龙眼果皮形态结构比较观察及其与果实耐贮运的关系

比较了福建省 1 0个主栽龙眼品种果实的果皮形态和结构 ,结果表明 :不同品种在果皮厚度、外果皮表面颜色、龟状纹、放射线、瘤状突、刺毛、外果皮皮孔、周皮层厚度、栓质层厚度和连续性、中果皮薄壁组织细胞排列、石细胞大小、含量、排列和分布 ,维管束发达状况、排列和分布 ,内果皮表皮细胞排列和角蜡质层厚度等方面均存在着明显差异。风梨味、东壁、油潭本、乌龙岭、红核子、蕉眼龙眼果皮厚 ,外果皮表面瘤状突和剌毛多 ,外果皮周皮层、栓质层厚且连续性好 ,中果皮石细胞 (团 )含量多且排列紧密 ,分布在中果皮外侧且在中果皮中所占比例大 ,维管束发达且排列有序 ,内果皮角蜡质层厚 ;这些品种果实耐贮运、抗病性强。而水涨、赤壳、福眼、普明庵龙眼果皮薄 ,外果皮周皮层薄、栓质层不发达 ,中果皮石细胞 (团 )含量少、分布分散 ,维管束不发达 ,薄壁组织细胞胞间隙大 ,皮孔间隙大、皮孔通道与中果皮组织细胞间隙相通 ;这些品种的果实不耐贮运、抗病性弱。讨论了龙眼外果皮表面主色为褐色和内果皮比外果皮更容易褐变的解剖学原因及龙眼果皮形态结构与果实耐贮运的关系。

A comparative observation on pericarp mor phology and structure and its relationship to storability and transport of longan fruit

The pericarp morphology and structure of longan(Dimocarpus longan Lour.)fruit among ten varieties,being the chief cultivars in Fujian Province,were investigated. The results indicated that there were apparent differences in pericarp thickness,exocarp surface color,moires,radial lines,tumor shape projecting and setas,exocarp lenticels,periderm layer thickness,suberin layer thickness and continuity,mesocarp parenchyma cell arrangement, stone cell size,content,arrangement and distribution,the developed state,arrangement and distribution of vascular bundle,the arrangement of epidermis cells and the thickness of cuticle and wax layer in the endocarp,depending on various cultivars. Fruits of cvs. Fengliwei,Dongbi,Youtanben,Wulongling,Honghezi and Jiaoyan,had thick pericarp,many tumor shape projecting and setas in the exocarp surface,thick periderm layer,thick suberin layer with good continuity in the exocarp,many stone-cell(groups)with closer arrangement which distributed in mesocarp surface and had large proportion when stone-cell(groups)thickness compared to mesocarp thickness,developed vascular bundle with regular arrangement,thick cuticle and wax layer in the endocarp,which was associated with strong resistant to diseases,had good storage and transport. Whereas fruits of cvs. Shuizhang,Chike,Fuyan and Pumingan,with thinner pericarp,thinner periderm layer and undeveloped suberin layer in the exocarp,little stone-cell(groups)with dispersal distribution,undeveloped vascular bundle,larger interstices between parenchyma cells in the mesocarp,larger interstices for lenticels and lenticel ducts connected with cell interstices of mesocarp tissue,tended to have low resistant to diseases,poor storage and transport. The anatomical reasons for the main color(brown)of longan exocarp surface and easier browning in endocarp than in exocarp of the fruit,longan pericarp morphology and structure in relation with fruit storability and transport were discussed.