The Effect Of Seed Traits On Germination Of Common Plants In An Alpine Meadow On The Northeastern Qing-Hai Tibet Plateau

In this study,the relationship between seed germination characteristics and seed shape(the three-dimension variance of length,width and height),volume,density or surface/volume ratio were studied.We revealed the influence of seed shape and size on seed germination and spread,and provided theoretical basis for the formation mechanism of soil seed bank.The results showed:(1)Seed germination percentage and germination rate decreased significantly,mean germination time significantly prolonged with the increase of seed volume;germination rate decreased significantly,mean germination time significantly delayed with the enlargement of seed density.(2)The seed germination percentage and germination rate were both significantly positively correlated with the variance of seed three-dimensional,but the variance of seed three-dimensional weren't significantly correlated with mean germination time,there was a trend that flat and elongated seeds had higher germination percentage and rate.(3)Seed germination percentage and germination rate decreased significantly,mean germination time significantly postponed with the increase of seed surface/volume ratio.Seed surface/volume ratio represents the contact surface of seed with the environment,the small seed had a larger surface/volume ratio,could to get enough water in a relatively short time,oxygen and other conditions of germination,this one of the reasons that seeds had higher germination percentage and rate.(4)Each character of seed had a significant effect on seed germination characteristics of interaction,the correlation between the germination characteristics and seed shape still significant which eliminated the seed mass,volume,surface/volume ratio.The correlation between germination characteristics and other traits have increased after eliminating the effect of seed shape,the effects of seed shape on the seed germination characteristics had an independent effect,the influence of other seed traits on seed germination had more limited to the seed shape.(5)We founded the rules by the division of species in five family of widely distributed,seeds germination characteristics and seed traits almost had no significant correlation of Poaceae and Fabaceae;the germination percentage and germination rate were both significantly negatively correlated with the seed mass and shape,significantly positively correlated with surface/volume ratio,but not significantly correlated between mean germination time with seed traits of Asteraceae;the germination percentage was significantly positively correlated with the seed shape,mean germination time was significantly positively correlated with the seed shape and seed mass of Scrophulariaceae;the mean germination time was significantly positively correlated with the seed shape and mass,but significantly positively correlated with surface/volume ratio,the germination percentage and germination rate were both no significantly correlated with the seed traits of Apiaceae.Thus,there is no common regularity between the seed traits and the seed germination characteristics in species of different family,which could were affected by phylogenetic.Therefore,seed germination characteristics and seed traits had a certain synergy evolution,but the correlation between them could subjected by the phylogenetic and other environmental conditions,further research and analysis were needed.