Study On Germplasm Innovation And Fruit Quality Evaluation Of The Genus Fragaria Species Native To China

Wild strawberry has the characters of rich fruit nutrition,aromatic fruit and strong stress resistant and so on.The wild strawberry resources native to China are very abundant,but lack of effective utilization.The evaluation of fruit traits and quality is the premise of wild strawberry utilization.The fruit traits,quality and aroma components of 76 wild strawberry resources native to China(contained 11 species and 2 gene-types)were evaluat in this study.Six excellent wild strawberry resources were select to perform interspecific hybridization and germplasm innovation with cultivars.This research aims to lay a theoretical foundation for the classification and utilization of wild strawberries.The main results were as follows: The fruit characters and quality of 76 wild strawberries were evaluat.The Fragaria pentaphylla Lozinsk,F.nubicola Lindl and F.moupinensis Card had red-fruited genetype and white-fruited genetype.The oval,long oval,ellipse,spherical,conical,long conical,cylindrical and abnormal fruits were observing from wild strawberries.The fruit aroma of species F.vesca L,F.mandschurica Staudt,F.orientalis Lozinsk and Wild pentaploid genetype were very intensity.The cumulative contribution rate of the first three principal component variants for 12 fruit trait and quality indexs of wild strawberry resources native to China reached 80.52%,which could represent the variation of the 12 indexs.The DPPH vitality,total phenol,ABTS vitality,flavonoids,sugar acid ratio,solid,total sugar,solid acid ratio,vitamin C,anthocyanin and fruit weight contributed significantly to the first principal component(PC1).The composite score of principal component from high to low are F.orientalis Lozinsk,F.mandschurica Staudt,F.vesca L.,F.viridis Duch,Wild pentaploid genetype,F.gracilis Lozinsk,F.corymbosa Lozinsk,F.nubicola Lindl,F.chinensis Lozinsk,F.tibetica Staudt et Dickoré,Gansu genetype,F.moupinensis Card and F.pentaphylla Lozinsk.The results of correlation analysis showed that the fruit weight had little or no correlation with the others indexes;the titrable acid exhibited negative correlation or no correlation with the others indexes;the soluble solid exhibited positive correlation with the others indexes(except fruit weight and titratable acid).The flavonoids,anthocyanins,total phenols,DPPH vitality and ABTS vitality were positively correlating between each other.The aroma components of 76 wild strawberries were measure by GC-MS.The 232 aroma compounds were detecting,including 101 esters,35 alcohols,27 aldehydes,19 acids,17 ketones,15 alkenes and 18 kinds of other aroma substances.Among them,the Gamma-decalactone,Methyl anthranilate,Hexyl acetate,1-octene-3-alcohol,Linalool,Trans-2-hexenal and 4-methoxy-2,5-dimethyl-3(2H)-furanone are the most common characteristic fruit aroma compounds and exist in almost all of wild strawberries.The F.orientalis Lozinsk exhibited most abundant aromatic compounds,which 103 compounds were identify.The aroma content of Wild pentaploid genetype,F.orientalis Lozinsk,F.vesca L and F.mandschurica Staudt were significantly higher than other species.According to cluster analysis the 76 resources could be divide into three categories.The first group included F.viridis Duch,F.pentaphylla Lozinsk,F.gracilis Lozinsk,Gansu genetype,F.moupinensis Card,F.tibetica Staudt et Dickoré,F.nubicola Lindl,F.chinensis Lozinsk,F.pentaphylla f.alba,F.mandschurica Staudt,F.moupinensis f.alba,F.nubicola f.alba,F.corymbosa Lozinsk and F.vesca L;The second group included F.orientalis Lozinsk;The third group included Wild pentaploid genetype.The first group could be clustered 9 subgroups.The subgroups I contained F.viridis;the subgroup II contained F.pentaphylla;the subgroup III contained F.gracilis,Gansu genetype genetype(GS1,GS4,GS5 and GS6),F.moupinensis,F.tibetica,F.nubicola and F.chinensis;the subgroup VI contained F.pentaphylla f.alba;the subgroup?contained F.mandschurica;the subgroup ? contained F.moupinensis f.alba and F.nubicola f.alba;the subgroup ? contained F.corymbosa;the subgroup ? contained F.corymbosa;the subgroup ? contained F.vesca.The hybridization incompatibility was observing in Fragaria.The hybrids could not obtained when wild strawberry(2x,4x and 5x)used as the female parent crossed with cultivars(8x);on the contrary,it was easy to obtain hybrids.Interspecific hybrids exhibited poor fertility,even could not beared fruit.The growth vigour of hybrids often lower than cultivars,just the opposite in cold resistance;the growth vigour and cold resistance of the most interspecific hybrids were between the parents.At the backcross between the dodecploid strawberry interspecific hybrid ‘YH15-10'(12x)and the cultivated varieties(8x),the plant morphology,ferility and fruit size of the hybrids gradually restore to the cultivars,and its cold resistance was improved compared with the cultivated strawberries.By observing the ploidy of hybrids(5x,6x,7x,8x,9x,10 x and 12x)and the ploidy and pollen size of the hybrid parents,speculate that the unreduced gametes might be exist in F.orientalis,Wild pentaploid genetype and cultivar ‘Yuhime',and the incomplete gametes might be exist in Wild pentaploid genetype and ‘YH15-10'.The fruit traits,quality and aroma components of the hybrids of YH15-10×F.orientalis,Allstar×YH15-10,Akihime×YH15-10 and YH15-10×Akihime were evaluat.Some offsprings with heterobeltiosis were obtaining.Among them,17 individuals exhibited(8x and 10x)good fruit quality,especially in soluble solids,vitamin C,total phenol,DPPH vitality and ABTS vitality.Some of the superior individuals such as YO24-10(8x),YO24-13(10x),AY5-113(10x)and YA6-17(10x)exhibited more fruit aroma content and fruit aroma compounds than the than contrast cultivar ‘Sachinoka'.They were integrated the specific aroma compounds Myrtenyl acetate,(-)-Myrtenol and 2-Undecanone of the F.orientalis and Wild pentaploid genetype,and showed unique aroma.They exhibited strong utilization value.