Fruit pedicel is the bridge linking the parent tree and the fruit, which is an important channel for water and nutrients transport to the fruit. The genetic specificity determines the characteristics of the pedicel and the fruit, but the relationship between the pedicel structure and the fruit characteristics is unexplored. Combining the investigation of fruit characteristics, the statistical analysis of the pedicel structural properties, and the 2D and 3D anatomical observation of the pedicel, this study found distinctive contributions of the pedicel elements to the fruit characteristics in four pear species. The European pear (Conference) showed distinct fruit shape index and pedicel structural properties compared with the oriental pears (Akizuki, Yali, and Nanguoli). The fruit size positively correlated with pedicel length, fiber area, pedicel diameter, the area percentage of the cortex, and the area percentage of phloem; however, fruit firmness and soluble solids concentration are showed a stronger positive correlation with xylem area, pith area, the area percentage of xylem, the area percentage of sieve tube, and the area percentage of pith. Pedicel elements, including pith, fiber, and cortex, likely play a certain role in the fruit growth due to the variations of their characteristics demonstrated in the four pear species. The porosity, the ratio of the surface area to the volume, and the spatial arrangement of the vessels showed significant variations across the pear species, indicating the distinction of the hydraulic conductance of the pedicels. Our findings provided direct evidence that pedicel structural elements contributed distinctively to the fruit characteristics among pear species.

以‘烟富3号’苹果为试材,对树冠上、中、下部果实,树冠内膛和外围果实,不同枝龄、朝向侧枝以及不同类型结果枝果实进行了单果质量、果实糖酸含量以及果实色泽等比较,研究了着果位置、枝条朝向等对果实品质的影响,从而探索优化树形和结果枝的培养方法,为苹果生产提供技术参考.结果 表明:树冠垂直方向,上部果实单果质量小于中、下部果实,而果实内在品质以及果实色泽方面上部果实优于中、下部果实,树冠水平方向果实品质差异较小;2年生侧枝果实纵、横径均大于3年生侧枝;下垂枝和平斜枝果实大小优于直立枝果实,且下垂枝结果效率为5.4％,显著高于平斜枝和直立枝;短果枝果实在果实大小和糖度方面均优于中、长果枝果实.综合以上结果可知,果实着生部位、枝龄、枝条朝向以及结果枝类型对果实品质有重要影响,因此在苹果树形结构和结果枝培养过程中,注意树冠上部枝条的培养和生长势的均衡,中下部枝条的疏剪更新控制,以及保留年轻和稳定的结果枝条,是苹果高品质生产的关键技术措施之一.

为了解梨果柄生长发育对果实品质的影响,该试验以11个梨品种为材料,对果实主要经济性状、可溶性糖、矿质养分等进行了测定分析,并对果柄显微组织结构进行了解剖观察.结果显示:(1)梨不同品种间果柄形态及显微结构存在明显差异,大果型品种果柄内有10个维管束,中果型品种有9个维管束,小果型品种有5个维管束.(2)大果型砂梨品种中,果柄横截面维管束占比越高,单果重越大.(3)梨果柄粗度与果实大小之间存在显著相关关系,且相关性大小表现为白梨大于砂梨.(4)同一梨品种的中果柄和粗果柄果实的可溶性总糖含量显著高于细果柄果实.(5)果柄粗度影响果实果肉矿质养分含量,'秋月'的中果柄和粗果柄果实的Ca和B含量显著优于细果柄果实,且中果柄果实的含量最高.研究表明,梨不同品种的果柄形态结构不同,且果柄发育状况影响果实生长发育,尤其果柄粗度是限制果实大小和影响果实品质的重要因素之一;同一梨品种的中果柄果实品质优于粗果柄和细果柄果实.

为了明确梨中间砧对雪青梨根系生长发育及果实品质的影响,试验以南水沟1号、东7-28、中矮3号、OH×F51中间砧为试验材料,以豆梨为基砧,雪青梨为接穗品种,对梨根系发育和果实品质相关指标进行测定,对糖代谢相关基因SOT2和SUT1表达量进行分析.结果表明:东7-28作中间砧与接穗、基砧亲和性好,没有出现小脚现象,生根数量多,果实品质较好,单果重最大,可溶性固形物含量较高,可滴定酸含量低,果糖、山梨醇含量较高,苹果酸和柠檬酸含量低.南水沟1号叶片较大,单果重仅次于东7-28,果实蔗糖含量较高.中矮3号生根量少,果实可溶性固形物含量低,苹果酸和柠檬酸含量高,果实中SOT2和SUT1表达量高于其他组合. OH×F51有明显的小脚现象,冠幅小,树势弱,果实小.综上所述,东7-28作中间砧效果好,其次是南水沟1号.