of reduced stress tolerance.