苹果不同矮化砧木品种叶片的组织细胞学研究

Histological Studies of Leaves from different Apple Dwarf Rootstock Cultivars

明确苹果砧木矮化性与叶片组织性状的关系,可以为苹果砧木矮化性的鉴定提供理论依据。选取了非矮化砧木海棠、半矮化砧木(SH_3、SH_(37))、矮化砧木(SH_(38)、M_(26)、B_9、Mark)、极矮化砧木P_(22)共8个苹果砧木品种为试材,在光学显微镜下,测量了叶片横截面的组织细胞结构,并对不同矮化程度砧木的叶片厚度及其上表皮、下表皮、栅栏组织和海绵组织的厚度进行了比较分析。结果表明:苹果不同砧木品种的叶片厚度为173.70~219.46μm,其中矮化砧木品种M_(26)和Mark的指标值较高;上表皮厚度为8.06~13.50μm,其中非矮化砧木品种海棠的指标值最大且显著高于其他品种;下表皮厚度为8.23~10.49μm,其中半矮化砧木品种SH_3和SH_(37)的指标值显著较高;栅栏组织厚度为90.00~110.88μm,其中极矮化砧木品种P_(22)的指标值显著高于其他品种,不同矮化砧木类型的叶片栅栏组织厚度平均值顺序为极矮化>矮化>半矮化>非矮化,叶片栅栏组织厚度随着砧木矮化程度的加大而逐渐增加;海绵组织厚度为61.72~85.85μm,其中非矮化砧海棠的指标值最大;栅海比为1.05~1.55,其中半矮化砧木品种SH_3和极矮化砧木品种P_(22)的指标值显著较高,不同矮化程度砧木类型的叶片栅海比平均值顺序为极矮化>半矮化>矮化>非矮化,大体表现为砧木品种矮化程度越高,叶片栅海比越大。因此认为,叶片栅栏组织厚度可以作为筛选苹果矮化砧木的一项指标。

To make clear the relationship between dwarf and leaf tissue characteristics of apple rootstock could provide theoretical basis for the identification of dwarf of apple root. Taking the non dwarf rootstock Malus spectabilis, semi dwarf rootstocks SH3 and SH37, and dwarf rootstocks SH38, M26, B9 and Mark, and extremely dwarf rootstock P22 as the materials, the histiocytic structure of leaf cross section was observed using optical microscope, and the thickness of leaf, upper epidermis, lower epidermis, palisade tissue and spongy tissue were compared and analyzed. The results showed that the leaf thickness of different apple rootstocks ranged from 173.70 μm to 219.46 μm, and that of M26 and Mark was higher. The upper epidermis thickness of tested root- stocks were 8.06-13.50 μm, and that of M. spectabilis was significantly higher than that of other rootstocks. The lower epidermis thickness of tested rootstocks was 8.23-10.49 μm, and that of SH3 and SH37 was obviously higher. The palisade tissue thickness of the tested rootstocks was 90.00-110.88 μm, and that of P22 was signifi-cantly higher than that of other rootstocks. The order of average palisade tissue thickness of different dwarf types of rootstocks was extremely dwarf rootstock 〉 dwarf rootstock〉semi dwarf rootstock〉non dwarf rootstock. The palisade tissue thickness ineieased with the dwarf degiee increasing. The spongy tissue thickness of the tested rootstocks was 61.72-85.85 μm, and that of M. spectatabilis was the highest. The palisade spongy ratio was 1.05-1.55, and that of SH3 and P22 was significantly higher. The order of the ratio of palisade tissue to spongy tissue was extremely dwarf rootstock〉semi dwarf rootstock〉dwarf rootstock〉non dwarf rootstock, by and large, the more dwarf, the higher the ratio. So the palisade tissue thickness could be an index for the selection of apple dwarf rootstcok.