Analysis Of Morphological Characteristics And Chilling Tolerance Differences Between Dark Green And Wild Type Plants Of Anthurium Andraeanum 'Sonate'

Anthurium andraeanum Lind,is one of the most popular tropical evergreen perennial flowers because of its brilliant color and fantastic spathe shape.But anthurium germplasm relatively scarce in our country,and few cultivars were bred.A dark green mutant in A.andraeanum 'Sonate'was obtained in in vitro culture in our lab,which may be a new germplasm.The morphology of wild type and dark green type plants was characterized and the differences of chilling tolerance of the two kinds of plants were investigated.The results showed as followings:1.Comparing to the wild type A.andraeanum,the dark green mutant showed a significant differences in the morphology.The leaf width,leaf length,petiole width,spadix width and spadix width were decreased.While the pedicel length and stomatal density were increased.The color on the petiole and stalk of the mutants was changed from green to red,and the spathe is scarlet in color.Futhermore,anthocyanin contents of blades and spathe in dark green type are higher than wild type,rising to 189.8%,144.94%respectively.Meanwhile,anthocyanin contents of petiole and pedicel in dark green type showed 5.20 and 3.72 folds increasing than wild type.2.After 12 day treatment under 14?,dark green mutant did not show obvious symptoms of chilling injure,while wild-type had been injured significantly by chilling since the 6th day.During chilling stress,higher water content in the leaf of the dark green type was observed.3.With the extension of low temperature treatment time,in dark green type,the activity of CAT enzyme firstly increased and then decreased,the activity of SOD had a rising trend for the previous 6 day,and became relatively stable.While in wild type plants,CAT and SOD activity showed a 'decrease-increase-decrease' curve.In addition,activity of POD,content of proline and soluble sugar in the two types of plants increased at the beginning and then decreased,except that the dark green type accumulated more proline and sugar.Dark green and wild type plants accumulated soluble protein at a similar rate under chilling stress.After12 d of chilling treatment and then rewarmed to 25?,dark green type recovered faster from the low temperature injure than the wild type.Our results suggested that dark green plants presented higher tolerance to chilling because they had higher activities of defense enzymes,higher contents of soluble sugar and proline,and suffered less membrane damage under chilling stress.The mechanism of chilling tolerance of dark green type needs to be explored in future study.