Identification and Analysis on True or False Hybrids from Hybridization Populations of Litchi( Litchi chinensis Sonn.) Using EST-SSR Markers

In order to better distinguish true hybrids in litchi crossbreeding,F1generations of two litchi hybridized combinations namely that‘Xuehuaizi’בGuiwei’and‘Xuehuaizi’בJiaohesanyuehong’were used as materials to identify true hybrids,to construct mapping populations and to study the genetic diversities of the two populations with EST-SSR markers.The results showed that F1generations of the two hybrid populations could be identified with an identification rate of100%by the combination of four pair primers,respectively,and the 159 individual plants of the two populations were true hybrids.In addition,variations were exited in leaf morphology of the progenies of the two populations and bands of parents absented were occurred on genotype.The clustering analysis showed that 113 F1plants from the hybridized combination of‘Xuehuaizi’בGuiwei’were clustered into six categories（similarity coefficient was 0.68）,and 63.72%（72 plants）of which clustered into one group with male parent.The genetic distances between 32 plants（28.3%）and their parents were far which indicated that larger variation or recombinant appeared in these plants.Forty six hybrid progenies of the combination of‘Xuehuaizi’בJiaohesanyuehong’were divided into two categories when the similarity coefficient was 0.642 and most individual plants（60.87%）showed closer genetic relationship with female parent and partial maternal genetic tendency.It is concluded that EST-SSR markers are suitable to identify true hybrids of litchi.The construction of the two F1mapping populations has established basis for further genetic linkage mapping,meanwhile,has accumulated materials for cultivar improvement of litchi.

Bufo gargarizans:What’s in a Name?

The taxonomic status of Bufo species in East Asia,particularly those closely related to B.gargarizans,has been controversial for over half a century,and recent molecular studies further fueled the dispute.Whether B.andrewsi,B.bankorensis,B.minshanicus,B.sachalinensis,B.tibetanus,and B.tuberculatus constitute valid species or are geographic or ecological variants of B.gargarizans is at the centre of the discussion.Most of these forms possess morphological diagnostic traits,but those differences are minimal and often inconsistent.Molecular data produced many contradictory patterns.Lack of clear diagnostic characters,different usage or definition of various names,mis-identified specimens,limited amount of data or samples,and frequent inter-specific hybridization may all have contributed to the current controversies.Some contradiction may also result from differences between similarity-based clustering and gene tree-based branching patterns.Nevertheless,a dominant allopatric differentiation pattern within this species complex is apparent,and several regional population groups have been identified.Some of the groups resemble old names(e.g.B.minshanicus,B.tibetanus),while others are new.These groups may represent geographic or ecological variants,incipient species,or valid species,and the current data do not warrant a convincing taxonomic revision.To move forward,a single study with comprehensive sampling and genomic data is needed to establish a solid framework,which will define naturally existing population clusters/lineages,and detect their levels of divergence and approximate geographic boundaries.Morphological and ecological examination will follow to understand their biology,determine their taxonomic status,and identify consistent diagnostic characters if necessary.

Relationship between hypertriglyceridemic-waist phenotype and clustering of cardiovascular risk factors in middle and aged population

Objective To explore the relationship between hypertriglyceridemic-waist(HTWC)phenotype and clustering of cardiovascular risk factors in middle and aged population.Methods A community-based cross-sectional survey was conducted in 5 communities of Chengdu city from 2013-10 to 2014-05 and 1004 subjects from(40-79)years of age were investigated.HTWC was de-