摘要
[目的]鉴定和评价沃柑变异材料,为利用提供依据.[方法]采用流式细胞仪、石蜡切片和扫描电镜方法进行倍性和叶片显微结构鉴定,比较形态特征和果实品质.[结果]变异材料为二、四混倍体(2x+4x),倍性细胞比例为2x∶4x=39.1∶60.9;混倍体的叶片长、宽、周长和面积比二倍体显著增加14.75％、31.01％、19.38％和46.09％,叶形指数显著减小12.61％;两者均为两性花,花瓣数、花瓣颜色、花丝离合状态和花柱状态相同,花瓣长度和宽度均显著大于二倍体;种子均为单胚类型,单粒质量、横径和纵径较二倍体分别显著增加30.77％、8.12％和26.64％;单果质量、纵径、横径、果形指数、果皮厚度和果实硬度比二倍体分别显著增加29.67％、13.38％、8.57％、3.85％、38.31％和16.37％,单果种子数显著减少61.68％;可溶性固形物和可滴定酸含量无显著差异,可食率显著降低,出汁率高,维生素C含量显著增加39.70％;叶片、下表皮、栅栏组织和海绵组织厚度较二倍体分别显著增加19.75％、10.10％、9.38％和43.92％,气孔长度和密度分别显著减小7.36％和15.76％,气孔宽度显著增加5.09％.[结论]鉴定获得了沃柑二、四混倍体新种质,与二倍体在形态特征、果实品质及叶片显微结构等方面存在较大差异.
Abstract
[Objective]Orah(Citrus reticulata)is an important late-maturing citrus variety.Previously,putative polyploid bud mutation materials were discovered in Orah.In this study,the material was iden-tified and evaluated in terms of ploidy,morphological characteristics,fruit quality and leaf microstruc-ture to provide a theoretical basis for its utilization.[Methods]Flow cytometry was used for ploidy identification,the paraffin sections were used for leaf microstructure identification,scanning electron microscopy was used for stomatal morphology,size and density identification,the morphological char-acteristics of leaves,flowers,seeds and fruits were compared,and the conventional methods were used to determine fruit quality parameters such as soluble solids content,titratable acid content,vitamin C content,edible rate and juice yield.[Results]Orah was diploid,while the variant material was a mixo-ploid of diploid and tetraploid(2x+4x),with a cell ratio of 2x∶4x=39.1∶60.9.There were differences in leaf morphology between the mixoploid and diploid.The mixoploid leaves were ovate with short acumi-nate tips and dark green color,while the diploid leaves were broad-lanceolate with gradually acuminate tips.The length,width,perimeter and area of the mixoploid leaves were 101.68 mm,54.29 mm,266.02 mm and 3 598.92 mm2,respectively,which were 14.75％,31.01％,19.38％and 46.09％higher than those of the diploid,respectively.The leaf shape index was 1.87,which was 12.61％lower.Both had bisexual flowers with similar petal numbers,petal colors,filament cohesion states and style states.The petal length and width of the mixoploid were 14.48 mm and 8.22 mm,respectively,which were signifi-cantly larger than those of the diploid,increasing by 34.32％and 49.18％,respectively.The seeds were both monoembryonic,and the mixoploid had higher seed weight,transverse diameter and longitudinal di-ameter than the diploid,increasing by 30.77％,8.12％and 26.64％,respectively.The single fruit weight of the mixoploid was 206.16 g,the longitudinal diameter of fruit was 63.37 mm,the transverse diameter was 77.90 mm,the fruit shape index was 0.81,the peel thickness was 4.26 mm,and the fruit firmness was 6.47 kg·cm-2,which were 29.67％,13.38％,8.57％,3.85％,38.31％and 16.37％higher than those of the diploid,respectively.However,the number of seeds per fruit was 8.2,which was 61.68％lower than that of the diploid.There were no significant differences in soluble solids content(15.10％)and ti-tratable acid content(0.58％)between the mixoploid and diploid.The edible rate decreased by 8.09％,the juice yield increased by 4.34％,and the vitamin C content increased by 39.70％.The cellular ar-rangement of the transverse section tissue structure of the mixoploid leaves was basically the same as that of the diploid.The thicknesses of the leaf,upper epidermis,lower epidermis,palisade tissue and spongy tissue were 310.96 μm,12.26 μm,72.89 μm and 227.94 μm,respectively,which were 19.75％,4.15％,10.10％,9.38％and 43.92％higher than those of the diploid,respectively.The stomatal length and density were 7.35 μm and 520.40 per mm2,respectively,which were 7.36％and 15.76％lower,re-spectively.The stomatal width was 3.33 μm,which was 5.09％higher.[Conclusion]In this study,a new mixoploid germplasm of Orah with diploid and tetraploid was identified.There were significant differences between the mixoploid and diploid in leaf,flower,seed,fruit morphology,fruit quality and leaf microstructure.Overall,the mixoploid showed larger and thicker leaves,increased petal length and width,increased seed weight,transverse and longitudinal diameters,but reduced number of seeds per fruit.The thicknesses of the leaf,upper and lower epidermis,palisade tissue and spongy tissue in-creased,while the stomatal length and density decreased and the stomatal width increased.Additionally,there were increases in single fruit weight,fruit transverse and longitudinal diameters and vitamin C content.This mixoploid can be used as a new type of single-embryo type of small-nucleus and large-fruit Orah,and can also be further used as a new germplasm resource for breeding program.
基金项目
广西重点研发计划(桂科AB23026033)
广西农业科学院基本科研业务专项(桂农科2023YM71)
南宁市科技重大专项(20212140)
广西柑橘创新团队桂南综合试验站(nycytxgxcxtd-2021-05-06)
国家现代农业产业技术体系桂中南柑橘综合试验站(CARS-26)
国家科技期刊平台
NSTL
万方数据