| Chrysanthemum morifolium is a perennial perennial flower of the genus Compositae,which is native to China.Cutting chrysanthemum has many varieties,strong ornamental,profound cultural connotation,and annual sales rank first in the world.Cuttings chrysanthemums'Iwa-no-hakusen'and'Floral Yuka'are popular white chrysanthemum cutting varieties that are popular in the market.They are mainly used for funeral and sacrificial flowers in Korea and Japan.The cultivation area is large.'Jinshan'is a yellow cutting chrysanthemum variety introduced from Japan in recent years.Has great ornamental and economic value.‘Jinshan'is a yellow cutting chrysanthemum cultivars introduced from Japan in recent years.The flower pattern is beautiful and golden,and it has broad market prospects.However,the current seedlings rely on imports,resulting in higher production costs.Therefore,it is of great practical significance to develop novel cultivars of cutting chrysanthemum and use the tissue culture and rapid propagation techniques to breed cutting yellow chrysanthemum'Jinshan'.On the basis of tissue culture and rapid propagation of cutting chrysanthemum,dinitroaniline mutagens?pendimethalin and trifluralin?and colchicine were used to induce the germination of sterile seedlings and stems with axillary buds of'Iwa-no-hakusen'and'Floral Yuka'.Mutant plants with good traits were obtained,and in vitro ploidy mutagenesis system of cutting Chrysanthemum morifolium was established.The study also used the bud stems of cutting chrysanthemum'Jinshan'.The segment is an explant,and a technical system of'Jinshan'tissue culture is established.The main results of this study are as follows:1.The system of in vitro ploidy mutagenesis of cutting chrysanthemum'Iwa-no-hakusen'and'Floral Yuka'was established,and the optimal combination of mutagens was found.Three ploidy breeding mutagens:pendimethalin,trifluralin and colchicine were used,and the combination of impregnation method and tissue culture was used to induce the cutting white chrysanthemum'Iwa-no-hakusen'and'Floral Yuka'.For'Iwa-no-hakusen',the optimum dosage of pendimethalin and trifluralin was200?mol·L-1 for 36 h and 150?mol·L-1 for 36 h,respectively;the optimum dose of colchicine was 0.1%solution for 12 hours,and the mutation rate of trifluralin group was 36.67%.For'Floral Yuka',the optimal doses of pendimethalin and trifluralin were 150?mol·L-1 for 36 h and 200?mol·L-1 for 24 h respectively,and colchicine was 0.05%solution for 12 h,and the mutation rate of trifluralin group was 41.67%.The highest mutation rate,the induction effect of the three reagents:trifluralin>pendimethalin>colchicine.2.The ploidy identification of chromosomes was performed on the primary mutants.The primary mutants of'Iwa-no-hakusen'and'Floral Yuka'were observed and compared with the sterile root tips of the control group.The two cut chrysanthemum chromosomes are all aneuploid based on hexaploid?2n=6x=54?.The number of chromosomes in the primary mutant plants increased significantly,with about 70-80,but no somatic cells with 108 chromosomes were observed.3.Perform vane stomatal observation on the mutant.The stomata of the mutant plants induced by colchicine,pendimethalin and trifluralin showed significant changes,the stomata of the leaves increased significantly,and the stomatal density decreased.The stomata lengths of'Baifan'and'Floral Yuka'mutants treated with dinitroaniline inducer increased by 17.99%and 16.70%,respectively;stomatal width increased by 31.78%and 8.88%,respectively;stomatal density decreased by 4.85%and 50.25,respectively.%.The stomata lengths of the'Iwa-no-hakusen'and'Floral Yuka'mutant plants increased by 21.29%and 32.65%,respectively;the stomata width increased by 18.29%and 24.38%,respectively;the stomatal density decreased by 17.20%and 56.39%,respectively.4.Agronomic traits were observed and compared in the flowering stage of the mutant plants.Three generations of in vitro culture and primary mutant'Iwa-no-hakusen'sterile seedlings were planted into production greenhouses.The agronomic traits of the flowering stage were observed.The agronomic traits of plant height,stem diameter,internode length,leaf length,leaf width,inflorescence diameter and lingual flower number of each mutant were counted.The morphological changes of the mutant plants were obvious,the plant height was significantly decreased,the leaves were significantly increased,the inflorescence diameter was increased but not significant,the number of lingual flowers increased and the morphology changed.Compared with the control group'Iwa-no-hakusen',the plant height and internode length of the primary mutant plants decreased by41.88%and 25.64%,respectively;the stem diameter increased by 24.09%;the leaf length and leaf width increased by 10.07%,respectively.21.23%;the flower diameter increased by 12.25%;the number of ligatures increased by 17.11%.Compared with the control group'Iwa-no-hakusen',the plant height of the three subcultured mutant plants decreased by 46.88%and 35.96%,respectively;the stem diameter increased by 18.80%;the leaf length and leaf width increased respectively.22.85%and 18.29%;the flower diameter increased by 7.54%;the number of lingual flowers increased by 16.33%.This indicates that these genetic traits can be retained by rapid propagation in vitro.5.To develop a simple and easy evaluation system,and select 8excellent individual plants in the mutant.The overall performance of the excellent individual plants is:the plant type is tight,the leaves are large and compact,the flower head is full,the inflorescence diameter is large,the flower color is white,and the linguistic flower is mostly laurel and tube.Among them,the excellent single plants 1,4,and 7 were derived from a three-generation mutant of 150?mol·L-1 of trifluralin for 24 h,and the excellent single plants 2 and 5 were derived from pendimethalin impregnated with 150?mol·L-1.The three-generation mutants of the excellent single plants 3 and 6 were from the primary mutant plants treated with 100?mol·L-1 trifluralin for 36 h and 12 h,respectively.The excellent single plant 8 was from pendimethalin at 100.The third-generation mutant asexual progeny with a treatment time of?mol·L-1 of 24 h.6.Developed a tissue culture and rapid propagation technology system for the single-head cutting yellow chrysanthemum'Jinshan'.The shoot propagation section of the original seedling cuttings was used as the explant,and the tissue culture rapid propagation system of'Jinshan'was established.The optimum selection of adventitious bud induction medium was MS+1.5 mg/L6-BA+0.05 mg/L NAA;the optimal proliferation medium is MS+1.5 mg/L 6-BA+0.2 mg/L NAA;in the rooting test,1/2MS+IBA 0.20 mg/L is most beneficial to the rooting of cutting yellow chrysanthemum'Jinshan'Cultivation;when the seedlings are transplanted,after 4 days of opening and capping,a small amount of water is sprayed every day,and the 1:1 ratio of the grass and the vermiculite is used as the substrate,and the effect of transplanting the seedlings can be obtained. |
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