| The chrysanthemum morifolium ‘Jinba’ was used in this study. The stem tip of ‘Jinba’was treated with ethyl methane sulfonate which is a chemical mutagen. The objective of theexperiment was to build chrysanthemum mutant library, survey the character of thephenotypic and screen the photoperiod-insensitivity mutants. The photoperiod-insensitivitymutants were verified by molecular markers and their photosynthetic characteristics, whilethe stomas and vascular bundles were analyzed. The results showed as follows:1. Constructure of the mutant library of chrysanthemumSince plant height, leaf, flowering and floral organ mutants were acquired, thechrysanthemum mutant library was constructed successfully. The variable types were rich andthe rate of visible phenotypic mutation was6.31%.(1) Plant height mutants. The average height of control plants was108.21cm while those ofmutant plants were18.81cm. Among these mutant plants, the highest plant reached58.3cmand the lowest was8.0cm.(2) Leaf mutants. There were64plants’ leaves treated with EMS that were different fromthose of controls. The rate of leaves mutation was1.45%. Several types were as follows:Leaf shape mutants. The shape of the controlled leaves was nearly ovate. Among thesemutation types, we found lanceolate leaves, nearly rotund leaves and asymmetric leaves; Thecontrolled leaf margin was serrate. Among these mutation types, entire, dentate and sinuousmargin were found; The crack of the controlled leaf had2symmetrical deep chasms. In thismutant library, we found mutants with one pair of deep chasm, lobed chasm and no chasm;The opex of the controlled leaf was acuminate, just the opposite, mutants were acute, obtuse,truncate and retuse; The base of the controlled leaf was cordate, but we found auriculate,cuneate, oblique and rounded leaves in these mutants; The vein of the controlled leaf wasclear and obvious and the major vein was a straight line located in the middle of the leaf. In this study, some leaf shape mutants whose main veins on one side of leaves were observed.Leaf color mutants. There were3kinds of mutants. The first kind, the leaf base wasyellow, and the color became weak gradually from the main vein to the leaf margin. Thesecond kind, the leaf was yellow, but the leaf vein was green. The third kind, the yellow spotunevenly scattered in the leaf surface.(3) Florescence mutants. We found159florescence mutants and the mutation frequency was3.59%. The earliest flower bud came into being on June5, and entered into the stage of fullblooming on July18, about89days earlier than the controls.(4) In this mutant library,233flower organ mutants were found and the mutation frequencywas5.27%. Mutation types included as follows:Flower bud mutants. Compared with the controlled, the flower bud mutants presentedcylinder, obconical and round sphere; The flower bud color mutants were purple or chartreuse;Some bud abortion mutants were found.Involucre mutants. The outer involucres were like leaves. Two rounds of the adjacentinvolucres separated from each other and formed a large cavity. The outer involucres werecoated with white redfiliform. Something looked like white, transparent and mucous coveredthe involucre.Inflorescence mutants. The first, the involucres appeared on the inflorescence plate. Thesecond, the involucres were dysplasia or deficiency, with the result that a pat of theinflorescence or all the inflorescence exposed outside. The last, lingulate flowers and tubularflowers were missing.Lingulate flower mutants. The lingulate flower became small, wide or tubular. The foliarbud or flower bud appeared in the lingulate flower.2. Molecular identification and related characteristics’ research of the photoperiod-insensitivity mutants in chrysanthemumMolecular identification and related characteristics’ research of the photoperiod-insensitivity mutants. The results show as follows: The florescence of mutants was about59days earlier than that of controls; the plant height, leaves and flower diameter were all smallercompared with those of controls, but the mutants grow well; From the PCR amplification, thedifference between the mutants and the contrasts was in the increase or lack of the amplified fragment; The photosynthetic characteristics, such as the net photosynthetic rate (Pn),stomatal conductance (Gs), transpiration rate (Tr) and intercellular CO2concentration are allsignificantly lower than the contrasts with a significant difference; The number of mutant’sstomata significantly reduces, and some appear variation; The variation of vascular bundlesdisplays different in the size and shape of the vascular bundles, the shape of the catheter, thesize of the primary phloem and primary xylem. |
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