摘要:
以东魁杨梅(Myrica rubra cv.Dongkui)为受试生物,研究了中、高剂量和不同施用频率的多效唑(paclobutrazol,代号PP333)处理对果树正常生长和结果的影响。实验设4个处理,分别为无PP333施用记录、5年前施用后停用、连续5年施用300 mg·kg-1 PP333和连续5年施用400 mg·kg-1 PP333。结果显示,300~400 mg·kg-1 PP333处理使东魁杨梅叶片硬度增大,叶片颜色加深,反卷;枝条纤维素含量增加,断枝承受力降低;果实单果重减小,可溶性固形物含量降低。杨梅叶片和树皮细胞结构的检测结果表明,300~400 mg·kg-1 PP333处理使叶片栅栏组织和海绵组织细胞紧缩,细胞变小,海绵组织增厚,呈失水皱缩状;树皮木质部的细胞大小和密度无明显变化,但韧皮部的细胞密度变大,细胞间空隙减小。连续施用300~400 mg·kg-1的PP333会导致杨梅叶片和土壤中PP333的残留和积累。研究表明,中、高剂量的PP333对杨梅的生长和生殖均有不利影响。
Abstract:
To investigate the effect of paclobutrazol (PP333) on growth and fruiting of Dongkui bayberry (Myrica rubra), four treatments were designed, including CK group in which PP333 was never used, T1 treatment in which PP333 was used five years ago and then stopped, T2 treatment in which 300 mg·kg-1 PP333 (middle dose) was applied consecutively for 5 years and T3 treatment in which 400 mg·kg-1(high dose) PP333 was applied consecutively for 5 years. Results showed that application of 300~400 mg·kg-1 PP333 treatment led to the increase in leaf hardness and branch cellulose content, and the decrease in branch bearing capacity. Compared with the CK group, PP333 treatment darkened leaf color and caused leaf curl, and decreased single fruit weight and its soluble solid content. Moreover, 300~400 mg·kg-1 PP333 treatment increased the thickness of spongy tissue, and made palisade and spongy cells smaller, tighter and appearing dehydrated. After PP333 treatment, no significant change was found in number and size of xylem cells, whereas phloem cells appeared to be much smaller and tighter than that of CK. PP333 residue was detected in soil and leaf of Dongkui bayberry in T2 and T3 treaments. It is concluded that PP333 application with middle and high doses could exert adverse effect on growth and reproduction of Dongkui bayberry.
点击查看大图
下载:
