The Inheritance Of Fruits Trait In Pear Crossing Progenies And The Fruit Traits’ Difference Between Wilds And Cultivars

In order to investigate the inheritance of pear fruit traits,this study measured single fruit weight,longitudinal diameter,transverse diameter,fruit shape index,soluble solid content and stone cell content using the reciprocal crossing populations ’Dangshansuli’ and’Housui’ and crossing population ’Niitaka’×’Hongxiangsu’.Also,this study compared the fruit traits’ difference between wilds and cultivars in Pyrus pyrifolia and Pyrus ussuriensis.The results provided solid foundation for guiding the selecting of pear crossing parents,genetic improvement of fruit traits and research of fruit domestication.1.This study analyzed the inheritance of soluble sugar and organic acid in pear fruit using the reciprocal crossing populations ’Dangshansuli’ and ’Housui’ over two successive years.The results showed that the content of most individual acids and sugars,total acid and total sugar content were higher than that of ’Dangshansuli’ and lower than that of’Housui’,trending to an average between the parents.’The content of oxalate,quinatc,malate,shikimate,and total acid in progenies were higher when ’Housui’ was the maternal parent,suggesting that the selection of the maternal parent during the breeding process has important effects on the acid content.Conversely,individual and total sugar content did not show significant effects of the maternal parent.In addition,glucose content in progenies showed the increasing trend and sorbitol content showing the transgressive inheritance trait.The correlations for total sugar and total acid of the two populations between two years were significant and positive,showing stable content of sugar and acid.Significant and positive correlations were also found between different components,including oxalate and malate,shikimate and quinate,and citrate and shikimate.This study measured single fruit weight,longitudinal diameter,transverse diameter,fruit shape index,soluble solid content and stone cell content.The results showed that single fruit weight,longitudinal and transverse diameter of ’Dangshansuli’ and ’Housui’progenies had a decreasing trend,of which single fruit weight was a quantitative trait inheritance controlled by polygene.Fruit shape index,which was affected greatly by its parents,had a high genetic heritability.Soluble solids content was a quantitative trait inheritance and controlled obviously by additive genes,many transgressive individuals arose as well.Stone cell content of progeny fruit had a close relationship with its parents,trending to an average between the parents.2.This study measured single fruit weight,longitudinal diameter,transverse diameter,fruit shape index,fruit shape,soluble solid content and stone cell content based on 197 progenies of crossing population ’Niitaka’×’Hongxiangsu’.The results showed that single fruit weight,longitudinal and transverse diameter of progenies had a decreasing trend.Single fruit weight was a quantitative trait inheritance controlled by polygene.The majority fruit shape were roundness and fusiform.Parents made important impact of progenies’fruit shape.Fruit shape index trend to an average between the parents.The genetic heritabilities of soluble solid content were high.Much progenies showed transgressive inheritance on soluble solid content.Stone cell content of progenies showed skewed normal distribution.Most progenies with stone cell content between two parents.4.This study compared the difference of fruit traits between wilds and cultivars in various growth periods,including single fruit weight,longitudinal diameter,transverse diameter,soluble sugar,organic acid and stone cell content were measured in all breeds.The results suggested that:single fruit weight,longitudinal diameter and transverse diameter of cultivars increased more fastly than wild breeds during fruit growing.Stone cell content in mature fruits of all breeds was significant lower than immature fruits.It in wilds was significant higher than in cultivars in mature fruits.Soluble sugar content increased as the fruit grow.Fructose content in cultivar breeds were all higher than in wild breeds in different growth periods.Organic acid content decresed as the fruit grow.Malate,quinimate and citrate content in cultivars were lower than in wilds.In mature fruits of Pyrus ussuriensis,polyphenols content in wilds were signigicant higher than in cultivars.Cultivars were come from wilds though selection and domestication.